Associations of serum persistent organic pollutant concentrations with incident diabetes in midlife women: The Study of Women's Health Across the Nation Multi-Pollutant Study.

BACKGROUND: Organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs) are persistent organic pollutants (POPs) that can negatively impact metabolic health through pathways including endocrine disruption. Few studies have evaluated diabetes risk associated with PBDEs. Little is known about the joint effect of exposure to POP mixtures on diabetes risk. OBJECTIVES: We investigated the relationship between POPs, individually and as mixtures, and diabetes development over 18 years (1999-2016) in midlife women. METHODS: We measured lipid-standardized serum concentrations of 34 PCBs, 19 OCPs, and 14 PBDEs in 1040 midlife women aged 45-56 years from the Study of Women's Health Across the Nation. We tested the association between POPs measured in 1999/2000 and incident diabetes using Cox proportional hazards models. We evaluated diabetes risk associated with the overall POP mixture using Quantile-Based G-Computation (QBGC). RESULTS: For most mixture components, single pollutant and mixtures analyses indicated null associations with diabetes risk, however results were inconsistent. After adjustment, hazard ratios (HRs) of developing diabetes (95% CI) associated with upper exposure tertiles (T2/T3) compared with the first tertile (T1), were 1.7 (1.0, 2.8) at T2 and 1.5 (0.84, 2.7) at T3 for hexachlorobenzene and 1.9 (1.1, 3.3) at T2 and 1.6 (0.88, 2.9) at T3 for PCB 123. A doubling of PBDE 47 was associated with 1.11 (1.00, 1.24) times the risk of T2D. QBGC identified no association for the overall joint effect of the POP mixture on diabetes (HR = 1.04 [0.53, 2.07]). CONCLUSION: Exposure to a mixture of PCBs, OCPs, and PBDEs was not associated with incident diabetes in midlife U.S. women, although some individual POPs demonstrated significant yet inconsistent associations with diabetes. Non-linear and non-monotonic dose-response dynamics deserve further exploration. More research is needed on the diabetogenic effects of PBDEs.

Development and performance of an analytical method for polychlorinated naphthalenes and other persistent organic pollutants in dried blood spots.

BACKGROUND: Dried blood spots (DBSs) collected and archived in newborn screening programs (NSP) represent a potentially valuable resource for assessing exposure to a range of organic and inorganic chemicals in newborns. This study develops and optimizes a method to measure polychlorinated naphthalenes (PCNs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochlorine pesticides (OCPs) in DBS using the isotope dilution technique, ultrasonic-assisted liquid-liquid extraction, simple cleanup, triple quadrupole GC-MS/MS analysis, and background correction. RESULTS: We minimize the number of extraction repetitions and the volume of solvent, which helps increase throughput while minimizing the potential for contamination. We obtained high recovery and precision for most compounds, and method detection limits (MDLs) were sufficiently low to detect the more prevalent compounds based on representative sample of the US population. MDLs averaged 0.020 ng/mL (recovery: 107 %, precision: 4 %) for PCNs, 0.021 ng/mL (recovery: 97 %, precision: 4 %) for PCBs, 0.021 ng/mL (recovery: 117 %, precision: 2 %) for OCPs, and 0.021 ng/mL (recovery: 96 %, precision: 3 %) for PBDEs. SIGNIFICANCE AND NOVELTY: To our knowledge, this is the first study presenting an analytical method and for PCNs in DBS, and one of the few studies providing an assessment of method performance for persistent organic pollutants in DBS. The optimized method can be applied to a wide range of applications, including exposure assessment, environmental epidemiology, forensics, environmental surveillance, and ecological monitoring.

Cross-shift changes in pulmonary function and occupational exposure to particulate matter among e-waste workers in Ghana.

