Disparities in joint exposure to environmental and social stressors in urban households in Greater Boston.

OBJECTIVES: Understanding how environmental and social stressors cluster is critical to explaining and addressing health disparities. It remains unclear how these stressors cluster at fine spatial resolution in low to medium-income, urban households. We explored patterns of environmental and social exposures at the household-level and potential predictors of these joint exposures in two environmental justice communities in the Greater Boston area. METHODS: We recruited 150 households in Chelsea, MA and the Dorchester neighborhood of Boston, MA, between 2016 and 2019 and collected data on two domains: environmental and social stressor. For each domain, we fit Latent Class Analysis (LCA) models to exposure data to assess intra-domain variability, and cross-classified the resultant classes to identify joint exposure profiles. We compared differences in the distribution of these profiles by participants' demographic and household characteristics using χ2, Fisher's exact, Analysis of Variance, and Kruskal-Wallis tests. RESULTS: We identified two latent classes in each domain: High environmental (n = 90; 60.4%), Low environmental (n = 59; 39.6%), High Social (n = 31; 20.8%), and Low Social (n = 118; 79.2%). Cross-classification yielded four joint exposure profiles: Both Low (n = 46, 30.9%); Both High (n = 18, 12.1%); High environmental-Low Social (n = 72, 48.3%); and Low environmental-High Social (n = 13, 8.7%). Significant group differences were found by housing type (e.g., single-family vs. multi-family) (Fisher's exact p = 0.0016), housing tenure (p = 0.0007), and study site (p < 0.0001). We also observed differences by race/ethnicity, income, and education: households that were Hispanic/Latinx, below the poverty level, and with lower education were more likely to be in the Both High group. CONCLUSIONS: Our analyses confirmed that environmental and social stressors cluster in socially disadvantaged households. Housing type, housing tenure, and location of the residence were also strong predictors of cluster membership, with renter and multi-family residents at risk of high exposures to environmental and social stressors.

A process for creating data report-back tools to improve equity in environmental health.

BACKGROUND: Although there is increasing interest in reporting results of environmental research efforts back to participants, evidence-based tools have not yet been applied to developed materials to ensure their accessibility in terms of literacy, numeracy, and data visualization demand. Additionally, there is not yet guidance as to how to formally assess the created materials to assure a match with the intended audience. METHODS: Relying on formative qualitative research with participants of an indoor air quality study in Dorchester, Massachusetts, we identified means of enhancing accessibility of indoor air quality data report-back materials for participants. Participants (n = 20) engaged in semi-structured interviews in which they described challenges they encountered with scientific and medical materials and outlined written and verbal communication techniques that would help facilitate engagement with and accessibility of environmental health report-back materials. We coupled these insights from participants with best practice guidelines for written materials by operationalizing health literacy tools to produce accessible audience-informed data report-back materials. RESULTS: The resulting data report-back materials had a 7th -grade reading level, and between a 4th -8th grade level of overall document complexity. The numeracy skills required to engage with the material were of the lowest demand, and we incorporated best practices for risk communication and facilitating understanding and actionability of the materials. Use of a rigorous assessment tool provides evidence of accessibility and appropriateness of the material for the audience. CONCLUSIONS: We outline a process for developing and evaluating environmental health data reports that are tailored to inspire risk-reduction actions, and are demonstrably accessible in terms of their literacy, numeracy, and data visualization demand. Adapting health literacy tools to create and evaluate environmental data report-back materials is a novel and evidence-based means of ensuring their accessibility.

High prevalence of chronic kidney disease of unknown etiology among workers in the Mesoamerican Nephropathy Occupational Study.

