Contributions of neighborhood physical and social environments to racial and ethnic disparities in birth outcomes in California: A mediation analysis.

BACKGROUND: Racially minoritized populations experience higher rates of adverse birth outcomes than White populations in the U.S. We estimated the mediating effect of neighborhood social and physical environments on disparities in adverse birth outcomes in California. METHOD: We used birthing parent's residential address for California live birth records from 2019 to estimate census block group Area Deprivation Index and census tract level measures of ambient fine particulate matter (PM2.5), drinking water contamination, tree canopy coverage, as a measure of greenspace, potential heat vulnerability, and noise. We performed mediation analysis to assess whether neighborhood factors explain racial/ethnic disparities in preterm birth (PTB) and term-birth low birth weight (TLBW) comparing Black, Latinx, and Asian with White births after controlling for individual-level factors. RESULTS: Black, Latinx, and Asian parents had PTB rates that were 67%, 36%, and 11% higher, and TLBW rates that were 150%, 38%, and 81% higher than Whites. Neighborhood deprivation contributed 7% (95% CI: 3%, 11%) to the Black-White and 9% (95% CI: 6%, 12%) to the Latinx-White disparity in PTB, and 8% (95% CI: 3%, 12%) of the Black-White and 9% (95% CI: 5%, 15%) of the Latinx-White disparity in TLBW. Drinking water contamination contributed 2% (95% CI: 1%, 4%) to the Latinx-White disparity in PTB. Lack of greenspace accounted for 7% (95% CI: 2%, 10%) of the Latinx-White PTB disparity and 7% (95% CI: 3%, 12%) of the Asian-White PTB disparity. PM2.5 contributed 11% (95% CI: 5%, 18%), drinking water contamination contributed 3% (95% CI: 1%, 7%), and potential heat vulnerability contributed 2% (95% CI: 1%, 3%) to the Latinx-White TLBW disparity. Lack of green space contributed 3% (95% CI: 1%, 6%) to the Asian-White TLBW disparity. CONCLUSIONS: Our study suggests social environments explain portions of Black/Latinx-White disparities while physical environments explain Latinx/Asian-White disparities in PTB and TLBW.

Climate Justice Implications of Natech Disasters: Excess Contaminant Releases during Hurricanes on the Texas Gulf Coast.

Extreme weather events are becoming more severe due to climate change, increasing the risk of contaminant releases from hazardous sites disproportionately located in low-income communities of color. We evaluated contaminant releases during Hurricanes Rita, Ike, and Harvey in Texas and used regression models to estimate associations between neighborhood racial/ethnic composition and residential proximity to hurricane-related contaminant releases. Two-to-three times as many excess releases were reported during hurricanes compared to business-as-usual periods. Petrochemical manufacturing and refineries were responsible for most air emissions events. Multivariable models revealed sociodemographic disparities in likelihood of releases; compared to neighborhoods near regulated facilities without a release, a one-percent increase in Hispanic residents was associated with a 5 and 10% increase in the likelihood of an air emissions event downwind and within 2 km during Hurricanes Rita and Ike (odds ratio and 95% credible interval= 1.05 [1.00, 1.13], combined model) and Harvey (1.10 [1.00, 1.23]), respectively. Higher percentages of renters (1.07 [1.03, 1.11], combined Rita and Ike model) and rates of poverty (1.06 [1.01, 1.12], Harvey model) were associated with a higher likelihood of a release to land or water, while the percentage of Black residents (0.94 [0.89, 1.00], Harvey model) was associated with a slightly lower likelihood. Population density was consistently associated with a decreased likelihood of a contaminant release to air, land, or water. Our findings highlight social inequalities in the risks posed by natural-technological disasters that disproportionately impact Hispanic, renter, low-income, and rural populations.

PFAS-Contaminated Pesticides Applied near Public Supply Wells Disproportionately Impact Communities of Color in California.