Introduction: Little is known on the association between cross-shift changes in pulmonary function and personal inhalation exposure to particulate matter (PM) among informal electronic-waste (e-waste) recovery workers who have substantial occupational exposure to airborne pollutants from burning e-waste. Methods: Using a cross-shift design, pre- and post-shift pulmonary function assessments and accompanying personal inhalation exposure to PM (sizes <1, <2.5 µm, and the coarse fraction, 2.5-10 µm in aerodynamic diameter) were measured among e-waste workers (n = 142) at the Agbogbloshie e-waste site and a comparison population (n = 65) in Accra, Ghana during 2017 and 2018. Linear mixed models estimated associations between percent changes in pulmonary function and personal PM. Results: Declines in forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) per hour were not significantly associated with increases in PM (all sizes) among either study population, despite breathing zone concentrations of PM (all sizes) that exceeded health-based guidelines in both populations. E-waste workers who worked "yesterday" did, however, have larger cross-shift declines in FVC [-2.4% (95%CI: -4.04%, -0.81%)] in comparison to those who did not work "yesterday," suggesting a possible role of cumulative exposure. Discussion: Overall, short-term respiratory-related health effects related to PM exposure among e-waste workers were not seen in this sample. Selection bias due to the "healthy worker" effect, short shift duration, and inability to capture a true "pre-shift" pulmonary function test among workers who live at the worksite may explain results and suggest the need to adapt cross-shift studies for informal settings.

Determinants of urinary dialkyl phosphate metabolites in midlife women: the Study of Women's Health Across the Nation Multi-Pollutant Study (SWAN-MPS).

BACKGROUND: Biomonitoring data and determinants of urinary dialkylphosphate (DAP) metabolites, markers of organophosphate pesticides, in racially diverse, non-occupationally exposed populations are scarce. OBJECTIVE: This study evaluated urinary concentrations and potential determinants of DAP metabolites of organophosphate pesticides in a multi-site, multi-racial/ethnic cohort of women aged 45-56 years, the Study of Women's Health Across the Nation Multi-Pollutant Study (SWAN-MPS). METHODS: We analyzed 963 urine samples collected in 1999-2000, the baseline of SWAN-MPS for longitudinal studies, and quantified DAP metabolites, including dimethyl alkylphosphates (DMAPs): dimethylphosphate (DMP), dimethylthiophosphate (DMTP), dimethyldithiophosphate (DMDTP); and diethyl alkylphosphates (DEAPs): diethylphosphate (DEP), diethylthiophosphate (DETP), diethyldithiophosphate (DEDTP), using gas chromatography and triple quadrupole mass spectroscopy. Adjusted least squared geometric means (LSGMs) and 95% confidence intervals (CIs) were computed to compare DAP concentrations by socio-demographic, behavioral and dietary factors. RESULTS: The geometric means (geometric standard deviations) of total DAPs, DMAPs, and DEAPs were 141 (2.63) nmol/L, 102 (2.99) nmol/L, and 26.8 (2.46) nmol/L, respectively. Body mass index (BMI) was inversely associated with DMAPs and DEAPs: LSGM (95% CI) = 68.8 (55.7-84.9) and 21.0 (17.7-25.0) nmol/L for women with obesity vs. 102 (84.7-123) and 30.1 (25.7-35.1) nmol/L for women with normal/underweight, respectively. Fruit consumption was positively (74.9 (62.1-90.2) for less than 5-6 servings/week vs. 105 (84.8-130) nmol/L for 1 serving/day and more) whereas meat consumption was inversely associated with DMAPs (110 (95.0-128) for seldom vs. 82.3 (59.5-114) nmol/L for often consumption). Fresh apple consumption appears to be attributed to the DMAP differences. Alcohol consumption was positively associated with DEAPs (27.5 (23.1-32.7) for 2 drinks/week and more vs. 23.0 (20.0-26.6) nmol/L for less than 1 drink/month). Black women had higher concentrations of DEAPs compared with White women (27.3 (21.2-35.2) vs. 23.2 (20.2-26.7) nmol/L). IMPACT STATEMENT: Organophosphate pesticides (OPs) are synthetic chemicals and currently the most widely used type of insecticides. We examined multi-site, multi-ethnic cohort of midlife women in the U.S. that offers a unique opportunity to evaluate major determinants of OP exposure. We improved OP metabolite detection rates and obtained accurate concentrations using an improved analytical technique. Our findings suggest that consumptions of fruit, meat and alcohol are important determinants of OP exposure for midlife women. Higher concentrations of diethyl OP metabolites in Black women compared to White women, even after accounting for dietary intake, suggests additional, but unknown racial-ethnic differences that affect exposure.

