Environmental Health Perspectives最新文献

Background: Coccidioidomycosis, caused by inhalation of Coccidioides spp. spores, is an emerging infectious disease that is increasing in incidence throughout the southwestern US. The pathogen is soil-dwelling, and spore dispersal and human exposure are thought to co-occur with airborne mineral dust exposures, yet fundamental exposure-response relationships have not been conclusively estimated.

Objectives: We estimated associations between fine mineral dust concentration and coccidioidomycosis incidence in California from 2000 to 2017 at the census tract level, spatiotemporal heterogeneity in exposure-response, and effect modification by antecedent climate conditions.

Methods: We acquired monthly census tract-level coccidioidomycosis incidence data and modeled fine mineral dust concentrations from 2000 to 2017. We fitted zero-inflated distributed-lag nonlinear models to estimate overall exposure-lag-response relationships and identified factors contributing to heterogeneity in exposure-responses. Using a random-effects meta-analysis approach, we estimated county-specific and pooled exposure-responses for cumulative exposures.

Results: We found a positive exposure-response relationship between cumulative fine mineral dust exposure in the 1-3 months before estimated disease onset and coccidioidomycosis incidence across the study region [incidence rate ratio (IRR) for an increase from 0.1 to $1.1{\mu g/m}^3=1.60$; 95% CI: 1.46, 1.74]. Positive, supralinear associations were observed between incidence and modeled fine mineral dust exposures 1 [$\text{IRR}=1.13$ (95% CI: 1.10, 1.17)], 2 [$\text{IRR}=1.15$ (95% CI: 1.09, 1.20)] and 3 [$\text{IRR}=1.08$ (95% CI: 1.04, 1.12)] months before estimated disease onset, with the highest exposures being particularly associated. The cumulative exposure-response relationship varied significantly by county [lowest IRR, western Tulare: 1.05 (95% CI: 0.54, 2.07); highest IRR, San Luis Obispo: 3.01 (95% CI: 2.05, 4.42)]. Season of exposure and prior wet winter were modest effect modifiers.

Discussion: Lagged exposures to fine mineral dust were strongly associated with coccidioidomycosis incidence in the endemic regions of California from 2000 to 2017. https://doi.org/10.1289/EHP13875.

Background: Uterine fibroids disproportionately affect Black women, and exposure to chemicals from hair relaxers or straighteners ("straighteners") may contribute to fibroid development.

Objectives: We examined the association between straightener use and prevalent young-onset uterine fibroids (diagnosed before age 36 y), as well as incident fibroids (diagnosed age 36-60 y), with a focus on Black women. We also examined differences in associations across birth cohorts as proxies for formulation changes.

Methods: Data from 4,162 Black women in the Sister Study, a prospective cohort of women 35-74 y of age (enrolled 2003-2009), were analyzed. We used logistic regression to estimate odds ratios (ORs) for the association of straightener use at 10-13 y of age and self-reported young-onset fibroids. We used Cox regression to assess hazard ratios (HRs) for straightener use (age 10-13 y and in 12 months before enrollment) and incident fibroids among 779 premenopausal Black women. Similar analyses were conducted in 40,782 non-Hispanic White women.

Results: Over 70% of Black women used straighteners. In comparison with no use, any [$\text{OR}=1.15$; 95% confidence interval (CI): 0.96, 1.36] and frequent use ($\text{OR}=1.18$; 95% CI: 0.99, 1.42) of straighteners at 10-13 y of age were associated with young-onset fibroids. This association was most apparent among those born between 1928 and 1945 ($\text{OR}=1.78$; 95% CI: 1.15, 2.74) and 1965-1974 ($\text{OR}=1.64$; 95% CI: 0.82, 3.29). Fibroid incidence from 36 to 60 y of age was modestly associated with use of straighteners at 10-13 y of age [hazard ratio $\left(\text{HR}\right)=1.14$; 95% CI: 0.81, 1.63] and in the 12 months prior to enrollment ($\text{HR}=1.32$; 95% CI: 0.88, 2.00). Among non-Hispanic White women, straightener use at 10-13 y of age was similarly associated with young-onset fibroids ($\text{OR}=1.23$; 95% CI: 1.03, 1.47) despite lower use ($\le 5\%$) of straighteners. Sensitivity analyses indicated a potential for bias due to fibroid misclassification, with an overestimation of the effect likely if nulliparous women or women from households with lower education reported their fibroid status less accurately.

Discussion: Hair straightener use may be positively associated with fibroid risk. https://doi.org/10.1289/EHP14493.

Background: Unregulated contaminants in drinking water, such as per- and polyfluoroalkyl substances (PFAS), can contribute to cumulative health risks, particularly in overburdened and less-advantaged communities. To our knowledge, there has been no nationwide assessment of socioeconomic disparities in exposures to unregulated contaminants in drinking water.

Objective: The goals of this study were to identify determinants of unregulated contaminant detection among US public water systems (PWSs) and evaluate disparities related to race, ethnicity, and socioeconomic status.

Methods: We gathered data from the US Environmental Protection Agency's (US EPA's) Third Unregulated Contaminant Monitoring Rule (2013-2015), PWS characteristics, sociodemographic data, and suspected pollution sources from regulatory databases. We included four target contaminants (or classes) with industrial sources: PFAS, 1,4-dioxane, 1,1-dichloroethane, and chlorodifluoromethane (HCFC-22). Associations were evaluated with pairwise comparison tests and generalized logistic mixed-effects regression models for six dichotomous outcomes: detection of each of four target contaminants, detection of $\ge 1$ target contaminant, and PWS exceedance of $\ge 1$ US EPA health reference level that was in effect in 2017.

