CEPA 1999 Annual Report for April 2010 to March 2011
- Executive Summary
- 1 Administration (Part 1)
- 2 Public Participation (Part 2)
- 3 Information Gathering, Objectives, Guidelines and Codes of Practice (Part 3, Section 3.1)
- 3 Information Gathering, Objectives, Guidelines and Codes of Practice (Part 3, Section 3.2)
- 3 Information Gathering, Objectives, Guidelines and Codes of Practice (Part 3, Sections 3.3-3.5)
- 4 Pollution Prevention (Part 4)
- 5 Controlling Toxic Substances (Part 5)
- 6 Animate Products of Biotechnology (Part 6)
- 7 Controlling Pollution and Managing Waste (Part 7)
- 8 Environmental Emergencies (Part 8)
- 9 Government Operations and Federal and Aboriginal Lands (Part 9)
- 10 Compliance and Enforcement (Part 10)
- Appendix A: Contacts
- Appendix B: Draft and Final Assessment Decisions of Chemicals Management Plan Challenge Substances
3 Information Gathering, Objectives, Guidelines and Codes of Practice (Part 3)
The following sections provide examples of the type and range of research undertaken in 2010–2011.
188.8.131.52 Air Quality Research in Support of the Clean Air Regulatory Agenda
Air quality research in support of the Clean Air Regulatory Agenda (CARA) provides coordinated, timely, credible and relevant information to Canadians and decision makers about the health risks and environmental impacts of current and future levels of air pollutants, through research, monitoring, modeling and scientific assessment.
The program primarily focuses on the pollutants responsible for smog, acid deposition and mercury pollution (e.g., sulphur dioxide, nitrogen oxides, volatile organic compounds, PM, ozone and mercury).
Information derived from this program also enables Canada to track the effectiveness of measures to improve air quality, such as those implemented under CEPA 1999, the Canada-wide Standards for PM, ozone and mercury, the Canada–United States Air Quality Agreement, and the United Nations Economic Commission for Europe's Convention on Long-range Transboundary Air Pollution.
Activities under the program in 2010–2011 included the following:
Urban air pollution originates from many sources, and as a result, Canadians inhale a complex mixture of pollutants. The composition and variability of these mixtures were examined in detail across Montréal's urban area. Neighbourhoods affected to varying degrees by an industrial sector (e.g., petrochemical) and/or by heavy traffic were compared to identify better indicators of specific pollution sources. Some compounds, such as nitrogen oxides, had a tendency to be associated with most mixtures, particularly those related to traffic, and thus show good potential as indicators of population exposure to traffic pollutants. Although other compounds were better indicators of exposure to industrial sector pollutants, nitrogen oxides also exhibited some link to these emissions and therefore they may represent the best single pollutant indicator of the level of exposure. Certain compounds were strongly linked to specific industrial sectors (e.g., sulphur oxides) and thus they were not always part of the common mixtures. Moreover, the ratios of some of the common pollutants varied by neighbourhood (e.g., relative amounts of some hydrocarbons). Pollutant mixtures also showed seasonal variability, which can have an effect on population exposure.
In southern Ontario, Canadians are exposed to a constantly varying mixture of home-grown pollution, pollution from U.S. sources along and near the Great Lakes and long-range-transport pollution from farther upwind of the Great Lakes region. The weather patterns in the Great Lakes make it difficult to determine which of these geographic areas plays a greater role, particularly during smog episodes. During the reporting period, a suite of scientific results was released that document the outcome of an intensive study focused on far-southwestern Ontario. Measurement experts, meteorological researchers and air quality modelers worked closely together to determine the sources of the two main smog ingredients, ozone and PM2.5, as well as the factors that influence their levels. Rapid ozone and PM2.5 creation was found to occur over the lakes and in long but narrow regions over land. Emissions from relatively local sources, those close to the Great Lakes on both sides of the border, were found to be a major contributor; this will help to focus attention on these areas for future efforts to improve and also to forecast air quality.
New PM formation and transformation pathways were established through laboratory studies, advancing our understanding of how PM and gaseous pollutants interact with each other and how far pollutants are able to be transported. Research into these new pathways will be used to enhance the capacity of air quality models to predict PM levels across Canada. Overall, such research is expected to boost regulatory decision support in the future.
Inventories of PM emissions from commercial ships were validated using ship-borne measurements. Black carbon and sulfur emission levels from ships are being reduced in response to regulations on fuel sulfur contents in emission control areas on the west coast of North America. Black carbon emission reduction is an unanticipated outcome of such regulations. The research demonstrated the effectiveness of fuel-use regulations in improving air quality in coastal cities where commercial shipping is a major source of air pollution.
To investigate the role of Canada's forests as sinks or sources of aerosol particles, an experiment was conducted with university collaborators to measure the fluxes of particles and volatile organic compounds at the Borden Forest Research Station. Surprisingly, this forest appears to act as a net source of particles 60% of the time. The processes responsible for this observation require further study, but may involve the reaction of human-source gaseous pollutants with biogenic organic emissions of the forest.
An intensive field study using ozone sonde (balloon instrumentation) and lidar (laser-based remote sensing technology) instruments was conducted to investigate the production of ozone from boreal forest fires and to quantify the impact of boreal biomass burning on the global tropospheric composition. Satellite sensors were also used to verify the results of this collaborative study. This information will help improve model predictions regarding the long-range transport of these emissions.
Environment Canada is the lead contributor to the World Meteorological Organization's Global Assessment of Precipitation Chemistry and Deposition, a collaborative initiative of the Global Atmosphere Watch Programme aimed at informing the global scientific and policy communities of the chemical composition of precipitation and atmospheric deposition of major compounds, on global and regional scales. During the reporting period, observations from international, national and regional monitoring networks around the globe were gathered and carefully screened for quality and comparability. Models of total global deposition estimates were generated and integrated together with these measurements to fill in spatial gaps and present a more complete picture of global atmospheric deposition. Assessment chapters are in their draft stage.
The Ocean–Atmosphere–Sea Ice–Snowpack (OASIS) project is one of 44 Canadian-funded projects--and one of five led by Environment Canada scientists--that commenced during International Polar Year (IPY). OASIS focused on the role of atmosphere-surface interactions in the fate of pollutants, such as mercury and ozone, over the Arctic Ocean. In collaboration with American and European scientists, Environment Canada scientists gained new insights into the chemistry responsible for ozone and mercury depletion. The findings of the OASIS study about the important role of the lower Arctic atmosphere in determining the extent to which ozone and mercury affect this area are now documented. The results also show that the retention rate for mercury deposited in the Arctic is higher in the Arctic Ocean than on the snow or on the land, thus affecting the amount of mercury entering the Arctic ecosystem. These findings will help improve forecasting capabilities over the Arctic Ocean. The legacy of IPY includes ongoing deployments of automated buoys that were developed under OASIS. These buoys measure pollutants and meteorology and transmit the data through satellite communications. A network of these buoys will help unravel the processes responsible for ozone and mercury depletion during the Arctic spring.
The trans-Pacific transport of pollutants from Asia, Europe and elsewhere can have a significant influence on the regional air quality. The number of measurement sites on Canada's west coast has been increased in order to better understand the current influences on air quality and to provide a baseline against which to demonstrate changing contributions. Data from a new low-level site on the west coast of Vancouver Island, an elevated site in the Yukon, and a mountain site in Whistler, British Columbia, will provide information on transport events from both the northern and southern west coast at multiple elevations. In addition, intensive field measurements were deployed at two field sites on Whistler Mountain during the summer of 2010 to study the chemical and physical properties of clouds and aerosols in the region. Sources of particles at Whistler come not only from the long-range transport of pollution, but from forest emissions and fires as well. In collaboration with multiple university partners, the summer of 2010 study produced a comprehensive suite of results to describe emissions, chemical transformation, and resultant gas and aerosol products. This new information on aerosol formation and cloud properties will be incorporated into air quality and climate models to increase the predictive capacity of these tools.
Field measurements of ambient ammonia are currently underway in areas of the country associated with extensive agricultural activity. In collaboration with university partners, levels of ammonia are being determined in major Canadian cities and emissions from natural and agricultural surfaces have been studied. Environment Canada has recently published the results of some of their laboratory studies investigating the uptake of ammonia by particulate matter (PM). The field measurements and laboratory studies undertaken in 2010–2011 will assist in the establishment of baseline ambient levels of ammonia, enhance our understanding of the role of ammonia in particle formation, and provide a means to evaluate emission inventories and air quality forecasting models.
