Children are often exposed to harmful chemicals in air, water, soil, food, food packaging, and plastics. However, low-income children and children of color are disproportionately impacted by these exposures, according to the authors of a study that examines disparities in neurotoxic exposures and their harmful effects on children by race, ethnicity, and economic status.
The review, published Wednesday in Environmental Health Perspectives, highlights racial disparities in toxic chemical exposures and neurodevelopmental outcomes in children. The researchers analyzed 218 epidemiological studies conducted over nearly 50 years that examined exposures to air pollution, lead, mercury, organophosphate pesticides, phthalates, polybrominated diphenyl ethers, and polychlorinated biphenyls.
“As a result of discriminatory practices and policies, low-income children and children of color are currently and historically disproportionately exposed to chemicals without their knowledge or consent where they live, work, play, pray, and learn,” said Devon Payne-Sturges, an associate professor at the University of Maryland School of Public Health. “Their neighborhoods are more likely to be located near factories, chemical plants, Superfund sites, highways and more vehicle traffic, or by agricultural fields where pesticides are applied.”
Across the studies, greater lead exposures were found among low-income and Black children, higher ambient air pollution was found in predominantly non-white and low-income communities, and Black and Hispanic children were exposed to higher levels of OP pesticides.
“It is important we begin these studies from pregnancy because many of these chemicals can cross the placenta and are routinely detected in cord blood or other fetal tissues,” said Tanya Khemet Taiwo, an assistant professor at Bastyr University and a lead author of this study. “During embryonic and fetal development, infancy, early childhood and adolescence, toxic chemical exposures may cause lasting harm to the brain that interferes with a child’s ability to reach their full potential.”
Health disparities, particularly among children, are often understudied by environmental health researchers, Taiwo and Payne-Sturges said. While many studies have reported greater exposure to neurotoxic chemicals among families with low incomes and families of color, most researchers have not examined how race, ethnicity, and economic hardship interact with those exposures to produce differing outcomes, as noted in the paper.
Increasing the reporting of underlying disparities and improving treatment of race and ethnicity variables can drive health equity in environmental epidemiological studies. “As researchers, we have poorly defined these variables for years. And when policy action is often so closely tied to peer-reviewed scientific evidence, it is just one way that we are failing communities who are facing some of the worst environmental challenges,” said Lariah Edwards, an associate research scientist at Columbia University’s Mailman School of Public Health, who was not involved with the study.
The study authors also noted the problems that may result from poorly defined variables. “Conflating ethnicity and race (i.e. ethnoracial coding schemes) imply mutual exclusivity between groups and may mask health disparities among certain populations like Black Hispanic populations,” said Payne-Sturges. “This means that the potentially higher rates of exposure or disease outcomes among Black Hispanics or those who identify as Afro-Latino get averaged out if combined with a larger Hispanic/Latino population category.”
The research review uncovered another problem: the conspicuous lack of studies that examined the exposures and neurodevelopmental outcomes among American Indian, Alaska Native, and Asian American communities.
The authors of this study are participants in Project TENDR, an alliance of 50 leading scientists, health professionals, and advocates focused on protecting children from toxic chemicals and pollutants harmful to brain development, and on eliminating disproportionate exposures to children of color and children from low-wealth communities.
The study’s findings suggest that future research should focus on the cumulative impact of exposure disparities, said Aisha S. Dickerson, an assistant professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health who was not involved with the study. She also said this research may guide the design of better interventions to reduce or eliminate health disparities in the most vulnerable populations, including children who experience neurodevelopmental deficits as a consequence of hazardous exposures.
On a grassroots level, local organizations have been collaborating with their communities to address the impacts of exposure to toxins through education, policy, and advocacy initiatives.
“The Arctic’s Indigenous communities face some of the world’s highest levels of lead and aviation gas, compounded by climate change. We’re working with tribes, community councils, firefighter unions, and municipalities to collectively advocate for a ban on these toxins,” said Pamela Miller, the founder and executive director of Alaska Community Action on Toxics, a community-based organization dedicated to eliminating the production and release of harmful chemicals by industry and military sources. The organization’s research and work helped ban four classes of flame-retardant chemicals from children’s products.
And policy changes are needed at the federal level, the study authors said. “FDA and EPA can act now — not later — to safeguard families from neurotoxic chemicals by banning phthalates from food contact materials; eliminating lead from residential environments, aviation gas, and children’s foods; ending the use of organophosphate pesticides and setting air pollution standards to protect child brain development,” said Payne-Sturges, who was a policy specialist at the EPA for 12 years.