Results: More than 97 million US residents were served by a PWS with detectable levels of 1,4-dioxane (22% of PWSs), HCFC-22 (5.8%), 1,1-dichloroethane (4.7%), and/or PFAS (4.0%). Unregulated contaminant detection was more frequent among large systems, urban systems, and systems using groundwater or a combination of groundwater and surface water. In comparison with PWSs with no detectable levels of these unregulated contaminants, PWSs with detectable levels served counties with higher proportions of Hispanic residents (17% vs. 13%), as did PWSs that exceeded EPA health reference levels in comparison with PWSs with no exceedances (18% vs. 14%). There were persistent positive associations between proportions of Hispanic residents and detections of target contaminants, even after accounting for pollution sources.

Discussion: Previously, inequities in exposures to drinking water contaminants were underestimated because prior studies have focused on regulated contaminants. PWSs serving counties with more Hispanic residents, non-Hispanic Black residents, and urban households may benefit from additional resources to proactively mitigate unregulated chemical contamination. Future studies should evaluate factors underlying these disparities to promote actions that protect water quality for all residents. https://doi.org/10.1289/EHP14721.

Background: Occupational heat-related illness (OHI) is a health threat to workers that can be fatal in severe cases. Effective and feasible measures are urgently needed to prevent OHI.

Objectives: We evaluated the effectiveness of a multifaceted intervention, TEMP, in reducing the OHI risk among outdoor workers in the power grid industry.

Methods: A cluster randomized controlled trial was conducted with power grid outdoor workers in Southern China from 4 July 2022 to 28 August 2022. Work groups were randomly allocated (1:1) to the intervention or control groups. The multifaceted intervention TEMP comprised mobile application (app)-based education training (T), personal protective equipment [PPE (E)], OHI risk monitoring (M), and educational posters (P). Four follow-ups were conducted every 2 wk after the trial began. The primary outcome was the OHI incidence, and the secondary outcome was PPE usage. The app usage was considered as the compliance of intervention in the intervention group. The primary analysis used was intention-to-treat analysis. Multilevel analyses using random effects logistic regression models were performed to compare the odds of OHI between the two groups, adjusted for individual-level (education and work position) and work-related (including water intake when feeling thirsty, cooling measures, and poor sleep before work) covariates.

Results: Of 528 participants, 422 (79.92%) were males, and the $\text{mean}\pm \text{SD}$ age was $36.36\pm 8.18$ y. The primary outcome, OHI incidence, was 1.80% in the intervention group and 4.82% in the control group at the end of the whole follow-up. OHI mainly occurred between 1100 and 1500 hours, with nausea, significantly increased heart rate, and oliguria being the top three reported OHI symptoms. Compared with the control group, the adjusted odds ratios between the intervention group and control group were 0.73 [95% confidence interval (CI): 0.30, 1.76] in the first follow-up wave, with 0.38 (95% CI: 0.15, 0.97), 0.29 (95% CI: 0.08, 1.05), and 0.39 (95% CI: 0.13, 1.19) in the following three follow-up waves, respectively. The intervention also significantly improved PPE usage in the intervention group.

Discussions: This multifaceted intervention reduced the OHI risk among outdoor workers in the power grid industry. However, further research is needed to design a more flexible intervention strategy and evaluate its effectiveness in a larger population. https://doi.org/10.1289/EHP14172.

Background: Increasing evidence supports an association of endocrine-disrupting chemical (EDC) exposures with adverse biological effects in humans and wildlife. Recent studies reveal that health consequences of environmental exposures may persist or emerge across generations. This creates a dual conundrum: that we are exposed to contemporary environmental chemicals overlaid upon the inheritance of our ancestors' exposure profiles. Even when legacy EDCs are phased out, they may remain relevant due to persistence in the environment together with intergenerational inheritance of their adverse biological effects. Thus, we all possess a body burden of legacy contaminants, and we are also increasingly exposed to new generations of EDCs.

Objectives: We assessed the effects of direct and ancestral exposures to EDCs across six generations on anxiety-like behaviors in male rats using our "two hits, three generations apart" multigenerational EDC exposure experimental model. We investigated two classes of EDCs with distinct hormonal actions and historical use-the weakly estrogenic polychlorinated biphenyl (PCB) mixture Aroclor 1221 (A1221) and the anti-androgenic fungicide vinclozolin (VIN)-in both the maternal and paternal line. We also determined if a hormonal mechanism drives these effects across generations.

Methods: Rats were gestationally exposed to A1221, VIN, or vehicle [dimethyl sulfoxide (DMSO)] in the F1 generation. Three generations later, the F4 generation was given the same or a different exposure. Anxiety-like behavior was measured in the open field test, light:dark box, and elevated plus maze across generations. Serum was collected at the end of the experiment, and concentrations of estradiol and corticosterone were analyzed.

Results: Although direct exposure did not affect behavior in F1 males, ancestral exposure to VIN decreased anxiety-like behavior in the F3 paternal line compared to vehicle. In the F4 paternal line, ancestral A1221 followed by direct exposure to VIN increased anxiety-like behavior compared to controls. In the F6 maternal line, relative to vehicle, the double ancestral hits of A1221/VIN decreased anxiety-like behavior. Serum hormones weakly predicted behavioral changes in the F4 paternal line and were modestly affected in the F4 and F6 maternal lines.

Discussion: Our data suggest that anxiety-like behavioral phenotypes emerge transgenerationally in male rats in response to EDC exposure and that multiple hits of either the same or a different EDC can increase the impact in a lineage-specific manner. https://doi.org/10.1289/EHP15684.