Worcester is representative of many old manufacturing towns across the country. “With a decline in manufacturing, you get a decline in certain types of pollution, but you are also left with ongoing problems such as lead contamination in soil, which is typical of a lot of older American towns and cities,” said Katherine Kiel, an environmental economist at the College of the Holy Cross in Worcester. “Low-income housing is often built where property is cheapest. Unfortunately these areas often have more pollution.”
The eaves of Ford’s home – one of Worcester’s iconic triple-decker apartment houses – are blackened by soot from trucks and cars. From her front porch, she can see the on-ramp to the interstate highway that bisects the city.
“This feels like a depressed town. There are a lot of neglected, dilapidated places. It’s not very child-friendly,” said Ford, who is not using her real name for fear that her son will be bullied at school about his learning disabilities.
Ford is black, as is roughly 12 percent of Worcester. One small study published last year found that women in Boston who faced racial discrimination and community violence had higher levels of a stress hormone linked to preterm birth.
Gang activity and a drug raid at a house nearby have brought community violence close to home. “My husband and I didn’t see it at first when we moved here, but it’s pervasive,” said Ford.
Rates of violent crimes in Worcester are about 17 percent higher than the national average. In 2010, there were roughly 471 assaults, armed robberies and murders per 100,000 inhabitants in Worcester. The national average for that same period was 404 violent crimes per 100,000 people, according to the FBI’s Uniform Crime Reports.
She worries constantly about the safety of her kids. Four of them, all under the age of 15, live at home.
When Ford’s son was born in 2004, he seemed healthy. “Looking back, there were signs of developmental delays early on, like he drooled too much, but we didn’t think much of it,” she said.
When he was two, his doctor found that his blood lead levels were elevated, though they fell below the commonly defined threshold for harmful effects of lead. Ten micrograms per deciliter has traditionally been defined as the harmful level, but recently the Centers for Disease Control and Prevention lowered it to five, recognizing that harmful effects can occur at lower levels.
Synergy between lead and stress
With lead pollution, “the toxicity of lead may be stronger in a child also exposed to the stress of poverty,” said Dr. Robert Wright, a pediatrician and environmental health scientist at the Harvard School of Public Health, and husband of Rosalind Wright.
Lead exposure, which has been linked to reduced IQs, attention problems and aggressive behavior, may be more detrimental to low-income kids than to children with higher socioeconomic status. Children in Boston began to show IQ deficits at blood lead levels as low as six micrograms per deciliter of blood, while kids from families with more financial resources only began to show cognitive deficits at levels greater than 10, according to one study.
“If this synergy exists between stress and lead, from a biological perspective, it’s plausible this link exists between stress and other neurotoxic pollutants, such as mercury and polychlorinated biphenyls (PCBs) as well,” said Robert Wright.
For years, toxicologist Deborah Cory-Slechta of University of Rochester and her colleagues have studied the combined effects of lead and stressful conditions on lab rats. Lead plus stress had effects on their learning ability and brains that did not occur with either of those factors alone, according to their research.