BACKGROUND: Mortality from chronic kidney disease of unknown etiology (CKDu) is extremely high along the Pacific coast of Central America, particularly among sugarcane workers. The Mesoamerican Nephropathy Occupational Study (MANOS) is a prospective cohort study of CKDu among agricultural and non-agricultural workers in El Salvador and Nicaragua. The objective of this manuscript is to describe the MANOS cohort recruitment, baseline data collection, and CKDu prevalence after two rounds. METHODS: Workers with no known diabetes, hypertension, or CKD were recruited from sugarcane, corn, plantain, brickmaking, and road construction industries (n = 569). Investigators administered questionnaires, collected biological samples, and observed workers for three consecutive workdays at the worksite. Serum specimens were analyzed for kidney function parameters, and used to calculate estimated glomerular filtration rate (eGFR). At six months, serum was collected again prior to the work shift. CKD at baseline is defined as eGFR ≤ 60 ml/min/1.73m2 at both timepoints. Age-standardized prevalence was calculated by industry, country, and demographic measures. Kidney function parameters were compared by CKD status. RESULTS: Prevalence of CKD at baseline was 7.4% (n = 42). Age-standardized prevalence was highest in Salvadoran sugarcane (14.1%), followed by Salvadoran corn (11.6%), and Nicaraguan brickmaking (8.1%). Nicaraguan sugarcane had the lowest prevalence, likely due to kidney function screenings prior to employment. CONCLUSION: Despite efforts to enroll participants without CKD, our identification of prevalent CKD among agricultural and non-agricultural workers in the MANOS cohort indicates notable kidney disease in the region, particularly among sugarcane workers.

Mixed methods assessment of personal heat exposure, sleep, physical activity, and heat adaptation strategies among urban residents in the Boston area, MA.

The growing frequency, intensity, and duration of extreme heat events necessitates interventions to reduce heat exposures. Local opportunities for heat adaptation may be optimally identified through collection of both quantitative exposure metrics and qualitative data on perceptions of heat. In this study, we used mixed methods to characterize heat exposure among urban residents in the area of Boston, Massachusetts, US, in summer 2020. Repeated interviews of N = 24 study participants ascertained heat vulnerability and adaptation strategies. Participants also used low-cost sensors to collect temperature, location, sleep, and physical activity data. We saw significant differences across temperature metrics: median personal temperature exposures were 3.9 °C higher than median ambient weather station temperatures. Existing air conditioning (AC) units did not adequately control indoor temperatures to desired thermostat levels: even with AC use, indoor maximum temperatures increased by 0.24 °C per °C of maximum outdoor temperature. Sleep duration was not associated with indoor or outdoor temperature. On warmer days, we observed a range of changes in time-at-home, expected given our small study size. Interview results further indicated opportunities for heat adaptation interventions including AC upgrades, hydration education campaigns, and amelioration of energy costs during high heat periods. Our mixed methods design informs heat adaptation interventions tailored to the challenges faced by residents in the study area. The strength of our community-academic partnership was a large part of the success of the mixed methods approach.

Biomarkers of kidney injury among children in a high-risk region for chronic kidney disease of uncertain etiology.

BACKGROUND: Mesoamerican Nephropathy (MeN), a form of chronic kidney disease of uncertain etiology, is a leading cause of death in Central America. The disease often presents in young adult male agricultural workers and progresses rapidly. Given the young age at presentation, we hypothesized that children in Central America experience subclinical kidney injury prior to working life. METHODS: We assessed specimens from a cross-sectional study of youth, aged 7-17 years, predominantly residing in a high-risk region of Nicaragua (n = 210). We evaluated urinary concentrations and risk factors for kidney injury biomarkers neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), interleukin-18 (IL-18), monocyte chemoattractant protein 1 (MCP-1), and chitinase-3-like protein 1 (YKL-40). We evaluated the association between biomarkers and contemporaneous eGFR and compared biomarker concentrations with reference values from healthy children in other countries. RESULTS: Median uNGAL, uIL-18, and uKIM-1 concentrations exceeded healthy reference values. A one-year increase in age was associated with 40% increase in odds of being in the highest quartile of uNGAL (OR 1.4; (95%CI 1.2, 1.5); p < 0.0001). Youth who reported ever experiencing dysuria had 2.5 times the odds of having uNGAL concentrations in the top quartile (OR 2.5; (95%CI 1.4, 4.6); p = 0.003). Girls had significantly higher concentrations of all biomarkers than boys. Nine percent of children demonstrated low eGFR (≤ 100 ml/min/1.73 m2), while 29% showed evidence of hyperfiltration (eGFR ≥ 160 ml/min/1.73 m2), both potentially indicative of renal dysfunction. CONCLUSIONS: Children residing in regions of Nicaragua at high risk for MeN may experience subclinical kidney injury prior to occupational exposures.

