Occupational Chemical Exposures Research Articles

Recruitment strategies for studying occupational and environmental chemical exposures in a community-based birth cohort study in Ecuador

Recruitment strategies for studying occupational and environmental chemical exposures in a community-based birth cohort study in Ecuador

Environmental risk score of multiple pollutants for kidney damage among residents in vulnerable areas by occupational chemical exposure in Korea

This study aimed to develop an environmental risk score (ERS) of multiple pollutants (MP) causing kidney damage (KD) in Korean residents near abandoned metal mines or smelters and evaluate the association between ERS and KD by a history of occupational chemical exposure (OCE). Exposure to MP, consisting of nine metals, four polycyclic aromatic hydrocarbons, and four volatile organic compounds, was measured as urinary metabolites. The study participants were recruited from the Forensic Research via Omics Markers (FROM) study (n = 256). Beta-2-microglobulin (β2-MG), N-acetyl-β-D-glucosaminidase (NAG), and estimated glomerular filtration rate (eGFR) were used as biomarkers of KD. Bayesian kernel machine regression (BKMR) was selected as the optimal ERS model with the best performance and stability of the predicted effect size among the elastic net, adaptive elastic net, weighted quantile sum regression, BKMR, Bayesian additive regression tree, and super learner model. Variable importance was estimated to evaluate the effects of metabolites on KD. When stratified with the history of OCE after adjusting for several confounding factors, the risks for KD were higher in the OCE group than those in the non-OCE group; the odds ratio (OR; 95% CI) for ERS in non-OCE and OCE groups were 2.97 (2.19, 4.02) and 6.43 (2.85, 14.5) for β2-MG, 1.37 (1.01, 1.86) and 4.16 (1.85, 9.39) for NAG, and 4.57 (3.37, 6.19) and 6.44 (2.85, 14.5) for eGFR, respectively. We found that the ERS stratified history of OCE was the most suitable for evaluating the association between MP and KD, and the risks were higher in the OCE group than those in the non-OCE group.

Increased cancer risk in HIV-infected individuals occupationally exposed to chemicals: Depression of p53 as the key driver.

The growing exposure to occupational chemicals and the spread of human immunodeficiency virus (HIV) infection are major global health issues. However, there is little data on the carcinogenic risk profile of HIV-infected individuals who have been occupationally exposed to chemical mixtures. This study therefore investigated the levels of cancer risk biomarkers in HIV-infected individuals exposed to occupational chemicals, exploring the relationship between apoptotic regulatory and oxidative response markers as a measure of cancer risk. Study participants (mean age 38.35±0.72 years) were divided into four groups according to their HIV status and occupational chemical exposure: 62 HIV-positive exposed (HPE), 66 HIV-positive unexposed (HPU), 60 HIV-negative exposed (HNE), and 60 HIV-negative unexposed (HNU). Serum p53, β-cell lymphoma-2 (bcl2), 8-hydroxydeoxyguanosine (8-OHdG), superoxide dismutase (SOD), and malondialdehyde (MDA) were measured using standard methods. Clusters of differentiation 4 (CD4+) T-lymphocytes were enumerated using flow cytometry. Serum p53 and bcl2 levels in HPE (0.91±0.11ng/ml and 122.37±15.77ng/ml) were significantly lower than HNU (1.49±0.15ng/ml and 225.52±33.67ng/ml) (p < 0.05), respectively. Wildtype p53 and bcl2 were positively and significantly correlated with 8-OHdG (r = 0.35, p<0.001; r = 0.36, p<0.001) and SOD (r = 0.38, p<0.001; r = 0.39, p<0.001). After controlling for gender, age, BMI, and cigarette smoking, both HIV status and SOD activity were significantly associated with wildtype p53 and bcl2 (p < 0.05). Malondialdehyde was significantly higher in the HPE (0.72 ± 0.01 mg/ml) than in the HNE (0.68 ± 0.01 mg/ml) and HNU (0.67 ± 0.01 mg/ml) groups (p < 0.05). The HPE group showed significantly lower CD4 counts than the HNE and HNU groups. Individuals who are HIV-infected and occupationally exposed to chemicals have a constellation of depressed immunity, elevated oxidative stress, and loss of tumour suppressive functions, which together intensify cancer risk, providing valuable scientific and public health bases for preventive measures in this vulnerable population.

Characterizing the Burden of Occupational Chemical Exposures by Sociodemographic Groups in the United States, 2021.