Contaminated drinking water from widespread environmental pollutants such as perfluoroalkyl and polyfluoroalkyl substances (PFAS) poses a rising threat to public health. PFAS monitoring in groundwater is limited and fails to consider pesticides found to contain PFAS as a potential contamination source. Given previous findings on the disproportionate exposure of communities of Color to both pesticides and PFAS, we investigated disparities in PFAS-contaminated pesticide applications in California based on community-level sociodemographic characteristics. We utilized statewide pesticide application data from the California Department of Pesticide Regulation and recently reported concentrations of PFAS chemicals detected in eight pesticide products to calculate the areal density of PFAS applied within 1 km of individual community water systems' (CWSs) supply wells. Spatial regression analyses suggest that statewide, CWSs that serve a greater proportion of Latinx and non-Latinx People of Color residents experience a greater areal density of PFAS applied and greater likelihood of PFAS application near their public supply wells. These results highlight agroecosystems as potentially important sources of PFAS in drinking water and identify areas that may be at risk of PFAS contamination and warrant additional PFAS monitoring and remediation.

Hurricane Harvey and the risk of spontaneous preterm and early-term birth.

Background: Hurricane Harvey made landfall in August 2017 and resulted in catastrophic flooding in Houston, Texas. Prior studies of hurricanes and preterm birth have found conflicting results. We tested the hypotheses that exposure to Hurricane Harvey was associated with a higher risk of spontaneous pre- and early-term birth and assessed vulnerable subpopulations. Methods: We conducted a retrospective study of singleton births using administrative birth records in the nine-county greater Houston area from 2015 to 2019. We estimated the likelihood of pre- and early-term births using logistic regression, comparing births occurring during or within 1, 2, or 4 weeks of Hurricane Harvey to unexposed reference periods encompassing the same dates 2 years prior and after. Stratified models assessed effect modification by degree of flooding, birth parent age, high- vs. low-risk pregnancy, race/ethnicity, and prenatal care. Results: Among 15,564 births, we found no association between exposure to Hurricane Harvey and spontaneous preterm birth within 1 week adjusted (odds ratio [OR], 1.06; 95% confidence interval [CI] = 0.91, 1.25) but a 14% higher odds of spontaneous early-term birth (OR, 1.14; 95% CI = 1.04, 1.25). The odds of early-term birth were even higher in neighborhoods with severe flooding (OR, 1.21; 95% CI = 1.05, 1.38), segregated neighborhoods (OR, 1.23; 95% CI = 1.03, 1.47), and among foreign-born Hispanics (OR, 1.21; 95% CI = 1.04, 1.53) and pregnant people receiving no prenatal care (OR, 1.37; 95% CI = 1.03, 1.82). Effect estimates were attenuated or null when considering 2-week or 4-week lags to define exposure. Conclusions: Hurricane Harvey was associated with higher odds of spontaneous early-term birth up to 1 week later, especially among socially marginalized populations.

Race, Racism, and Drinking Water Contamination Risk From Oil and Gas Wells in Los Angeles County, 2020.

Objectives. To evaluate the potential for drinking water contamination in Los Angeles (LA) County, California, based on the proximity of supply wells to oil and gas wells, and characterize risk with respect to race/ethnicity and measures of structural racism. Methods. We identified at-risk community water systems (CWSs) as those with supply wells within 1 kilometer of an oil or gas well. We characterized sociodemographics of the populations served by each CWS by using the 2013-2017 American Community Survey. We estimated the degree of redlining in each CWS service area by using 1930s Home Owners' Loan Corporation security maps, and characterized segregation by using the Index of Concentration at the Extremes. Multivariable regression models estimated associations between these variables and CWS contamination risk. Results. A quarter of LA County CWSs serving more than 7 million residents have supply wells within 1 kilometer of an oil or gas well. Higher percentages of Hispanic, Black, and Asian/Pacific Islander residents and a greater degree of redlining and residential segregation were associated with higher contamination risk. Conclusions. Redlining and segregation predict drinking water contamination risks from oil development in LA County, with people of color at greater risk. (Am J Public Health. 2023;113(11):1191-1200. https://doi.org/10.2105/AJPH.2023.307374).

Toxic Tides and Environmental Injustice: Social Vulnerability to Sea Level Rise and Flooding of Hazardous Sites in Coastal California.

