Environmental Health Perspectives最新文献

Background: Environmental change in coastal areas can drive marine bacteria and resulting infections, such as those caused by Vibrio vulnificus, with both foodborne and nonfoodborne exposure routes and high mortality. Although ecological drivers of V. vulnificus in the environment have been well-characterized, fewer models have been able to apply this to human infection risk due to limited surveillance.

Objectives: The Cholera and Other Vibrio Illness Surveillance (COVIS) system database has reported V. vulnificus infections in the United States since 1988, offering a unique opportunity to both explore the forecasting capabilities machine learning could provide and to characterize complex environmental drivers of V. vulnificus infections.

Methods: Machine learning models, in the form of random forest classification models, were trained and refined using the epidemiological data from 2008 to 2018, six environmental variables (sea surface temperature, salinity, chlorophyll a concentration, sea level, land surface temperature, and runoff rate) and categorical encoders to assess our predictive potential to forecast V. vulnificus infections based on environmental data.

Results: The highest-performing model, which used balanced classes, had an Area Under the Curve score of 0.984 and a sensitivity of 0.971, highlighting the potential of machine learning to anticipate areas and periods of V. vulnificus risk. A higher false positive rate was found when the model was applied to real-world imbalanced surveillance data, which is pertinent amid modeled underreporting and misdiagnosis ratios of V. vulnificus infections. Further models were also developed to explore multilevel spatial resolution, finding state-specific models can improve specificity and early warning system potential by exclusively using lagged environmental data.

Discussion: The machine learning approach was able to characterize nonlinear and interacting environmental associations driving V. vulnificus infections. This study accentuates the potential of machine learning and robust surveillance for forecasting environmentally associated marine infections, providing future directions for improvements, further application, and operationalization. https://doi.org/10.1289/EHP15593.

Background: Sugarcane burning is an agricultural practice that is implemented to increase sugar yields. However, sugarcane burning produces air pollutants associated with adverse health outcomes. This review summarizes the current knowledge of the defined exposures and health effects associated with sugarcane burning and identifies research gaps.

Methods: A scoping review was conducted using PubMed, Scopus, and Web-of-Science to identify peer-reviewed literature on health and exposure investigations associated with air pollution from burning sugarcane. Studies were eligible if they included both an air pollution measurement and a health outcome assessment in human workers and surrounding communities or animal studies associated with sugarcane burning.

Results: A total of 24 studies passed our inclusion criteria, including 19 observational and five experimental studies. All observational studies were conducted in Brazil or the United States with the majority focused on respiratory (65%, 15/24), cardiovascular (13% 3/24), and renal (13%, 3/24) health outcomes. The most frequently assessed air pollutants were particulate matter [with aerodynamic diameter $\le 2.5\mu m$ (${\mathrm{PM}}_{2.5}$) and with aerodynamic diameter $\le 10\mu m$ (${\mathrm{PM}}_{10}$)] and total suspended particulates (TSP). Of the observational studies, 42% (8/19) were prospective cohorts, and 58% (11/19) employed an ecological design and applied variable exposure assessment methods. The experimental studies all used rodent models with varied exposure routes and pollutants.

Discussion: This review supports a well-documented link between air pollution from sugarcane burning and adverse health effects in workers and neighboring communities with respiratory, renal, and cardiovascular health effects; however, several knowledge gaps were identified, including the need for expansion of studies geographically, application of more advanced exposure science to characterize and quantify sugarcane emission components, probing of emerging health effects (i.e., kidney disease) and associated biomarkers, and evaluation of vulnerable populations that neighbor sugarcane operations. Furthermore, pairing exposure measurements and health assessments in the same study would increase our knowledge and better inform policies to improve the health of workers and communities impacted by sugarcane burning. https://doi.org/10.1289/EHP14456.

Background: Cerebral palsy (CP) is the most common permanent neuromotor disorder diagnosed in childhood. Although most cases have unknown etiology, emerging evidence suggests environmental risk factors of CP.

Objectives: We investigated whether ambient toxic air contaminants (TACs) in the maternal residential area during pregnancy, specifically volatile organic compounds (VOCs) and metals, were associated with offspring CP risk in California.