Objectives. To estimate the number and prevalence of workers in the United States exposed to chemical hazards available in the Canadian job-exposure matrix (CANJEM) database and examine exposure disparities across sociodemographic groups. Methods. We merged US worker demographic data from the Current Population Survey with CANJEM to characterize the burden and sociodemographic distribution of 244 chemical exposures in the United States in 2021. An interactive version of the full data set is available online (https://deohs.washington.edu/us-exposure-burden). Results. Of the chemical exposures examined, the most prevalent were cleaning and antimicrobial agents (14.7% of workforce estimated exposed), engine emissions (12.8%), organic solvents (12.1%), polycyclic aromatic hydrocarbons (10.1%), and diesel engine emissions (8.3%). Racial and ethnic minoritized groups, persons with lower educational attainment, foreign-born noncitizens, and males were generally overrepresented in exposure to work-related chemical hazards. Conclusions. In the United States, marginalized sociodemographic groups are estimated to experience an inequitable burden to many chemical exposures because of occupational segregation. Data from this analysis can inform occupational and public health research, policy, and interventions aimed at reducing the burden of disease and health inequities in the United States. (Am J Public Health. 2024;114(1):57-67. https://doi.org/10.2105/AJPH.2023.307461).

Investigation of the Relationship between Spontaneous Abortion, Serum Pesticides, and Polychlorinated Biphenyl Levels.

Occupational and environmental chemical exposure have been associated with adverse reproductive consequences. This study investigates the relationship between spontaneous abortion and blood pesticide and polychlorinated biphenyl (PCB) levels. A survey was conducted, and blood samples were collected from 200 patients, consisting of 100 cases with spontaneous abortion and 100 cases with normal deliveries. A total of 150 different pesticides, including organophosphates, organochlorines, carbamates, and pyrethroids, were screened in the collected blood samples and analyzed quantitatively using Tandem mass spectrometry-specifically in combination with liquid chromatography and gas chromatography-tandem mass spectrometry methods. Eight types of PCBs were analyzed with the gas chromatography-tandem mass spectrometry method. The groups were compared based on these analyses. The mean age of the participants was 28.09 ± 4.94 years. In 59% of the spontaneous abortion group, 5.05 ± 1.97 chemicals were detected in different amounts. (p < 0.05). Analysis of the samples identified the presence of β-Hexachlorocyclohexane (β-HCH), delta-hexachlorocyclohexane (δ HCH), Hexachlorobenzene (HCB), Pentachlorobiphenyl-28 (PCB-28), Pentachlorobiphenyl-52 (PCB-52), o,p'-Dichlorodiphenyldichloroethylene (o,p'-DDE), p,p'-Dichlorodiphenyldichloroethylene (p,p'DDE), o,p'-Dichlorodiphenyldichloroethane (o,p'-DDD), p,p'-Dichlorodiphenyldichloroethane (p,p'-DDD), Pentachlorobiphenyl-118 (PCB-118), Pentachlorobiphenyl-101 (PCB-101), Pentachlorobiphenyl-153 (PCB-153), Pentachlorobiphenyl-138 (PCB-138), Pentachlorobiphenyl-202 (PCB-202), Pentachlorobiphenyl-180 (PCB-180) as well as Fibronil, Buprimate, Acetoclor, Acemiprid, Pentimanthalin, and Triflokystrobin. The spontaneous abortion group had significantly higher exposure to PCB-101, PCB-52, PCB-138, and δ-HCH (p < 0.05). Women included in the study had high pesticide and PCB exposure rates. Many of the blood samples contained multiple pesticides with endocrine-disrupting effects. Higher exposure to organochlorine compounds in the serum was identified in the group with spontaneous abortions.