Changes in Adipose Tissue and Circulating Concentrations of Persistent Organic Pollutants in Midlife Women.

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) are persistent organic pollutants (POPs) that bioaccumulate in adipose tissue. We investigated the relationship between change in central adiposity and changes in circulating concentrations of POPs over a 12-year period during the midlife. Serum concentrations of 34 PCBs and 19 OCPs were measured at four time points (1999/2000, 2002/03, 2005/06, 2009/11) in a cohort of midlife women, the Study of Women's Health Across the Nation. Linear mixed models were used to test the association between a change in waist circumference and a change in serum POP concentrations. Sixty-five women contributed 181 PCB observations. Fifty-nine women contributed 151 OCP observations. After adjustment for covariates (study site, race and ethnicity, age at baseline, parity), a one-inch (2.54 cm) increase in the change in waist circumference between visits was associated with a 4.9% decrease in the change in serum concentration of PCB 194 (95% CI: -8.0%, -1.6%). No associations were observed for other PCB congeners or the presence of OCPs. An increase in the difference in waist circumference over time was not associated with a change in the difference in serum concentrations of PCBs and OCPs except for PCB 194, possibly due to the high lipophilicity.

Residential exposure associations with ALS risk, survival, and phenotype: a Michigan-based case-control study.

Background: Environmental exposures impact amyotrophic lateral sclerosis (ALS) risk and progression, a fatal and progressive neurodegenerative disease. Better characterization of these exposures is needed to decrease disease burden. Objective: To identify exposures in the residential setting that associate with ALS risk, survival, and onset segment. Methods: ALS and control participants recruited from University of Michigan completed a survey that ascertained exposure risks in the residential setting. ALS risk was assessed using logistic regression models followed by latent profile analysis to consider exposure profiles. A case-only analysis considered the contribution of the residential exposure variables via a Cox proportional hazards model for survival outcomes and multinomial logistic regression for onset segment, a polytomous outcome. Results: This study included 367 ALS and 255 control participants. Twelve residential variables were associated with ALS risk after correcting for multiple comparison testing, with storage in an attached garage of chemical products including gasoline or kerosene (odds ratio (OR) = 1.14, padjusted < 0.001), gasoline-powered equipment (OR = 1.16, padjusted < 0.001), and lawn care products (OR = 1.15, padjusted < 0.001) representing the top three risk factors sorted by padjusted. Latent profile analysis indicated that storage of these chemical products in both attached and detached garages increased ALS risk. Although residential variables were not associated with poorer ALS survival following multiple testing corrections, storing pesticides, lawn care products, and woodworking supplies in the home were associated with shorter ALS survival using nominal p values. No exposures were associated with ALS onset segment. Conclusion: Residential exposures may be important modifiable components of the ALS susceptibility and prognosis exposome.

Metal mixtures associate with higher amyotrophic lateral sclerosis risk and mortality independent of genetic risk and correlate to self-reported exposures: a case-control study.

Background: The pathogenesis of amyotrophic lateral sclerosis (ALS) involves both genetic and environmental factors. This study investigates associations between metal measures in plasma and urine, ALS risk and survival, and exposure sources. Methods: Participants with and without ALS from Michigan provided plasma and urine samples for metal measurement via inductively coupled plasma mass spectrometry. Odds and hazard ratios for each metal were computed using risk and survival models. Environmental risk scores (ERS) were created to evaluate the association between exposure mixtures and ALS risk and survival and exposure source. ALS (ALS-PGS) and metal (metal-PGS) polygenic risk scores were constructed from an independent genome-wide association study and relevant literature-selected SNPs. Results: Plasma and urine samples from 454 ALS and 294 control participants were analyzed. Elevated levels of individual metals, including copper, selenium, and zinc, significantly associated with ALS risk and survival. ERS representing metal mixtures strongly associated with ALS risk (plasma, OR=2.95, CI=2.38-3.62, p<0.001; urine, OR=3.10, CI=2.43-3.97, p<0.001) and poorer ALS survival (plasma, HR=1.42, CI=1.24-1.63, p<0.001; urine, HR=1.52, CI=1.31-1.76, p<0.001). Addition of the ALS-PGS or metal-PGS did not alter the significance of metals with ALS risk and survival. Occupations with high potential of metal exposure associated with elevated ERS. Additionally, occupational and non-occupational metal exposures associated with measured plasma and urine metals. Conclusion: Metals in plasma and urine associated with increased ALS risk and reduced survival, independent of genetic risk, and correlated with occupational and non-occupational metal exposures. These data underscore the significance of metal exposure in ALS risk and progression.

