Journal of Exposure Science and Environmental Epidemiology最新文献

Background: Night markets-a unique element of Asian culture-involve various cooking methods and combustion, generating air pollutants with adverse health effects. However, there is no scientific literature on whether air pollutants from night markets affect indoor air quality and the lung function of children in nearby households.

Objective: We evaluated the impacts of night market, specifically market opening days and household distance from the market, on indoor air quality and the lung function of children in nearby households.

Methods: Using real-time monitoring equipment, we measured concentrations of particulate matter (PM)₁, PM_2.5, PM₁₀, carbon dioxide (CO₂), carbon monoxide (CO), nitrogen dioxide, sulfur dioxide (SO₂), ozone, total volatile organic compound (TVOC), airborne bacteria, and fungi in 58 households located near a night market. Additionally, we assessed the lung function values of children living in these households.

Results: PM₁ and PM_2.5 concentrations were significantly higher during opening days than during closing days. The lung function values for children were significantly lower in households located ≤595 m from the market (near group) than in those located >595 m from the market (far group). Higher CO₂, CO, SO₂, TVOCs, and PM₁₀ concentrations and poor lung function were observed in children in the near group.

Impact statement: PM₁ and PM_2.5 concentrations were significantly higher during opening days of the night market than during closing days. Children residing near the night market (≤595 m) exhibited significantly lower lung function values than those living in houses located >595 m from the market.

Background: There is increasing attention on the effects of residential fossil fuel combustion, particularly the use of natural gas or oil, on indoor air quality. Given the prevalent use of natural gas in Canadian homes, understanding its influence on indoor air quality is important.

Objective: This study investigated associations between indoor levels of nitrogen dioxide (NO₂), carbon monoxide (CO), formaldehyde, and acetaldehyde with potential emission sources and other influencing factors in 344 homes in four Canadian cities.

Methods: Using mixed models and general linear models, we evaluated the associations between potential sources and pollutant concentrations, conducting both city-specific and pooled analyses for winter and summer seasons.

Results: Our findings indicated that gas stoves, present in 24% of the homes, were significantly associated with increased indoor NO₂ concentrations, resulting in a 191% increase in winter and a 114% increase in summer. Additionally, the presence of gas stoves was strongly associated with a 43% increase in peak hourly CO levels in winter. The presence of gas clothes dryers was significantly associated with increased indoor NO₂ levels (47% in summer and 54% in winter). Oil heating was significantly associated with a 58% increase in winter indoor NO₂ levels. Gas heating was associated with a 62% increase in winter NO₂ levels in older homes (built before 1949), with marginal significance. Aldehyde levels were primarily associated with off-gassing from building materials and household activities. Other factors associated with indoor pollutant levels included housing characteristics, occupant behaviors, indoor environmental conditions, and outdoor sources.

Impact: This study enhances understanding of the association between fossil fuel combustion and indoor air quality in predominantly detached homes. It highlights differences in pollutant levels between homes with gas and electric cooking, which can inform advice on cooking practices to reduce emissions in homes.

Background: Certain occupations have greater risk for per- and polyfluoroalkyl substances (PFAS) exposure because of PFAS use in occupation-associated materials.

Objective: We sought to assess whether PFAS concentrations differed by occupation among certain Arizona workers and whether concentrations differed over time by occupation.

Methods: Serum concentrations for 14 PFAS were measured among 1960 Arizona Healthcare, Emergency Responder, and Other Essential Worker Study participants. Samples were collected at enrollment and periodically during July 2020-April 2023. Occupational categories included firefighters, other first responders, healthcare workers, and other essential workers. We fit multilevel regression models for each PFAS to estimate differences in geometric mean concentrations or odds of PFAS detection at enrollment by occupational category. For participants with ≥1 serum sample, we evaluated for yearly longitudinal differences in PFAS concentrations by occupational category. We used other essential workers for comparison, and adjusted for age, sex, race and ethnicity, year, and residential county.

