A BETR way to track toxic pollutants

Why are chemicals that have been banned for over a decade still being detected in the environment? How is it that chemicals and other pollutants such as particulate matter turn up hundreds or even thousands of miles from their sources? These are just two of the questions that a team of American and Canadian scientists hope will be answered using a model they have developed to track pollutants across North America. In the short term, the model's developers are concentrating on using it to assess rates of exposure from food sources, but they hope to expand the model to include global data, a step they hope will help policy makers better understand the consequences of pollution.