Deployment to Military Bases With Open Burn Pits and Respiratory and Cardiovascular Disease.

Importance: Many veterans who served in Afghanistan and Iraq during Operations Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) were deployed to military bases with open burn pits and exposed to their emissions, with limited understanding of the long-term health consequences. Objective: To determine the association between deployment to military bases where open burn pits were used for waste disposal and the subsequent risk of developing respiratory and cardiovascular diseases. Design, Setting, and Participants: This retrospective observational cohort study used Veterans Health Administration medical records and declassified deployment records from the Department of Defense to assess Army and Air Force veterans who were deployed between 2001 and 2011 and subsequently received health care from the Veterans Health Administration, with follow-up through December 2020. Data were analyzed from January 2023 through February 2024. Exposure: Duration of deployment to military bases with open burn pits. Main Outcomes and Measures: Diagnosis of asthma, chronic obstructive pulmonary disease, interstitial lung disease, hypertension, myocardial infarction, congestive heart failure, ischemic stroke, and hemorrhagic stroke. Results: The study population included 459 381 OEF and OIF veterans (mean [SD] age, 31.6 [8.7] years; 399 754 [87.0%] male). Median (IQR) follow-up from end of deployment was 10.9 (9.4-12.7) years. For every 100 days of deployment to bases with burn pits, veterans experienced increased adjusted odds for asthma (adjusted odds ratio [aOR], 1.01; 95% CI, 1.01-1.02), chronic obstructive pulmonary disease (aOR, 1.04; 95% CI, 1.02-1.07), hypertension (aOR, 1.02; 95% CI, 1.02-1.03), and ischemic stroke (aOR, 1.06; 95% CI, 0.97-1.14). Odds of interstitial lung disease, myocardial infarction, congestive heart failure, or hemorrhagic stroke were not increased. Results based on tertiles of duration of burn pit exposures were consistent with those from the continuous exposure measures. Conclusions and Relevance: In this cohort study, prolonged deployment to military bases with open burn pits was associated with increased risk of developing asthma, COPD, and hypertension. The results also point to a possible increased risk in ischemic stroke. The novel ability to use integrated data on deployment and health outcomes provides a model for additional studies of the health impact of environmental exposures during military service.

Evaluation of disposable protective garments against epoxy resin permeation and penetration from anti-corrosion coatings.

INTRODUCTION: Epoxy-based resin formulations are a frequent cause of allergic and irritant contact dermatitis in the construction and painting industries. Cases of epoxy resin contact dermatitis continue to persist across many sectors and are likely attributable to the growing use of epoxy products, including epoxy-based anti-corrosion coatings and inadequate skin protection. There are no published performance data against epoxy resins for garment materials and gloves to guide proper material selection in the workplace. OBJECTIVES: The objective of this study was to evaluate the resistance of 5 protective garment materials against permeation and penetration by bisphenol A diglycidyl ether and its higher oligomers found commonly in epoxy-based anti-corrosion coatings. METHODS: Five disposable garment materials were evaluated for resistance to bisphenol A diglycidyl ether monomers and oligomers during contact with epoxy-based anti-corrosion coatings, including latex gloves, nitrile gloves, Tyvek coveralls, polypropylene/polyethylene (PP/PE) coveralls, and a cotton T-shirt. A permeation test cell system was used to evaluate each garment material against an epoxy-based zinc-rich primer and an epoxy-based intermediate coating using a realistic application method. Glass fiber filters were used to collect permeating and penetrating epoxy resin during a 120-min test period. Bisphenol A diglycidyl ether quantification was performed with high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry. Paint loading, coating thickness, and homogeneity were assessed on polytetrafluoroethylene filters sprayed in series in permeation test cells. RESULTS: Latex gloves provided the least resistance to permeation by BADGE in coating formulations, with a maximum cumulative permeation over the 2-h test interval of 21.7 ng cm-2 with the primer and 513.8 ng cm-2 with the intermediate coating product. Nitrile gloves were not permeated by either coating formulation. The Tyvek coveralls provided greater protection as compared to the PP/PE coveralls. The cotton T-shirt was penetrated by bisphenol A diglycidyl ether more frequently than any of the tested garment materials and resulted in a maximum cumulative penetration of 128 ng cm-2 with the primer and 28.0 ng cm-2 with the intermediate coating. CONCLUSION: Although all the garment materials evaluated during this study provided sufficient protection to prevent cumulative permeation in excess of the established acceptable permeation thresholds, the use of nitrile gloves and Tyvek coverall is highly recommended to minimize skin exposure to bisphenol A diglycidyl ether. We recommend cotton T-shirts to be used under Tyvek coveralls as a secondary layer of skin protection and for added comfort, but not as a primary protection layer.

