Geohealth最新文献

Approximately 39% of U.S. homes are now located in the Wildland-Urban Interface (WUI) and are at elevated risk of burning during wildfires. WUI fires emit a cocktail of chemicals from the combustion of anthropogenic materials, including compounds that may differ from the burning of biogenic-only materials. There is currently limited knowledge on the mixture composition of combustible materials in WUI homes, representing a data gap and need to further characterize exposure chemistries and toxicological impacts of WUI-relevant smoke exposures. To address this issue, this study integrated combustible materials in an average American WUI home to derive what we are referring to as the “Burning ExposHome.” Items such as structural materials, plumbing, furnishings, and appliances were included in the Burning ExposHome. Calculations were based on an average American household, a 2,016 sq. ft. single family home of four bedrooms, using materials typical to California due to the high incidence of WUI fires in that geographic region. All materials were sorted and summed by type of base material such as wood materials, plastics, textiles, and metals. This list is notably modular and detailed per item, allowing for the addition/subtraction of components to address future study designs. In summary, the total combustible mass of an average American home was around 46,500 kg, including 81% wood materials, 6% plastics, and 2% metals. This list of materials serves as a foundational mixture of home materials to integrate into exposure characterization, mechanistic toxicology, and ecological/human health research addressing wildfires occurring at the growing WUI.

Coccidioidomycosis (Valley fever, VF) is a climate-sensitive infectious disease caused by inhaling soil-dwelling fungus Coccidioides, mostly reported in southwestern USA. Although soil moisture (SM) and soil temperature (ST) are known to shape the fungal lifecycle, their effects on coccidioidomycosis remain understudied. Most prior studies have relied on their proxies—precipitation and air temperature—that might not accurately capture soil hydrothermal dynamics. We conducted multivariable negative binomial regressions to estimate seasonal associations between incidence and climate drivers—including SM, ST, and wind speed from the North American Land Data Assimilation Phase 2 (NLDAS-2), and PM₁₀-based dusty-day counts—in Arizona's hyperendemic counties (Maricopa, Pima, and Pinal) from 2000 to 2022. We found higher incidence in areas with hotter, drier soils and more seasonal dusty days. Multi-year soil hydrothermal cycles—alternating wet–dry and cool–hot periods along with concurrent dry, dusty conditions—significantly influenced incidence. Notably, no antecedent dry–cool seasons were linked to increased incidence, indicating moisture and/or heat are prerequisites for fungal growth and dispersal. SM showed more consistent and widespread effects than ST across seasons and lags, with winter and spring soils most influential. Higher incidence followed wetter winters and monsoons, and dry, hot springs and falls. Our models using NLDAS-2 SM and ST data showed robust performance and generalizability across exposure seasons. Our results support adding multi-year soil indicators—with up to 3-year lead times—into early-warning systems to enhance VF forecasting and better prepare endemic regions for the challenges of a warming, drying, and increasingly variable climate.

With the many health implications of droughts and floods known, and the many adverse secondary and tertiary effects of the Covid-19 pandemic still lingering, it is important to study the complex interactions of epidemics, droughts, and floods. To gain insights into this issue, we have constructed epidemic, drought, and flood indices for the Ming and Qing dynasties of China in a period of more than 400 years. Using adaptive fractal analysis, we find that the time series of epidemic, drought, and flood indices possess long-range correlations of different degrees in different regions of China. More importantly, the scaling behavior for the cross correlations between the epidemic and the drought indices in Northern China is characterized by a non-stationary emergent behavior rather than by a long-range correlation, while this scaling behavior is close to the boundary of stationarity and non-stationarity in the Central China. This scaling is up to about 16 years, highlighting that on average, outbreak of large-scale epidemics may occur not shorter than once every 32 years. Interestingly, the emergent behavior can be characterized as a Zipf's law for the ranked size of the epidemics, mostly in the Northern China, and sometimes also involving some regions in the Central China.

