Integrated Atmospheric Deposition Network (IADN)

The Integrated Atmospheric Deposition Network (IADN) has been in operation since 1990 under the guidance of an implementation plan signed that year. The first implementation plan committed the United States and Canada to work cooperatively towards the initiation of the IADN. Currently, the program is comprised of Environment Canada and the U.S. Environmental Protection Agency (U.S. EPA).

IADN is specifically called for, by name, in Annex 15 of the Great Lakes Water Quality Agreement (GLWQA). In Canada, these activities are delivered federally through the Great Lakes program, and activities delivered at the provincial level are described in the Canada-Ontario Agreement (COA). The mandate for IADN also resides in Section 112(m) of the U.S. Clean Air Act Amendments of 1990 (CAA). The U.S./Canada Great Lakes Binational Toxics Strategy (GLBTS), signed in 1997, calls for monitoring of the atmospheric deposition of toxic chemicals to the Great Lakes basin. Many of the challenges in the GLBTS are directly related to IADN capabilities and goals. 

The goals of IADN are to:

  1. Determine the atmospheric loadings and trends (both spatial and temporal) of priority toxic chemicals to the Great Lakes and its basin on, at least, a biennial basis.
  2. Acquire quality-assured air and precipitation concentration measurements, with attention to continuity and consistency of those measurements, so that trend data are not biased by changes in network operations or personnel.

A peer review by international experts reviewed the operation of the network between 2002-2008 and concluded that ‘IADN is a model for multi-national, long-term atmospheric and deposition monitoring of persistent organic pollutants (POPs)...as such, IADN is an important resource for policymakers and researchers.'

IADN is coming to the end of the Third Implementation Plan (IP3). A draft of the Fourth Implementation Plan (IP4) will be prepared by the spring of 2010 and will be finalized in the fall of 2010 and will be based on input from stakeholders and the Binational Executive Committee (BEC).

The research side of IADN is continually developing methods for new and emerging compounds of interest. Methods for polybrominated diphenyl ethers (PBDEs) have been successfully implemented and are the newest compounds added to the list of routinely monitored analytes. IADN is closely linked with the domestic management of chemicals in Canada through the Chemicals Management Plan.

Data requests can be made through the National Atmospheric Chemistry.(NatChem)