Occupational exposure to potentially toxic elements alters gene expression profiles in formal and informal Brazilian workers

Chemical elements, such as toxic metals, have previously demonstrated their ability to alter gene expression in humans and other species. In this study, microarray analysis was used to compare the gene expression profiles of different occupational exposure populations: a) informal workers who perform soldering of jewelry inside their houses (n = 22) in São Paulo (SP) State; and b) formal workers from a steel company (n = 10) in Rio de Janeiro (RJ) state, Brazil. Control participants were recruited from the same neighborhoods without occupational chemical exposure (n = 19 in SP and n = 8 in RJ). A total of 68 blood samples were collected and RNA was extracted and hybridized using an Agilent microarray platform. Data pre-processing, statistical and pathway analysis were performed using GeneSpring software. Different expression was detected by fold-change analysis resulting in 16 up- and 33 down-regulated genes in informal workers compared to the control group. Pathway analysis revealed genes enriched in MAPK, Toll-like receptor, and NF-kappa B signaling pathways, involved in inflammatory and immune responses. In formal workers, 20 up- and 50 down-regulated genes were found related to antimicrobial peptides, defensins, neutrophil degranulation, Fc-gamma receptor-dependent phagocytosis, and pathways associated with atherosclerosis development, which is one of the main factors involved in the progression of cardiovascular diseases. The gene IFI27 was the only one commonly differentially expressed between informal and formal workers and is known to be associated with various types of cancer. In conclusion, differences in gene expression related to occupational exposure are mainly associated with inflammation and immune response. Previous research has identified a link between inflammation and immune responses and the development of chronic diseases, suggesting that prolonged occupational exposures to potentially toxic elements in Brazilian metal workers could lead to negative health outcomes. Further analysis should be carried out to investigate its direct effects and to validate causal associations.

Association between maternal occupational exposure to cleaning chemicals during pregnancy and childhood wheeze and asthma.

Asthma is a leading cause of childhood morbidity in the U.S. and a significant public health concern. The prenatal period is a critical window during which environmental influences, including maternal occupational exposures, can shape child respiratory health. Cleaning chemicals are commonly encountered in occupational settings, yet few studies have examined the potential link between prenatal occupational exposures to cleaning chemicals and risk of childhood wheeze and asthma. We evaluated the potential influence of maternal occupational exposure to cleaning chemicals during pregnancy on pediatric asthma and wheeze at child age 4-6 years in 453 mother-child pairs from two longitudinal pregnancy cohorts, TIDES and GAPPS, part of the ECHO prenatal and early childhood pathways to health (ECHO-PATHWAYS) consortium. Maternal occupational exposure to cleaning chemicals was defined based on reported occupation and frequency of occupational use of chemicals during pregnancy. Child current wheeze and asthma outcomes were defined by parental responses to a widely-used, standardized respiratory outcomes questionnaire administered at child age 4-6 years. Multivariable Poisson regression with robust standard errors was used to estimate relative risk (RR) of asthma in models adjusted for confounding. Effect modification by child sex was assessed using product interaction terms. Overall, 116 mothers (25.6%) reported occupational exposure to cleaning chemicals during pregnancy, 11.7% of children had current wheeze, and 10.2% had current asthma. We did not identify associations between prenatal exposure to cleaning chemicals and current wheeze [RRadjusted 1.03, 95% confidence interval (CI): 0.56, 1.90] or current asthma (RRadjusted 0.89, CI: 0.46, 1.74) in the overall sample. Analyses of effect modification suggested an adverse association among females for current wheeze (RR 1.82, CI: 0.76, 4.37), compared to males (RR 0.68, CI: 0.29, 1.58), though the interaction p-value was >0.05. We did not observe evidence of associations between maternal prenatal occupational exposure to cleaning chemicals and childhood wheeze or asthma in the multi-site ECHO-PATHWAYS consortium. We leveraged longitudinal U.S. pregnancy cohorts with rich data characterization to expand on limited and mixed literature. Ongoing research is needed to more precisely characterize maternal occupational chemical exposures and impacts on child health in larger studies.

Parental occupational exposure to chemicals and risk of breast cancer in female offspring

ObjectivesParental exposure to chemicals at work has been hypothesized to be a potential predisposing factor for breast cancer in next generations. The objective of the present nationwide nested case-control study was to contribute with evidence to this area. MethodsWomen with primary breast cancer were identified using the Danish Cancer Registry and they were required to have information on either maternal or paternal employment history, which resulted in the inclusion of 5587 cases. For each case, 20 female cancer free controls were matched on year of birth using the Danish Civil Registration System. Employment history was linked to job exposure matrices to assess specific occupational chemical exposures. ResultsFor maternal exposures, we observed an association between ever exposure to diesel exhaust (OR = 1.13, 95% CI: 1.01–1.27) and exposure to bitumen fumes in the perinatal period (OR = 1.51, 95% CI: 1.00–2.26) and breast cancer in female offspring. Highest cumulative exposure to benzo(a)pyrene, diesel exhaust, gasoline and bitumen fumes was further indicated to increase the risk. Results further indicated a stronger association between diesel exhaust (OR = 1.23, 95% CI: 1.01–1.50) and benzo(a)pyrene exposure (OR = 1.23, 95% CI: 0.96–1.57) and estrogen receptor negative tumors than tumors with ER expression, while bitumen fumes seemed to elevate the risk of both hormonal subtypes. For paternal exposures, the main results did not indicate any associations with breast cancer in female offspring. ConclusionsOur study suggests an elevated breast cancer risk in daughters of women occupational exposed to some occupational pollutants, including diesel exhaust, benzo(a)pyrene and bitumen fumes. These findings need to be confirmed in future large-scale studies before any firm conclusions can be reached.