In late fall 2010, Environment Canada began conducting ambient air measurements of polycyclic aromatic compounds and selected metals in the Athabasca oil sands region of Alberta. The goal of this project is to calculate the annual atmospheric deposition of these pollutants to the surrounding environment. In the oil sands region, atmospheric deposition is the main pathway for these contaminants to reach sensitive ecosystems.
High-resolution air quality model and trajectory simulations showed that air pollution in the vicinity of Lake St. Clair is sometimes the result of helical (corkscrew) recirculation flow along the lake's southern edge, each return loop taking 1.2 to 3.0 hours. This recirculation resulted in rapid formation of sulphate and organic aerosols, each circulation loop bringing fresh precursor emissions back over the lake.
Environment Canada's air quality forecast model GEM-MACH15 provided special forecast guidance for an international climate and air quality field campaign (CalNex 2010) conducted in the spring of 2010 over southern California. The GEM-MACH15 forecast was also included in a comparative study involving several air quality forecast centres in North America to identify biases and uncertainties in current air quality model forecasts. The goal was to provide direction for model improvement and to assess the understanding of the processes vital to air quality and climate interactions.
To better understand the impact of climate change on air quality, the air quality model was coupled to a regional climate model and three ten-year summer simulations of air pollution were carried out. The model results suggest that air quality will worsen in the future under a changing climate, but would be greatly improved through the co-benefit reductions of smog precursors expected to occur under the Intergovernmental Panel on Climate Change's recommendations for reducing greenhouse-gas emitting activities.
184.108.40.206 Air Quality Research in Support of the Chemicals Management Plan
Research studies that were undertaken in support of the CMP in 2010–2011 included the following:
Environment Canada continued to provide leadership, direction and recommendations on new and existing air-related analytical testing methods suitable for targeted chemicals under the CMP. A preliminary study was performed on selected personal care products to assess the volatility of methylsiloxanes, which are ingredients in these products. This study will lead to the development of a guidance document to help risk managers evaluate siloxanes in these products.
Earlier research led to the development of new reference methods for chlorinated paraffins. These validated reference methods helped with the determination of the level of quantification (LoQ) for chlorinated paraffins in aqueous and solid matrices in the environment. The LoQ is suggested as a baseline to assist in establishing a virtual elimination target.
The regulatory reference method entitled Reference method for the analysis of 2-butoxyethanol (2-BE) and other glycol ethers (GEs) in selected products (automotive and household cleaners, paints, paint strippers and solvents) was published in 2010–2011 in support of the existing 2-Butoxyethanol Regulations. This reference method for the determination of 2-butoxyethanol and other glycol ethers is available on Environment Canada's website.
The development and evaluation of new analytical capabilities to measure platinum group elements (PGEs), extensively used in automobile catalytic converters, in airborne PM and sediments/sludges continued. The study is supporting research aimed at evaluating whether PGEs in sewage sludge/lake sediments originates from the use of these elements in industrial processes, consumer goods or road/airborne sources. Environment Canada is also developing and implementing analytical methods to address the knowledge gaps in atmospheric science linked to the changing characteristics of the volatile and semi-volatile chemicals emitted from new vehicle engines that are fitted with novel emission control technologies and using a wide array of conventional and renewable fuels.
A study was carried out to determine whether certain antioxidants (CMP substances) that are used to stabilize gasoline and diesel fuels could be detected in the exhaust emissions of vehicles using these fuels. These additives, including 2,4,6-tri-tert-butylphenol and selected substitutes, are used to prevent the formation of engine-fouling residues. The results will inform decisions related to risk management of these additives and their alternatives.
An analytical method was developed and tested to measure lanthanum and other lanthanoids (cerium to lutetium) in coarse and fine PM collected at selected sites within the NAPS network. The study concluded that for the coarse (PM10-2.5) particulate fraction, the relative concentration pattern of the lanthanoids mimics that found in the Earth's crust, whereas for the fine (PM2.5) particulate fraction, the relative concentration pattern is similar to that observed in catalysts used in fluidized-bed catalytic cracking in petroleum refining operations. Therefore, this study supports the previous reports that lanthanoids are reliable tracers of emissions related to the oil-refining industry.
Research was conducted to determine the effect of aging on the volatilization potential and bioavailability of brominated flame retardants (BFRs) in soil. Some key findings of the study are that the degradation of BFRs in soil occurs in two phases and that these chemicals are vulnerable to degradation. In addition, the volatility of BFRs lessens over time because they become more strongly bound to the soil as they age. The outcome of this research will help improve existing regional and global atmospheric transport models by capturing soil-air exchange processes. It will also further understanding of the environmental fate (bioavailability) of chemicals in soil.
3.2.2 Climate Research
Environment Canada continued to provide science-based information on the past, present and future climate. It focused on how climate is changing, the causes and effects of this change, and its attribution to natural and human causes. Activities under the climate research program in 2010–2011 included:
- Enhancement and application of global and regional climate models: to simulate global and regional climate change, attribute observed climatic changes to specific causes, and predict seasonal and longer-term climatic variations.
- Transformation of raw climate model output into climate scenarios, including climate extremes, for use in impact assessment and adaptation decision support.
- Monitoring and data analysis, to document and understand climate trends and variations.
- Cold-climate and land-surface process research: to understand the mechanisms of climate change, particularly in northern regions.
- GHG monitoring and research: to improve monitoring methods, quantify anthropogenic and natural sources, and to put these into a continental and global context.
The Department's climate research continues to support GHG mitigation policies and adaptation planning. It is coordinated with international efforts under the World Meteorological Organization and World Climate Research Program and contributes to the Intergovernmental Panel on Climate Change (IPCC). Below are examples of this work.
- Research has been conducted with Environment Canada's Second Generation Canadian Earth System Model (CanESM2), which represents the physical climate system and biogeochemical cycles (carbon and sulphur). The results indicate that climate stabilization near the 2°C limit, as agreed to under the Copenhagen Accord, requires the immediate leveling off of global carbon dioxide (CO2) emissions, and the implementation of mitigation technologies/strategies within a few decades. This would lead to the net removal of CO2 from the atmosphere before the end of the century. A 3°C target can be met if emissions level off within a few decades and then decline rapidly to roughly 1970 levels by the end of the century. Minimal effort to reduce emissions will lead to warming of nearly 6°C by the year 2100, with continued warming thereafter.
- Climate simulations indicate that global temperatures stabilize almost immediately following a cessation of emissions and remain at the level reached when emissions ceased. However, irreversible and ongoing climatic changes (temperature and precipitation) are projected to occur at regional scales even after human CO2 emissions are eliminated, adding to our understanding of the spatial scales of irreversible climate change.
- Detection and attribution studies have shown that human-induced GHG increases have contributed to the observed intensification of heavy precipitation events over large parts of the Northern Hemisphere, including North America, mid-latitude Eurasia, and India. Research results also suggest that the global climate models used in the study may have underestimated the observed trend, suggesting that future changes in extreme precipitation, predicted by the models, may also be underestimated, such that extreme precipitation events may intensify more quickly in the future than projected and that impacts may be more severe than currently estimated. The research made use of outputs from multiple climate models driven by anthropogenic forcing from 1951 to 1999 and the results were compared with observations from the same time period.
- Atmospheric cooling from the effect of anthropogenic carbonaceous aerosol particles on the reflectivity of sunlight by water clouds remains an uncertainty for climate prediction. Observations show, for the first time, that the contribution from carbonaceous material in the particles to this effect is greater than that from sulphur in the particles, as suggested by a small fraction of global climate model simulations.
- In evaluating the robustness of the standard metrics developed to compare the global warming potential (GWP) of CH4 and N2O with that of CO2, it was found that the global warming effect of CH4 and N2O may be 20% higher than indicated using the current metric of 100 year GWP. Research results were obtained using simulations from the coupled carbon version of the University of Victoria's Earth System Climate model to evaluate the feedbacks of warming induced by CH4 and N2O on the carbon cycle, and demonstrate that the future evolution of stratospheric ozone will be sensitive to the relative changes in CO2 and N2O in the future.
220.127.116.11 Chemicals Management Plan Substances
The Department carried out research to support the assessment of substances under the CMP. The research was synthesized and sent to risk assessors to allow them to make better-informed decisions on substance assessment.