Descriptive characterization of sound levels in an environmental justice city before and during a global pandemic.

Many environmental justice communities face elevated exposures to multiple stressors, given biases in urban and environmental policy and planning. This paper aims to evaluate sound level exposure in a densely populated environmental justice city in close proximity to major roadways, a nearby airport and high levels of industrial activity. In this study we collected various sound level metrics to evaluate the loudness and frequency composition of the acoustical environment in Chelsea, Massachusetts, USA. A total of 29 week-long sites were collected from October 2019 to June 2020, a time period that also included the influence of the COVID-19 pandemic, which drastically altered activity patterns and corresponding sound level exposures. We found that Chelsea is exposed to high levels of sound, both day and night (65 dB (A), and 80 dB and 90 dB for low frequency, and infrasound sound levels). A spectral analysis shows that 63 Hz was the dominant frequency. Distance to major roads and flight activity (both arrivals and departures) were most strongly correlated with all metrics, most notably with metrics describing contributing from lower frequencies. Overall, we found similar patterns during the COVID-19 pandemic but at levels up to 10 dB lower. Our results demonstrate the importance of noise exposure assessments in environmental justice communities and the importance of using additional metrics to describe communities inundated with significant air, road, and industrial sound levels. It also provides a snapshot of how much quieter communities can be with careful and intentional urban and environmental policy and planning.

Chronic kidney diseases in agricultural communities: report from a workshop.

In June 2018, the National Institute of Diabetes and Digestive and Kidney Diseases and the National Institute of Environmental Health Sciences sponsored a workshop to identify research gaps in an increasingly common form of chronic kidney disease in agricultural communities, often termed "CKDu." The organizers invited a broad range of experts who provided diverse expertise and perspectives, many of whom had never addressed this particular epidemic. Discussion was focused around selected topics, including identifying and mitigating barriers to research in CKDu, creating a case definition, and defining common data elements. All hypotheses regarding etiology were entertained, and meeting participants discussed potential research strategies, choices in study design, and novel tools that may prove useful in this disease. Achievements of the workshop included robust cross-disciplinary discussion and preliminary planning of research goals and design. Specific challenges in implementing basic and clinical research and interventions in low- and middle-income countries were recognized. A balanced approach to leveraging local resources and capacity building without overreaching was emphasized.

Prevalence and Risk Factors for CKD Among Brickmaking Workers in La Paz Centro, Nicaragua.

RATIONALE & OBJECTIVE: In Central America, there is a high prevalence of chronic kidney disease (CKD) of nontraditional etiology often observed among agricultural workers. Few studies have assessed CKD prevalence among workers in nonagricultural occupations, which was the objective of this investigation. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: Male and female workers (n = 224) employed by artisanal brickmaking facilities in La Paz Centro, Nicaragua. PREDICTORS: Age, sex, education, smoking status, body mass index, alcohol consumption, water consumption, first-degree relative(s) with CKD, years worked, hours worked per week, job category, study visit (baseline and follow-up), and self-reported hypertension and diabetes. OUTCOMES: CKD defined as estimated glomerular filtration rate (eGFR) < 60mL/min/1.73m2 at 2 time points 4 months apart and CKD stage. ANALYTICAL APPROACH: A linear mixed-effects model with an unstructured covariance matrix was used to evaluate the association between demographics, occupational risk factors, and eGFR at baseline. The interaction between risk factors and time with change in eGFR was also evaluated. Multivariable logistic regression models were used to evaluate predictors of CKD. RESULTS: The CKD prevalence was 12.1% (n = 27), 100% of cases were male, 30% had stage 5 CKD (eGFR < 15mL/min/1.73m2), and 22% were younger than 35 years. Proportions of participants with eGFRs < 60mL/min/1.73m2 at baseline and follow-up were 13.8% and 15.2%, respectively. Linear regression analysis demonstrated significant predictors of lower kidney function at baseline including oven work, older age, lack of education, and having an immediate family member with CKD. Predictors of CKD identified using logistic regression analysis included oven work and lack of education. LIMITATIONS: Crude job classification measures, loss to follow-up, self-reported exposures. CONCLUSIONS: The prevalence of CKD is high in this population of brick workers, suggesting that the epidemic of CKD affecting Mesoamerica is not limited to agricultural workers. These results are consistent with the hypothesis that occupational heat exposure is a risk factor for kidney disease in this region.