Air, Dermal, and Urinary Metabolite Levels of Backpack and Tractor Sprayers Using the Herbicide Acetochlor in Thailand.

Acetochlor is a chloroacetanilide selective pre-emergent herbicide used for controlling grass and broadleaf weeds in crops. This study compared the acetochlor exposures of backpack and tractor sprayers and assessed whether dermal or air exposures were more important contributors to the overall body burden as measured by urinary metabolites. Sixty sugarcane farmers in Nakhonsawan province, Thailand participated in the study, and breathing zone air and dermal patch samples were collected during spraying. Urine samples were collected before spraying, at the end of the spraying task, and on the day after spraying. For backpack and tractor sprayers, there was no significant difference in their breathing zone air concentrations, total body dermal samples, or urinary 2-methy-6-methyaniline (EMA) concentrations on the day after spraying. In addition, although most backpack and tractor sprayers wore long pants and long sleeve shirts, they were still exposed to acetochlor, as evidenced by a significant increase in the urinary EMA from before spraying (GM = 11.5 µg/g creatinine) to after spraying (GM = 88.5 µg/g creatinine) to the next day (GM = 111.0 µg/g creatinine). Breathing zone air samples were significantly correlated with those of total body dermal patch samples and with urinary EMA concentrations after spraying. This suggests that both air and dermal exposure contribute to urinary EMA levels.

Urinary Cypermethrin Metabolites among Conventional and Organic Farmers in Thailand.

Cypermethrin, a pyrethroid insecticide, is frequently spread on agricultural farmlands and is also used in households in Thailand. Conventional pesticide-using farmers (n = 209) were recruited from the Phitsanulok and Nakornsawan provinces. Certified organic farmers (n = 224) were also recruited in the Yasothorn province. The farmers were interviewed via a questionnaire and the urine from their first morning void was collected. The urine samples were analyzed for 3-phenoxybenzoic acid (3-PBA), cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (cis-DCCA), and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (trans-DCCA). The results showed no significant difference in the urinary cypermethrin metabolites between the conventional farmers and the organic farmers, for whom the usage of cypermethrin was not accounted for. However, when conventional farmers who used cypermethrin on the farm and in the home were compared with conventional farmers who did not use any cypermethrin or with organic farmers, a significant difference was noted for all metabolites except for trans-DCCA. These findings show that the most significant exposures to cypermethrin are among conventional farmers who use the insecticide on their farms or in their homes. However, measurable levels of all metabolites were found among both conventional and organic farmers who only used cypermethrin in the home or not at all, suggesting that the at-home use of pyrethroids and other possible exposures from pyrethroid residues on market-bought food may contribute to urinary levels of pyrethroids that exceed those of the general population in the US and Canada.

Burn Pit Exposure Assessment to Support a Cohort Study of US Veterans of the Wars in Iraq and Afghanistan.

OBJECTIVE: For a cohort study of veterans' health conditions, we conducted an exposure assessment for 109 bases in Iraq and Afghanistan and 17 outside transit site bases. METHODS: The Department of Defense records were used to determine burn pit usage and waste disposal methods for each base in each year during the period of 2001 to 2014. RESULTS: In the final cohort of 475,326 veterans, who had more than 80% of their deployment time characterized by our exposure matrix, only 14.5% were found to have no burn pit exposure. The 2009 Department of Defense regulations on burn pits did produce changes in waste segregation, as well as adding incineration and local disposal of waste. CONCLUSION: Most Iraq and Afghanistan veterans were stationed on bases that had burn pits, although the contents disposed of in the burn pits changed over time.