We investigate the effect of extreme heat on home births in India, proposing that such extreme weather events may impede access to health facilities for childbirth. Utilizing geocoded data from the 2019–2021 Demographic and Health Survey for India, we identified the place of delivery of 208,368 births as home versus health facility. We incorporated maximum values for gridded wet-bulb globe temperatures (WBGT_max) and dry-bulb temperatures (DBT_max) corresponding to delivery dates and maternal residences. We defined context-specific extreme heat events using several percentile-based thresholds (between 80th and 95th) over varying durations (1–5 days). We used Generalized Estimating Equations (GEE) with inverse probability of treatment weighting, incorporating socioeconomic factors and state-level fixed effects, and adjusted for seasonality. We tested for effect-measure-modification by socio-economic factors (e.g., caste, wealth), healthcare access factors (e.g., rural/urban place of residence, difficultly in accessing healthcare), and contextual factors (e.g., long-term mean temperature, prevalence of institutional delivery). Both WBGT_max and DBT_max-based heatwave exposures were associated with increased likelihood of home births, with WBGT exposures demonstrating an earlier onset of significant associations at lower percentile thresholds while DBT showed stronger associations at higher thresholds and longer durations. Effect modification analyses revealed heightened impacts in warmer regions, states not designated as high-focus under the Janani Suraksha Yojana program, and non-Hindu populations. We find that extreme heat may compromise delivery at health facilities in India. Findings call for improved health system preparedness via early warning systems and advanced resource allocation to mitigate some of these effects.

California wildfires have grown increasingly frequent and intense over recent decades, raising serious public health concerns. In response, the California Air Resources Board (CARB) 2022 Scoping Plan outlines land management strategies to reduce wildfire risk and associated emissions under various climate change scenarios. This study evaluates the health benefits of CARB's official mitigation pathway, the S3 scenario, compared to a business-as-usual approach, using three global climate models (GCMs) and three future time slices. We apply the GEOS-Chem model to estimate fire-induced PM_2.5 concentrations and use the U.S. EPA's BenMAP-CE tool, along with a wildfire-specific chronic mortality dose-response function, to assess associated morbidity and mortality. Results suggest that S3 can significantly reduce fire-related PM_2.5 exposure, particularly in northern and central California where concentrations are typically highest—and where S3 treatments are most effective. In 2035 under the second generation Canadian Earth System Model GCM, for instance, S3 is associated with 1,927 fewer premature deaths and substantial reductions in asthma- and respiratory-related emergency room visits. However, health benefits vary by GCM and year, underscoring the influence of meteorological conditions on fire activity and health outcomes. These findings point to the importance of strategically timed and located land management actions and integrating climate variability into future mitigation planning.

Previous research has primarily focused on the impact of climatic variables and air pollution on Hand, Foot, and Mouth Disease (HFMD). However, there remains limited understanding of how air pollution levels modify these relationships across different regions and populations. This study employed a two-stage, multi-city time-series analysis using data from 13 cities in Jiangsu Province (2015–2023) to explore these effects. A multistage analytical approach, including the distributed lag non-linear model, multivariate meta-regression, and attributable risk calculation, was used to quantify the association between climatic variables, air pollutants, and HFMD. Findings indicated that HFMD incidence is closely associated with meteorological conditions, with peak risk at 24.8°C for average temperature and 89.2% for average relative humidity. Low average wind speed and short sunshine hours (SH) also contributed to increased risk. Air pollutants, such as PM_2.5, SO₂, and O₃, significantly modified these associations. For example, PM_2.5 and SO₂ increased HFMD risk at higher temperatures, while O₃ reduced risk. Under low humidity, some pollutants exhibited protective effects, though risk increased with high humidity. NO₂ had the strongest influence in reducing variability, while high PM_2.5 and SO₂ concentrations weakened the protective effects of SH. These findings emphasize the non-linear influence of climatic variables on HFMD risk and suggest that air pollution's modification of these relationships varies by gender, age, and location. This provides important insights for developing targeted, timely public health warnings.

Extreme weather events (EWEs) continue to threaten the health and well-being of populations across the globe. However, risk from drought and floods is not evenly distributed spatially nor are all populations equally at risk for poor health outcomes. Globally, people living with HIV/AIDS (PLHIV) face a particular set of challenges with EWE exposure including increased susceptibility to disease progression from care disruptions and medication adherence, and general population concentration in areas where rainfall is both highly variable and key to economic well-being. To mitigate the impacts of EWE exposure on PLHIV, it is necessary to understand the historical EWE exposure patterns at HIV care clinics. In this paper, we link open-source measures of drought and flood events to clinic locations from the International epidemiology Databases to Evaluate AIDS (IeDEA) network, a longitudinal study of over 2 million people living with and at risk for HIV in 44 different countries around the globe enrolling in HIV care from 2006 to present. Using generalized additive models fit to clinic-level drought and flood exposures, we show how exposures vary across and within countries, model each clinic's probability of exposure to a drought or flood to identify high-risk areas, and describe how this historical exposure record could ultimately be used to identify at-risk populations for a wide variety of study designs. While EWEs occurred at HIV care clinics around the globe, we found that clinic locations in Southern Africa are particularly vulnerable to flood and drought events as compared to other IeDEA clinic regions and locations.

