Construction workers had twice as much lead dust in their homes as janitorial or autobody workers, but lead levels also varied by demographics and other work and home factors.
“Take-home” exposure is when dangerous contaminants come home on workers’ bodies and clothing, unintentionally exposing their families and causing issues including child lead poisoning.
And lead dust from construction is a particularly dramatic take-home exposure here in the Boston area, according to a new study by researchers from the Boston University School of Public Health and the Harvard T.H. Chan School of Public Health.
Published in the journal Environmental Research, the study found that construction workers had twice as much lead dust in their homes as janitorial or autobody workers. Some homes had lead dust at levels that have been recorded in homes near Superfund sites and lead smelters—or Boston homes in the early ‘90s, back when the gasoline burned by Boston traffic was leaded.
But the researchers also found that lead levels varied by sociodemographics such as race/ethnicity, job factors including stability and hygiene, and home factors such as when a building was built, showing that take-home exposure needs to be tackled from multiple angles, says Diana Ceballos, assistant professor of environmental health at SPH and a research scientist and instructor at the Harvard Chan School, who led the study, who led the study.
Ceballos and the other researchers are from the Center for Research on Environmental and Social Stressors in Housing Across the Life Course (CRESSH), a collaboration between SPH and the Harvard T.H. Chan School of Public Health.
They recruited 30 Boston-area households with at least one child in the home: 23 households of construction workers (prioritizing those working in renovations, bridge constructions, welding, metal work, and demolitions), 5 of janitorial workers, and 2 of autobody workers.
The researchers instructed the families to refrain from vacuuming their homes for a week, then visited, vacuumed up dust samples, and looked at other factors such as the presence of chipping paint and what kind of heating and cooking fuel they used. The researchers also interviewed the workers, gathering sociodemographic, home, and work information.
Lead levels varied widely, from 20 to 8,300 parts per million (ppm), but construction workers’ homes generally had more than twice the levels as the other workers’ homes, with an average of 775ppm compared to 296ppm. Five of the construction workers’ homes had lead levels over the US government’s recommended limit for outdoor child play areas, 400ppm, similar to levels observed in previous studies of homes near Superfund sites and lead smelters, or in Boston before the 1996 ban on leaded gasoline.
After analyzing their results, the researchers found that, while there were too few households in the study to confidently pinpoint the factors associated with higher levels of lead, they were able to see that ethnicity, work hygiene behaviors, and when the home was built all influenced the levels of lead in a home.
“We were not able to detangle exactly which social factors because it was a small sample (which we knew from the start), but we were able to verify there is a problem,” Ceballos says. “Now, it will be easier to detangle things more in future studies.”
Next, the researchers are conducting a pilot study, funded by the US Department of Housing and Urban Development (HUD), that will test multiple education and environmental interventions with Boston-area construction worker households, looking for the most effective ways to reduce lead take-home exposures.
The current study was coauthored by Melissa Miller (SPH’19) and Jenna Quinn (SPH’20), who were students and graduate research assistants while working on the study with Ceballos; and Robert F. Herrick, Zhao Dong, Andrew Kalweit, and John G. Spengler of the Harvard T.H. Chan School of Public Health.