Acute Kidney Injury in Sugarcane Workers at Risk for Mesoamerican Nephropathy.

RATIONALE & OBJECTIVE: Mesoamerican nephropathy (MeN), a form of chronic kidney disease (CKD) of unknown cause in Central America, affects young individuals working in physically strenuous occupations. Repeated episodes of work-related kidney injury may lead to CKD in this setting. We aimed to better understand the burden and natural history of acute kidney injury (AKI) in workers at risk for MeN. STUDY DESIGN: Cross-sectional study of active sugarcane workers, followed by prospective follow-up of individuals with AKI. SETTING & PARTICIPANTS: 326 sugarcane workers with normal preharvest serum creatinine (Scr) values and no history of CKD in an MeN hotspot in Nicaragua near the end of the harvest, and prospective follow-up of workers with AKI. PREDICTOR: AKI during the harvest, as defined by Scr level increase ≥ 0.3mg/dL over baseline to a level ≥ 1.3mg/dL. OUTCOMES: Kidney function trajectory and development of CKD over 12 months. ANALYTICAL APPROACH: Linear regression models were used to analyze the association between job category and kidney function. For workers with AKI, the effect of time on Scr level was evaluated using linear mixed effects. RESULTS: 34 of 326 participants were found to have AKI, with a median late-harvest Scr level of 1.64mg/dL in the AKI group. Workers without AKI had a median Scr level of 0.88mg/dL. AKI was more common among cane cutters compared with other field workers. Participants with AKI had variable degrees of kidney function recovery, with median 6- and 12-month Scr values of 1.25 and 1.27mg/dL, respectively (P < 0.001 for each follow-up value compared to late-harvest Scr). When we compared workers' kidney function before the AKI episode to their kidney function at last follow-up, 10 participants with AKI developed de novo estimated glomerular filtration rate < 60mL/min/1.73m2 and 11 had a >30% decrease in estimated glomerular filtration rate. LIMITATIONS: Follow-up limited to 1 year and some loss to follow-up in the prospective component of the study. Broad definition of AKI that includes both acute and subacute kidney injury. CONCLUSIONS: In a group of sugarcane workers with normal preharvest kidney function, newly decreased kidney function developing during the harvest season was common. Of those with kidney injury, nearly half had established CKD 12 months later.

Self-rated health and its association with perceived environmental hazards, the social environment, and cultural stressors in an environmental justice population.

BACKGROUND: Communities with large minority populations often are located near sources of pollution and have higher crime rates, which may work in combination with other factors to influence health. Poor self-rated health is related to chronic health conditions and premature mortality, with minority populations most likely to report poor health. To address how both resident perception of neighborhood environments and chronic health conditions individually and collectively influence health, we examined self-rated health and its association with multiple types of perceived environmental hazards in a majority-Hispanic urban population. METHODS: We conducted interviews with 354 residents of Chelsea, Massachusetts, US and asked about self-rated health, perceptions of their neighborhood, including participant-reported environmental hazards (e.g., air quality, odors and noise), aspects of the social environment (e.g., feeling safe, neighborhood crime, social cohesion), and culture-related stressors (e.g., immigration status, language stress, ethnic identity). Log-linear models examined the independent and multivariable associations between these factors and fair/poor self-rated health, controlling for socio-demographic characteristics and preexisting health conditions. RESULTS: Forty-one percent of participants reported fair/poor self-rated health. Participants frequently perceived environmental hazards such as problems with pests and regular noise disturbance as well as feeling unsafe. In a multivariable model, a greater number of reported noise disturbances (≥ 2 noise sources = 1.53 [1.04-2.26]) and reported insecurity with immigration status (1.66 [1.01-2.73]) were positively associated with fair/poor self-rated health. High social cohesion was inversely associated (0.74 [0.48-1.14]) with fair/poor self-rated health in the multivariable model. CONCLUSIONS: Negative perceptions of environmental hazards and reported cultural stressors were significantly associated with fair/poor self-rated health among residents in a low-income majority-minority community, with social cohesion having a beneficial association with self-rated health. Efforts to improve health should recognize the importance of public perceptions of social and environmental hazards found in neighborhood environments, and benefits of strengthening community connections.

