Researchers examine cumulative health risks
New Bedford residents, like those in many cities, are at risk for high rates of attention deficit hyperactivity disorder and high blood pressure, according to state and federal studies.
Now, researchers from Boston University School of Public Health, Brigham and Women’s Hospital, and Northstar Learning Centers are studying the reasons why, trying to unravel what they believe is a myriad of combining factors - from PCBs and prenatal tobacco exposure for ADHD, to diet and fine particulate matter exposure for high blood pressure - that may be increasing the illness risk for residents.
The research is part of a growing effort nationally to study the cumulative impact on health of human activities, including pollution, racial discrimination, malnutrition, poverty, and other factors that may disproportionately harm some communities. The problem can be a vexing one to solve, especially in the United States, where environmental policy tends to regulate individual pollutants or their sources in isolation.
Now the Science and Environmental Health Network - a nonprofit that promotes a more precautionary approach for environmental and public health policy - and the Collaborative on Health and the Environment - an international partnership to address environmental health issues - have launched a national project to address the problem of multiple stresses on ecosystems, communities, and human health. The project’s website (cumulativeimpacts.org) assembles information on the latest science, emerging best practices, analytical tools, and legal headway and obstacles.
The US Environmental Protection Agency is beginning to examine cumulative risk, and California has begun to address the health impact of cumulative stressors on communities. That state is now working on developing “precautionary approaches’’ to figure out ways to reduce cumulative impacts.
A 2009 National Academy of Sciences study recommended significant policy shifts to identify and assess cumulative risks to people and the environment.
Katie Silberman, associate director of Science and Environmental Health Network, said efforts are in an experimental stage, in large part because most environmental laws and governmental agency decisions are designed to examine and regulate each harmful impact separately. She said challenges are great: It is difficult to measure how factors such as pollution and poverty influence each other, much less persuade regulatory agencies to work together to solve them.
“It’s a tricky problem, but a crucial one,’’ said Silberman. “ . . . Diseases linked to environmental exposures - like asthma and birth defects - are on the rise, and we need new policy tools to reduce harm on a broad level.’’
Jonathan Levy, the BU professor of environmental health leading the New Bedford study, hopes to ultimately devise better methods to assess cumulative risk. “We are trying to [understand] what are the contributions of multiple chemicals and nonchemical stressors,’’ Levy said.