Volatile methyl siloxanes (VMSs)
Studies on the long-range transport and physical-chemical properties of VMSs were accelerated in 2010–2011 to assist in the risk assessment of these chemicals. A method for the determination of VMS in water was finalized and used for the determination of VMS in influent, effluent and receiving waters from municipal wastewater treatment plants in southern Ontario and southern Quebec. Concentrations of decamethylcyclopentasiloxane (D5) ranged from 7.8 to 135 micrograms per litre (μg/L) in wastewater treatment plant effluents and from <0.004 to 1.5 μg/L in surface waters. D5 is a major VMS, which has been assessed as toxic under CEPA 1999, and is used in personal care products and in industrial applications as solvents, lubricants, coatings and sealants. In addition, a method for the determination of VMS in sediment and soil was developed. It was used to determine levels of VMS in sediments in the receiving waters of municipal effluents, soils from sludge-amended agricultural lands, and sediments in Ontario and Quebec. Concentrations of D5 ranged from 0.023 to 5.8 μg/g in sediments and from 26 to 328 μg/g in biosolids from wastewater treatment plants.
Fathead Minnows were exposed to a wide range of concentrations of cyclic siloxane D5. During the 65-day exposure period, few effects were seen. Egg hatching and larval fish survival and growth were normal. Juvenile fish survival and growth were good in all concentrations, being similar to those of the control fish. At environmentally relevant exposure levels, the concentrations of D5 in fish were about 5000 times the concentrations of D5 in water. Fathead Minnows exposed to the highest D5 concentrations had higher condition factors (a measure of general well-being) than the control fish that had not been exposed to D5.
Detailed research reports and data were provided to risk assessors, for use in their risk assessment of D5 in the Canadian environment, and also to a board of review.
Perfluorinated chemicals (PFCs) remain a concern in Canada due to their toxicity, persistence and potential for biomagnification. Research on PFCs in the aquatic environment continued in 2010–2011, with a focus on identifying new fluorinated chemicals. Perfluoroalkylcyclohexane sulfonate (PFECHS), a new class of fluorinated substances that is reportedly used as an erosion inhibitor in aircraft hydraulic fluids, was measured for the first time in Great Lakes fish and waters. The highest concentrations in water were found in Lake Michigan. The actual source of the chemical is unknown, although it likely enters the lakes from wastewater treatment plant effluents. Studies continued on the perfluoroalkyl phosphates and phosphonates that are used as an anti-grease coating on paper products and in floor polishes. A cross-Canada survey showed that these chemicals are present in surface waters at concentrations similar to those of other chemicals such as perfluorooctanoic acid.
A sediment core sampled from the centre of the western basin of Lake Ontario was analyzed for platinum group elements (PGEs) and rare earth elements (REEs) as part of a CMP-funded study of metals in the environment. PGEs are widely used in automobile catalytic converters and often detected in road dust; REEs are used in electronic devices and released during burning or recycling. Neither group of elements had been previously determined in the Great Lakes. Platinum and palladium, the major PGEs in automobile catalysts, showed maximum concentrations in sediments dated to the 1990s and early 2000s. REEs were detected in the same sediment core but showed no distinctive historical trends, implying that their current use has little impact on the open lake.
Studies began on zinc pyrithione (ZnP), which has been used to replace tributyl tin as a ship anti-corrosion agent, and on other chemically related zinc-based organic chemicals that are used as commercial lubricants, fuel additives and greases. Initial measurements of zinc in sediment cores from Toronto Harbour and the western basin of Lake Ontario showed major deposition of zinc-based products since the 1940s. Methods for determining ZnP and other specific zinc chemicals are under development.
An impact assessment of inorganic mixtures associated with sediments and waters from the Lac Dassarat area in Quebec was initiated as part of a three-year, three-pronged bioassessment (spatial, temporal and historical). Conducted by the ministère des Ressources naturelles et de la Faune du Québec, this assessment was launched to monitor the effect of remediation of an abandoned metal mining site.
Phosphate ester flame retardants
Research continued on the presence of flame retardants in surface waters. A series of phosphate ester flame retardants, which are replacements for the banned PBDEs, were determined in wastewater treatment plant effluents and surface waters in Canada. The predominant phosphate ester in treated effluent and surface waters was tris(butoxyethyl) phosphate (TBEP), which was present at concentrations ranging from 29 to 6800 ng/L. TBEP is used as a plasticizer in rubber and plastics.
Studies were initiated on benzotriazoles (BTZs) and substituted benzothiazoles (BThZs), widely used as corrosion inhibitors, in surface waters. BTZs are also used in aircraft de-icing fluids and as UV absorbers in polymers, and as household detergent additives. BTZ was detected for the first time in Canada in the surface waters of Hamilton Harbour and western Lake Ontario, at concentrations ranging from 60 to 610 ng/L.
A sediment toxicity system was developed using a test battery of liquid and solid phases for sediments contaminated with brominated derivatives of bisphenol A. Regulators will be able to predict the toxicity of both the solid and liquid phase of sediments based on the physical and chemical characteristic of compounds and sediment properties such as grain size, organic carbon, and interstitial water pH. Results indicate that tetrabrominated bisphenol A was less toxic than its debrominated derivatives. The Hydra test proved to be the most sensitive, with an EC50 of 0.1 mg/L for all debrominated derivatives, 0.2 mg/L for tetrabromobiphenol A, and 1.3 mg/L for bisphenol A.
Tetrabromobisphenol A bis(2,3-dibromopropyl ether) (TBBPA-DBPE) is an additive flame retardant for polyolefins and polymers, high-density polyethylene, and low-density polyethylene. TBBPA-DBPE is a potential replacement product for high-volume penta- and octa-BDPE flame retardants that are being phased out of production and use. The substance is also used in fabricated plastic sheet materials. TBBPA-DBPE was chosen for toxicological characterization by the National Institute of Environmental Health Sciences. A study was undertaken to synthesize the potential degradation products of TBBPA-DBPE. Five breakdown products of TBBPA-DBPE have been synthesized in a pure form. These standards will be used to study toxicity, carcinogenicity and genotoxicity.
Dyes and pigments
Environment Canada assessed several dyes to determine their sublethal toxicity to invertebrates (Hyalella) and fish (Fathead Minnow). Toxicity to fish was seen at low concentrations (approximately 10–15 µg/L measured) of the dis-azo dye Disperse Yellow 7. Sudan Red G, a mono-azo dye, was also toxic to Fathead Minnow larvae at a concentration of 100 µg/L. The anthracenedione dye Acid Blue 80 was non-toxic at 7.7 mg/L. Data from fish indicate a delayed toxic response, with larval fish succumbing four to five days after hatching. This finding is important to bioassays for the assessment of toxicity in fish embryos or hatchlings, when toxicity of these compounds would be greatly underestimated. Preliminary results from chronic toxicity tests with Hyalella indicate that survival was affected by Disperse Yellow 7 and Acid Blue 129 at 120 and 7000 µg/L, respectively. Life-cycle tests (ten weeks) were then conducted with Disperse Yellow 7 at sublethal concentrations, and although survival and growth of Hyalella were not affected, reproduction was lower than that of control individuals at the lowest tested concentration (8 µg/L). Chemical analysis is in progress, and based on data from fish toxicity tests, the toxicity estimates for these compounds to Hyalella will be lower when they are based on measured water concentrations. Research was also conducted on the overall environmental mobility and fate of various azo dyes. Disperse Yellow 7, Sudan 3, and Sudan Red G were all found to bind strongly to sediment organic matter; only Sudan 3 bound irreversibly, showing that Disperse Yellow 7 and Sudan Red G remain bioavailable and susceptible to environmental transformation. In the case of Disperse Yellow 7, transformation products were identified using a very-high-resolution liquid chromatograph (and included known carcinogens like phenylenediamine and benzidine). These data will be used to support CMP risk assessments and compared with expected or measured environmental concentrations, to determine whether these dyes pose a potential concern to the environment downstream of textile dyeing facilities or municipal wastewater outfalls.
18.104.22.168 Pesticides and Herbicides
Research begun in 2008–2010 was continued in 2010–2011 to examine the use of short-term in situ (caging in the field) exposures using a freshwater crustacean (Hyalella) as a indicator to predict long-term effects of current-use pesticides in aquatic ecosystems. Patterns of decreased survival and acetylcholinesterase (AChE) activity have been consistently observed over three field seasons after caging Hyalella for one week in streams in the Niagara Region of southern Ontario, where organophosphate and carbamate insecticides (which inhibit AChE activity) were detected. AChE inhibition appears to be an early warning indicator of organophosphate exposure and/or effects occurring in situ; similar results were obtained in laboratory tests with two organophosphates routinely detected at field sites. Maximum AChE inhibition occurred rapidly in Hyalella exposed to these same organophosphates (four days), but recovery of AChE activity after Hyalella were transferred to clean water was much slower (>14 days). This finding is important when assessing the risk of pesticide use to aquatic organisms, as short-term exposures to pesticides may have effects after the exposure has ceased. Laboratory studies to identify the effects of individual pesticides and pesticide mixtures measured at sites during in situ exposure are ongoing.