Biomarkers of Kidney Injury Among Nicaraguan Sugarcane Workers.

BACKGROUND: In Central America, an epidemic of chronic kidney disease of unknown cause disproportionately affects young male agricultural workers. STUDY DESIGN: Longitudinal cohort study. SETTING & PARTICIPANTS: 284 sugarcane workers in 7 jobs were recruited from one company in northwestern Nicaragua. Blood and urine samples were collected before and near the end of the 6-month harvest season. PREDICTORS: Job category (cane cutter, seeder, seed cutter, agrichemical applicator, irrigator, driver, and factory worker); self-reported water and electrolyte solution intake. OUTCOMES & MEASUREMENTS: Changes in levels of urinary kidney injury biomarkers normalized to urine creatinine level, including neutrophil gelatinase-associated lipocalin (NGAL), interleukin 18 (IL-18), N-acetyl-ß-d-glucosaminidase (NAG), and albumin; serum creatinine-based estimated glomerular filtration rate (eGFR). RESULTS: Mean eGFR was 113 mL/min/1.73 m(2) and <5% of workers had albuminuria. Field workers had increases in NGAL and IL-18 levels that were 1.49 (95% CI, 1.06 to 2.09) and 1.61 (95% CI, 1.12 to 2.31) times as high, respectively, as in non-field workers. Cane cutters and irrigators had the greatest increases in NGAL levels during the harvest, whereas cane cutters and seeders had the greatest increases in IL-18 levels. Electrolyte solution consumption was associated with lower mean NGAL and NAG levels among cane cutters and lower mean IL-18 and NAG levels among seed cutters; however, there was no overall effect of hydration among all workers. On average, workers with the largest increases in NGAL and NAG levels during the harvest had declines in eGFRs of 4.6 (95% CI, 1.0 to 8.2) and 3.1 (95% CI, -0.6 to 6.7) mL/min/1.73 m(2), respectively. LIMITATIONS: Surrogate exposure measure, loss to follow-up. CONCLUSIONS: Results are consistent with the hypothesis that occupational heat stress and volume depletion may be associated with the development of kidney disease, and future studies should directly measure these occupational factors. The presence of urine tubular injury markers supports a tubulointerstitial disease that could occur with repeated tubular injury.

Characterization of Mesoamerican Nephropathy in a Kidney Failure Hotspot in Nicaragua.

BACKGROUND: Mesoamerican nephropathy (MeN) is a kidney disease of unknown cause that mainly affects working-age men in Central America. Despite being a major cause of morbidity and mortality in this region, its clinical characteristics have not been well defined. STUDY DESIGN: Cross-sectional family-based study. SETTING & PARTICIPANTS: 266 members of 24 families with high chronic kidney disease (CKD) burdens in a MeN hotspot in Northwestern Nicaragua. We compared clinical and biochemical characteristics of affected individuals first with their unaffected relatives and then with NHANES (National Health and Nutrition Examination Survey) participants with CKD in order to reveal identifying features of MeN. PREDICTOR: CKD defined as serum creatinine level ≥ 1.5mg/dL in men and ≥1.4mg/dL in women. OUTCOMES: Clinical and biochemical parameters, including serum sodium, potassium, bicarbonate, calcium, magnesium, phosphorus, and uric acid. RESULTS: Hyperuricemia, in many cases severe, was common among patients with MeN. Uric acid levels in patients with MeN were higher than those in NHANES participants (mean, 9.6 vs 7.4mg/dL for men in each group) despite more frequent use of uric acid-lowering medications in Nicaraguan individuals (71.7% vs 11.2%). In multivariable linear mixed-effects regression analysis, uric acid levels were 2.0mg/dL (95% CI, 1.0-3.0; P<0.001) higher in patients with MeN compared with their NHANES counterparts after adjusting for age, estimated glomerular filtration rate, and uric acid-lowering therapies. In contrast to prior reports, hyponatremia and hypokalemia were not common. LIMITATIONS: CKD defined by single serum creatinine measurement; population likely not representative of full MeN phenotype spectrum across Central America; major differences between MeN and NHANES groups in important characteristics such as age, ancestry, and recruitment method. CONCLUSIONS: Hyperuricemia out of proportion to the degree of decreased kidney function was common among Nicaraguan patients with MeN. Our results suggest that rather than being solely a consequence of CKD, hyperuricemia may play a role in MeN pathogenesis, a hypothesis that deserves further study.