Association between Occupational Chemical Exposure and Sperm Parameters; A Narrative Review

Association between Occupational Chemical Exposure and Sperm Parameters; A Narrative Review

Ambient Environmental Ozone and Variation of Fractional Exhaled Nitric Oxide (FeNO) in Hairdressers and Healthcare Workers

Fractional exhaled nitric oxide (FeNO) is a breath-related biomarker of eosinophilic asthma. The aim of this study was to investigate FeNO variations due to environmental or occupational exposures in respiratory healthy subjects. Overall, 14 hairdressers and 15 healthcare workers in Oslo were followed for 5 workdays. We registered the levels of FeNO after commuting and arriving at the workspace and after ≥3 h of work, in addition to symptoms of cold, commuting method, and hair treatments that were performed. Both short- and intermediate-term effects after exposure were evaluated. Environmental assessment of daily average levels of air quality particulate matter 2.5 (PM2.5), particulate matter 10 (PM10), nitrogen dioxide (NO2), sulphur dioxide (SO2), and ozone (O3) indicated a covariation in ozone and FeNO in which a 35-50% decrease in ozone was followed by a near 20% decrease in FeNO with a 24-h latency. Pedestrians had significantly increased FeNO readings. Symptoms of cold were associated with a significant increase in FeNO readings. We did not find any FeNO increase of statistical significance after occupational chemical exposure to hair treatments. The findings may be of clinical, environmental and occupational importance.

Implementing a suspect screening method to assess occupational chemical exposures among US-based hairdressers serving an ethnically diverse clientele: a pilot study.

There are over 700,000 hairdressers in the United States, and it is estimated that >90% are female and 31% are Black or Hispanic/Latina. Racial and ethnic minorities in this workforce may be exposed to a unique mixture of potentially hazardous chemicals from products used and services provided. However, previous biomonitoring studies of hairdressers target a narrow list of compounds and few studies have investigated exposures among minority hairdressers. To assess occupational chemical exposures in a sample of US-based Black and Latina hairdressers serving an ethnically diverse clientele by analyzing urine specimens with a suspect screening method. Post-shift urine samples were collected from a sample of US female hairdressers (n = 23) and office workers (n = 17) and analyzed via reverse-phase liquid chromatography coupled to high-resolution mass spectrometry. Detected compounds were filtered based on peak area differences between groups and matching with a suspect screening list. When possible, compound identities were confirmed with reference standards. Possible exposure sources were evaluated for detected compounds. The developed workflow allowed for the detection of 24 compounds with median peak areas ≥2x greater among hairdressers compared to office workers. Product use categories (PUCs) and harmonized functional uses were searched for these compounds, including confirmed compounds methylparaben, ethylparaben, propylparaben, and 2-naphthol. Most product use categories were associated with "personal use" and included 11 different "hair styling and care" product types (e.g., hair conditioner, hair relaxer). Functional uses for compounds without associated PUCs included fragrance, hair and skin conditioning, hair dyeing, and UV stabilizer. Our suspect screening approach detected several compounds not previously reported in biomonitoring studies of hairdressers. These results will help guide future studies to improve characterization of occupational chemical exposures in this workforce and inform exposure and risk mitigation strategies to reduce potential associated work-related health disparities.

