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

Predictors of Toxic Metal/Metalloid Exposures Among Mexican Americans in Starr County, Texas

BACKGROUND

Arsenic, cadmium, and lead are toxic elements that widely contaminate our environment. These toxicants are associated with acute and chronic health problems, and evidence suggests that minority communities, including Hispanic/Latino Americans, are disproportionately exposed. Few studies have assessed culturally specific predictors of exposure to understand the potential drivers of racial/ethnic exposure disparities.

OBJECTIVE

We sought to evaluate acculturation measures as predictors of metal/metalloid (hereafter "metal") concentrations among Mexican American adults to illuminate potential exposure sources that may be targeted for interventions.

METHODS

As part of a longitudinal cohort, 510 adults, aged 35 to 69 years, underwent baseline interview, physical examination, and urine sample collection. Self-reported acculturation was assessed across various domains using the Short Acculturation Scale for Hispanics (SASH). Multivariable linear regression was used to assess associations between acculturation and urinary concentrations of arsenic, cadmium, and lead. Ordinal logistic regression was utilized to assess associations between acculturation and a metal mixture score. Lastly, best subset selection was used to build a prediction model for each toxic metal with a combination of the acculturation predictors.

RESULTS

After adjustment, immigration factors were positively associated with arsenic and lead concentrations. For lead alone, English language and American media and food preferences were associated with lower levels. Immigration and parental heritage from Mexico were positively associated with the metal mixture, while preferences for English language, media, and food were negatively associated.

CONCLUSION

Acculturation-related predictors of exposure provide information about potential sources of toxic metals, including international travel, foods, and consumer products. The findings in this research study provide information to empower future efforts to identify and address specific acculturation-associated toxicant exposures in order to promote health equity through clinical guidance, patient education, and public policy.

Understanding the Cardiovascular and Metabolic Health Effects of Air Pollution in the Context of Cumulative Exposomic Impacts

Poor air quality accounts for more than 9 million deaths a year globally according to recent estimates. A large portion of these deaths are attributable to cardiovascular causes, with evidence indicating that air pollution may also play an important role in the genesis of key cardiometabolic risk factors. Air pollution is not experienced in isolation but is part of a complex system, influenced by a host of other external environmental exposures, and interacting with intrinsic biologic factors and susceptibility to ultimately determine cardiovascular and metabolic outcomes. Given that the same fossil fuel emission sources that cause climate change also result in air pollution, there is a need for robust approaches that can not only limit climate change but also eliminate air pollution health effects, with an emphasis of protecting the most susceptible but also targeting interventions at the most vulnerable populations. In this review, we summarize the current state of epidemiologic and mechanistic evidence underpinning the association of air pollution with cardiometabolic disease and how complex interactions with other exposures and individual characteristics may modify these associations. We identify gaps in the current literature and suggest emerging approaches for policy makers to holistically approach cardiometabolic health risk and impact assessment.

Race/Ethnicity and Other Predictors of Early-Onset Type 2 Diabetes Mellitus in the US Population

OBJECTIVES

Among US adults aged 20 + years in the USA with previously diagnosed type 2 diabetes mellitus (T2DM), we aimed to estimate the prevalence of early-onset T2DM (onset at age < 50.5 years) and to test associations between early-onset T2DM and race/ethnicity, and other hypothesized predictors.

METHODS

We pooled data from the annual National Health and Nutrition Examination Surveys (NHANES) over the years 2001 through 2018. We tested hypotheses of association and identified predictors using stepwise logistic regression analysis, and 11 supervised machine learning classification algorithms.

RESULTS

After appropriate weighting, we estimated that among adults in the USA aged 20 + years with previously diagnosed T2DM, the prevalence of early-onset was 52.9% (95% confidence intervals, 49.6 to 56.2%). Among Non-Hispanic Whites (NHW) the prevalence was 48.6% (95% CI, 44.6 to 52.6%), among Non-Hispanic Blacks: 56.9% (95% CI, 51.8 to 62.0%), among Hispanics: 62.7% (95% CI, 53.2 to 72.3%). In the final multivariable logistic regression model, the top-3 markers predicting early-onset T2DM in males were NHB ethnicity (OR = 2.97; 95% CI: 2.24-3.95) > tobacco smoking (OR = 2.79; 95% CI: 2.18-3.58) > high education level (OR = 1.65; 95% CI: 1.27-2.14) in males. In females, the ranking was tobacco smoking (OR = 2.59; 95% CI: 1.90-3.53) > Hispanic ethnicity (OR = 1.49; 95% CI: 1.08-2.05) > obesity (OR = 1.30; 95% CI: 0.91-1.86) in females. The acculturation score emerged from the machine learning approach as the dominant marker explaining the race disparity in early-onset T2DM.

CONCLUSIONS

The prevalence of early-onset T2DM was higher among NHB and Hispanic people, than among NHW people. Independently of race/ethnicity, acculturation, tobacco smoking, education level, marital status, obesity, and hypertension were also predictive.

Bidirectional modification effects on nonlinear associations of summer temperature and air pollution with first-ever stroke morbidity

High temperature and air pollution may induce stroke morbidity. However, whether associations between high temperature and air pollution with stroke morbidity are modified by each other is still unclear. Data on 23,578 first-ever stroke patients in Shenzhen, China, during the summers of 2014-2018 were collected. Distributed lag nonlinear models were used to assess the modifying effects of air pollution stratified by the median for the associations between summer temperature and stroke morbidity at 0-3 lag days; modifying effects of temperature stratified by the minimum morbidity temperature on the associations between air pollution and stroke morbidity at the same lags were also estimated. The attributable risks of high temperature and high pollution on stroke morbidity were quantified. Stratified analyses of gender, age, migration type, and complication type were conducted to assess vulnerable population characteristics. Summer high temperature may induce stroke morbidity at high-level PM2.5, PM10, O3, SO2, and NO2 conditions, with attributable fraction (AF) of 2.982% (95% empirical confidence interval [eCI]: 0.943, 4.929), 3.113% (0.948, 5.200), 2.841% (0.943, 4.620), 3.617% (1.539, 5.470), and 2.048% (0.279, 3.637), respectively. High-temperature effects were statistically insignificant at corresponding low-level air pollution conditions. High-level PM2.5, PM10, and O3 may induce stroke morbidity at high-temperature conditions, with AF of 3.664% (0.036, 7.196), 4.129% (0.076, 7.963), and 4.574% (1.009, 7.762), respectively. High-level PM2.5, PM10, and O3 were not associated with stroke morbidity at low-temperature conditions. The effects of high temperature and high pollution on stroke morbidity were statistically significant among immigrants and patients with hypertension, dyslipidemia, or diabetes but insignificant among natives and patients without complications. The associations of summer temperature and air pollution with first-ever stroke morbidity may be enhanced bidirectionally. Publicity on the health risks of combined high temperature and high pollution events should be strengthened to raise protection awareness of relevant vulnerable populations.

Hormonal Injustice: Environmental Toxicants as Drivers of Endocrine Health Disparities

The toll of multiple endocrine disorders has increased substantially in recent decades, and marginalized populations bear a disproportionate burden of disease. Because of the significant individual and societal impact of these conditions, it is essential to identify and address all modifiable risk factors contributing to these disparities. Abundant evidence now links endocrine dysfunction with exposure to endocrine-disrupting chemicals (EDCs), with greater exposures to multiple EDCs occurring among vulnerable groups, such as racial/ethnic minorities, those with low incomes, and others with high endocrine disease burdens. Identifying and eliminating EDC exposures is an essential step in achieving endocrine health equity.