A study has been under way since 2009 to understand the transfer and fate of sulfonylurea herbicides between the main environmental compartments (air, precipitation and water) in the catchment of the Yamaska River, in Quebec, which drains a large agricultural watershed. The study sites are located at the mouth of the river, immediately upstream of the Bay Saint-François to Lake Saint-Pierre. Preliminary results indicate the presence of these herbicides, with a short life cycle (<5 days) in surface waters, but not in air or precipitation, suggesting a rapid transfer between the field and the river.
Amphibian populations are in decline worldwide and contaminants such as pesticides have been identified as one of the potential causes of this decline. Juvenile Leopard Frogs were exposed to glyphosate or atrazine for 21 days and then challenged with a chytrid fungus. The fungal infection had no effect. However, exposure to glyphosate significantly reduced the growth of juvenile frogs by the end of the herbicide treatment. Exposure to atrazine significantly reduced frog growth (i.e. weight) 73 days after the herbicide treatment. No other effects were detected. These results suggest that exposure to these herbicides may affect future survival and reproduction of Leopard Frogs, since these factors are both negatively affected in frogs displaying reduced growth. In another experiment, exposure to high concentrations of glyphosate proved fatal to American Toads, indicating that this pesticide is toxic at higher concentrations.
22.214.171.124 Municipal Wastewater Effluents
The Department carried out several research studies to assess the effects of municipal wastewater effluents on wild and laboratory fish and on feral mussels. Chemical characterizations of the effluents were also performed to assess pharmaceutical and personal care products, as well as conventional toxicants such as ammonia, metals, and hydrocarbons, among others.
Fathead Minnows were exposed for a complete life cycle in the laboratory to secondary-treated municipal wastewater effluents from cities in Ontario. Growth, health and reproductive status were assessed in fish at five months of age. Pharmaceutical and personal care products and endocrine-disrupting compounds detected in the municipal wastewater effluents included (in descending order of concentration): trimethoprim, carbamazepine, bisphenol A, sulfamethoxazole, diclofenac, monensin sodium, ciprofloxacin, norfloxacin, clofibric acid and bezafibrate (at 560 to 140 ng/L) and naproxen, gemfibrozil and ketoprofen (at 57 to 32 ng/L). The fish grew well in all three effluents, but reproduction was reduced in two of the three effluents. The long-term exposures show the complex response of fish to municipal wastewater effluents, with normal growth but decreased reproductive output. This is a collaborative study with the Ontario Ministry of the Environment, which is undertaking the detailed measurement of pharmaceutical and personal care products in the municipal wastewater effluents.
Regina treats its wastewater at a modern treatment plant located on Wascana Creek. In winter, treated wastewater effluent makes up almost 100% of the creek's streamflow. Four surveys conducted from 2005 to 2007, during different seasons, indicated that nitrogen (N) and phosphorus (P) concentrations were higher at sites downstream of the treatment plant than at an upstream control site. Results indicate that nitrate and nitrite concentrations far surpassed World Health Organization limits for drinking water and sensitive taxa, while ammonia, nitrate and nitrite concentrations exceed not only the Canadian water quality guidelines for the protection of aquatic life but U.S. EPA guidelines as well. High ammonia concentrations may be responsible for decreases not only in planktonic algal biomass and production observed downstream but also reductions in primary production to bacterial production ratios. The Wascana Creek study highlights the considerable problems associated with excess nutrients in effluent-dominated ecosystems. It also underlines the need for better controls on ammonia inputs from wastewater treatment plants in such ecosystems.
Environment Canada conducted research to evaluate the occurrence and endocrine-disrupting effects of veterinary and human pharmaceutical products and pesticides and to understand their impacts on the health of the aquatic environment. The Grand River watershed was selected for the initial studies under this project, as it represents one of the river systems most affected by agricultural practices and municipal wastes in Canada. Moreover, this watershed was used in previous studies aimed at developing an understanding of the effects of treatment processes on biological responses in receiving environments. Field studies were conducted in November 2010 to assess sentinel fish species under recrudescent conditions in terms of growth, reproduction (gonadosomatic indices and histology) and survival. Only male fish were sampled, which allowed us to expand on this existing study evaluating the presence of the intersex condition while maximizing the number of sites sampled. Male darters along an agricultural gradient in the Conestogo River (Waterloo, Ontario) did not differ significantly between sites for length or body weight, fish condition (fish weight- to-length ratio) or in relative liver size. Histological analyses of pre-spawning males serve to evaluate the reproductive status of male darters and the potential of the intersex condition in male fish in these systems. Passive sampling devices were also deployed along gradients of agricultural activities associated with domestic wastewater discharges for a period of 21 days in November 2010 to allow accumulation of lipophilic compounds and polar organic compounds suspended in the water column. Finally, water samples were taken from each site to measure conductivity, ammonia, total Kjeldahl nitrogen, dissolved phosphorus, total phosphorus, dissolved chloride, nitrite and nitrate. These results confirm that these sites are highly impacted by nonpoint-source agricultural activities.
A new analytical method was developed to allow detection of antibiotics (e.g., ciprofloxacin and enrofloxacin) and organic contaminants at trace levels in environmental waters subject to discharges of municipal wastewater. While conventional methods allow the detection of antibiotics and other organic contaminants (pharmaceuticals) in municipal wastewater, surface water and drinking water at concentrations between 2 and 289 ng/L, the detection limits of the new method were reduced to levels as low as 0.5–60 ng/L.
In collaboration with the Canadian Water Network, caged mussels and Fathead Minnows were deployed at sites upstream and downstream of municipal effluent outfalls in the St. Lawrence River and in Grand River. The presence of pharmaceutical products in the water column was assessed using semi-permeable membrane devices. Preliminary results revealed that the immune system of mussels exposed to municipal wastewaters was affected and that biotransformation activity was increased after two weeks of exposure at the sites downstream of the effluent outfalls.
The in vitro immunotoxicity and hepatoxicity of untreated and treated municipal wastewater samples from 15 large Canadian cities were examined in an attempt to obtain a clearer picture of the toxic risk of municipal wastewater effluents to fish. Special emphasis was put on xenobiotic biotransformation, oxidative stress, genotoxicity and estrogenic activity. A toxicogenomic approach using gene expression arrays was also used to understand the basic risk potential of municipal wastewater effluents.
Studies of the Johnny Darter, a small bottom-dwelling fish, upstream and downstream of the Montréal wastewater effluent outfall in the St. Lawrence River demonstrated that parasite species composition differs between polluted and reference sites. This result corroborates previous results on Spottail Shiners and Yellow Perch. Furthermore, the number of parasite species is lower in fish exposed to the municipal effluents than in those upstream. These results support previous studies that suggest the food web in the effluents is altered, possibly due to the high organic inputfrom the wastewater treatment plant.
Wastewater discharges into the aquatic environment affect the quality and functioning of ecosystems by creating toxic stress, which affects the health of animal populations and changes the energy transfers supporting aquatic biological production. Research conducted in 2009 and 2010 focused on identifying the effects of municipal wastewater discharges on populations of Muskellunge, a top predator fish in the St. Lawrence River. The analysis of the levels of trace metals and stable isotopes in fish captured upstream and downstream of the Montréal effluent outfall shows that fish exposed to wastewater have characteristic contamination profiles. The levels of 15 pharmaceuticals measured in three fish organs (muscle, liver and brain) were also significantly higher in fish caught downstream of the discharge point, which shows a continuous exposure of organisms to these substances in the natural environment.
Studies in the Grand River, Ontario, have shown that freshwater mussels living downstream of the outfalls of multiple wastewater treatment plants and urban runoff discharge points have significantly lower condition factors, impacted immune responses, and shorter life spans than mussels living upstream. The steady increase in the amount of bioaccumulated metals (Pb, Cu, Cr, Zn, Al) in wild mussels reflects the increase in urban inputs moving downstream. These results indicate that freshwater mussels living downstream of urban areas experience cumulative negative effects. Current studies are investigating whether the observed trend of increased proportions of egg-carrying females downstream of municipal effluents indicates feminization of the mussel population.
Various studies conducted in collaboration with the OECD community were designed to assess the toxicity of cadmium-based quantum dots, nano-silver, dendrimers (a drug vector) and nanozinc, to better understand the potential environmental risk of these nano compounds to aquatic life.
A method was developed for the physical characterization (size distribution) of nanoparticles. More methods are still needed for the chemical characterization of nanoparticles and their degradation/transformation products.