Sea level rise (SLR) and heavy precipitation events are increasing the frequency and extent of coastal flooding, which can trigger releases of toxic chemicals from hazardous sites, many of which are in low-income communities of color. We used regression models to estimate the association between facility flood risk and social vulnerability indicators in low-lying block groups in California. We applied dasymetric mapping techniques to refine facility boundaries and population estimates and probabilistic SLR projections to estimate facilities' future flood risk. We estimate that 423 facilities are at risk of flooding in 2100 under a high emissions scenario (RCP 8.5). One unit standard deviation increases in nonvoters, poverty rate, renters, residents of color, and linguistically isolated households were associated with a 1.5-2.2 times higher odds of the presence of an at-risk site within 1 km (ORs [95% CIs]: 2.2 [1.8, 2.8], 1.9 [1.5, 2.3], 1.7 [1.4, 1.9], 1.5 [1.2, 1.9], and 1.5 [1.2, 1.9], respectively). Among block groups near at least one at-risk site, the number of sites increased with poverty, proportion of renters and residents of color, and lower voter turnout. These results underscore the need for further research and disaster planning that addresses the differential hazards and health risks of SLR.

It's electric! An environmental equity perspective on the lifecycle of our energy sources.

Energy policy decisions are driven primarily by economic and reliability considerations, with limited consideration given to public health, environmental justice, and climate change. Moreover, epidemiologic studies relevant for public policy typically focus on immediate public health implications of activities related to energy procurement and generation, considering less so health equity or the longer-term health consequences of climate change attributable to an energy source. A more integrated, collective consideration of these three domains can provide more robust guidance to policymakers, communities, and individuals. Here, we illustrate how these domains can be evaluated with respect to natural gas as an energy source. Our process began with a detailed overview of all relevant steps in the process of extracting, producing, and consuming natural gas. We synthesized existing epidemiologic and complementary evidence of how these processes impact public health, environmental justice, and climate change. We conclude that, in certain domains, natural gas looks beneficial (e.g., economically for some), but when considered more expansively, through the life cycle of natural gas and joint lenses of public health, environmental justice, and climate change, natural gas is rendered an undesirable energy source in the United States. A holistic climate health equity framework can inform how we value and deploy different energy sources in the service of public health.

Dietary predictors of prenatal per- and poly-fluoroalkyl substances exposure.

BACKGROUND: Per- and poly-fluoroalkyl substances (PFAS) are commonly detected in a variety of foods and food packaging materials. However, few studies have examined diet as a potential source of PFAS exposure during pregnancy. In the present cross-sectional study, we examined prenatal PFAS levels in relation to self-reported consumption of meats, dairy products, and processed foods during pregnancy. METHODS: Participants were enrolled in the Chemicals in Our Bodies study, a demographically diverse pregnancy cohort in San Francisco, CA (N = 509). Diet was assessed using a self-reported interview questionnaire administered during the second trimester. Participants were asked on average how many times a day, week, or month they ate 11 different foods since becoming pregnant. Responses were categorized as at least once a week or less than once a week and foods were grouped into three categories: processed foods, dairy products, and meats. Twelve PFAS (ng/mL) were measured in second trimester serum samples. We investigated relationships between consumption of individual dairy products, meats, and processed foods and natural log-transformed PFAS using separate linear regression models adjusted for maternal age, education, race/ethnicity, and nativity. RESULTS: Seven PFAS were detected in ≥65% of participants. Consumption of dairy milk and cheese at least once per week was moderately associated with elevated levels of perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDeA) relative to those who ate dairy products less than once week. The strongest associations observed were with PFDeA for dairy milk (ß = 0.2, 95% confidence interval [CI] = 0.02, 0.39) and PFNA for cheese (ß = 0.22, 95% CI = 0.02, 0.41). Eating fish, poultry, and red meat at least once per week was associated with higher levels of perfluoroundecanoic acid, PFDeA, PFNA, and perflucorooctane sulfonic acid. CONCLUSIONS: Results indicate that consumption of animal products may contribute to elevated prenatal PFAS levels.

Redlining has led to increasing rates of nephrolithiasis in minoritized populations: a hypothesis.

PURPOSE OF REVIEW: The persistent rise in kidney stone prevalence in recent decades has prompted much speculation as to the causes. There has been some discussion about the effect of heat on nephrolithiasis. Here, we review recent data and postulate that heat may play a role in stone formation on a large scale and among African-Americans in particular. RECENT FINDINGS: African-Americans are the race/ancestry group with faster rates of increasing incidence and prevalence of kidney stones. We make the observation that urban heat islands in the United States have resulted in part from the effects of redlining, a practice of systematic segregation and racism in housing that led to the development of neighborhoods with substantial disparities in environmental conditions. SUMMARY: In this thought experiment, we propose that the disproportionate rise in the prevalence of nephrolithiasis in minoritized populations correlates with increased temperatures specifically in neighborhoods adversely affected by the practice of redlining. We discuss phenomena in support of this hypothesis and ongoing work to test this theory.

Neighborhood conditions and birth outcomes: Understanding the role of perceived and extrinsic measures of neighborhood quality.

Living in a disadvantaged neighborhood has been associated with adverse birth outcomes. Most prior studies have conceptualized neighborhoods using census boundaries and few have examined the role of neighborhood perceptions, which may better capture the neighborhood environment. In the present study, we examined associations between extrinsic and perceived neighborhood quality measures and adverse birth outcomes. Methods: Participants resided in the San Francisco Bay Area of California and were enrolled in Chemicals in Our Bodies, a prospective birth cohort (N = 817). The Index of Concentration at the Extremes (ICE) for income, Area Deprivation Index (ADI), and the Urban Displacement Project's measure of gentrification were included as census block group-level extrinsic neighborhood quality measures. Poor perceived neighborhood quality was assessed using an interview questionnaire. Linear regression models were utilized to examine associations between extrinsic and perceived neighborhood quality measures, and gestational age and birthweight for gestational age z-scores. Covariates in adjusted models were chosen via a directed acyclic graph (DAG) and included maternal age, education, and marital status. Results: In adjusted models, having poor perceived neighborhood quality was associated with higher birthweight z-scores, relative to those who did not perceive their neighborhood as poor quality (ß = 0.21, 95% confidence intervals = 0.01, 0.42). Relative to the least disadvantaged tertile, the upper tertile of the ADI was associated with a modest reduction in gestational age (ß = -0.35, 95% confidence intervals = -0.67, -0.02). Conclusions: In the Chemicals in Our Bodies study population, extrinsic and perceived neighborhood quality measures were inconsistently associated with adverse birth outcomes.

The Relationship of Historical Redlining with Present-Day Neighborhood Environmental and Health Outcomes: A Scoping Review and Conceptual Model.

Following the Great Depression and related home foreclosures, the federal government established new agencies to facilitate access to affordable home mortgages, including the Home Owners' Loan Corporation (HOLC) and Federal Housing Administration (FHA). HOLC and FHA directed widespread neighborhood appraisals to determine investment risk, referred to as "redlining," which took into account residents' race. Redlining thereby contributed to segregation, disinvestment, and racial inequities in opportunities for homeownership and wealth accumulation. Recent research examines associations between historical redlining and subsequent environmental determinants of health and health-related outcomes. In this scoping review, we assess the extent of the current body of evidence, the range of outcomes studied, and key study characteristics, examining the direction and strength of the relationship between redlining, neighborhood environments, and health as well as different methodological approaches. Overall, studies nearly universally report evidence of an association between redlining and health-relevant outcomes, although heterogeneity in study design precludes direct comparison of results. We critically consider evidence regarding HOLC's causality and offer a conceptual framework for the relationship between redlining and present-day health. Finally, we point to key directions for future research to improve and broaden understanding of redlining's enduring impact and translate findings into public health and planning practice.

High-resolution gridded estimates of population sociodemographics from the 2020 census in California.

This paper introduces a series of high resolution (100-meter) population grids for eight different sociodemographic variables across the state of California using data from the 2020 census. These layers constitute the 'CA-POP' dataset, and were produced using dasymetric mapping methods to downscale census block populations using fine-scale residential tax parcel boundaries and Microsoft's remotely-sensed building footprint layer as ancillary datasets. In comparison to a number of existing gridded population products, CA-POP shows good concordance and offers a number of benefits, including more recent data vintage, higher resolution, more accurate building footprint data, and in some cases more sophisticated but parsimonious and transparent dasymetric mapping methodologies. A general accuracy assessment of the CA-POP dasymetric mapping methodology was conducted by producing a population grid that was constrained by population observations within block groups instead of blocks, enabling a comparison of this grid's population apportionment to block-level census values, yielding a median absolute relative error of approximately 30% for block group-to-block apportionment. However, the final CA-POP grids are constrained by higher-resolution census block-level observations, likely making them even more accurate than these block group-constrained grids over a given region, but for which error assessments of population disaggregation is not possible due to the absence of observational data at the sub-block scale. The CA-POP grids are freely available as GeoTIFF rasters online at github.com/njdepsky/CA-POP, for total population, Hispanic/Latinx population of any race, and non-Hispanic populations for the following groups: American Indian/Alaska Native, Asian, Black/African-American, Native Hawaiian and other Pacific Islander, White, other race or multiracial (two or more races) and residents under 18 years old (i.e. minors).

Racial Disparities in Climate Change-Related Health Effects in the United States.

PURPOSE OF REVIEW: Climate change is causing warming over most parts of the USA and more extreme weather events. The health impacts of these changes are not experienced equally. We synthesize the recent evidence that climatic changes linked to global warming are having a disparate impact on the health of people of color, including children. RECENT FINDINGS: Multiple studies of heat, extreme cold, hurricanes, flooding, and wildfires find evidence that people of color, including Black, Latinx, Native American, Pacific Islander, and Asian communities are at higher risk of climate-related health impacts than Whites, although this is not always the case. Studies of adults have found evidence of racial disparities related to climatic changes with respect to mortality, respiratory and cardiovascular disease, mental health, and heat-related illness. Children are particularly vulnerable to the health impacts of climate change, and infants and children of color have experienced adverse perinatal outcomes, occupational heat stress, and increases in emergency department visits associated with extreme weather. The evidence strongly suggests climate change is an environmental injustice that is likely to exacerbate existing racial disparities across a broad range of health outcomes.

Prenatal PFAS and psychosocial stress exposures in relation to fetal growth in two pregnancy cohorts: Applying environmental mixture methods to chemical and non-chemical stressors.

BACKGROUND: Prenatal exposure to individual per­ and poly­fluoroalkyl substances (PFAS) and psychosocial stressors have been associated with reductions in fetal growth. Studies suggest cumulative or joint effects of chemical and non-chemical stressors on fetal growth. However, few studies have examined PFAS and non-chemical stressors together as a mixture, which better reflects real life exposure patterns. We examined joint associations between PFAS, perceived stress, and depression, and fetal growth using two approaches developed for exposure mixtures. METHODS: Pregnant participants were enrolled in the Chemicals in Our Bodies cohort and Illinois Kids Development Study, which together make up the ECHO.CA.IL cohort. Seven PFAS were previously measured in 2nd trimester maternal serum samples and were natural log transformed for analyses. Perceived stress and depression were assessed using self-reported validated questionnaires, which were converted to t-scores using validated methods. Quantile g-computation and Bayesian kernel machine regression (BKMR) were used to assess joint associations between PFAS, perceived stress and depression t-scores and birthweight z-scores (N = 876). RESULTS: Individual PFAS, depression and perceived stress t-scores were negatively correlated with birthweight z-scores. Using quantile g-computation, a simultaneous one quartile increase in all PFAS, perceived stress and depression t-scores was associated with a slight reduction in birthweight z-scores (mean change per quartile increase = -0.09, 95% confidence interval = -0.21,0.03). BKMR similarly indicated that cumulative PFAS and stress t-scores were modestly associated with lower birthweight z-scores. Across both methods, the joint association appeared to be distributed across multiple exposures rather than due to a single exposure. CONCLUSIONS: Our study is one of the first to examine the joint effects of chemical and non-chemical stressors on fetal growth using mixture methods. We found that PFAS, perceived stress, and depression in combination were modestly associated were lower birthweight z-scores, which supports prior studies indicating that chemical and non-chemical stressors are jointly associated with adverse health outcomes.

The Drinking Water Tool: A Community-Driven Data Visualization Tool for Policy Implementation.

The Drinking Water Tool (DWT) is a community-driven online tool that provides diverse users with information about drinking water sources and threats to drinking water quality and access due to drought. Development of the DWT was guided by the Community Water Center (CWC) as part of the Water Equity Science Shop (WESS), a research partnership integrating elements of community-based participatory research and the European Science Shop model. The WESS engages in scientific projects that inform policy change, advance water justice, and reduce cumulative exposure and disproportionate health burdens among impacted communities in California. WESS researchers conducted qualitative analysis of 15 stakeholder interviews regarding the DWT, including iterative feedback and the stakeholder consultation process as well as stakeholder perceptions of the tool's impact on California water policy, organizing, and research. Results indicate that the DWT and the stakeholder engagement process which developed it were effective in influencing policy priorities and in promoting interagency coordination at multiple levels to address water equity challenges and their disproportionate burdens, particularly among rural and low socioeconomic status areas and communities of color.

Associations of COVID-19 Related Work Stressors with Psychological Distress: Racial and Ethnic Disparities in Californian Workers.

The COVID-19 pandemic continues to exert immense societal impacts, with recent data showing inequitable distribution of consequences among racial and ethnic groups. The objective of this study was to assess associations between COVID-related work stressors and psychological distress, with special emphasis on differences by race and ethnicity. Data were from the population-based California Health Interview Survey (CHIS) 2020. Associations of individual and cumulative work stressors, including job loss, reduced work hours, and working from home, with psychological distress in 12,113 workers were examined via multivariable linear regression, and stratified analyses were conducted for racial and ethnic subgroups. After adjustment for covariates, compared to workers with no work stressors, those who experienced either one or two/more work stressors had higher psychological distress (ßs and 95% CIs were 0.80 [0.51, 1.09] and 1.98 [1.41, 2.56], respectively). Notably, experiencing cumulative (two/more) work stressors had much stronger effects on psychological distress among participants who were Black (ß and 95% CI were 3.51 [1.09, 5.93]) or racial minorities (ß and 95% CI were 3.57 [1.10, 6.05]). Occupational consequences of the COVID-19 pandemic were associated with increased psychological distress in Californian workers and inequitably distributed, with racial and ethnic minorities suffering the greatest burden.

Extreme heat and its association with social disparities in the risk of spontaneous preterm birth.

BACKGROUND: Climate change is increasing the frequency and intensity of heatwaves. Prior studies associate high temperature with preterm birth. OBJECTIVES: We tested the hypotheses that acute exposure to extreme heat was associated with higher risk of live spontaneous preterm birth (≥20 and <37 completed weeks), and that risks were higher among people of colour and neighbourhoods with heat-trapping landcover or concentrated racialised economic disadvantage. METHODS: We conducted a retrospective cohort study of people giving birth between 2007 and 2011 in Harris County, Texas (Houston metropolitan area) (n = 198,013). Exposures were daily ambient apparent temperature (ATmax in 5°C increments) and dry-bulb temperatures (Tmax and Tmin >historical [1971-2000] summertime 99th percentile) up to a week prior for each day of pregnancy. Survival analysis controlled for individual-level risk factors, secular and seasonal trends. We considered race/ethnicity, heat-trapping neighbourhood landcover and Index of Concentration at the Extremes as effect modifiers. RESULTS: The frequency of preterm birth was 10.3%. A quarter (26.8%) of people were exposed to ATmax ≥40°C, and 22.8% were exposed to Tmax and Tmin >99th percentile while at risk. The preterm birth rate among the exposed was 8.9%. In multivariable models, the risk of preterm birth was 15% higher following extremely hot days (hazard ratio [HR] 1.15 (95% confidence interval [CI] 1.01, 1.30) for ATmax ≥40°C vs. <20°C; HR 1.15 (95% CI 1.02, 1.28) for Tmax and Tmin >99th percentile). Censoring at earlier gestational ages suggested stronger associations earlier in pregnancy. The risk difference associated with extreme heat was higher in neighbourhoods of concentrated racialised economic disadvantage. CONCLUSIONS: Ambient heat was associated with spontaneous preterm birth, with stronger associations earlier in pregnancy and in racially and economically disadvantaged neighbourhoods, suggesting climate change may worsen existing social inequities in preterm birth rates.

Inequities in Drinking Water Quality Among Domestic Well Communities and Community Water Systems, California, 2011‒2019.

Objectives. To evaluate universal access to clean drinking water by characterizing relationships between community sociodemographics and water contaminants in California domestic well areas (DWAs) and community water systems (CWSs). Methods. We integrated domestic well locations, CWS service boundaries, residential parcels, building footprints, and 2013-2017 American Community Survey data to estimate sociodemographic characteristics for DWAs and CWSs statewide. We derived mean drinking and groundwater contaminant concentrations of arsenic, nitrate, and hexavalent chromium (Cr[VI]) between 2011 and 2019 and used multivariate models to estimate relationships between sociodemographic variables and contaminant concentrations. Results. We estimated that more than 1.3 million Californians (3.4%) use domestic wells and more than 370 000 Californians rely on drinking water with average contaminant concentrations at or above regulatory standards for 1 or more of the contaminants considered. Higher proportions of people of color were associated with greater drinking water contamination. Conclusions. Poor water quality disproportionately impacts communities of color in California, with the highest estimated arsenic, nitrate, and Cr(VI) concentrations in areas of domestic well use. Domestic well communities must be included in efforts to achieve California's Human Right to Water. (Am J Public Health. 2022;112(1):88-97. https://doi.org/10.2105/AJPH.2021.306561).