Comparison of agreement in asthmagen exposure assessments between rule-based automatic algorithms and a job exposure matrix in healthcare workers in Australia and Bhutan

Background:Assessment of occupational exposures is an integral component of population-based studies investigating the epidemiology of occupational diseases. However, all the available methods for exposure assessment have been developed, tested and used in high-income countries. Except for a few studies examining pesticide exposures, there is limited research on whether these methods are appropriate for assessing exposure in LMICs. The aim of this study is to compare a task-specific algorithm-based method (OccIDEAS) to a job-specific matrix method (OAsJEM) in the assessment of asthmagen exposures among healthcare workers in a high-income country and a low- and middle- income country (LMIC) to determine an appropriate assessment method for use in LMICs for future research.Methods:Data were obtained from a national cross-sectional survey of occupational asthmagens exposure in Australia and a cross-sectional survey of occupational chemical exposure among Bhutanese healthcare workers. Exposure was assessed using OccIDEAS and the OAsJEM. Prevalence of exposure to asthmagens and inter-rater agreement were calculated.Results:In Australia, the prevalence was higher for a majority of agents when assessed by OccIDEAS than by the OAsJEM (13 versus 3). OccIDEAS identified exposures to a greater number of agents (16 versus 7). The agreement as indicated by κ (Cohen’s Kappa coefficient) for six of the seven agents assessed was poor to fair (0.02 to 0.37). In Bhutan, the prevalence of exposure assessed by OccIDEAS was higher for four of the seven agents and κ was poor for all the four agents assessed (-0.06 to 0.13). The OAsJEM overestimated exposures to high-level disinfectants by assigning exposures to all participants from 10 (Bhutan) and 12 (Australia) ISCO-88 codes; whereas OccIDEAS assigned exposures to varying proportions of participants from these ISCO-codes.Conclusion:There was poor to fair agreement in the assessment of asthmagen exposure in healthcare workers between the two methods. The OAsJEM overestimated the prevalence of certain exposures. As compared to the OAsJEM, OccIDEAS appeared to be more appropriate for evaluating cross-country exposures to asthmagens in healthcare workers due to its inherent quality of assessing task-based determinants and its versatility in being adaptable for use in different countries with different exposure circumstances.

Development of environmental risk score of the biomarker for chronic kidney disease in residents exposed to pollutant mixtures

BACKGROUND AND AIM: To develop an environmental risk score (ERS) of biomarkers for chronic kidney disease (CKD) in residents exposed to multipollutant. METHOS: Multipollutant with nine metals, four PAH metabolites, and four VOC metabolites measured in urine was constructed from the Forensic Research via Omics Markers (FROM) study in Korea (n=298). Beta-2-microglobulin (β2-MG), N-acetyl-β-D-glucosaminidase (NAG), and estimate glomerular filtration rate (eGFR) were used as CKD markers. Optimal models were selected among elastic net models (ENET), adaptive elastic net models (AENET), weighted quantile sum regression (WQS), Bayesian weighted quantile sum regression (BWQS), Bayesian kernel machine regression (BKMR), Bayesian additive regression tree (BART), and super learner (SL) by comparing mean squared error adjusted for sex and age. The selected models were stratified with a history of occupational chemical exposure (OCE) and additionally adjusted for urinary cotinine level. Variable importance (VI) was estimated to evaluate the associations between each pollutant and biomarkers of CKD. RESULTS: The performance of ERS based on BKMR was the best-fitting model and ERS based on SL or BART performed better than other models. The model with BKMR could not be used due to overfitting as the number of covariates increased. When stratified with a history of OCE, the most effective metabolites for β2-MG, NAG, and eGFR were Sb (VI=0.47), Hg (VI=0.13), and Pb (VI=0.34) in the non-OCE group, and V (VI=0.39), Hg (VI=1.19), and 1-ohp (VI=0.10) in the OCE group, respectively. CONCLUSION: This study suggests that ERS, especially the SL and BART model, stratified with a history of OCE were fitted when evaluating the association between multipollutant and CKD. KEYWORDS: Metals, multipollutant, environmental risk score, machine learning, kidney disease The Korea Environment Industry and Technology Institute through the Core Technology Development Project for Environmental Disease Prevention and Management, funded by the Korea Ministry of Environment (grant number 2021003320003).

