Study Shows Which Chemicals Are Likely to Build Up In Food Chains

A recent federal study detailed a model that could determine whether harmful chemicals are likely to accumulate in humans and other species atop the food chain.

The study, led by the U.S. Geological Survey and published in the journal Environmental Science and Technology, said that the pattern -- called biomagnification -- is linked to a chemical's ability to be metabolized by an organism and to dissolve in water.

Researchers said that chemicals that are poorly metabolized can remain in tissue and be passed up the food chain "in higher, more toxic amounts," while compounds that don't dissolve tend to build up in fat.

The analysis also found that certain ecosystems are more vulnerable to biomagnification. Ocean food webs that included birds and mammals were particularly prone to chemical accumulation, perhaps due to their longer food chains.

Persistent organic pollutants first became a concern for scientists following the rise of DDT more than 50 years ago, which resulted in harmful effects on the environment and human health.

The USGS study also developed a screening model to help identify potentially dangerous chemicals -- either in development or already on the market -- for both industry and regulators.

Chlorinated flame retardants and PCBs, in particular, were likely to biomagnify nearly 100 percent of the time.

"We need to learn from our previous mistakes and have more informed and responsible design and use of chemicals in the environment,” said co-author Karen Kidd of the University of New Brunswick.