Progress was made in 2010–2011 on evaluating the bioaccumulation and toxicity of nano iron, nano-silver, nano titanium and nano zinc in the benthic crustacean Hyalella azteca. The research was conducted as part of Environment Canada's risk assessment of these materials and in support of Canada's commitment to the Organisation for Economic Co-operation and Development. The toxicity of all nano forms was either lower than or similar to that of simple ionic forms of the same metal. Nano forms of silver and iron were not toxic; however, the ionic forms of these nanomaterials did not cause effects on aquatic organisms. A preliminary report was submitted to the Canadian Working Group on Nano Materials.
126.96.36.199 Fate of Mercury
As part of the research program on mercury pollution, research on the transportation and deposition of atmospheric mercury along the St. Lawrence Valley continued in 2010–2011 with continuous measurements at two sampling sites: Longue-Pointe-de-Mingan and Saint-Anicet). This study aims to evaluate the importance of sources of mercury on the receiving environment. The mercury data are correlated with meteorological data at each site to develop models of changes in atmospheric concentrations of mercury according to the different points of known sources. The results provide information that is useful for monitoring and modeling the fate of mercury in the environment.
A study on the mechanisms of transport and transfer of total mercury and methyl mercury inside a maple tree was conducted at an experimental site in Saint-Anicet, near Lake Saint-François, Quebec. The study aims to describe and understand the cycle of mercury and different chemical forms present in the deciduous forest and to evaluate the toxic impacts of mercury on the aquatic environment.
3.2.4 Wildlife and Soil
188.8.131.52 Substance-specific Research
Research continued on the fate and geographic and temporal trends in contaminants in Canadian and circumpolar Polar Bears and their food webs, in relation to factors influenced by climate change. One study provided the first known evidence that the earlier onset of sea-ice breakup, one effect of Arctic warming, has contributed to the dietary shift observed in Polar Bears from western Hudson Bay in the Canadian sub-Arctic. Furthermore, this research suggests that this dietary shift has contributed to a more rapid increase in the levels of some persistent and bioaccumulative contaminants found in the Polar Bears from this subpopulation. The pollutants studied contain the compounds chlorine and bromine, and include PCBs, organochlorine pesticides, and PBDE flame retardants. To identify the sources of these contaminants, fatty acids and carbon isotopes were measured as dietary tracers. Over time, where the sea ice broke up at an earlier date, the dietary tracers showed that Polar Bears ate more open-water prey species, which accumulate higher contaminant levels. Another effect of warming waters in Hudson Bay has been to alter the diet of a seabird species, the Thick-billed Murre. Stable isotope analyses of murre eggs over a 17-year period has shown a shift in prey to lower trophic-level (lower level in the food chain) fish species, resulting in a reduced exposure to chemical contaminants. This change in exposure has affected the temporal trends in levels of monitored contaminants.
Work continued on the effects of contaminants on the thyroid systems of birds and other wildlife, and on biomarker methods that could be used to measure thyroid system change. One in vitro study demonstrated the binding of selected PCB and PBDE flame retardant congeners, and their hydroxylated and methoxylated analogues, to human and gull blood albumin and transthyretin transport proteins, which demonstrates potential displacement of natural hormones at the binding sites. The results suggest that hydroxylated PCB and PBDE analogues may present an exposure concern to the thyroid system in free-ranging gulls.
Studies continued on emerging contaminants and their fate in marine mammals. One study, conducted in collaboration with Norwegian and Finnish researchers, investigated the concentrations and patterns of organochlorine pesticides as well as PBDE flame retardants and their hydroxylated PBDE analogues and metabolites in tissues and blood of Ringed Seals from two populations with differing levels of contamination. Findings indicate that levels and patterns of organochlorine pesticides and PBDEs differ between the two populations, and that these differences may be due to their contrasting diets and related differences in exposure to contaminants.
Another study, conducted in collaboration with researchers from the United States, reported on the presence and concentrations of several congeners and classes of organohalogen contaminants (and/or their metabolites) in cerebrospinal fluid of dolphins and seals from the western North Atlantic. Cerebellum grey matter was also opportunistically analyzed in three individual dolphins. The levels of all contaminants detected were higher in the cerebellum grey matter than in the cerebrospinal fluid. A number of organohalogen contaminants identified in the cerebrospinal fluid and cerebellum in this study have been shown to be developmental neurotoxicants in experiments on rodents. Although the possible effects of multiple and concurrent exposures to these contaminants remain unclear, additive and/or synergistic effects on the central nervous system should be considered.
Work continued on to identify and characterize and to determine the spatial and temporal trends in legacy and emerging contaminants in eggs of Herring Gulls from sites across the Laurentian Great Lakes, as well as in eggs of fish-eating seabird bioindicator species and in other selected wildlife in the Arctic, Pacific, and Atlantic marine environments and in the St. Lawrence River–Great Lakes ecosystem. One study reported on the presence of perfluorinated carboxylates and sulfonates, as well as perfluorinated and polyfluorinated precursor compounds, in Herring Gull eggs from 15 colonies across the Great Lakes. The source of these compounds is likely the gull's aquatic diet. The level of contamination varied among gull colonies and lakes, with higher concentrations found in eggs from colonies in proximity to highly urbanized and industrialized sites on Lake Erie and Lake Ontario. This work has been expanded to contribute to an ongoing national contaminants monitoring program that assesses spatial and geographic trends in chemicals of concern in aquatic and terrestrial avian bioindicator species across Canada in industrial areas, in rural and remote areas, and at point-source sites. The findings from this monitoring program are used to evaluate environmental responses following regulatory actions on chemicals, and contribute to the CMP. The results of this program show that European Starlings nesting near landfill sites show elevated levels of perfluorooctane sulfonate, while Tree Swallows nesting near wastewater treatment plants have detectable levels of bisphenol A in their blood plasma but not in their eggs.
A multi-tiered in vitro/in vivo toxicity screening approach was used to determine the toxic effects of four brominated flame retardants (BFRs) and their influence on gene expression in domestic chicken liver cells and whole embryos. The chicken is used as a surrogate avian species for wild birds. The four BFRs were hexachlorocyclopentadienyl-dibromocyclooctane (HCDBCO), bis(2-ethylhexyl) tetrabromophthalate (BEHTBP), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) and decabromodiphenylethane (DBDPE); the latter three have been detected in biota, including wild birds. None of the BFRs were toxic to liver cells or embryos at levels exceeding those detected in the environment. However, they did alter the expression of genes associated with xenobiotic metabolism and the thyroid hormone pathway. A preliminary study on two polybrominated diphenyl ether-replacement organophosphate flame retardants, tris(1,3-dichloro-2-propyl) phosphate (TDCPP) and tris(1-chloro-2-propyl) phosphate (TCPP), did reveal cytotoxicity (cell damage) and significant changes in genes associated with xenobiotic metabolism, thyroid hormone regulation, and growth and lipid metabolism in chicken liver and brain cells. These results were similar to those observed for hexabromocyclododecane, a compound that is now being phased out due to its toxicity.
Studies were completed that compared the effects of two isomers (linear and technical grade) of perfluorooctane sulfonate (PFOS) on gene expression in cultured avian liver cells. The results indicate that technical-grade PFOS affected the expression of more genes than did linear PFOS. The technology used for this research (DNA microarrays) was highly successful and is currently being used to determine the biochemical and molecular effects of in-use perfluoralkyl compounds (PFCs). Two PFOS-replacement PFCs, perfluorohexane sulfonate (PFHxS) and perfluorohexanoic acid (PFHxA), were injected into the eggs of developing chicken embryos. Both compounds decreased hatching success at levels exceeding those detected in the environment and PFHxS negatively affected embryonic growth.
Laboratory studies on liver cell cultures of three species of bird determined that highly purified (i.e., dioxin-free) hexachlorobenzene caused induction of cytochrome P4501A (an enzyme used as an environmental biomarker) in each species. These studies were the first to confirm that hexachlorobenzene meets one of the criteria for being formally considered a “dioxin-like” chemical, which would influence its possible inclusion in the “toxic equivalency” risk assessment scheme for wild birds. The results of this work are being used as part of an environmental risk assessment in the United States.
Laboratory studies were conducted on the effects of perfluoroalkyl compounds on gene expression in cultured avian liver and brain cells to determine and predict the potential toxic effects of current-use perfluoroalkyl compounds. The Glaucous Gull, an Arctic top predator, was used as a bioindicator species for investigating relationships between contaminant levels (organochlorines and PCBs, mercury and selenium) and measures of oxidative stress in Canadian Arctic ecosystems. Contaminant levels were low and associations between contaminant exposure and oxidative stress were weak. Nevertheless, glutathione peroxidase activity rose with increasing concentrations of selenium in the liver; levels of thiols declined as levels of mercury, organochlorines and PCBs rose; and at one of the two study sites, levels of lipid peroxidation were elevated with increasing levels of mercury in the liver. These results suggest that contaminants may have a harmful effect on gull physiology even at low exposure levels.