Avocational exposure associations with ALS risk, survival, and phenotype: A Michigan-based case-control study.

INTRODUCTION: Environmental exposures strongly influence ALS risk and identification is needed to reduce ALS burden. Participation in hobbies and exercise may alter ALS risk and phenotype, warranting an assessment to understand their contribution to the ALS exposome. METHODS: Participants with ALS and healthy controls were recruited from University of Michigan and self-completed a survey to ascertain hobbies, exercise, and avocational exposures. Exposure variables were associated with ALS risk, survival, onset segment, and onset age. RESULTS: ALS (n = 400) and control (n = 287) participants self-reported avocational activities. Cases were slightly older (median age 63.0 vs. 61.1 years, p = 0.019) and had a lower educational attainment (p < 0.001) compared to controls; otherwise, demographics were well balanced. Risks associating with ALS after multiple comparison correction included golfing (odds ratio (OR) 3.48, padjusted = 0.004), recreational dancing (OR 2.00, padjusted = 0.040), performing gardening or yard work (OR 1.71, padjusted = 0.040) five years prior to ALS and personal (OR 1.76, padjusted = 0.047) or family (OR 2.21, padjusted = 0.040) participation in woodworking, and personal participation in hunting and shooting (OR 1.89, padjusted = 0.040). No exposures associated with ALS survival and onset. Those reporting swimming (3.86 years, padjusted = 0.016) and weightlifting (3.83 years, padjusted = 0.020) exercise 5 years prior to ALS onset had an earlier onset age. DISCUSSION: The identified exposures in this study may represent important modifiable ALS factors that influence ALS phenotype. Thus, exposures related to hobbies and exercise should be captured in studies examining the ALS exposome.

Environmental risk scores of persistent organic pollutants associate with higher ALS risk and shorter survival in a new Michigan case/control cohort.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a fatal, progressive neurogenerative disease caused by combined genetic susceptibilities and environmental exposures. Identifying and validating these exposures are of paramount importance to modify disease risk. We previously reported that persistent organic pollutants (POPs) associate with ALS risk and survival and aimed to replicate these findings in a new cohort. METHOD: Participants with and without ALS recruited in Michigan provided plasma samples for POPs analysis by isotope dilution with triple quadrupole mass spectrometry. ORs for risk models and hazard ratios for survival models were calculated for individual POPs. POP mixtures were represented by environmental risk scores (ERS), a summation of total exposures, to evaluate the association with risk (ERSrisk) and survival (ERSsurvival). RESULTS: Samples from 164 ALS and 105 control participants were analysed. Several individual POPs significantly associated with ALS, including 8 of 22 polychlorinated biphenyls and 7 of 10 organochlorine pesticides (OCPs). ALS risk was most strongly represented by the mixture effects of OCPs alpha-hexachlorocyclohexane, hexachlorobenzene, trans-nonachlor and cis-nonachlor and an interquartile increase in ERSrisk enhanced ALS risk 2.58 times (p<0.001). ALS survival was represented by the combined mixture of all POPs and an interquartile increase in ERSsurvival enhanced ALS mortality rate 1.65 times (p=0.008). CONCLUSIONS: These data continue to support POPs as important factors for ALS risk and progression and replicate findings in a new cohort. The assessments of POPs in non-Michigan ALS cohorts are encouraged to better understand the global effect and the need for targeted disease risk reduction strategies.

Volatile Organic Compounds in Disposable Diapers and Baby Wipes in the US: A Survey of Products and Health Risks.