Portable Air Cleaner Usage and Particulate Matter Exposure Reduction in an Environmental Justice Community: A Pilot Study.

Particulate matter (PM) exposure is associated with adverse health outcomes, including respiratory illness. A large fraction of exposure to airborne contaminants occurs in the home. This study, conducted over 5 months in a community with high asthma rates (Chelsea, MA, USA), investigated the use of portable air cleaners (PACs) to reduce indoor PM. Seven asthma-affected households participated, receiving a PAC (Austin Air Health Mate HEPA filter), a QuantAQ sensor to measure PM1, PM2.5, PM10 (µg/m3), and a HOBO plug-load data logger to track PAC usage. Results describe hourly and daily PM concentrations and PAC usage for each household. Hourly average PM concentrations decreased when PACs were turned on (vs. when they were turned off) across households during the study period: PM1 decreased by 0.46 µg/m3, PM2.5 decreased by 0.69 µg/m3, and PM10 decreased by 3.22 µg/m3. PAC usage varied for each household, including constant usage in one household and only usage at certain times of day in others. Higher filtration settings led to lower PM, with significant reductions in some, but not all, homes. Our findings highlight some difficulties in implementing household PAC interventions, yet also provide evidence to support household-level interventions to reduce PM and other indoor sources of air pollution. We also highlight academic-community partnerships as contributing to evidence-based solutions.

Derangement in Nicotinamide Adenine Dinucleotide Metabolism is Observed During Acute Kidney Injury Among Male Agricultural Workers at Risk for Mesoamerican Nephropathy.

Introduction: Mesoamerican nephropathy (MeN) is a chronic kidney disease (CKD) which may be caused by recurrent acute kidney injury (AKI). We investigated urinary quinolinate-to-tryptophan ratio (Q/T), a validated marker of nicotinamide adenine dinucleotide (NAD+) biosynthesis that is elevated during ischemic and inflammatory AKI, in a sugarcane worker population in Nicaragua with high rates of MeN. Methods: Among 693 male sugarcane workers studied, we identified 45 who developed AKI during the harvest season. We matched them 1:1 based on age and job category with 2 comparison groups: (i) "no kidney injury," active sugarcane workers with serum creatinine (sCr) <1.1 mg/dl; and (ii) "CKD," individuals no longer working in sugarcane due to their CKD, who had additional 1:1 matching for sCr. We measured urine metabolites using liquid chromatography coupled tandem mass spectrometry (LC-MS/MS) and compared Q/T and other metabolic features between the AKI and comparison groups. Results: Urine Q/T was significantly higher in workers with AKI than in those with no kidney injury (median interquartile Range [IQR]: 0.104 [0.074-0.167] vs. 0.060 [0.045-0.091], P < 0.0001) and marginally higher than in workers with CKD (0.086 [0.063-0.142], P = 0.059). Urine levels of the NAD+ precursor nicotinamide were lower in the AKI group than in comparison groups. Conclusion: Workers at risk for MeN who develop AKI demonstrate features of impaired NAD+ biosynthesis, thereby providing new insights into the metabolic mechanisms of injury in this population. Therapeutic use of oral nicotinamide, which may ameliorate NAD+ biosynthetic derangement and fortify against kidney injury, should be investigated to prevent AKI in this setting.

Facilitators and Barriers for Keeping Cool in an Urban Heat Island: Perspectives from Residents of an Environmental Justice Community.