Microbiome alterations from volatile organic compounds (VOC) exposures among workers in salons primarily serving women of color

Salon workers, especially those serving an ethnically and racially diverse clientele (i.e., Black/Latina), may experience disparately high levels of workplace exposures to respiratory irritants, including volatile organic compounds (VOCs). Salon workers are also reported to have a greater risk of developing respiratory conditions compared to the general population. Emerging evidence suggests that occupational chemical exposures may alter the human microbiome and that these alterations may be an important mechanism by which workplace VOC exposures adversely impact respiratory health. This preliminary research investigated the potential effects of 28 VOC urinary biomarkers on the 16S rRNA nasal microbiome in 40 workers from salons primarily serving women of color (Black and Dominican salons) compared to office workers. Our exploratory analysis revealed significant differences in microbial composition by worker group; namely dissimilar levels of Staphylococcus species (S. epidermidis and S. aureus, specifically) in salon workers compared to office workers, and higher alpha diversity levels in workers in Dominican salons compared to workers in Black salons. Within-sample alpha diversity levels tended to be decreased with higher VOC urinary biomarker concentrations, significantly for carbon disulfide, acrolein, acrylonitrile, crotonaldehyde, and vinyl chloride biomarkers. Our research highlights that occupational exposures, particularly to chemicals like VOCs, can impact the respiratory microbiome in the vulnerable salon worker group. Further understanding of the potential effects of chemical mixtures on microbial composition may provide key insights to respiratory health and other adverse health outcomes, as well as direct prevention efforts in this largely historically understudied occupational population.

Urinary Metabolites of Polycyclic Aromatic Hydrocarbons in Firefighters: A Systematic Review and Meta-Analysis.

Firefighters are intermittently exposed to complex, mixed pollutants in random settings. Of those pollutants, PAHs (polycyclic aromatic hydrocarbons) are the most commonly studied and best understood. PAH exposure can occur via multiple routes; therefore, the levels of hydroxylated metabolites of PAHs in urine have been used as a biomonitoring tool for risk assessment. We performed a systematic review and meta-analysis of the literature to estimate the levels of urinary hydroxylated PAH (OHPAH) among firefighters, determine risk attributions, and, finally, evaluate the scope of preventive efforts and their utility as diagnostic tools. The meta-regression confirmed increases in OHPAH concentrations after fire activities by up to 1.71-times (p-values: <0.0001). Samples collected at a time point of 2–4 h after a fire suppression showed a consistent, statistically significant pattern as compared with baseline samples. The National Fire Protection Association (NFPA) standard 1582 Standard on Comprehensive Occupational Medical Program for Fire Departments lists various health examinations, including a urinalysis for occupational chemical exposure if indicated and medical screening for cancers and cardiovascular diseases. Biomonitoring is a valuable screening tool for assessing occupational exposure and the results of this meta-analysis support their inclusion in regular health screenings for firefighters.

Chemical pollutants in closed environments of transportation and storage of non-dangerous goods – Insufficient legislation, low awareness, and poor practice in Hungary

ABSTRACT Several chemical pollutants can accumulate within the closed environments of transportation and storage. Pollutants are mainly residues of pesticides, volatile organic compounds and components of diesel exhaust. The study objectives were to (i) review the regulations relevant to occupational chemical exposures in closed environments of inland transportation and storage; and (ii) explore the practice of preventing these exposures. A systematic search and content analysis of international and Hungarian nation legal documents were carried out. In addition, semi-structured interviews with occupational health and safety (OHS) professionals and warehouse managers were conducted. Analysis of legal documents highlighted the lack of explicit regulations on the investigated problem. The 21 interviews revealed that the participants had limited knowledge about the pollutants; they deemed chemical exposure rare and related health effects negligible. The revealed limitations indicate that this field should be more specifically regulated and OHS professionals should be better informed about these workplace hazards.

Environmental neurotoxicants and inflammasome activation in Parkinson's disease - A focus on the gut-brain axis.

Inflammasomes are multi-protein complexes expressed in immune cells that function as intracellular sensors of environmental, metabolic and cellular stress. Inflammasome activation in the brain, has been shown to drive neuropathology and disease progression by multiple mechanisms, making it one of the most attractive therapeutic targets for disease modification in Parkinson's Disease (PD). Extensive inflammasome activation is evident in the brains of people with PD at the sites of dopaminergic degeneration and synuclein aggregation. While substantial progress has been made on validating inflammasome activation as a therapeutic target for PD, the mechanisms by which inflammasome activation is triggered and sustained over the disease course remain poorly understood. A growing body of evidence point to environmental and occupational chemical exposures as possible triggers of inflammasome activation in PD. The involvement of the gastrointestinal system and gut microbiota in PD pathophysiology is beginning to be elucidated, especially the profound link between gut dysbiosis and immune activation. While large cohort studies confirmed specific changes in the gut microbiota in PD patients compared to age-matched healthy controls, recent research suggest that synuclein pathology could be initiated in the gastrointestinal tract. In this review, we present a summarized perspective on current understanding on inflammasome activation and the gut-brain-axis link during PD pathophysiology. We discuss multiple environmental toxicants that are implicated as the etiological agents in causing idiopathic PD and their mechanistic underpinnings during neuroinflammatory events. We additionally present future directions that needs to address the research questions related to the gut-microbiome-brain mechanisms in PD.

