Mixture toxicity, cumulative risk, and environmental justice in United States federal policy, 1980–2016

Toxic chemicals — “toxicants” — have been studied and regulated as single entities, and, carcinogens aside, almost all toxicants, single or mixed and however altered, have been thought harmless in very low doses or very weak concentrations. Yet much work in recent decades has shown that toxicants can injure wildlife, laboratory animals, and humans following exposures previously expected to be harmless. Additional work has shown that toxicants can act not only individually and cumulatively but also collectively and even synergistically and that they affect disadvantaged communities inordinately — and therefore, as argued by reformers, unjustly. As late as December 2016, the last full month before the inauguration of a president promising to rescind major environmental regulations, the United States federal environmental-health establishment, as led by the Environmental Protection Agency (EPA), had not developed coherent strategies to mitigate such risks, to alert the public to their plausibility, or to advise leadership in government and industry about their implications. To understand why, we examined archival materials, reviewed online databases, read internal industry communications, and interviewed experts. We confirmed that external constraints, statutory and judicial, had been in place prior to EPA’s earliest interest in mixture toxicity, but we found no overt effort, certainly no successful effort, to loosen those constraints. We also found internal constraints: concerns that fully committing to the study of complex mixtures involving numerous toxicants would lead to methodological drift within the toxicological community and that trying to act on insights from such study could lead only to regulatory futility. Interaction of these constraints, external and internal, shielded the EPA by circumscribing its responsibilities and by impeding movement toward paradigmatic adjustment, but it also perpetuated scientifically dubious policies, such as those limiting the evaluation of commercial chemical formulations, including pesticide formulations, to only those ingredients said by their manufacturers to be active. In this context, regulators’ disregard of synergism contrasted irreconcilably with biocide manufacturers’ understanding that synergism enhanced lethality and patentability. In the end, an effective national response to mixture toxicity, cumulative risk, and environmental injustice did not emerge. In parallel, though, the National Institute of Environmental Health Sciences, which was less constrained, pursued with scientific investigation what the EPA had not pursued with regulatory action.https://doi.org/10.1186/s12940-021-00764-

Blood and urine levels of long half-life toxicants by nativity among immigrants to the United States

One's place of birth is a major determinant of his or her exposure to environmental toxicants. By understanding biological burdens of long half-life toxicants by race and nativity we can better understand geographic variation in toxicant distribution. We used the National Health and Nutrition Examination Survey (1999–2006) biomonitoring data to examine differences in blood and urine levels of long half-life environmental toxicants of foreign-born relative to US-born people by race/ethnicity. We log transformed blood and urine measures of 51 environmental toxicants. We then used “seemingly unrelated regression,” a robust technique for making multiple comparisons across a group of variables with correlated error terms, to examine differences in blood and urine toxicants by nativity and race. We found that, compared to native-born Americans, the foreign-born are generally more likely to be exposed to metals (p < 0.001) and organochlorine pesticides (p < 0.001), but less likely to be exposed to dioxin-like compounds (p < 0.001) or polyflourinated compounds (p < 0.001). While levels of toxicants varied greatly by region of birth, US-born participants had consistently higher levels of dioxin-like compounds and polyflourinated compounds

Collaborating for Success: A Case Study on Mentoring, Partnering, and Teaching

Master of Library and Information Science (MLIS) graduates seeking employment in academic libraries are often expected to possess user instruction and public service skills. However, it is difficult for students to achieve this experience through coursework alone. To address this disconnect, librarians at the University of Maryland (UMD) College Park Libraries created a Research and Teaching Fellowship to allow MLIS students at UMD to gain practical instruction experience. The authors present the experience of one MLIS student in collaboration with a subject librarian and a faculty member to plan, implement, and assess an information literacy instruction session for an undergraduate course in public health. The article discusses the benefits of mentoring for the MLIS student and subject liaison librarian, and the impact on the undergraduate student learning. This article addresses a gap in the literature on opportunities for MLIS students to gain instruction, collaboration, and assessment experience by presenting a successful model in place at UMD

Collaborating for Success: A Case Study on Mentoring, Partnering, and Teaching

Master of Library and Information Science (MLIS) graduates seeking employment in academic libraries are often expected to possess user instruction and public service skills. However, it is difficult for students to achieve this experience through coursework alone. To address this disconnect, librarians at the University of Maryland (UMD) College Park Libraries created a Research and Teaching Fellowship to allow MLIS students at UMD to gain practical instruction experience. The authors present the experience of one MLIS student in collaboration with a subject librarian and a faculty member to plan, implement, and assess an information literacy instruction session for an undergraduate course in public health. The article discusses the benefits of mentoring for the MLIS student and subject liaison librarian, and the impact on the undergraduate student learning. This article addresses a gap in the literature on opportunities for MLIS students to gain instruction, collaboration, and assessment experience by presenting a successful model in place at UMD.​This research was supported in part by an appointment to the NLM Associate Fellowship Program sponsored by the National Library of Medicine and administered by the Oak Ridge Institute for Science and Education