Background: Extreme heat is a leading cause of morbidity and mortality during summer months in the United States. Risk of heat exposure and associated health outcomes are disproportionately experienced by people with lower incomes, people of color, and/or immigrant populations. Methods: As qualitative research on the experiences of residents in heat islands is limited, this community-based study examined barriers and coping strategies for keeping cool among residents of Chelsea and East Boston, Massachusetts-environmental justice (EJ) areas that experience the urban heat island effect-through semistructured interviews and qualitative content analysis. Results: Results indicate that all participants (n = 12) had air conditioning, but high energy bills contributed to low use. Eight participants were self-described heat-sensitive, with five experiencing poor health in heat. In addition, nine reported insufficient hydration due to work schedules, distaste of water, or perceptions of it being unsafe. Discussion: This research highlights the importance of understanding perceptions of residents in EJ communities to contextualize vulnerability and identify multipronged heat coping strategies and targeted interventions.

Ethical considerations for genetic research in low-income countries: perceptions of informed consent, data sharing, and expectations in Nicaragua.

Genetic research presents numerous ethical, legal, and social implications (ELSI), particularly when the research involves collaborations between investigators in high and low-income countries. Some ELSI issues are universal, and others are specific to context and culture. This study investigates perceptions of genetic research in Nicaragua, Central America, where local and U.S. based researchers have collaborated for over a decade. A total of 43 residents from northwestern Nicaragua, a region with high mortality rates attributed to chronic kidney disease of non-traditional causes (CKDnt), were interviewed, including research participants in ongoing studies (n = 36), health professionals (n = 3), labor leaders (n = 2), and family members of research participants (n = 2). Questions focused on informed consent, data-sharing, and post-study expectations. Audio recordings of interviews conducted in Spanish were transcribed and translated into English. English transcripts were coded and analyzed using NVivo 12 software. The lack of familiarity with terms in the consent form presented a barrier to participant comprehension of key elements of the genetic research study, raising concerns about the validity of informed consent. Research participants often viewed their participation as access to health care. Health professionals emphasized the importance of long-term partnerships between foreign-based researchers and local health institutions. Leaders and family members recommended that they be informed of research studies and allowed the opportunity to consent, as they felt the benefits and risks of research also apply to them. Our findings identified genetic research practices to be improved upon in order to be more responsive to the contextual realities of collaborators living in low-resource settings.

Metabolic Features of Increased Gut Permeability, Inflammation, and Altered Energy Metabolism Distinguish Agricultural Workers at Risk for Mesoamerican Nephropathy.

Mesoamerican nephropathy (MeN) is a form of chronic kidney disease found predominantly in young men in Mesoamerica. Strenuous agricultural labor is a consistent risk factor for MeN, but the pathophysiologic mechanism leading to disease is poorly understood. We compared the urine metabolome among men in Nicaragua engaged in sugarcane harvest and seed cutting (n = 117), a group at high risk for MeN, against three referents: Nicaraguans working less strenuous jobs at the same sugarcane plantations (n = 78); Nicaraguans performing non-agricultural work (n = 102); and agricultural workers in Spain (n = 78). Using proton nuclear magnetic resonance, we identified 136 metabolites among participants. Our non-hypothesis-based approach identified distinguishing urine metabolic features in the high-risk group, revealing increased levels of hippurate and other gut-derived metabolites and decreased metabolites related to central energy metabolism when compared to referent groups. Our complementary hypothesis-based approach, focused on nicotinamide adenine dinucleotide (NAD+) related metabolites, and revealed a higher kynurenate/tryptophan ratio in the high-risk group (p = 0.001), consistent with a heightened inflammatory state. Workers in high-risk occupations are distinguishable by urinary metabolic features that suggest increased gut permeability, inflammation, and altered energy metabolism. Further study is needed to explore the pathophysiologic implications of these findings.

Heat stress and heat strain among outdoor workers in El Salvador and Nicaragua.

