Geographic differences in exposures to metals and essential elements in pregnant women living in Suriname.

BACKGROUND: In Suriname, 20% of pregnancies end in adverse birth outcomes. While prenatal exposure to metals may lead to adverse health outcomes, exposure assessments in Suriname are scant. Environmental contamination from mercury (Hg) used in artisanal goldmining in the Amazonian Interior, and the uncontrolled use of pesticides in suburban regions are of particular concern. OBJECTIVE: This study assessed geographic differences in exposures to metals and essential elements in pregnant Surinamese women. METHODS: This study is a subset (n = 400) of the Caribbean Consortium for Research in Environmental and Occupational Health (CCREOH) cohort study. Sector-field inductively-coupled plasma mass spectrometry was used to determine concentrations of lead (Pb), Hg, selenium (Se), cadmium (Cd), manganese (Mn) and tin (Sn) in whole blood of the pregnant women. High vs. low exposures to Pb and Hg were determined and were based respectively on CDC (3.5 ug/dL) and USEPA (3.5 ug/L) action levels. Differences in geographic exposures were tested with the Mann-Whitney U-test, and differences between blood elemental concentrations and action levels for Pb and Hg with the Wilcoxon signed rank test. The association between demographics and high exposures of Pb and Hg was examined with multivariate logistic regression models. RESULTS: The median concentrations of Pb, Hg and Se (5.08 µg/dL, 7.87 µg/L, and 228.26 µg/L respectively) in Interior women, were higher than the Urban and Suburban regions (p < 0.001), and higher than internationally accepted action levels (p < 0.001). The median concentrations of Mn and Sn found in Suburban women (17.55 and 0.97 ug/L respectively) were higher than Urban and Interior regions (p < 0.02). SIGNIFICANCE: Pregnant women living in Suriname's Amazonian Interior are exposed to Hg and Pb at levels of public health concern. Urgently needed is a comprehensive source characterization assessment and the development, implementation and monitoring of environmental health policies, specifically addressing the chemicals of concern. IMPACT: In a subset of participants enrolled in the CCREOH environmental epidemiology cohort study elevated levels of Hg and Pb were identified. This is the first comprehensive exposure assessment in the Surinamese population. Health concerns include adverse birth- and neurodevelopmental outcomes. Geographic differences require a tailored approach to health intervention and comprehensive source characterization. Future research should ascertain the role of Se as a potential protective factor. Environmental policy development, implementation and monitoring is pivotal to mitigate exposures to these neurotoxicants.

Understanding occupational heat exposure in the United States and proposing a quantifying stress index.

PURPOSE: Millions of workers exposed to the outdoor environment are extremely susceptible to extreme heat. Although several articles analyzed heat-related illnesses, injuries, fatalities at the country level, few investigated regional and state statistics especially for OSHA Region 4 and the state of Alabama, U.S, which we explored in this study. METHODS: We studied the number of heat-days over 90 °F (32.2 °C) heat-index within our study area, analyzed heat-related injury and illnesses to calculate their incidence rate during 2015 to 2019, observed the nature of such incidents, their monthly occurrence, and incidence trend over average air temperature. We conducted a comparative analysis of heat-related fatalities between construction and all industries. The existing heat regulations by OSHA and some state agencies have also been summarized. RESULTS: We observed the highest mean, maximum heat-days and injury-illness rate in the south and southeast part of Region 4; increase in incidence rate from 0.03 in 2017 to 0.28 per 10,000 employees in 2018 for the contiguous U.S; highest injury-illness rate (HIR) in OSHA Region 1, 4 and 6; highest HIR in Lee, Montgomery, Mobile and Madison counties of Alabama; 34.7% (construction) and 31.3% (all industries) of all cases experiencing nonclassifiable heat-light effects; high fatalities in construction industry with a trend of 1 death/5 years; increased mortality in all occupations with 1 death/2.4 years. We also proposed a Heat-Stress Index (HSI) as a routine heat-stress measure on jobsite. CONCLUSION: The findings from this research and the proposed index can help in understanding heat-related risk at a regional level and implementing workplace interventions.

Development of a conceptual framework for risk assessment of elevated internal temperatures in landfills.

Subsurface elevated temperatures (SETs) often occur in landfills and pose great threats to their structural and environmental integrity. Current landfill gas monitoring practices only recommend maintaining certain soil gases percentages, with no integrated strategy for predicting subsurface temperature. As a solution, this paper proposes a comprehensive risk assessment framework specific to SET mitigation. The risk model (RSET) was constructed by incorporating independent gas variables (methane, carbon dioxide, oxygen, residual nitrogen, and temperature) identified in the existing literature as SET indicators, and analyzing gas-well data from the Bridgeton Landfill. Upon identifying these gas indictors and their safety thresholds, we found a significant association (p-value < 0.05) between safe-unsafe ranges of gas variables and subsurface temperature. Temperatures above 80 °C were found to be associated with 100%, 92.3%, and only 4% of the unsafe ranges of methane, residual nitrogen, and oxygen, respectively. As the correlation between gases and temperature seemed to vary for different gas combinations, we developed the RSET by incorporating into these correlation coefficients event intensities specific to certain gas combinations, and then normalizing the RSET scale over a 0-10 range. Over the study period, we identified 22.29% of cases as medium risk at the Bridgeton Landfill and 17.7% as high risk. SETs are governed by different combinations of safe-unsafe ranges of parameters rather than any individual parameters alone. Subsequently, we used a decision tree algorithm to assess the risk types associated with RSET values. The proposed RSET can serve as a monitoring and decision-making tool for landfill authorities for managing and preventing SET incidents.

The impact of stay-at-home orders on air-quality and COVID-19 mortality rate in the United States.

Since the beginning of the pandemic in the U.S., most jurisdictions issued mitigation strategies, such as restricting businesses and population movements. This provided an opportunity to measure any positive implications on air quality and COVID-19 mortality rate during a time of limited social interactions. Four broad categories of stay-at-home orders (for states following the order for at least 40 days, for states with less than 40 days, for states with the advisory order, and the states with no stay-at-home order) were created to analyze change in air quality and mortality rate. Ground-based monitoring data for particulate matter (PM2.5, PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2) and carbon monoxide (CO) was collected during the initial country-wide lockdown period (15 March-15 June 2020). Data on confirmed COVID-19 cases and deaths were also collected to analyze the effects of the four measures on the mortality trend. Findings show air quality improvement for the states staying under lockdown longer compared to states without a stay-at-home order. All stay-at-home order categories, except states without measures were observed a decrease in PM2.5 and the core-based statistical areas (CBSAs) within the longer mitigation states had an improvement of their air quality index (AQI).