Phytoextraction Potential of Sunn Hemp, Sunflower, and Marigold for Carbaryl Contamination: Hydroponic Experiment.

The phytoextraction ability and responses of sunn hemp, sunflower, and marigold plants were investigated toward carbaryl insecticide at 10 mg L-1 and its degradative product (1-naphthol). All test plants exhibited significant carbaryl removal capability (65-93%) with different mechanisms. Marigold had the highest translocation factor, with carbaryl taken up, translocated and accumulated in the shoots, where it was biotransformed into 1-naphthol. Consequently, marigold had the least observable toxicity symptoms caused by carbaryl and the highest bioconcentration factor (1848), indicating its hyperaccumulating capability. Sunflower responded to carbaryl exposure differently, with the highest carbaryl accumulation (8.7 mg kg-1) in roots within 4 days of cultivation, leading to a partial toxicity effect. Sunn hemp exhibited severe toxicity, having the highest carbaryl accumulation (91.7 mg kg-1) that was biotransformed to 1-naphthol in the sunn hemp shoots. In addition, the different models were discussed on plant hormone formation in response to carbaryl exposure.

Prevalence and Factors Associated with Musculoskeletal Disorders among Thai Burley Tobacco Farmers.

This cross-sectional analysis study aimed to identify the prevalence and factors associated with musculoskeletal disorders (MSDs) among Thai Burley tobacco farmers. Subjects included 603 burley tobacco farmers from Sukhothai province. Farmers were interviewed twice, (during planting and harvesting seasons), with a questionnaire consisting of demographic and health characteristics, musculoskeletal symptoms, and ergonomic exposure questions. The subjects average age was 49.5 years, more were female (58.5%), most had only a primary education (74.3%), 38% were overweight or obese. Farmers had a significantly higher prevalence of MSDs in the lower back (37.1%), knee (28.7%), shoulder (22.9%), wrist (19.9%), and hip (8.3%) during the harvesting season than in the planting season (p < 0.05). Models found that factors influencing MSDs prevalence during planting included long work hours in seedling, tasks such as topping tobacco plants, and using machine tools, after controlling for age, gender, and body mass index (BMI). While in the harvesting season, models found tasks conducted as a group had lower MSDs prevalence than individual work when carrying fresh tobacco to the barn, piercing/threading and curing the leaves, baling the bundles, and transporting the finished goods. We recommended working in groups to reduce workload and MSDs, especially during harvesting, in burley tobacco farming.

Assessment of personal inhalation and skin exposures to polymeric methylene diphenyl diisocyanate during polyurethane fabric coating.

Methylene diphenyl diisocyanate (MDI) monomers and polymeric MDI (pMDI) are aromatic isocyanates widely used in the production of polyurethanes. These isocyanates can cause occupational asthma, hypersensitivity pneumonitis, as well as contact dermatitis. Skin exposure likely contributes toward initial sensitization but is challenging to monitor and quantitate. In this work, we characterized workers' personal inhalation and skin exposures to pMDI in a polyurethane fabric coating factory for subsequent health effect studies. Full-shift personal and area air samples were collected from eleven workers in representative job areas daily for 1-2 weeks. Skin exposure to hands was evaluated concomitantly with a newly developed reagent-impregnated cotton glove dosimeter. Samples were analyzed for pMDI by liquid chromatography-tandem mass spectrometry. In personal airborne samples, the concentration of 4,4'-MDI isomer, expressed as total NCO, had a geometric mean (GM) and geometric standard deviation (GSD) of 5.1 and 3.3 ng NCO/m3, respectively (range: 0.5-1862 ng NCO/m3). Other MDI isomers were found at much lower concentrations. Analysis of 4,4'-MDI in the glove dosimeters exhibited much greater exposures (GM: 10 ng/cm2) and substantial variability (GSD: 20 ng NCO/cm2; range: 0-295 ng NCO/cm2). MDI inhalation exposure was well below occupational limits for MDI for all the job areas. However, MDI skin exposure to hands was substantial. These findings demonstrated the potential for substantial isocyanate skin exposure in work settings with very low airborne levels. This exposure characterization should inform future studies that aim to assess the health effects of work exposures to MDI and the effectiveness of protective measures.