BACKGROUND: There is growing attention on occupational heat stress in Central America, as workers in this region are affected by a unique form of chronic kidney disease. Previous studies have examined wet bulb globe temperatures and estimated metabolic rates to assess heat stress, but there are limited data characterizing heat strain among these workers. OBJECTIVE: The aims were to characterize heat stress and heat strain and examine whether job task, break duration, hydration practices, and kidney function were associated with heat strain. METHODS: We used data from the MesoAmerican Nephropathy Occupational Study, a cohort of 569 outdoor workers in El Salvador and Nicaragua who underwent workplace exposure monitoring, including continuous measurement of core body temperature (Tc), heart rate (HR), physical activity, and wet bulb globe temperature (WBGT), over the course of three days in January 2018 - May 2018. Participants represented five industries: sugarcane, corn, plantain, brickmaking, and construction. RESULTS: Median WBGTs were relatively high (>27 °C) at most sites, particularly when work shifts spanned the afternoon hours (e.g., 29.2 °C among plantain workers). Sugarcane workers, especially cane cutters in both countries and Nicaraguan agrichemical applicators, had the highest estimated metabolic rates (medians: 299-318 kcal/hr). Most workers spent little time on break (<10% of the shift), as determined by physical activity data. Overall, sugarcane workers-particularly those in Nicaragua-experienced the highest Tc and HR values. However, a few workers in other industries reached high Tc (>39 °C) as well. Impaired kidney function (estimated glomerular filtration rate <90 mL/min/1.73 m2) was associated with higher Tc and HR values, even after adjustment. SIGNIFICANCE: This is the largest study to-date examining heat stress and strain among outdoor workers in Central America. Workers at sugar companies regularly experienced Tc > 38°C (76.9% of monitored person-days at Nicaraguan companies; 46.5% at Salvadoran companies). Workers with impaired kidney function had higher measures of Tc and HR. IMPACT STATEMENT: This study examined levels of occupational heat stress and heat strain experienced among outdoor workers in five industries in El Salvador and Nicaragua. We characterized heat stress using wet bulb globe temperatures and estimated metabolic rate and heat strain using core body temperature and heart rate. Sugarcane workers, particularly cane cutters and Nicaraguan agrichemical applicators, performed more strenuous work and experienced greater levels of heat strain. Impaired kidney function was associated with higher heart rates and core body temperatures.

Characterizing the Environmental Health Literacy and Sensemaking of Indoor Air Quality of Research Participants.

This study is based on in-depth semi-structured interviews with the participants of an indoor air quality monitoring study. The purpose of the interviews was to capture participants' perceptions of indoor air quality and engage them in a discussion of those factors that influenced their behavior. Interview study participants (n = 20) noted the importance of family health concerns and their own sensory awareness of possible contaminants. They discussed their level of personal control over their home environment as well as their access to needed resources. This study is based on grounded theory and applies interpretivist epistemological methods. Study findings offer insights into how people perceive their home environment and what influences their decision making and action. Analyses indicate that perceived agency, risk perception, access to resources, and information all influenced participants' sense of ability to take action as well as their interest in taking action. These insights serve to challenge some of the current work in environmental health literacy which tends to focus on and measure an individual's knowledge or skills. Our analysis suggests that consideration be given to a number of factors that include perceived agency, access to resources, and the quality of information provided.

COVID-19 and CKD: Employment, Food Security and Healthcare in El Salvador.

Background: In Central America, the COVID-19 pandemic coexists with a devastating epidemic of chronic kidney disease of unknown origin. The consequences of these overlapping health crises remain largely unknown. Methods: We assessed vulnerability to and impact of the first wave of COVID-19 on participants in a cohort study of chronic kidney disease (CKD) in El Salvador (n = 229). Participants were contacted by phone during August and September 2020. We queried changes to employment, healthcare access, household income and food security due to the pandemic (from March 2020 until the time of the interview) and COVID-19-associated symptoms during that time. Findings: We reached 94% of the cohort (n = 215). Nearly 40% of participants reported an unexpected change in employment or work activities and 8.8% reported new unemployment due to the pandemic. Participants with CKD (n = 27) had higher odds of reporting new income insecurity, food insecurity, and reductions in medical care access due to the pandemic. COVID-19-associated symptoms (an approximation of disease) were reported in 7.0% (n = 15). Participants with CKD were more likely to report COVID-19-associated symptoms compared to those without CKD, although these differences were not statistically significant. Conclusions: Overall, participants with CKD suffered greater economic consequences as a result of the pandemic and may have experienced higher incidence of COVID-19 disease, although laboratory diagnostics would be required to draw this conclusion. Longitudinal analyses are required to comprehensively evaluate the implications of the pandemic for individuals with CKD in Central America.