Studies continued to examine the effects and toxicokinetics of selected BFRs on captive American Kestrels, Zebra Finches, Ranch Mink, and Snapping Turtles. In American Kestrels, exposure to beta-tetrabromoethylcyclohexane (TBECH), one of two isomers found in the commercial flame retardant TBECH, induced changes in reproductive success and behaviour as well as nestling growth. Earlier research on the American Kestrel was instrumental to the acceptance of the United Nation's Stockholm Convention Draft Risk Profile of hexabromocyclododecane in October 2010; it demonstrated long-term, multi-generational effects following short-term exposure to the commercial flame retardant mixture DE-71. Zebra Finches exposed to a PBDE as nestlings showed effects on song and reproductive behaviours, but these were not associated with significant effects on brain morphology. In mink, a BFR (bis[2,4,6-tribromophenoxy] ethane, BTBPE) was found to accumulate largely in abdominal fat but not in the liver, while environmentally relevant exposures had minimal effects on reproduction, juvenile growth or thyroid function. Contaminant uptake and possible oxidative stress in Snapping Turtles and mink exposed to BTBPE is currently an area of active research.
Research was completed on the exposure of Tree Swallows to various chemicals associated with wastewater treatment plants, particularly current-use flame retardants and those flame retardants recently banned but still persistent in the environment. Nearly all of the measured flame retardants were detected in the eggs of Tree Swallows, and some were associated with reproductive and developmental changes in the birds.
Research was also conducted to examine the exposure of Peregrine Falcons to flame retardants. Dechlorane Plus and several other halogenated flame retardants were detected for the first time in falcon eggs, and comparisons were made with results obtained from falcon eggs collected in Spain. Generally, Peregrine Falcon eggs in Canada had higher concentrations of the measured flame retardants than did eggs from Spain. These contaminants were also measured in the blood plasma of nestling Peregrine Falcons from the Great Lakes–St. Lawrence River Basin. Preliminary assessments indicate significant regional differences and associations with some of the flame retardants, thyroid hormones and retinol, measured in the falcon nestlings. Stable isotope data will also be analyzed to identify the possible role of trophic level in contaminant and biomarker patterns.
An ongoing assessment of the impact of methyl mercury, lake acidity and related stressors on the breeding success of Common Loons and other wildlife across Canada continued through studies in Nova Scotia, Quebec, Ontario and western Canada. An assessment of the impacts of acid deposition on the biodiversity and abundance of aquatic invertebrates, amphibians, and fish in lakes in Nova Scotia continued.
Studies of the toxicity of methyl mercury to developing avian embryos continued to be undertaken for a variety of seabird species, to determine the comparative sensitivities of these species to methyl mercury exposure and to estimate toxic-effect concentrations. Analysis of mercury trends (from 1972 to 2008) in seabird eggs collected along the Atlantic coast began.
Exposure and effects studies of Bald Eagle nestlings continued on the Pacific coast of North America. Results show that exposure of Bald Eagles to PCBs and dichlorodiphenyltrichloroethane (DDT)-related compounds was highly influenced by trophic level (i.e., place in the food chain). However, levels of BFR retardants did not appear to be influenced by trophic level, perhaps suggesting some capacity of the animals to metabolize those chemicals. Findings indicate that PCBs continue to have an effect on eagle physiology more than 30 years after their use was banned. In cooperation with colleagues from the United States, a long-term study of contaminants in Bald Eagles around the Great Lakes region was completed. Results showed that both PCBs and DDT negatively impacted reproductive success up until the early part of the last decade, although the mechanisms of action were not determined.
A collaborative project with colleagues in Wales revealed that American and European populations of dippers were exposed to different patterns of persistent contaminants. Exposure of American Dippers to PCBs and BFRs was substantially greater as a result of their feeding on juvenile salmon, compared with the invertebrate diet of their European counterparts. Recent work has shown that the diet of female dippers changes during the breeding season, which has implications for the interpretation of contaminants in eggs.
Studies on perfluoroalkyl compounds in the blood plasma of adult Snapping Turtles, amphipods, and surface waters in Areas of Concern in the Great Lakes revealed unexpectedly high concentrations of perfluorooctane and perfluorohexane sulfonate in biota and water at a site downstream from an international airport. Efforts to identify the source of the contaminants are underway and the toxicity of these concentrations to Snapping Turtles will be assessed by examining their thyroid function following exposure.
An ongoing assessment of genetic mutation rates of Double-crested Cormorants from colonies downwind of steel mills continued in Hamilton Harbour. Airborne exposure to PAHs is being assessed through analysis of lung tissue, whereas fatty acids are being used to assess potential dietary exposure. Investigations of the relationships between contaminant levels and parasite load in fish-eating birds like the Great Lakes cormorants continued, with the objective of improving the understanding of how contaminants and parasites may be interacting to affect the health of wildlife.
Monitoring of contaminant (PAHs, mercury, arsenic) levels in fish-eating bird eggs from the oil sands region of Alberta revealed spatial differences and temporal changes in concentrations. Most notably, eggs collected from sites closer to oil sands operations had higher levels of some contaminants, and mercury levels in gull eggs from Lake Athabasca increased 40% from 1977 to 2009. More research is required to identify the sources of these contaminants.
To provide guidance on the information requirements in the risk assessments under CEPA 1999, previous research assessed the persistence of high-priority Domestic Substances List (DSL) microbial strains in soil microcosms. As a follow-up to this research, a draft guidance document was produced recommending a method for assessing the persistence of microbial strains in soil microcosms. Additionally, previously developed DNA genetic fingerprints of the DSL strains were used to assess new genetic tools for detecting nine DSL strains in pure culture, mixed blends and soil samples. Research was also completed on the evaluation of methods for assessing microbial consortia products. The data and methods will contribute to the risk assessment of the high-priority DSL microbial strains and consortia and potentially provide methods useful for enforcement responsibilities.
Soil toxicity tests were completed using medium-priority chemical substances under the CMP. Studies on the toxic effects of three xanthene dye compounds on a suite of soil organisms were conducted to evaluate their potential to predict the toxicity of other medium-priority substances within this class of dyes. Another CMP study evaluated the toxicity of two inorganic compounds (cobalt and silver) using a suite of terrestrial organisms (soil invertebrates, plants and microbial community) in a sandy soil. Similar studies evaluated the acute toxicity of one azo dye to Snapping Turtle eggs exposed in soil and three azo dyes to benthic invertebrates exposed in treated sediment. Work continued to examine the bioaccumulative potential of azo dyes. The results of these studies will provide biological response data to allow a more comprehensive assessment of selected priority CMP substances and improve the tools used for the assessment and management of other suspected persistent, bioaccumulative and inherently toxic chemicals.
Work continued on new methods of measuring emerging contaminants in wildlife, including perfluorinated compounds and replacement BFRs. A novel method was developed to identify and quantitatively determine perfluorooctane sulfonate in a commercial product and in environmentally relevant biological samples. With this method, perfluorooctane sulfonate-based compounds were identified in the technical product, in the eggs of Herring Gulls from the Great Lakes, and in the liver and blood plasma of Polar Bears from the Canadian Arctic.
Another method was developed to detect a number of emerging BFR contaminants in wildlife. This new highly sensitive analytical method was used to screen Herring Gull eggs collected from several sites in the Great Lakes and one site in the St. Lawrence River. Two previously unstudied BFR compounds were detected in gull eggs from these populations, indicating that these contaminants bioaccumulate to some degree in the Herring Gull's food chain and transferred to their eggs.
Several laboratory studies were conducted to determine and predict the sensitivity of avian species to the toxic effects of dioxins, PCBs and other dioxin-like compounds. The research resulted in a novel method that can be used to predict the sensitivity of any avian species to any dioxin-like compounds. This method is now being considered by the U.S. EPA to provide risk assessment decision support at contaminated sites. Work continued on a project to develop and validate a practical in vitro and in vivo biomarker platform that acts as a rapid screening tool for assessing the potential of chemical substances to cause early neurochemical and neuro-developmental toxicity in birds. The integrated suite of assays making up this biomarker platform will allow priority substances to be rapidly screened in order to identify chemicals that may require more in-depth toxicological assessment.