Methods: We conducted a case-cohort study that included CP cases ($N=906$) and a 20% random sample of all live singleton births ($N=\mathrm{184,954}$) who lived within a $5\text{-mile}$ (8-km) radius of air toxics monitoring stations in California during 2005-2015 as the control comparison group. CP cases were ascertained from diagnostic records of the California Department of Developmental Services. We a priori selected TACs with suspected neurotoxicity and developmental toxicity, including 14 VOCs and 6 metals. We estimated the adjusted risk ratio (RR) and 95% confidence interval (CI) for CP and the average maternal residential exposures to each TAC over the entire pregnancy using modified Poisson regression. For air contaminant mixtures, we used quantile-based g-computation to estimate the effects of mixtures of VOCs or metals. Finally, we performed a negative control exposure analysis on exposure estimates of 36-48 months after delivery to evaluate uncontrolled confounding bias.

Results: Maternal residential exposures to six VOCs (benzene, toluene, 1,3-butadiene, acetone, acetonitrile, and methylene chloride) and four metals (antimony, lead, nickel, and vanadium) were associated with 3%-25% higher risk of CP per interquartile range increase, and the estimated mixture effects of VOCs ($\text{RR}=1.24$; 95% CI: 1.08, 1.43) or metals ($\text{RR}=1.38$; 95% CI: 1.20, 1.58) were stronger. The observed associations were close to null for negative control exposures (36-48 months after delivery) to mixtures of VOCs or metals and CP.

Discussion: In California, maternal prenatal residential exposure to VOCs and metals in the outdoor air, largely attributed to mobile traffic emission sources, was associated with an increased risk of CP in offspring. https://doi.org/10.1289/EHP14742.

Background: Epidemiologic studies have shown that daily exposure to incense smoke is associated with greater risk of cardiovascular mortality, which suggests that chronic exposure to incense could be linked to atherosclerosis. We studied the association between home incense use and the risk of chronic limb-threatening ischemia (CLTI), the most severe outcome of peripheral arterial disease.

Methods: We used data from the Singapore Chinese Health Study, which recruited 63,257 Chinese participants 45-74 years old from 1993-1998. Data were collected via in-person interviews conducted at the participants' homes by trained interviewers. Linkage to the nationwide hospital discharge database was used to determine incident cases, defined as participants who underwent revascularization or lower extremity amputation for CLTI. Association between use of incense and risk of CLTI was examined using multivariable Cox proportional hazards regression models, adjusted for demographics and cardiovascular risk factors.

Results: In this cohort, 76.9% were current users of incense at recruitment, and 92.6% of those used incense daily at home. During a mean 18.8 years of follow-up, 1,097 participants developed CLTI. Compared to never or former users, current users had a 22% higher risk of CLTI [hazard ratio $\left(\text{HR}\right)=1.22$; 95% confidence interval (CI): 1.04, 1.43]. The risk was greater with chronicity of use, and the HR was highest and statistically significant in participants who had used incense daily for $>40$ years [$\text{HR}=1.25$ (95% CI: 1.06, 1.46)]. The results did not differ by sex, history of diabetes, or smoking status.

Conclusions: Daily exposure to incense in the home environment for more than 40 years was associated with a greater risk of developing CLTI. https://doi.org/10.1289/EHP14674.

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: Chlorination is a widespread method for drinking water disinfection that has the drawback of introducing potentially carcinogenic chemical by-products to drinking water.

Objective: We systematically evaluated the epidemiologic evidence of exposure to trihalomethane (THM) disinfection by-products and risk of cancer.

Methods: We conducted a systematic review and meta-analysis of epidemiologic studies that assessed the association of exposure to residential concentrations of THMs with risk of cancer in adults. A protocol was preregistered in PROSPERO (CRD42023435491). PubMed, Embase, Web of Science, and Cochrane were searched for publications up to April 2024. Study selection and risk of bias appraisal using the National Toxicology Program Office of Health Assessment and Translation (NTP OHAT) tool was done in duplicate. Summary risk estimates were assessed using random effects meta-analysis and one-stage dose-response meta-analysis.

Results: The literature search resulted in 2,022 records, of which 29 publications assessing 14 different cancers were eligible for inclusion. Summary relative risks (RRs) were estimated for bladder cancer and colorectal cancer based on 5,860 and 9,262 cases and 84,371 and 90,272 participants, respectively. The summary RR of bladder cancer for the highest exposed compared with the lowest was 1.33 (95% CI: 1.04, 1.71), and in the dose-response analysis, RRs were statistically significant above THM concentrations of $41\mu g/L$. For colorectal cancer, the summary RR was 1.15 (95% CI: 1.07, 1.24).

Conclusion: According to the World Cancer Research Fund criteria, we found limited-suggestive evidence that THM in drinking water increases the risk of bladder and colorectal cancer at levels below current regulatory limits in the US and EU, indicating that these fail to protect against cancer in the general population. https://doi.org/10.1289/EHP14505.

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.