Vehicular Air Pollution in Houston, Texas: An Intra-Categorical Analysis of Environmental Injustice

Ethnic and socioeconomic inequalities in air pollution exposure: a cross-sectional analysis of nationwide individual-level data from the Netherlands

BACKGROUND

Air pollution contributes to a large disease burden and some populations are disproportionately exposed. We aimed to evaluate ethnic and socioeconomic differences in exposure to air pollution in the Netherlands.

METHODS

We did a nationwide, cross-sectional analysis of all residents of the Netherlands on Jan 1, 2019. Sociodemographic information was centralised by Statistics Netherlands and mainly originated from the National Population Register, the tax register, and education registers. Concentrations of NO2, PM2·5, PM10, and elemental carbon, modelled by the National Institute for Public Health and the Environment, were linked to the individual-level demographic data. We assessed differences in air pollution exposures across the 40 largest minority ethnic groups. Evaluation of how ethnicity intersected with socioeconomic position in relation to exposures was done for the ten largest ethnic groups, plus Chinese and Indian groups, in both urban and rural areas using multivariable linear regression analyses.

FINDINGS

The total study population consisted of 17 251 511 individuals. Minority ethnic groups were consistently exposed to higher levels of air pollution than the ethnic Dutch population. The magnitude of inequalities varied between the minority ethnic groups, with 3-44% higher exposures to NO2 and 1-9% higher exposures to PM2·5 compared with the ethnic Dutch group. Average exposures were highest for the lowest socioeconomic group. Ethnic inequalities in exposure remained after adjustment for socioeconomic position and were of similar magnitude in urban and rural areas.

INTERPRETATION

The variability in air pollution exposure across ethnic and socioeconomic subgroups in the Netherlands indicates environmental injustice at the intersection of social characteristics. The health consequences of the observed inequalities and the underlying processes driving them warrant further investigation.

FUNDING

The Gravitation programme of the Dutch Ministry of Education, Culture, and Science, the Netherlands Organization for Scientific Research, the Netherlands Organisation for Health Research and Development, and Amsterdam University Medical Center.

Inequalities in Environmental Cancer Risk and Carcinogen Exposures: A Scoping Review

Background: Cancer is the leading cause of death in Canada and a major cause of death worldwide. Environmental exposure to carcinogens and environments that may relate to health behaviors are important to examine as they can be modified to lower cancer risks. Built environments include aspects such as transit infrastructure, greenspace, food and tobacco environments, or land use, which may impact how people move, exercise, eat, and live. While environments may play a role in overall cancer risk, exposure to carcinogens or healthier environments is not equitably spread across space. Exposures to carcinogens commonly concentrate among socially and/or economically disadvantaged populations. While many studies have examined inequalities in exposure or cancer risk, this has commonly been for one exposure. Methods: This scoping review collected and synthesized research that examines inequities in carcinogenic environments and exposures. Results: This scoping review found that neighborhoods with higher proportions of low-income residents, racialized people, or same-sex couples had higher exposures to carcinogens and environments that may influence cancer risk. There are currently four main themes in research studying inequitable exposures: air pollution and hazardous substances, tobacco access, food access, and other aspects of the built environment, with most research still focusing on air pollution. Conclusions: More work is needed to understand how exposures to these four areas intersect with other factors to reduce inequities in exposures to support longer-term goals toward cancer prevention.

California's early transition to electric vehicles: Observed health and air quality co-benefits

The transition to electric vehicles is projected to have considerable public health co-benefits, but most evidence regarding air quality and health impacts comes from projections rather than real-world data. We evaluated whether population-level respiratory health and air quality co-benefits were already detectable at the relatively low levels of zero-emissions vehicles (ZEVs: battery electric, plug-in hybrid, hydrogen fuel cell vehicle) adoption in California, and evaluated the ZEV adoption gap in underserved communities. We conducted a zip code-level ecologic study relating changes in annual number of ZEVs (nZEV) per 1000 population from 2013 to 2019 to: (i) annual average monitored nitrogen dioxide (NO2) concentrations and (ii) annual age-adjusted asthma-related emergency department (ED) visit rates, while considering educational attainment. The average nZEV increased from 1.4 per 1000 population in 2013 (standard deviation [SD]: 2.1) to 14.7 per 1000 in 2019 (SD: 14.7). ZEV adoption was considerably slower in zip codes with lower educational attainment (p < 0.0001). A within-zip code increase of 20 ZEVs per 1000 was associated with a - 0.41 ppb change in annual average NO2 (95 % confidence interval [CI]:-1.12, 0.29) in an adjusted model. A within-zip code increase of 20 ZEVs per 1000 population was associated with a 3.2 % decrease in annual age-adjusted rate of asthma-related ED visits (95 % CI:-5.4, -0.9). Findings were supported by a variety of sensitivity analyses. Observational data on the early phase ZEV transition in California provided a natural experiment, enabling us to document the first real-world associations between increasing nZEV and changes in air quality and health. Results suggest co-benefits of the early-phase transition to ZEVs but with an adoption gap among populations with lower socioeconomic status which threatens the equitable distribution of possible co-benefits.