Many thousands of diapers are worn by young children and the elderly, who have thin and sensitive skin that is highly vulnerable to chemicals, including volatile organic compounds (VOCs) that may be ingredients of these products or present as inadvertent or residual components. The levels and potential health risks of VOCs in diapers have not been reported previously. In this study, we collected 31 disposable hygiene products in the US market based on market share and analyzed 98 target VOCs using purge and trap sampling and thermal desorption/gas chromatography/mass spectrometer analysis. Exposures and risks were modeled using reasonable upper level exposure scenarios. Adult diapers contained the highest total target VOC concentration (median level of 23.5 µg/g), and the predominant VOCs were alkanes. In some diapers, the estimated noncancer risk from these VOCs was sometimes very large (hazard quotient of 1609) due to n-heptane. Baby diapers contained several known or suspected carcinogens, including benzene and 1,4-dioxane, and the lifetime cancer risk from some diapers approached 1 per million under a worst-case scenario. Store-brand products had higher levels of VOCs than generic brands, and products labeled "organic" or "for sensitive skin" did not necessarily have lower levels. Our results show that toxic VOCs were found in all tested disposable diapers and wipes at trace levels, and risks from using some diapers in high use exposure scenarios are high enough to warrant additional attention and possibly corrective measures. We recommend eliminating and monitoring toxic ingredients and disclosing all chemicals that may be in these products.

Community's Perception on Ambient Air and Noise Pollution: A Qualitative Study in Southwest Detroit.

Background: Low-income urban communities of color, specifically African American and Hispanic populations living in industrial areas, are disproportionately affected by environmental health hazards, including exposure to air pollution and noise. In Southwest Detroit, a densely populated area with extensive industry and traffic, many residents are chronically exposed to air and noise pollution, contributing to a high prevalence of chronic illnesses such as asthma and cardiovascular disease. Materials and Methods: To better understand environmental health concerns and perceptions of environmental hazards, we conducted phone interviews with 22 residents in Southwest Detroit. During the interviews, participants were asked to reflect on reports of air and noise pollution based on monitoring inside and outside of their home, how their health might be affected, and to identify their main environmental health concerns. Results: Through qualitative analysis of phone interview notes, we identified truck traffic and inadequate mitigation efforts as concerns for Southwest Detroit residents. Our results suggested that study participants are aware of their disproportionate exposures to air and noise pollution and that while some residents are actively involved in environmental justice efforts, additional structural preventive measures including reduced pollutant emissions, are necessary to preserve public health. Conclusion: This study demonstrates that residents of Southwest Detroit are aware of high levels of both air pollutants and noise and perceive environmental exposures as critical components affecting health, both key aspects of environmental health literacy. This awareness, along with policy change, can facilitate community involvement in evaluating, understanding, and potentially abating air and noise pollution among minority populations.

Low level exposure to hydrogen sulfide: a review of emissions, community exposure, health effects, and exposure guidelines.

Hydrogen sulfide (H2S) is a toxic gas that is well-known for its acute health risks in occupational settings, but less is known about effects of chronic and low-level exposures. This critical review investigates toxicological and experimental studies, exposure sources, standards, and epidemiological studies pertaining to chronic exposure to H2S from both natural and anthropogenic sources. H2S releases, while poorly documented, appear to have increased in recent years from oil and gas and possibly other facilities. Chronic exposures below 10 ppm have long been associated with odor aversion, ocular, nasal, respiratory and neurological effects. However, exposure to much lower levels, below 0.03 ppm (30 ppb), has been associated with increased prevalence of neurological effects, and increments below 0.001 ppm (1 ppb) in H2S concentrations have been associated with ocular, nasal, and respiratory effects. Many of the studies in the epidemiological literature are limited by exposure measurement error, co-pollutant exposures and potential confounding, small sample size, and concerns of representativeness, and studies have yet to consider vulnerable populations. Long-term community-based studies are needed to confirm the low concentration findings and to refine exposure guidelines. Revised guidelines that incorporate both short- and long-term limits are needed to protect communities, especially sensitive populations living near H2S sources.

Occupational history associates with ALS survival and onset segment.