Methods to measure thyroid and growth hormone concentrations in blood plasma samples collected from chickens and Herring Gulls were developed and validated. These methods will provide a relative measure of ecosystem health at different gull colonies throughout the Great Lakes Basin in combination with the use of a previously designed method to determine stress hormone levels in bird feathers.
Research continued towards the development of laboratory test methods using native amphibians to examine the biological effects and modes of action of priority compounds of interest and to generate compound-specific risk assessments and risk management models. Methods development included establishing procedure parameters, artificially induced reproduction, and endpoint measurements, which will lead to screening assays and standard methods for toxicity assessments using amphibians.
To develop guidance for the New Substances Notification Regulations, genomic tools are being evaluated to assess the presence of pathogens in bioengineered microbial consortia and to assess microbial community health.
3.2.5 Human Health
Health Canada continues to undertake research and assessments to support the development of regulations, guidelines and air quality objectives with the goal of reducing population exposures to indoor and outdoor air pollutants and improving human health.
184.108.40.206 Air Quality Health Impacts
As part of the Government of Canada's Clean Air Agenda, Health Canada is conducting research and developing tools that support regulatory and non-regulatory actions under CEPA 1999 aimed at improving air quality and human health, including the development of a national ambient air quality management system. Studies undertaken in 2010–2011 include investigations of the health risks associated with exposure to air pollutants emitted from industrial, transportation and indoor sources; mortality and morbidity risks associated with long-term exposure to air pollutants; and characterization of the spatial variability of ambient air pollutants.
Ambient air pollution
A number of complex outdoor monitoring studies have been conducted to characterize the spatial variability of ambient air pollutants and to examine the effect of land use (e.g., roadways, industry) on local ambient air pollution. Statistical models have been developed to predict air pollution levels in a given region based on land-use characteristics. These models are useful in large environmental health studies, as they can be used to provide cost-effective exposure measures. Activities in 2010–2011 included:
- Health Canada conducted spatial monitoring studies in Ottawa, London, Calgary, Halifax, and Montréal, building on the body of evidence of studies previously completed in Winnipeg and Hamilton. These studies took place over the winter and summer seasons. A study in Windsor was completed that will allow comparisons among seasons and years. The suite of pollutants examined for spatial variability in urban areas include nitrogen dioxide (NO2), sulphur dioxide (SO2), volatile organic compounds (VOCs), PAHs and PM.
- A study in Vancouver was completed that monitored for ultrafine particles and nitrogen oxides (NOx).
- In Sault Ste Marie, a study was initiated to investigate the health effects of daily exposure to air pollutants emitted from the coke ovens at a local steel mill. This is a cross-over study in which about 60 participants are exposed to ambient air and filtered air at a location near the plant, as well as ambient air away from the plant. The study uses protective equipment that can selectively filter out components of air pollutants and hence the participants' exposure can be more precisely characterized and the health effects better assessed. Participants' personal and outdoor exposure to ambient levels of SO2, NO2, PM, VOCs and PAHs, except when they are breathing filtered air (no exposure), is being assessed. The health parameters being assessed include lung function, biomarkers of oxidative stress and inflammation, blood pressure, and heart rate. This study is one of the first of its kind to systematically examine the effects of industrial air pollutants on healthy subjects without the effects of confounding factors.
Changes and expansion in the use of renewable or conventional fuels in Canada requires the assessment of potential human health risks and benefits associated with fuel production, transport, storage and use. Assessments addressing the life cycle of fuels are used to inform policy and regulatory decisions. As part of the health components of the federal Biofuels Lifecycle Risk Assessment, an assessment of the health risks and benefits associated with the use of biofuels in Canada was carried out and is near completion. This study focused on emissions characterization and population exposure and addressed the health implications associated with biofuels production, transport, storage, as well as its use in the transportation sector. The results of this work were used to support the further development of the Renewable Fuels Regulations.
Knowledge of the health effects of traffic-related air pollutants can be applied to the development of management tools and information that can be used by municipalities for urban planning. Activities in this area in 2010–2011 included:
- Health Canada initiated a series of studies examining exposure experienced using different modes of public transit in several urban centres. In Ottawa, a study examined the acute health effects of air pollution among cyclists. The exposure data from these studies are undergoing analysis.
- Additionally, research was undertaken in collaboration with the University of Windsor to establish the impact of traffic on surrounding areas by conducting monitoring and dispersion modeling of traffic-related air pollutants.
Emission reductions by industry are required to improve air quality, resulting in health and environmental benefits. A sector-based approach enables an understanding of the toxicity of the sector's emissions and its impact on the health of Canadians in order to inform technological options that are most cost-effective in reducing sources that represent the greatest health risk. Health impact assessments provide a means to evaluate specific regulatory and non-regulatory actions and to compare their impact across sectors. In 2010–2011 these assessments included:
- Sectoral air quality assessment modeling was completed for electricity, iron and steel, base metal smelters, cement, aluminum, and pulp and paper sectors.
- A human health risk assessment for carbon black, completed and published in the Canada Gazette, Part I (Vol. 145, No. 2, January 8, 2011).
- A health-based reference concentration for inhaled manganese, completed and published in the Canada Gazette, Part I (Vol. 144, No. 19, May 8, 2010).
Developed by Health Canada, the Air Quality Benefits Assessment Tool (AQBAT) is a computer simulation tool designed to estimate the human health and welfare benefits or damages associated with changes in Canada's ambient air quality. The program is applied to federal government policy proposals on air quality. Work involving the AQBAT in 2010–2011 included the following:
- AQBAT was used to assess the health benefits of different regulatory scenarios to reduce air pollution and greenhouse gases for the proposed regulatory framework for the proposed Reduction of Carbon Dioxide Emissions from Coal-Fired Generation of Electricity Regulations and was also used to conduct a comparison of biofuels and diesel.
- AQBAT is being updated to include a number of enhancements including population, air pollution, and baseline incidence data as well as revised concentration response functions and valuation parameters for selected outcomes and a mapping capability. Additional outcomes for consideration in this version include life expectancy, quality-of-life impacts in relation to chronic morbidity, and adverse pregnancy outcomes.
The Population Improvement Approach was developed by Health Canada, using atmospheric models provided by Environment Canada, as a tool to assist in setting national ambient air quality standards. The PIA identifies the percentage of Canadians that are exposed to ambient levels of PM and ozone above a given standard (e.g., a Canada-wide standard), and can be used to estimate changes in that percentage if the standard were changed (e.g., made more stringent).
Indoor air quality
As part of a comprehensive agenda to address air quality, Health Canada continued to assess the health impacts of indoor air contaminants to inform the development of risk management actions aimed at reducing indoor exposure. Final residential indoor air quality guidelines and scientific assessment documents are used as the basis for communication products for public health professionals and the public, aimed at guiding interventions to improve indoor air quality and reduce negative health impacts. In 2010–2011, the Department worked on draft residential indoor air guidelines for fine PM, nitrogen dioxide, benzene and naphthalene.
Further understanding of the health impacts and sources of exposure to indoor contaminants (released from household products, building materials, combustion appliances, or entering the home from outside) is vital given that Canadians spend 90% of their time indoors. Exposure studies provide a snapshot of different exposures experienced across the country in various indoor environments and help to pinpoint sources of exposure to inform risk management actions to protect health. In 2010–2011, residential exposure studies to collect data on a range of indoor air pollutants (e.g., PM, ozone, nitrogen dioxide, VOCs, formaldehyde, carbon monoxide, dust and fungal contaminants) were completed in Edmonton and Halifax, and in an apartment building in Ottawa. Corresponding outdoor monitoring was also completed at these locations to assist in determining the extent to which outdoor air quality influences indoor air levels; the data on this aspect and other factors is currently being analyzed. These data sets complement earlier exposure studies of Canadian homes and daycares conducted in Montréal, Regina and Québec.
220.127.116.11 Exposure and Biomonitoring
The Canadian Health Measures Survey (CHMS) is a national survey carried out by Statistics Canada, in partnership with Health Canada and the Public Health Agency of Canada, to collect information from Canadians about their health. Cycle 1 of the survey (2007–2009) included the collection of blood and urine samples from approximately 5600 randomly selected Canadians between the ages of 6 and 79 years, from 15 collection sites. The objectives of the biomonitoring component of the CHMS are to establish nationally representative blood and urine concentrations for a range of environmental chemicals and provide baseline data for tracking trends and comparisons with subpopulations in Canada and internationally. Through personal interviews and the collection of physical measurements, the survey provided benchmark data on indicators of environmental exposures, chronic diseases, infectious diseases, fitness, and nutritional status, as well as risk factors and protective characteristics related to these areas. In August 2010, Health Canada published the Report on Human Biomonitoring of Environmental Chemicals in Canada, which provides full biomonitoring results for chemicals measured during Cycle 1. Except for lead, these results provide the first-ever nationally representative biomonitoring data of all the chemicals measured. The second cycle (2009–2011) of CHMS includes children aged 3–5 years and an indoor air component. In 2010–2011, Cycle 2 data were collected from 18 sites across Canada. Planning for Cycles 3 and 4 was initiated.