Long-Term Exposure to Ambient Air Pollution and Type 2 Diabetes in Adults

PURPOSE OF REVIEW We identified 24 publications from January 2010 until September 2018 in the peer-reviewed literature addressing the relationship of long-term air pollution exposures and type 2 diabetes-related morbidity and mortality among adults. We examine key methodological issues, synthesize findings, and address study strengths and limitations. We also discuss biological mechanisms, policy implications, and future research needed to address existing knowledge gaps. RECENT FINDINGS In general, the studies included in this review employed rigorous methodology with large sample sizes, appropriate study designs to maximize available cohort study or administrative data sources, and exposure modeling that accounted for spatial patterns in air pollution levels. Overall, studies suggested increased risks of type 2 diabetes-related morbidity and mortality among adults associated with increased exposures; however, findings were not uniformly positive nor statistically significant. SUMMARY Current research is particularly limited regarding the biological mechanisms involved and the relationship between ozone and diabetes. Additionally, more research is needed to distinguish clearly the effects of nitrogen oxides from those of other pollutants and to identify potential subpopulations with greater susceptibility for certain pollutant exposures. A better understanding of the potential link between long-term ambient air pollution exposures and type 2 diabetes may provide opportunities for the reduction of health risks and inform future interventions for environmental protection and diabetes management

Environmental Health Disparities: A Framework Integrating Psychosocial and Environmental Concepts

Although it is often acknowledged that social and environmental factors interact to produce racial and ethnic environmental health disparities, it is still unclear how this occurs. Despite continued controversy, the environmental justice movement has provided some insight by suggesting that disadvantaged communities face greater likelihood of exposure to ambient hazards. The exposure–disease paradigm has long suggested that differential “vulnerability” may modify the effects of toxicants on biological systems. However, relatively little work has been done to specify whether racial and ethnic minorities may have greater vulnerability than do majority populations and, further, what these vulnerabilities may be. We suggest that psychosocial stress may be the vulnerability factor that links social conditions with environmental hazards. Psychosocial stress can lead to acute and chronic changes in the functioning of body systems (e.g., immune) and also lead directly to illness. In this article we present a multidisciplinary framework integrating these ideas. We also argue that residential segregation leads to differential experiences of community stress, exposure to pollutants, and access to community resources. When not counterbalanced by resources, stressors may lead to heightened vulnerability to environmental hazards

Income Inequality and US Children’s Secondhand Smoke Exposure: Distinct Associations by Race–Ethnicity

IntroductionPrior studies have found considerable racial and ethnic disparities in secondhand smoke (SHS) exposure. Although a number of individual-level determinants of this disparity have been identified, contextual determinants of racial and ethnic disparities in SHS exposure remain unexamined. The objective of this study was to examine disparities in serum cotinine in relation to area-level income inequality among 14 649 children from the National Health and Nutrition Examination Survey.MethodsWe fit log-normal regression models to examine disparities in serum cotinine in relation to Metropolitan Statistical Areas level income inequality among 14 649 nonsmoking children aged 3-15 from the National Health and Nutrition Examination Survey (1999-2012).ResultNon-Hispanic black children had significantly lower serum cotinine than non-Hispanic white children (-0.26; 95% CI: -0.38, -0.15) in low income inequality areas, but this difference was attenuated in areas with high income inequality (0.01; 95% CI: -0.16, 0.18). Serum cotinine declined for non-Hispanic white and Mexican American children with increasing income inequality. Serum cotinine did not change as a function of the level of income inequality among non-Hispanic black children.ConclusionsWe have found evidence of differential associations between SHS exposure and income inequality by race and ethnicity. Further examination of environments which engender SHS exposure among children across various racial/ethnic subgroups can foster a better understanding of how area-level income inequality relates to health outcomes such as levels of SHS exposure and how those associations differ by race/ethnicity.ImplicationsIn the United States, the association between children's risk of SHS exposure and income inequality is modified by race/ethnicity in a manner that is inconsistent with theories of income inequality. In overall analysis this association appears to be as predicted by theory. However, race-specific analyses reveal that higher levels of income inequality are associated with lower levels of SHS exposure among white children, while levels of SHS exposure among non-Hispanic black children are largely invariant to area-level income inequality. Future examination of the link between income inequality and smoking-related health outcomes should consider differential associations across racial and ethnic subpopulations