OBJECTIVE: To identify associations between occupational settings and self-reported occupational exposures on amyotrophic lateral sclerosis (ALS) survival and phenotypes. METHODS: All patients seen in the University of Michigan Pranger ALS Clinic were invited to complete an exposure assessment querying past occupations and exposures. Standard occupational classification (SOC) codes for each job and the severity of various exposure types were derived. Cox proportional hazards models associated all-cause mortality with occupational settings and the self-reported exposures after adjusting for sex, diagnosis age, revised El Escorial criteria, onset segment, revised ALS Functional Rating Scale (ALSFRS-R), and time from symptom onset to diagnosis. Multinomial logistic regression models with three categories, adjusted for age, assessed the association between occupational settings and exposures to onset segment. RESULTS: Among the 378 ALS participants (median age, 64.7 years; 54.4% male), poorer survival was associated with work in SOC code "Production Occupations" and marginally with work in "Military Occupation"; poor survival associated with self-reported occupational pesticide exposure in adjusted models. Among onset segments: cervical onset was associated with ALS participants having ever worked in "Buildings and Grounds Cleaning and Maintenance Occupations," "Construction and Extraction Occupations," and "Production Occupations"; bulbar onset with self-reported occupational exposure to radiation; and cervical onset with exposure to particulate matter, volatile organic compounds, metals, combustion and diesel exhaust, electromagnetic radiation, and radiation. CONCLUSION: Occupational settings and self-reported exposures influence ALS survival and onset segment. Further studies are needed to explore and understand these relationships, most advantageously using prospective cohorts and detailed ALS registries.

Integrating Interprofessional Collaborative Practice Into Occupational and Environmental Health and Safety Education: Results of a Feasibility Study.

OBJECTIVE: Although occupational health and safety programs are expected to prepare graduates to function in an interprofessional collaborative environment, research to support training in this area is far less common in this discipline than among clinical programs. We incorporated interprofessional education (IPE) competencies into an occupational health and safety course for graduate students in diverse disciplines (public health, engineering, nursing) and evaluated effectiveness. METHODS: We assessed course offerings for content learning and attitudes toward IPE and analyzed data using a mixed-methods approach. RESULTS: In general, students increased their understanding of the role of other disciplines, confidence in working in interprofessional teams, and valuation of IPE. CONCLUSION: Introducing IPE competencies into graduate education in worker health and safety is feasible and can equip students to more effectively work in occupational health-oriented multidisciplinary teams.

Association between toxic and essential metals in blood and global DNA methylation among electronic waste workers in Agbogbloshie, Ghana.

Aberrant global DNA methylation status is a known biomarker for increased disease risk, especially cancer. There is little published data on the association between toxic and essential metal mixtures and global DNA methylation in electronic waste (e-waste) workers. We aimed to establish the association between toxic and essential metals in blood and the effect of their interactions on global DNA methylation among e-waste recyclers and a reference group in Ghana. We used ICP-MS to measure the level of five metals (Se, Zn, Mn, Cd, and Pb) in the blood of 100 e-waste workers and 51 controls. We quantified blood DNA methylation levels of LINE-1 as an indicator of global DNA methylation. Cd, Mn, and Se levels were significantly higher in the reference group than in e-waste workers. Only Pb was significantly higher in the e-waste workers compared to the controls. Our linear regression analysis results showed a significant inverse association between Zn and LINE-1 DNA methylation (ßZn = - 0.912; 95% CI, - 1.512, - 0.306; p = 0.003) which corresponds to a 0.009 decrease in %LINE-1 methylation (95% CI, - 0.015, - 0.003; p = 0.003) for a 1% increase in Zn concentration. Potential interactions between Cd and Zn on global DNA methylation were observed. In summary, co-exposure to toxic and essential metals is associated with global (LINE-1) DNA methylation.

Associations of self-reported occupational exposures and settings to ALS: a case-control study.

BACKGROUND: Environmental exposures contribute to the pathogenesis of amyotrophic lateral sclerosis (ALS), a fatal and progressive neurological disease. Identification of these exposures is important for targeted screening and risk factor modification. OBJECTIVE: To identify occupational exposures that are associated with a higher risk of ALS using both survey and standard occupational classification (SOC) coding procedures, and to highlight how exposure surveys can complement SOC coding. METHODS: ALS participants and neurologically healthy controls recruited in Michigan completed a detailed exposure assessment on their four most recent and longest held occupations. Exposure scores were generated from the exposure survey, and occupations were assigned to SOC codes by experienced exposure scientists. RESULTS: This study included 381 ALS and 272 control participants. ALS participants reported higher duration-adjusted occupational exposure to particulate matter (OR = 1.45, 95% CI 1.19-1.78, p < 0.001), volatile organic compounds (OR = 1.22, 95% CI 1.02-1.45, p = 0.029), metals (OR = 1.48, 95% CI 1.21-1.82, p < 0.001), and combustion and diesel exhaust pollutants (OR = 1.20, 95% CI 1.01-1.43, p = 0.041) prior to ALS diagnosis, when adjusted for sex, age, and military service compared to controls. In multivariable models, only occupational exposure to metals remained significant risk (OR = 1.56, 95% CI 1.11-2.20, p = 0.011), although in an adaptive elastic net model, particulate matter (OR = 1.203), pesticides (OR = 1.015), and metals (1.334) were all selected as risk factors. Work in SOC code "Production Occupations" was associated with a higher ALS risk. SOC codes "Building and Grounds Cleaning and Maintenance Occupations", "Construction and Extraction Occupations", "Installation, Maintenance, and Repair Occupations", and "Production Occupations" were all associated with a higher exposure to metals as determined using survey data. DISCUSSION: Occupational exposure to particulate matter, volatile organic compounds, metals, pesticides, and combustion and diesel exhaust and employment in "Production Occupations" was associated with an increased ALS risk in this cohort.

Perfluoroalkyl Substances and Incident Natural Menopause in Midlife Women: The Mediating Role of Sex Hormones.

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) have been associated with earlier natural menopause; however, the underlying mechanisms are not well understood, particularly the extent to which this relationship is mediated by sex hormones. We analyzed data (1999-2017) on 1,120 premenopausal women from the Study of Women's Health Across the Nation (SWAN). Causal mediation analysis was applied to quantify the degree to which follicle-stimulating hormone (FSH) and estradiol levels could mediate the associations between PFAS and incident natural menopause. Participants with higher PFAS concentrations had shorter times to natural menopause, with a relative survival of 0.82 (95% confidence interval (CI): 0.69, 0.96) for linear perfluorooctane sulfonate (n-PFOS), 0.84 (95% CI: 0.69, 1.00) for sum of branched-chain perfluorooctane sulfonate (Sm-PFOS), 0.79 (95% CI: 0.66, 0.93) for linear-chain perfluorooctanoate (n-PFOA), and 0.84 (95% CI: 0.71, 0.97) for perfluorononanoate (PFNA), comparing the highest tertile of PFAS concentrations with the lowest. The proportion of the effect mediated through FSH was 8.5% (95% CI: -11.7, 24.0) for n-PFOS, 13.2% (95% CI: 0.0, 24.5) for Sm-PFOS, 26.9% (95% CI: 15.6, 38.4) for n-PFOA, and 21.7% (6.8, 37.0) for PFNA. No significant mediation by estradiol was observed. The effect of PFAS on natural menopause may be partially explained by variations in FSH concentrations.

Health benefits from cleaner vehicles and increased active transportation in Seattle, Washington.

BACKGROUND: Climate mitigation policies that focus on the transportation sector yield near-term health co-benefits that could motivate policy action. OBJECTIVE: We quantified CO2 emission reductions as well as the air pollution and health benefits of urban transportation policies promoting electric vehicles (EV) and walking and bicycling in Seattle, Washington. METHODS: We compared a business-as-usual scenario projected to 2035 with intervention scenarios in which 35% of gasoline vehicles were switched to EV, and 50% of car trips less than 8 kilometers were replaced by walking or bicycling. We modeled changes in primary traffic-generated oxides of nitrogen (NOx) and fine particulate matter (PM2.5) as well as walking and bicycling activity, CO2 emissions from traffic, and fatal traffic injuries due to the transportation policy scenarios. We estimated the impacts of these changes on annual cases of asthma and premature mortality in the Seattle population. RESULTS: Increasing the use of EV, walking, and bicycling is estimated to reduce CO2 emissions by 744 tons/year (30%) and lower annual average concentrations of primary traffic-generated NOx and PM2.5 by 0.32 ppb (13%) and 0.08 µg/m3 (19%), respectively. In Seattle, the lower air pollutant concentrations, greater active transportation, and lower fatal traffic injuries would prevent 13 (95% CI: -1, 28), 49 (95% CI: 19, 71), and 5 (95% CI: 0, 14) premature deaths per year, respectively and 20 (95% CI: 8, 27) cases of asthma per year. SIGNIFICANCE: Moving towards cleaner vehicles and active transportation can reduce CO2 emissions, improve air quality, and population health. The resulting public health benefits provide important motivation for urban climate action plans. IMPACT STATEMENT: Using key components of the health impact assessment framework, we quantify the environmental and health benefits of urban transportation policy scenarios that promote electric vehicle use and replace short car trips with walking and bicycling as compared with a business as usual scenario in 2035. Our findings demonstrate that transportation scenarios promoting cleaner vehicles and active transportation can reduce CO2 emissions, improve air quality, and increase physical activity levels, resulting in significant public health benefits.

Be alert for vapor intrusion of 1,4-dioxane from contaminated groundwater.

Vapor intrusion (VI) poses significant environmental problems that can degrade indoor air and pose human health risks. This study focuses on 1,4-dioxane, a widely-used volatile organic compound (VOC) that is found in groundwater, however, this compound has not received much attention in indoor air and measurement methods are not well developed. 1,4-dioxane is sufficiently volatile and highly mobile in groundwater, and thus can present a VI risk. In this study, we develop a sensitive analytical method for quantifying airborne 1,4-dioxane, provide a performance evaluation of the method, and initiate preliminary field measurements above a 1,4-dioxane groundwater plume. The method uses passive sampling, automated thermal desorption, and gas chromatography/mass spectroscopy. Numerous other VOCs can be simultaneously measured. A low detection limit (0.067 µg/m3) is attained, which allows quantification at concentrations below health-based guidelines. The performance evaluation suggests limits to sampling times in high humidity environments and other means to ensure good performance. The scenario analyses demonstrate potential impacts from shallow plumes, especially in flooded basements, and thus monitoring of 1,4-dioxane vapor intrusion in the flood season is an urgent need.

Occupational exposures to particulate matter and PM2.5-associated polycyclic aromatic hydrocarbons at the Agbogbloshie waste recycling site in Ghana.

Electronic waste (e-waste) disposal and recycling activities such as burning and smelting can emit particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), and other pollutants that expose workers and nearby communities. At informal e-waste recycling facilities, both emission controls and protective measures for workers are absent. This study characterizes personal exposures (breathing zone) of PM and PAHs of e-waste workers at the large Agbogbloshie e-waste site in Accra, Ghana. We collected gravimetric and optical measurements of PM2.5 and PM10 using shift samples for workers and for an age- and gender-matched reference population. PM2.5 filters were analyzed for 26 PAHs using gas chromatography/mass spectroscopy. Among e-waste workers, PM2.5 and PM10 concentrations were 99 ± 56 and 218 ± 158 µg/m3 (median ± interquartile range, optical measurements), respectively; these levels were 78 and 57% higher, respectively, than levels measured at a fixed site that was centrally located at the waste site. In the reference community, breathing zone PM2.5 and PM10 levels were lower, 49 ± 20 and 131 ± 108 µg/m3, respectively, and the fraction of coarse PM was larger. We detected all 26 target PAHs, of which naphthalene and phenanthrene were the most abundant. PAH concentrations were weakly correlated to PM levels, but PAH abundances, representing the fraction of PAH mass to the total PM2.5 mass collected, were strongly and inversely correlated to PM levels, suggesting multiple and different sources of PAHs and PM that affected exposures. Both PM and PAH levels were elevated for workers performing burning and dismantling, and both exceeded standards or risk-based guidelines, e.g., lifetime excess cancer risks for several PAHs were in the 10-4 to 10-6 range, indicating the need to reduce emissions as well as provide respiratory protection. The study emphasizes the importance of using personal and shift samples to accurately characterize worker exposure.