Pesticide residues on children's hands, home indoor surfaces, and drinking water among conventional and organic farmers in Thailand.

This study measured pesticide levels on children's hands, home indoor surfaces, and drinking water among Thai conventional and organic farm families in three provinces. Farm families in Nakhonsawan and Phitsanulok provinces were the conventional farmers and those in Yasothon province were the organic farmers. Samples were collected in the dry and wet seasons over 2 years (2017 and 2018). All samples were analyzed for organophosphates (OPs), carbamate, pyrethroid, triazines, glyphosate, and aminomethylphosphonic acid (AMPA). On children's hands, the highest concentrations for the 2 palmar surfaces were found for cypermethrin (7.46 µg) and fipronil (2.88 µg). On home surfaces of approximately 1000 cm2, the highest concentrations were found for cypermethrin (27.94 µg) and fipronil 49.76 µg)/1000 cm2. For the conventional farmers, the most common pesticides on children's hand wipes were cypermethrin and fipronil, which are used as in-home pesticides as well as agricultural pesticides. However, home surface wipes showed other pesticides associated with agriculture were presented in the home during the seasons when they were used, suggesting spray drift or carry home sources for these pesticides. During the wet season, pesticides were found in the drinking water of all provinces. Most common were fenitrothion, profenofos, fenthion, atrazine, and AMPA. Profenofos was found at levels above the health guidelines. During 2017, there was extensive flooding in Thailand which may have contributed to the drinking water contamination, even though most farmers report using tap water or bottled drinking water. Future work is needed to assess the risk of all sources of pesticide exposures in children and to repeat the drinking water pesticide contamination analysis.

Determinants of Hypertension amongst Rice Farmers in West Java, Indonesia.

The hypertension rate in Indonesia has increased significantly in the past five years, but there is limited information about the hypertension risk of farmers. Our study assesses the prevalence of hypertension in this population and examines the proportional risk of various work environment and lifestyle factors among farmers. A cross-sectional study was conducted in high and low heat stress agriculture areas of West Java, Indonesia. There were 354 male farmers aged 25 to 73 years old who participated in the study. We measured blood pressure and used a questionnaire on self-reported use of anti-hypertension drugs or diagnosis by a medical professional to define hypertension. We assessed occupational factors including farming methods, heat stress and pesticide use, and personal factors including obesity, food intake, smoking status, alcohol consumption. Multivariate analysis was used to evaluate factors potentially associated with prevalence of hypertension. Forty-six percent of farmers experience hypertension. Farming in a location with higher heat stress (WBGT) was significantly associated with increased risk of hypertension (adjusted prevalence ratio (aPR) 1.41, 95% confidence interval (CI) 1.01, 1.95). Farmers who used pesticide sprayers had an increased risk of hypertension (aPR 1.90, 95% CI 0.93, 3.87). No personal/lifestyle characteristics were significantly associated with hypertension, although ever smoking and ever consuming alcohol had an increased prevalence of hypertension. This study shows the importance of work environmental factors in the prevalence of hypertension and the necessity of public health education, identification and treatment of this "silent killer" among Indonesian farmers.

Pesticide exposure and risk of cardiovascular disease: A systematic review.