A three-year national survey of contaminants in Canadian drinking water is examining levels of disinfection by-products, both new and regulated, and selected emerging contaminants in drinking water. Sixty water treatment plants and distribution systems have been sampled across Canada. More than 100 water quality parameters and contaminant concentrations are being determined for each location. The data analysis continued in 2010–2011. This work will provide updated exposure data to be used in the preparation/update of the Guidelines for Canadian Drinking Water Quality.
Phase 1 of the multi-year Canadian House Dust Study was completed in 2010–2011. This project will provide nationally representative baseline estimates of chemicals found in urban house dust, with the initial determination of bioaccessible lead. Vacuum samples were collected from 1025 urban homes across Canada. Wipe sampling methodologies were also evaluated. This study will continue in 2011–2012 with examination of other important metals and organic chemicals. Canada is the first country to develop a national baseline for chemicals in house dust.
Studies are also underway on dermal absorption of substances being assessed under the CMP. Skin is a major route of entry to the human body for many substances, especially those in consumer products such as cosmetics. The study will increase our understanding of how chemicals are transported from the outer surface of the skin to internal layers and the circulatory system. This project is establishing routine test methods to measure the dermal absorption of chemicals that have been identified as a priority for assessment of their effects on human health. Results are expected in 2011.
There is also a national indoor air survey of chemicals focusing on selected priority chemicals in Canadian residential indoor air. Indoor air samples are being collected and analyzed in a national representative sample of Canadian homes whose occupants are participating in the CHMS, Cycle 2. Sample collection began in September 2009 and will be completed in December 2011. Results are expected to be released to the public through Statistics Canada in 2012. This project will continue in cycles 3 and 4 of the CHMS.
A toxicokinetic modeling study was initiated in 2009 to determine the Canadian population's exposure to pyrethroids. This study involved the development of human toxicokinetic models that were applied to two commonly used pyrethroid pesticides, permethrin and cypermethrin. Levels of metabolites from these pesticides were measured to determine the absorbed chemical dose. Such toxicokinetic models can be used to measure the relationship between the chemical by-products (biomarkers) measured in people and the amount of chemical absorbed. The results of the study will be available in 2011–2012.
18.104.22.168 Population Studies
A number of the population studies are largely multi-year research projects that were completed in 2010–2011. Various epidemiological studies were also conducted to assess exposure of targeted populations to specific chemicals.
The ongoing Maternal-Infant Research on Environmental Chemicals study is assessing the pregnancy health risks that may be associated with environmental exposure to heavy metals (lead, mercury cadmium, arsenic, and manganese). The health risks being assessed include elevated blood pressure and gestational hypertension among the women and fetal growth retardation among their infants. The study reached its recruitment target of 2000 pregnant women from the 10 selected clinical sites in 10 Canadian cities. Approximately 53 000 biomonitoring results have been uploaded to a database for analysis. Follow-up of participants through delivery is ongoing. The final report is expected in March 2012.
A Health Canada study on plastics and personal care product use in pregnancy has recruited 80 pregnant women from the Ottawa area and is collecting multiple maternal urine samples, detailed consumer product/food packaging diaries, infant urine and meconium, and breast milk samples. In 2010–2011, the participant questionnaires were collected and the collection and analyses of biospecimens for phthalates, BPA, triclosan and triclocarbon began. In addition, meconium was evaluated as a potential matrix for measuring in utero exposure.
A pilot study on chronic lead exposure among Canadians is assessing the feasibility of obtaining bone and blood lead measurements for different age and gender cohorts to measure both acute and chronic non-occupational lead exposure in the Canadian population. As of March 2011, 263 participants had been recruited into the study (97% of target), and lead assessments began, including analysis of blood samples and bone scans.
A three-year study was completed in Montréal to evaluate the importance of sources of lead exposure, such as drinking water in contact with lead service lines as well as dust and paint. The study compares Canadian children aged 1–5 living in areas served by lead service lines to children of the same age living in similar homes served by non-lead pipes. Another biomonitoring study focusing on lead exposure in young children living in a range of housing ages is underway in St. John's, Newfoundland and Labrador. Publication of the results of both studies is expected in 2011–2012.
A two-year biomonitoring study was initiated in 2008 to assess exposure to arsenic in drinking water from private wells in the Abitibi-Témiscamingue region of Quebec. The potential relationship between the arsenic concentrations in well waters and the internal doses in people, the prevalence of diabetes and the levels of thyroid hormones was evaluated. Preliminary results suggest associations between concentrations of arsenic in drinking water from private wells, internal doses in people, and thyroid function and diabetes. However, these observations need to be validated through other health studies. This study was completed in 2010–2011, and a final report is expected to be released in 2011–2012.
Another biomonitoring study on arsenic in rural Nova Scotia communities was conducted in 2009 and 2010 to develop and test a group of biomarkers of exposure and to explore both short- and long-term exposure to arsenic. The biomarkers are related to well-water concentrations of both total arsenic and inorganic arsenic species, which have different toxicity. In addition, a novel and recently developed non-invasive method for analysing concentrations of total arsenic in skin and nails was tested. The results are being analyzed and a final report is expected to be released in 2011–2012.
A two-year study initiated in 2009 on the assessment of long-term indoor residential pollution exposures among Canadian children is designed to provide estimates of exposure to contaminants in young children, through the analysis of data and information obtained as part of the Canadian Healthy Infant Longitudinal Development study biological samples (meconium, cord serum, and urine) and house dust. Samples were analysed for cotinine as a biomarker for tobacco smoke exposure, and a variety of phthalate metabolites and preliminary data interpretation was completed.
22.214.171.124 Mechanistic Studies
Health Canada led international efforts towards the establishment of an Organisation for Economic Co-operation and Development test guideline for transgenic rodent mutation assays, culminating in the international acceptance of a harmonized method. This test will allow better identification of those chemicals that cause genetic mutations with the potential to affect human health.
Toxicogenomic studies, which investigate changes in the function of all the genes of an organism in response to exposure to a chemical, were employed to assess the effects of exposure to engineered nanoparticles, such as nano-titanium dioxide and nano carbon black. Toxicogenomic approaches were determined to be effective in identifying biological perturbations very soon after exposure and before the appearance of any visible changes in health in the exposed animal model.
Studies to determine the characteristics and pathogenicity of various biotechnology microbes continued. Results achieved during 2010–2011 for four different microbial species were used in the corresponding Health Canada risk assessments of existing animate products of biotechnology. This research filled key gaps with data that would otherwise be unavailable.
A three-year project to develop “biomonitoring equivalents” is underway using physiological pharmacokinetic models for interpreting Canadian biomonitoring data. Health Canada is developing biomonitoring equivalents for several priority chemicals, for both risk assessment and management, and evaluating them for their application in biomonitoring surveillance initiatives. The first capacity development initiative was completed in March 2011 and the results are expected in 2011–2012.
126.96.36.199 Hazard Identification
In vivo studies examining the impact of perinatal exposure to a chemical mixture on the development of brain neuroimmunoinflammatory changes were completed. These changes are associated with age-related neurodegeneration in diseases such as Parkinson's. The results of this study should be available in 2011–2012.
A number of studies were completed comparing the effects of methylmercury on neurodevelopment with the use of molecular biomarkers of neurotoxicity. The results highlighted the complexity of contaminant-nutrient interactions, as co-administration of a phytochemical nutrient increased, decreased or had no effect on methylmercury pertubations, depending on the endpoint assessed.
A number of other in vivo and in vitro studies were conducted examining the effects of exposures to mixtures of endocrine disruptors to identify critical periods of development (in utero and/or postnatal) during which long-term adverse health effects might be induced. Components of these mixtures, as well as PBDEs, vanadium and nickel are tested on human cells in vitro to investigate mechanism of action and to identify potential predictive indicators of chemical-induced health impairments in humans.
Studies also investigated the effects of very low doses of bisphenol A and other CMP priority chemicals in the formation of fat cells from precursor cells. In addition, collaborative studies examined the impact of these substances on pancreatic beta cell function to identify substances that could cause or exacerbate diabetes. These studies suggested that bisphenol A may pose a risk of inducing metabolic syndrome.
- Date Modified: