By SARA GOODMAN of Greenwire
Mercury exposure in the United States increases with age, then starts
tapering off when people turn 50, the Centers for Disease Control and
Prevention found in a study released today.
The CDC study is the first to measure mercury exposure in a wider U.S.
population, following research that focused on young children and
women in their childbearing years. People are often exposed to mercury
through contaminated seafood, and a recent U.S. EPA survey found that
almost half of U.S. freshwater fish carry mercury in excess of federal
safe levels for human consumption.
The CDC data are part of a project assessing chemicals in people's
bodies. The agency has added 75 contaminants to its database, bringing
the total to 212 chemicals.
The survey analyzed blood, serum and urine samples from 2,500 people
as a part of the CDC's National Health and Nutrition Examination
Survey, which is released every two years.
The goal of the research is to determine which chemicals end up in
people's bodies and at what concentrations. It is meant to help
prioritize scientific work and for policymaking. Scientists chose
which chemicals to look for based on expected widespread exposure and
Among the report's findings:
Perchlorate was detected for the first time in all participants.
Perchlorate is a naturally occurring salt that is also a component of
rocket fuel and fireworks. High levels of perchlorate are known to
affect thyroid function, while the health effects of low-level
exposure are being debated.
Bisphenol A, or BPA, was found in more than 90 percent of the
participants' urine. BPA is an industrial chemical that mimics
estrogen and has been shown to cause developmental problems and
precancerous growth in animals.
Lead exposure has been decreasing since the 1970s, validating public
health efforts to reduce childhood exposure, the report says. Between
1999 and 2004, 1.4 percent of young children had elevated blood lead
levels, the smallest percentage of any of the prior survey periods.
But the health of high-risk children -- those living around lead-based
paint or lead dust -- remains a concern.
Acrylamide -- formed when foods containing carbohydrates are cooked at
high temperatures -- was detected for the first time and is common in
the U.S. population.
Biomonitoring detects a chemical's presence only and cannot evaluate
whether its detection signals adverse effects or disease, the report
cautions. Many environmental public health advocates say the findings
play a critical first step in prioritizing the thousands of chemicals
currently in the market today, many of which have little safety data
"Biomonitoring studies such as the ones conducted by the CDC provide
direct evidence that people are being exposed to harmful chemicals
without their knowledge, much less their consent," said Davis Baltz, a
senior associate with Commonweal, a nonprofit. "This is critical
information for decision-makers, who can then craft policy instruments
that will reduce or prevent exposures and also have a way to track
whether those instruments are working."
Sen. Frank Lautenberg (D-N.J.), said in a statement that CDC's
findings highlight the need to reform the Toxic Substances Control Act
(TSCA), the law governing all industrial chemicals on the marketplace.
"Far too little is known about the hundreds of chemicals that end up
in our bodies, and EPA has far too little authority to deal with the
chemicals that science has already proven dangerous," Lautenberg said.
Lautenberg said he plans to introduce legislation to reform TSCA early
next year that would require that EPA determine whether chemicals meet
new safety standards based on scientific risk assessment and that
chemical companies provide enough data to make that determination.
Lautenberg also wants EPA to prioritize taking action on chemicals
that present the greatest health risk.
Click here (pdf) to read the study.
Copyright 2009 E&E Publishing. All Rights Reserved.
For more news on energy and the environment, visit www.greenwire.com