The increase in pesticide consumption has a negative health impact. Studies point to an association between exposure to pesticides and cardiovascular disease (CVD), one of the leading causes of world mortality. This review synthesize evidence on the association between occupational exposure and environmental contamination by pesticides with CVDs from 1750 references databases (EBSCO, Medline, Science Direct, Scielo, Lilacs and Ovid) without date or language restriction. Selected 24 articles by PRISMA and Downs & Black methodologies, were included from inclusion criteria: original studies (case-control, cohort or cross-sectional design); clear CVD definition and exposure to pesticides; representative sample of the target population. The results show the occupational exposure to pesticides chlorpyrifos, coumafos, carbofuran, ethylene bromide, mancozeb, ziram, metalaxyl, pendimethalin and trifluralin was associated a risk of 1.8 to 3.2 for acute myocardial infarction. Primaphos, fenitrothion, malathion and deltamethrin pesticides were associated with a blood pressure increase. Environmental contamination by tetrachlorodibenzo-p-dioxin was associated with CVD with risk of 1.09 to 2.78 and organochlorine, 1.19 to 4.54; heavy metals, arsenic, trimethylarsine and dimethylarsinic acid with atherosclerosis and systemic arterial hypertension. These findings point to the association between exposure to pesticides and CVD, signaling the importance of greater rigor in the public policy related to pesticides.

Risk factors associated with hand tractor related injuries among rice farmers in Thailand.

Hand tractors are important machines used in the soil preparation process before sowing rice in the paddy's of Thailand. Previous research on injuries in rice farming indicated that working with a hand tractor may be one of main causes of injuries. This study investigated the prevalence of hand tractor-related injuries, their association risk factors and characteristic of injuries. The data were collected by face-to-face interview to 377 farmers from nearly all districts in Phra Nakhon Si Ayutthaya province. Among these rice farmers, the prevalence of injury was 41%. The most common type of injury was cuts (43.9%) and the most common source of injuries was stepping on a golden apple snail shell (33.1%). The bivariate Poisson regression models showed that self-reported normal working conditions that were associated with the risk of injury included sleeping problems (RR = 1.39), "Hustle Work (working quickly to complete plowing)" (RR = 1.48), feeling fatigue before work (RR = 1.60), and normal use of a leveler as attached plow equipment (RR = 1.41). However, a multivariate model showed only normal use of a leveler as attached equipment was associated with an increased use of injuries (RR = 1.47) after controlling for the other factors that were significant in the bivariate models. These results suggest that job stress protection should be recommended or redesign of the leveler attachment developed for hand tractors used in rice paddy fields.

Urinary Organophosphate Metabolites and Metabolic Biomarkers of Conventional and Organic Farmers in Thailand.

Organophosphate (OP) pesticides are used by most farmers to remove insects and to increase productivity; however, questions remain on the long-term health impacts of their use. This study assessed the relationship between OP biomarker levels and metabolic biomarker parameters. Conventional farmers (n = 213) and organic farmers (n = 225) were recruited, interviewed, and had physical health examinations. Serum glucose and lipid profiles, triglycerides, total cholesterol, high-density lipoproteins (HDL), and low-density lipoproteins (LDL) were measured. The average age, gender, education, and self-reported agricultural work time, work in second jobs, smoking status, alcohol consumption, insecticide use at home, home location near farmlands and years of pesticide use were significantly different between the conventional and organic farmers. The urinary OP metabolite levels were also significantly different between the two groups. With an increase in urinary diethyl phosphate, dimethyl phosphate and dialkyl phosphate metabolites, the total cholesterol, LDL and HDL, were significantly increased for all farmers after controlling for age, gender, alcohol consumption, years of pesticide use, and home location near farmlands. The results are consistent with our previous studies which suggests that pesticide usage, especially organophosphates, may increase the risk of cardiovascular disease and stroke among Thai farmers.

Hydrogeogenic fluoride in groundwater and dental fluorosis in Thai agrarian communities: a prevalence survey and case-control study.