The Ayeyarwady Delta in Myanmar, home to an estimated 12 million people, faces widespread arsenic contamination similar to other Asian deltas namely Bengal, Red River, and Mekong. Arsenic here primarily results from reductive dissolution of iron minerals in anoxic conditions driven by organic carbon. Here, we used digital elevation model (DEM) data to investigate how drainage density and hierarchical recharge pathways influence arsenic distribution, supported by combined data set of 136 wells (81 new, 55 from a prior study)—up to 215 m deep—along a 170 km west-to-east transect across the delta. Findings indicate arsenic hotspots in the mid-central region of the delta, where high drainage density appears to facilitate focused recharge, delivering organic carbon to underlying aquifers. Compared with other deltaic regions across Asia, the Ayeyarwady has fewer high-arsenic wells, with only 21% of our data set exceeding the local 50 μg/l limit. National screening data from 123,962 wells indicate that while only 8% exceed the regulatory limit of 50 μg/l set by Myanmar, 71% exceed the 10 μg/l guideline recommended by the World Health Organization (WHO). This highlights widespread exposure risk not addressed under the current national standard, particularly for rural communities. The observed variability in arsenic concentrations, driven by complex redox dynamics and groundwater flow patterns, indicates that contamination can occur even within short spatial intervals. A blanket-screening program focused on hotspot regions is essential to ensure that at-risk populations are not unknowingly exposed to unsafe drinking water.

Global bottom-up anthropogenic emission inventories show substantial spatial and temporal differences of short-lived pollutant emissions, which results in uncertainties in terms of air quality and human health impacts. In this study, we compare the emissions of trace gases and aerosols for the year 2015 from three different global emission inventories, the Community Emissions Data System (CEDS), the Copernicus Atmosphere Monitoring Service Global Anthropogenic Emissions (CAMS-GLOB-ANT), and Evaluating the Climate and Air Quality Impacts of Short-Lived Pollutants version 6b (ECLIPSEv6b). We then employ the Community Atmosphere Model with chemistry version 6.0 within the Community Earth System Model version 2.2.0 to quantify the atmospheric chemistry and air quality impacts from the above three anthropogenic emission inventories, with a focus on PM_2.5 (particulate matter with aerodynamic diameters equal or less than 2.5 μm) and ozone (O₃). Our results indicate that differences between emission inventories are largest for black carbon, organic carbon, ammonia and sulfur dioxide, in terms of global annual total emissions. These differences in emissions across CEDS, CAMS, and ECLIPSEv6b lead to substantial variations in global annual totals and spatial distribution patterns. This study shows that the global annual total PM_2.5-induced premature mortality is three times higher than that from O₃ mortality, indicating that PM_2.5 is the primary contributor compared with O₃. An inter-comparison of global human health impacts from CEDS, CAMS and ECLIPSEv6b indicates that 80% (CEDS), 81.2% (CAMS), and 77.6% (ECLIPSEv6b) of premature deaths due to anthropogenic activities are associated with Asia and Africa continents.

This study investigated the socioeconomic disparities of asthma incidence attributable to ambient particulate matter in aerodynamic diameter ≤2.5 μm (PM_2.5) exposures among schoolchildren in California, U.S. We found that schoolchildren attending public schools in more vulnerable communities, characterized by higher proportions of people of color, low educational attainment, and poverty, experienced elevated PM_2.5 exposures by 2.07–2.96 μg/m³. The disproportionate PM_2.5 exposures were likely driven by higher traffic-related emissions and point-source facility emissions in these communities. Using school-specific PM_2.5 concentrations, student enrollment numbers, and model-estimated (not directly observed) baseline age-specific asthma incidence rates, we calculated that the asthma incidence rate attributable to 2016 PM_2.5 exposures was 562 new cases per 100,000 schoolchildren [95% confidence interval (CI) = 311–854]. In absolute terms (i.e., asthma incidence), it was equivalent to 34,537 PM_2.5-related new asthma cases (95% CI = 19,090–52,493) among all schoolchildren. On average, more vulnerable communities experienced 140 excess new asthma cases per 100,000 schoolchildren (i.e., the difference in average asthma cases per 100,000 schoolchildren between more and less vulnerable groups) across all demographic factors considered. Examining health disparities separately by each demographic factor revealed that race/ethnicity was associated with the largest disparities (209 new cases per 100,000 schoolchildren), followed by educational attainment (128) and poverty (85). Our findings indicate the substantial socioeconomic disparities of asthma incidence attributable to PM_2.5 among schoolchildren in California. Addressing these health disparities could benefit from sustained and long-term emission reduction strategies, such as adopting zero-emission vehicles, which contribute to lower PM_2.5 levels.