Effects of occupational chemical exposure on the reproductive system

Effects of occupational chemical exposure on the reproductive system

522Occupational chemical exposures in pregnancy and fetal growth: evidence from the Born in Bradford Study

Abstract Background Understanding the effect of occupational exposure to endocrine disrupting chemicals (EDC) during pregnancy on inadequate fetal growth as measured by small-for-gestational age (SGA) and as measured by percentage of optimal birth weight (POBW) is not well understood. Methods We studied 4142 pregnant women who were in paid employment during pregnancy and participated in a population-based, prospective 2007–2011 birth cohort study, the Born in Bradford Study, with an estimated participation of 80%. Job titles were coded at 26–28 weeks' gestation at a 4-digit level according to 353 unit groups in the 2000 UK Standard Occupational Classification. They were then linked to expert judgment on exposure to each of ten EDC groups as assessed through a job exposure matrix. A modified Poisson regression was used to assess the risk of POBW and SGA associated with an increased risk of chemical exposures. Results The frequency of POBW&amp;lt;85 significantly increased for mothers exposed to pesticides [adjusted risk ratio (RRadj) 3.72, 95% confidence interval (CI) 1.40–9.91] and phthalates (RRadj 3.71, 95% CI 1.62–8.51). There was a 5-fold increase risk of SGA for mothers exposed to pesticides (RRadj 5.45, 95% CI 1.59–18.62). Veterinary nurses and horticultural trades were most frequently associated with exposure to pesticides while hairdressers, beauticians, and printing machine minders were associated with phthalates. Conclusion Maternal occupational exposure to estimated concentrations of pesticides and phthalates is associated with impaired fetal growth. Key messages The POBW is useful in measuring inadequate fetal growth in study of occupational chemical exposures.

Occupational exposure to potentially toxic elements in home-based and informal workers

BACKGROUND AND AIM: Biological matrices, such as blood, can be used to monitor occupational exposure to potentially toxic elements (PTEs). This research intended to evaluate the PTEs exposure in informal outsourced workers from Limeira–SP, Brazil, who perform jewelry soldering in the home environment. METHODS: Sixty-six individuals from the exposed group (informal workers and families) and 49 controls (without occupational chemical exposure) were included. As, Mn, Ni, Cd, Sb, Sn, Cu, Zn, Pb, and Hg concentrations in blood was determined by inductively coupled plasma mass spectrometry. Health information was collected using a questionnaire. RESULTS:Most participants were adults (53.9%), all those were female aged 19 to 62 years, and children and adolescents (1-18 years old) were 50.9% male and 49.1% female. No significant differences were found between the groups for smoking, exercise, medication consumption, educational level, and skin color variables (p0.05). Alcohol consumption (p=0.02; 60% of the exposed workers reported consuming alcohol) and time residing in the region (p=0.0005; 80.6% of the exposed group lived in the region for more than 15 years) were statistically significant variables. Among the health responses, only the symptom of shortness of breath showed a statistically significant difference between the groups (p=0.004; 88.9% of the exposed participants reported experiencing shortness of breath frequently). Although we did not have observed differences for respiratory diseases, 40.9% of the participants reported having bronchitis, asthma, or upper respiratory tract infection. Blood PTEs concentrations proved to be higher in the exposure group for As (0.44 µg L-1), Cd (0.21 µg L-1) and Pb (1.88 µg L-1) compared to controls (As=0.35 µgL-1, Cd=0.01 µgL-1, Pb=1.04 µgL-1). CONCLUSIONS:The workers and relatives constitute a particular risk group because of the home environment with uncontrolled occupational activity. The higher concentrations of PTEs in exposed population raises a concern and may impact health outcomes. Funded by FAPESP (#2018/18391-0; #2017/25424-9; #2017/20752-8). KEYWORDS: Biomonitoring, Occupational Exposure, Toxic Elements, Informality, Health