Air Toxics Research: Dioxin and Atrazine

Geographical distribution of U.S. and Canadian 1996 dioxin emissions. From Cohen M., Draxler, R., Artz, R., et al (2002), Modeling the Atmospheric Transport and Deposition of PCDD/F to the Great Lakes, Environmental Science and Technology, Volume 36, pages 4831-4845.

In addition to mercury, ARL has conducted world-class research on the atmospheric fate and transport of dioxin, atrazine, and other air toxics. A cornerstone of ARL’s work is a state-of-the-art modeling system that tracks emission sources and links these emissions to atmospheric transport, transformation, and deposition. This system directly supports air quality decision-makers, air quality forecasters, and the scientific research community.

As example, Dioxin is emitted to the atmosphere from a variety of sources, such as waste incineration. It eventually deposits to terrestrial and aquatic ecosystems where it can bioaccumulate. Resulting levels can result in wildlife and human toxicological risks. Understanding where dioxin emissions originate from; how and where they are transported and deposited; and what changes will occur due to emission controls is critical information for policy-makers and regulators.

There are many other important air toxics. Each has its own set of emissions sources, particular atmospheric fate and transport characteristics, and human/wildlife exposure pathways. Understanding the atmospheric behavior of these compounds, including source-receptor relationships, is critical information for policy-makers and regulators.