Carcinogenic air pollution along the United States' southern border: Neighborhood inequities in risk

Air pollution poses serious and socially inequitable risks to public health. Social disparities are marked along the US-Mexico border, yet prior research has not assessed inequities in air pollution exposure across the entire US-side of the border region. We apply an intersectional approach to examine contextually relevant sociodemographic variables, including (1) Hispanic/Latinx ethnicity by race and (2) nativity (US vs. Foreign) by citizenship, and cancer risks attributable to air pollution exposures. We pair data from the 2012-2016 American Community Survey with 2014 National Air Toxics Assessment estimates of carcinogenic risks from all sources of hazardous air pollutants at the census tract level (n = 1448) and use a series of generalized estimating equations to assess inequities in risk. Increased concentrations of renter-occupants, Hispanics, mid-to-high socioeconomic status households, and foreign-born citizens were associated with elevated risks. Hispanic ethnicity intersected with non-White racial identification to amplify risks. In contrast, increased concentrations of non-Hispanic Black people and foreign-born non-citizens were not associated with disparate risks. To ameliorate environmental health inequities in this context, research and policy actions must be tailored to the US-Mexico border and consider intersectional positions within the Hispanic population.

The Intersection of Immigrant and Environmental Health: A Scoping Review of Observational Population Exposure and Epidemiologic Studies

BACKGROUND

Transnational immigration has increased since the 1950s. In countries such as the United States, immigrants now account for > 15 % of the population. Although differences in health between immigrants and nonimmigrants are well documented, it is unclear how environmental exposures contribute to these disparities.

OBJECTIVES

We summarized current knowledge comparing immigrants' and nonimmigrants' exposure to and health effects of environmental exposures.

METHODS

We conducted a title and abstract review on articles identified through PubMed and selected those that assessed environmental exposures or health effects separately for immigrants and nonimmigrants. After a full text review, we extracted the main findings from eligible studies and categorized each article as exposure-focused, health-focused, or both. We also noted each study's exposure of interest, study location, exposure and statistical methods, immigrant and comparison groups, and the intersecting socioeconomic characteristics controlled for.

RESULTS

We conducted a title and abstract review on 3,705 articles, a full text review on 84, and extracted findings from 50 studies. There were 43 studies that investigated exposure (e.g., metals, organic compounds, fine particulate matter, hazardous air pollutants) disparities, but only 12 studies that assessed health disparities (e.g., mortality, select morbidities). Multiple studies reported higher exposures in immigrants compared with nonimmigrants. Among immigrants, studies sometimes observed exposure disparities by country of origin and time since immigration. Of the 50 studies, 43 were conducted in North America.

DISCUSSION

The environmental health of immigrants remains an understudied area, especially outside of North America. Although most identified studies explored potential exposure disparities, few investigated subsequent differences in health effects. Future research should investigate environmental health disparities of immigrants, especially outside North America. Additional research gaps include the role of immigrants' country of origin and time since immigration, as well as the combined effects of immigrant status with intersecting socioeconomic characteristics, such as race/ethnicity, income, and education attainment. https://doi.org/10.1289/EHP9855.

Multigenerational immigrant trajectories and children's unequal exposure to fine particulate matter in the US

Fine particulate matter is a serious health threat and exposures are particularly damaging for children. The environmental justice (EJ) literature shows that racial/ethnic minority communities experience disproportionate exposure to particulate pollution in the US. While important, those EJ studies tend to neglect people's complex identities, including their nativity and their families' generational histories of residence in the US. Yet there is growing interest in the intersection of immigrant populations and EJ. Our use of individual-level data enables examination of immigrant generational status by race/ethnicity, which provides insights on the intergenerational persistence of environmental injustice. We pair data on 12,570 US third graders (from 2013 to 2014) collected through the Early Childhood Longitudinal Survey with PM_2.5 concentrations for the census tracts of their home and school locations. We apply generalized estimating equations to test for intergenerational disparities in exposure and to examine how those disparities vary between racial/ethnic groups. Independent of race/ethnicity, first- and second-generation children have greater PM_2.5 exposure than 2.5- and third-generation children. However, generational status disparities in exposures vary based on race/ethnicity. First-generation White children face greater exposure than White children of later generational statuses, with inequalities attenuating by the second generation. In contrast, Hispanic/Latinx children experience no significant drop in exposure until the third generation. Among Asian and Black children, generational status was not a significant determinant of exposure. Results quantify the intergenerational persistence of environmental injustices for persons of color while showing the amelioration of inequalities for Whites after just one generation is born in the US, reflecting another facet of White privilege in the US.