Results: Adjusting for covariates, firefighters had higher perfluorohexanesulfonic acid (PFHxS), branched and linear perfluorooctanesulfonic acid (PFOS), and perfluoroheptanesulfonic acid (PFHpS) concentrations than other essential workers (geometric mean ratios 95% CIs: 1.26 [1.11-1.43]; 1.18 [1.06-1.32]; 1.19 [1.08-1.31]; and 1.19 [1.01-1.39], respectively). Healthcare workers had higher odds of detection of branched perfluorooctanoic acid (Sb-PFOA) and perfluorododecanoic acid (PFDoA) than other essential workers, adjusting for covariates (odds ratios 95% CIs: 1.35 [1.01-1.80]; 2.50 [1.17-5.34], respectively). During the 3-year study, we detected declines in PFAS concentrations among other essential workers; few longitudinal differences in concentrations by occupation were detected.

Impact statement: Using data from a large prospective cohort of frontline workers in Arizona, we compared serum concentrations of 14 per-and polyfluoroalkyl substances (PFAS) among firefighters, other first responders, healthcare workers, and other frontline essential workers. We found that firefighters have higher concentrations of certain PFAS chemicals and the odds of detecting other PFAS chemicals are higher among healthcare workers compared with people in other occupations. Our findings highlight the importance of further action to reduce PFAS exposure within highly exposed occupational groups, such as firefighters, and the need to expand evaluation of exposure among other occupations, including healthcare workers.

Background: Perfluoroalkyl substances (PFAS) are stable chemicals used in various applications. PFAS exposure has been associated with lower birth weight and immunological effects in children, and limited evidence further suggests adverse neurodevelopmental effects. Previous studies show that PFAS cross the placental barrier during pregnancy leading to prenatal exposure of the fetus. Research on the transplacental transfer efficiency (TTE) of PFAS in highly exposed populations is lacking.

Objective: This study aimed to estimate the TTE of eight PFAS and three perfluorooctane sulfonic acid (PFOS) isomers in a birth cohort with a wide range of PFAS exposures and to investigate if maternal exposure level impacted the estimated TTE.

Methods: The participants, most of whom had been exposed to PFAS-contaminated municipal drinking water, were recruited between 2015 and 2020 after the end of exposure. We collected maternal serum samples during pregnancy and at delivery, as well as umbilical cord serum. Serum samples were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). TTE was estimated as the ratio of the PFAS concentration in cord serum to maternal serum. We used generalized additive mixed models accounting for maternal characteristics to assess if maternal exposure level (i.e., high, intermediate, or background) modified the estimated TTE.

Results: The study included 200 dyads with matched cord and maternal serum samples. The exposure profile was dominated by perfluorohexane sulfonic acid (PFHxS) and PFOS. We observed the highest overall transfer efficiency for PFHxS (median TTE: 0.68) and the lowest for the n-PFOS isomer (median TTE: 0.33). Higher TTEs were observed for PFHxS and PFOS (total and isomers) in background-exposed dyads.

Impact statement: In a birth cohort with a wide range of exposures to primarily PFOS and PFHxS from contaminated drinking water, we found that the transplacental transfer efficiencies (TTE) of eight PFAS and three PFOS isomers were of considerable magnitude. The highest TTE were observed for PFOA and PFHxS, and for branched PFOS isomers compared with linear. Although we observed slightly lower TTE in mother-child dyads with high and intermediate exposures compared with dyads with background levels of exposure, the considerable TTE in highly exposed mothers implies high absolute prenatal exposure in children in contaminated areas.

Background: Analyzing and visualizing disparities in environmental risks can help assess place-based vulnerabilities and provide civic leaders and community members with essential data for promoting health equity and informing public health strategies.

Objective: We investigated the adaptation of a previously developed environmental vulnerability index to evaluate the cumulative impact of diverse stressors in Louisville Metro-Jefferson County, KY, with the goal of supporting multi-faceted targeted public health interventions at the census tract level.

Methods: We assessed countywide vulnerability variability using the Toxicological Prioritization Index interface across five domains with 32 publicly available data indicators, and modeled the effects of theoretical public health interventions.

Results: Our findings suggest that similar vulnerable areas are not always geographically clustered. Higher vulnerability scores were observed in the western and central areas of the county, with lower scores in the eastern regions. The index enabled the selection of the most at-risk census tracts for modeling targeted public health interventions to reduce cumulative environmental vulnerability.

Impact: Environmental vulnerabilities are not invariant features of urban environments. Rather, knowledge of these risks can guide the development and implementation of targeted solutions. This analysis demonstrated how publicly available data can support selection of feasible interventions to improve environmental equity. Targeted interventions to modify environmental conditions that support health can be developed and implemented locally with greater precision at the census tract level, yielding impactful outcomes.

Background: As climate change raises global temperatures, there remains a notable gap in understanding the body's mechanisms of heat stress defense exhibited by Heat Shock Protein (HSP) within the populations.

Objective: This study aims to investigate the expression level of HSP70 in response to indoor heat exposure among vulnerable populations in both urban and rural settings.

Methods: A comparative cross-sectional was conducted among 108 participants from urban and rural areas in Klang Valley, Malaysia. The study included face-to-face interviews, indoor heat exposure monitoring, and thermal stress classification using the Universal Thermal Climate Index (UTCI). HSP70 gene and protein expressions were analyzed using reverse-transcription quantitative polymerase chain reaction (RT-qPCR) and HSP70 High Sensitivity Enzyme-linked Immunosorbent Assay (ELISA), respectively.

Results: Urban areas experienced signficantly higher UTCI heat exposure levels than rural areas (p < 0.001). In response to heat stress, vulnerable populations in urban areas exhibited higher HSP70 gene relative expression and HSP70 protein expression. A significant mean difference in the plasma HSP70 protein expression was observed between the two groups (p < 0.001). The linear mixed model (LMM) revealed a significant association between UTCI heat exposure levels and HSP70 gene and protein expression in both groups (p < 0.001).

Impact: While previous studies have examined cellular responses to heat stress in healthy individuals within controlled experimental settings, our study uniquely focuses on vulnerable individuals in actual environmental conditions. This is crucial for establishing baseline information on the ability of these populations to adapt to climate change and surrounding temperatures. Such information is essential for building resilient communities and preventing fatal incidents such as heat stroke during extreme heat events. By highlighting the differences between urban and rural populations, this study provides critical information for policymakers and health practitioners to design location-specific and population-specific heat stress mitigation strategies.

Background: Childhood lead [Pb] exposure has been consistently linked to neurotoxic effects related to the prefrontal cortex, a critical mediating structure involved in decision-making, planning, problem-solving, and specific aspects of short-term memory, i.e., the components of executive functions [EFs]. Limited studies have taken a deeper phenotyping approach that assess Pb's effects across multiple EF dimensions simultaneously, which can be organized into hot [e.g., reward, motivation] and cold [e.g., primary cognitive processing] dimensions.

Objective: We investigated whether childhood Pb exposure affects hot and cold EF dimensions and assessed any sexually dimorphic effects.

Methods: Leveraging a longitudinal birth cohort based in Mexico City, children's (n = 602) whole blood Pb levels (mean 23.66 μg/L) were measured at ages 4-6 and they were administered several EF tasks at ages 6-9. Confirmatory factor analysis confirmed that six EF tests estimated two latent variables representing hot and cold EF dimensions. Structural equation modeling [SEM] estimated the neurotoxic effect of childhood Pb exposure on latent variables of hot [higher scores indicate improved performance] and cold [higher scores indicate poorer performance] EFs. Subsequently, a multi-group SEM explored potential effect modifications by child sex.

Results: Pb exposure was significantly associated with negative impacts on hot EF performance [b = -0.129, p = 0.004]. In both males (b = -0.128, p = 0.032) and females (b = -0.132, p = 0.027), childhood Pb exposure was significantly associated with a reduction in hot EF performance, with no evidence of an interaction with sex. Additionally, we found no association between Pb exposure and cold EF performance [b = 0.063, p = 0.392] and no notable sex differences.

Impact: The present study leverages a sophisticated SEM framework as an exploratory tool and a neurotoxic framework to analyze multidimensional cognitive data, aiming to delineate hot and cold EFs. Our findings are consistent with neurotoxicity secondary to childhood Pb exposure impacting hot EF performance more than cold EF, though comparable trends were noted in cold EF performance for both sexes. Our approach uniquely captures hot EF, the more emotional and self-regulatory aspect of EF, adding a novel dimension to the literature on Pb exposure and cognitive development.

