Upcoming Journal of Human Resources article uncovers the hidden effects of pollutants on cognitive development and academic performance in adolescents
Increasing environmental consciousness means that more people are reaching for metal straws, but we may not be aware of a much larger issue: the hidden toxins in the air. New research set to appear in the upcoming issue of the Journal of Human Resources suggests that pollutants from local Toxic Release Inventory (TRI) sites may impact the productivity and educational development of students in nearby schools.
Over the past four years, Claudia Persico, an assistant professor at American University, evaluated over one million elementary, middle, and high school students in Florida using their Florida Comprehensive Assessment Test (FCAT) scores, their level of academic success, and general wellness. With over 30% of schools in Florida existing within one mile of a TRI site, exposure to air pollution was found to be associated with lower test scores and a greater chance that students will be suspended from school, have greater numbers of absences from school and perform lower on their FCAT exams. Persico expanded on these results to determine if different proximities to TRI sites affected grade repetition, behavior, and health over time. When students’ records were examined, it was revealed that those who had been exposed to the pollution for a greater cumulative time had lower attendance records and more health concerns.
Persico joined us to discuss the genesis of her interest in this topic and the larger implications of the study. To learn more, read the full Journal of Human Resources preprint article, “The Effects of Local Industrial Pollution on Students and Schools.”
1. How did you decide to pursue this topic? What spurred this study?
I used to study the neurobiology of autism at the Boston University School of Medicine, but I became interested in why low-income children perform so much worse in school and are more likely to have disabilities. Because the developing brain is so vulnerable to the environment, this got me interested in studying pollution.
It turns out that in 2014 alone, Toxic Release Inventory (TRI) sites in America (which represent only one type of industrial plant) released 3.95 billion pounds of (untreated) toxic chemicals into the air, land, and water, out of 25.45 billion total pounds of toxic chemicals created in production-related wastes. Although we do not currently have comprehensive evidence on which pollutants are most harmful, the evidence we do have is worrisome and suggests a source of inequality that has not yet been explored in depth. Namely, since African American, Hispanic, and low-income families are more likely to live and attend school in close proximity to sources of pollution like toxic waste and TRI sites, where housing is less expensive, it is possible that exposure to pollution—which more affluent families can avoid because they can afford more costly housing—is one mechanism through which poverty produces negative cognitive and health outcomes over time.
2. You note that about 30 percent of children in Florida live within one mile of a TRI site. Is Florida an extreme case? How are the effects of pollutants on cognitive development applicable to other areas of the United States and the world?
There are currently about 21,800 TRI sites operating across the United States and the Environmental Protection Agency estimates that 59 million people (about 19 percent of the population) live within one mile of a TRI site (EPA 2014). We find that nearly 22 percent of all public schools were within one mile of a TRI facility in 2016 serving more than 11 million public school students.
While other countries don’t call their factories TRI sites, it is likely that my findings could generalize to power plants, pharmaceutical industry, chemical, metal, and concrete manufacturers, as well as other factories that produce pollution containing carcinogens or known developmental toxicants worldwide. It is difficult to know how many people this would affect given that there isn’t a central database for international pollution, but my guess is that many people are affected.
3. What is one takeaway from your article that you’d like to communicate to non-scholars (or policymakers)?
These findings have strong implications for where we locate schools, playgrounds, public housing and places children or pregnant women congregate. For a long time, we have known that neighborhoods matter to children’s long-term outcomes. We are starting to realize that pollution is one major reason why this is the case, that pollution might drive more inequality than we are comfortable with, and that the true costs of pollution are only beginning to be understood.
4. To what extent do you feel that your research could inspire change in policy?
I think policymakers are starting to be interested in these findings, and I am optimistic about the future. While the land near TRI sites is cheaper to build a school on in the short run, the truth is that these sites might jeopardize the very mission of the schools located there. This also says nothing of the long-run costs on the children exposed to this type of pollution. In the back of the envelope calculation, we find that being exposed to TRI pollution in school leads to a US$4,361 decrease in lifetime income per person (in present value terms). With 436,088 children in Florida ever attending school within one mile of an operating TRI site during this sample period, this result implies US$1,875,178,400 in lost lifetime earnings.
5. Will you continue to pursue similar questions or will you take your research in another direction?
Yes, I am pursuing several new projects about the true costs of pollution. For example, I have another new working paper (along with David Simon and Jenni Heissel) in which we compare students who have to switch from elementary to middle school or from middle school to high school as they progress through the school system. We compare children who switch from a school that is upwind from a highway to a school that is downwind of a highway, and again find that highway pollution affects students’ test scores, behavior, and absences. Children who attend school near a major highway are again more likely to be low income or minority than children attending school elsewhere.
Note: Toxic Release Inventory facilities are shown in blue and sites on the Superfund National Priorities List are shown in red.
Source: National Institutes of Health, Department of Health and Human Services. https://toxmap.nlm.nih.gov/toxmap
Claudia Persico is an applied policy scholar whose research focuses on environmental policy, inequality, health and education policy using causal inference methods. Persico is also an IZA Research Affiliate, and a Research Affiliate with the Institute for Policy Research at Northwestern University. Her research has recently been featured in the Quarterly Journal of Economics, the Journal of Labor Economics, and the Journal of Human Resources. Her current work examines the social and biological mechanisms underlying the relationships between poverty, the environment, and children’s cognitive development and health. In particular, much of her current research focuses on how early exposure to environmental pollution can cause inequality by affecting child health, development, behavior, and academic achievement. She has also studied how school funding affects long term outcomes, how school segregation impacts racial disproportionalities in special education, and how childhood exposure to pollution affects academic outcomes. Her research has been covered by the New York Times, the Washington Post, NPR, the Atlantic, and many other major media outlets. She was formerly an Assistant Professor at the University of Wisconsin-Madison.