Joint effects of prenatal exposure to per- and poly-fluoroalkyl substances and psychosocial stressors on corticotropin-releasing hormone during pregnancy.

BACKGROUND: Prenatal exposure to per- and poly-fluoroalkyl substances (PFAS) and psychosocial stressors has been associated with adverse pregnancy outcomes, including preterm birth. Previous studies have suggested that joint exposure to environmental chemical and social stressors may be contributing to disparities observed in preterm birth. Elevated corticotropin-releasing hormone (CRH) during mid-gestation may represent one biologic mechanism linking chemical and nonchemical stress exposures to preterm birth. METHODS: Using data from a prospective birth cohort (N = 497), we examined the cross-sectional associations between five individual PFAS (ng/mL; PFNA, PFOA, PFOS, PFHxS, and Me-PFOSA-AcOH) and CRH (pg/mL) using linear regression. PFAS and CRH were measured during the second trimester in serum and plasma, respectively. Coefficients were standardized to reflect change in CRH associated with an interquartile range (IQR) increase in natural log-transformed PFAS. We additionally examined if the relationship between PFAS and CRH was modified by psychosocial stress using stratified models. Self-reported depression, stressful life events, perceived stress, food insecurity, and financial strain were assessed using validated questionnaires during the second trimester and included as binary indicators of psychosocial stress. RESULTS: An IQR increase in PFNA was associated with elevated CRH (ß = 5.17, 95% confidence interval [CI] = 1.79, 8.55). Increased concentrations of PFOA were also moderately associated with CRH (ß = 3.62, 95% CI = -0.42, 7.66). The relationship between PFNA and CRH was stronger among women who experienced stressful life events, depression, food insecurity, and financial strain compared to women who did not experience these stressors. CONCLUSIONS: This cross-sectional study is the first to examine the relationship between PFAS exposure and CRH levels in mid-gestation. We found that these associations were stronger among women who experienced stress, which aligns with previous findings that chemical and nonchemical stressor exposures can have joint effects on health outcomes.

Residential proximity to hydraulically fractured oil and gas wells and adverse birth outcomes in urban and rural communities in California (2006-2015).

BACKGROUND: Prenatal exposure to hydraulic fracturing (HF), a chemically intensive oil and gas extraction method, may be associated with adverse birth outcomes, but no health studies have been conducted in California. METHODS: We conducted a retrospective cohort study of 979,961 births to mothers in eight California counties with HF between 2006 and 2015. Exposed individuals had at least 1 well hydraulically fractured within 1 km of their residence during pregnancy; the reference population had no wells within 1 km, but at least one oil/gas well within 10 km. We examined associations between HF and low birth weight (LBW), preterm birth (PTB), small for gestational age birth (SGA), and term birth weight (tBW) using generalized estimating equations and assessing urban-rural effect modification in stratified models. RESULTS: Fewer than 1% of mothers (N = 1,192) were exposed to HF during pregnancy. Among rural mothers, HF exposure was associated with increased odds of LBW (odds ratio [OR] = 1.74; 95% confidence interval [CI] = 1.10, 2.75), SGA (OR = 1.68; 95% CI = 1.42, 2.27) and PTB (OR = 1.17; 95% CI = 0.64, 2.12), and lower tBW (mean difference: -73 g; 95% CI = -131, -15). Among urban mothers, HF exposure was positively associated with SGA (OR = 1.23; 95% CI = 0.98, 1.55), inversely associated with LBW (OR = 0.83; 95% CI = 0.63, 1.07) and PTB (OR = 0.65; 95% CI = 0.48, 0.87), and not associated with tBW (mean difference: -2 g; 95% CI = -35, 31). CONCLUSION: HF proximity was associated with adverse birth outcomes, particularly among rural Californians.