Background: Environmental surveillance of infectious organisms holds tremendous promise to reduce human-to-human transmission in indoor spaces through early detection.

Objective: In this study we determined the applicability and limitations of wastewater, indoor high-touch surfaces, in-room air, and rooftop exhaust air sampling methods for detecting SARS-CoV-2 in a real world building occupied by residents recently diagnosed with COVID-19.

Methods: We concurrently examined the results of three 24-hour environmental surveillance techniques, indoor surface sampling, exhaust air sampling and wastewater surveillance, to the known daily census fluctuations in a COVID-19 isolation dormitory. Additionally, we assessed the ability of aerosol samplers placed in the large volume lobby to detect SARS-CoV-2 multiple times per day.

Results: Our research reveals an increase in the number of individuals confirmed positive with COVID-19 as well as their estimated human viral load to be associated with statistically significant increases in viral loads detected in rooftop exhaust aerosol samples (p = 0.0413), wastewater samples (p = 0.0323,), and indoor high-touch surfaces (p < 0.001)). We also report that the viral load detected in lobby aerosol samples was statistically higher in samples collected during presence of occupants whose COVID-19 diagnostic tests were confirmed positive via qPCR compared to periods when the lobby was occupied by either contact-traced (suspected positive) individuals or during unoccupied periods (p = 0.0314 and <2e-16).

Significance: We conclude that each daily (24h) surveillance method, rooftop exhaust air, indoor high-touch surfaces, and wastewater, provide useful detection signals for building owner/operator(s). Furthermore, we demonstrate that exhaust air sampling can provide spatially resolved signals based upon ventilation exhaust zones. Additionally, we find that indoor lobby air sampling can provide temporally resolved signals useful during short duration sampling periods (e.g., 2-4 hours) even with intermittent occupancy by occupants diagnosed with COVID-19.

Impact: Our research demonstrates that aerosol sampling can detect COVID-19 positive individuals in a real world lobby setting during very short occupancy periods. We demonstrate the effectiveness of rooftop exhaust aerosol, surface, and wastewater environmental surveillance in monitoring viral load in building occupants, both at the building scale and with ventilation zone-level resolution for aerosols. We provide actionable data for researchers, health officials and building managers who seek to determine which monitoring method is best for their building or study. This study is relevant in the fields of epidemiology, exposure sciences, biomonitoring, virology, public health, and healthy building design and management.

Background: Odors are a documented environmental justice challenge in Denver, Colorado. Complaints are an important modality through which residents express their concerns.

Objective: We investigated disparities in environmental justice related-variables, such as home and workplace census block groups (race/ethnicity, education levels, renter-occupied housing, median income and median home values, gentrification) by locations of odor complaints as well as that of potential malodorous facilities. We report key themes identified in complaints.

Methods: We obtained odor complaints for 2014-2023 and the locations of facilities required to submit an odor management plan as of 2023 from the Denver Department of Public Health and Environment. We downloaded residential census block group-level socioeconomic data from the 2016-2020 American Community Survey and workplace-based socioeconomic data from the Longitudinal Employer-Household Dynamics dataset for 2020. We assessed exposure to potential malodorous facilities and complaints within each census block group. We investigated exposure disparities by comparing distributions of environmental justice-related variables based on whether a complaint has been made against a facility, and census block group-level odor intensity categories. We used unsupervised machine learning to identify themes from the odor complaints.

Results: Less privileged census block groups were more likely to contain a potential malodorous facility. Importantly, our study also reveals disparities in the location of facilities, not just in traditional residence/-based environmental justice-related variables, but in workplace/-based factors as well. Our work points to the need to broaden our understanding of the structural racism forces that shape disparities from residential-based forces such as segregation to others such as access to transportation that result in workplace disparities. We did not observe similar disparities for odor complaints. Specific facilities were mentioned repeatedly in the complaints received.

Impact: Our study adds to the growing literature on disparities observed in exposure to odor using locations of potential malodorous facilities and complaints as a proxy.