BACKGROUND: Dental fluorosis can be a disease of social inequity in access to safe drinking water. This dental public health issue becomes prominent in socially disadvantaged agrarian communities in fluoride endemic areas where the standard irrigation system is unavailable and groundwater containing natural fluoride is the major drinking water source. This study aimed to determine the prevalence and severity of dental fluorosis in children and to evaluate its association with fluoride in groundwater in the aforementioned setting in Thailand. METHODS: A cross-sectional survey of 289 children in Nakhon Pathom Province was conducted in 2015. Children with very mild to severe fluorosis were regarded as 'cases' while their counterparts were 'controls' for a subsequent case-control study. Records of fluoride concentrations in groundwater used for household supply corresponding to resident and number of years by age of each child during 2008-2015 were retrieved. Other exposure variables were measured using a questionnaire. Prevalence ratio (PR), a measure indicating the relative effect of different levels of fluoride on dental fluorosis, was obtained from Poisson regression with robust standard error. RESULT: There were 157 children with very mild to moderate dental fluorosis (54.3% prevalence). The univariable analysis revealed that the prevalence of dental fluorosis among children with fluoride concentrations in water sources of 0.7-1.49 (index category 1) and ≥ 1.5 ppm (index category 2) was 1.62 (95% CI; 0.78, 3.34) and 2.75 (95% CI; 1.42, 5.31) times the prevalence among those with fluoride < 0.7 ppm (referent category). After adjusting for all covariates, the adjusted prevalence ratios in both index categories were 1.64 (95% CI; 0.24, 11.24) and 2.85 (95% CI; 0.44, 18.52) which were close to their corresponding crude estimates. Since the magnitude of confounding, measured by (PRcrude-PRadjusted)/PRadjusted, were less than 10% for both index categories; this indicated the limited confounding effect of all covariates. CONCLUSIONS: In fluoride endemic areas, groundwater containing natural fluoride utilized for household consumption resulted in high dental fluorosis prevalence, particularly in the groundwater with fluoride concentrations of ≥ 1.5 ppm.

Estimating Occupational Exposure to VOCs, SVOCs, Particles and Participant Survey Reported Symptoms in Central Thailand Rice Farmers Using Multiple Sampling Techniques.

Thailand is known for its agricultural productivity and rice exportation. Most farms use small machines and manual labor, creating potential exposure to multiple health hazards. A cross-sectional study was conducted to measure pollutants liberated during preparation, pesticide application, and harvesting. Thirty rice farmers, mostly males from 41 to 50 years old, participated. The participant survey data showed that 53.3% of the respondents spent >2 h per crop on preparation, <1 h on pesticide application, and about 1-2 h harvesting; 86.7% of the respondents maintained and stored mechanical applicators at home, suggesting possible after-work exposures. Gloves, fabric masks, boots, and hats were worn during all activities, and >90% wore long sleeved shirts and pants. VOCs and SVOCs were collected using charcoal tubes and solid phase micro sample extraction (SPME). An analysis of the charcoal and SPME samplers found that 30 compounds were detected overall and that 10 were in both the charcoal tubes and SPME samplers. The chemicals most often detected were 1, 1, 1 Trichloro ethane and xylene. Additionally, farmers experienced the highest exposure to particulates during harvesting. These results demonstrated that farmers experience multiple exposures while farming and that risk communication with education or training programs may mitigate exposure.

Occupational hazards, health conditions and personal protective equipment used among healthcare workers in hospitals, Thailand.

This cross-sectional study aimed to evaluate occupational hazards, health conditions and personal protective equipment used among healthcare workers. Information from the sample size of 1,128 healthcare workers were collected using questionnaires. The healthcare workers participated in this study were from five departments including inpatient, outpatient, surgery and anesthesia, nutrition service and hospital support services departments in five hospitals in Thailand. The results indicated that the majority of healthcare workers were female; these healthcare workers work 9.0 to 11.1 hours/day on average and were exposed to several chemical, biological and physical hazards. The healthcare workers in the nutrition service department reported the highest percentage of musculoskeletal disorder and respiratory problems. The highest percentage of skin problems were reported by healthcare workers in surgery and anesthesia department. The results showed musculoskeletal disorder, respiratory and skin problem significantly differed among healthcare workers in the five departments including the wrists/hands (p = 0.024), upper back (p = 0.009), chest pain symptoms (p = 0.004), and dry/wound symptoms (p = 0.013). Healthcare workers did not have adequate protection from work-related hazards in their workplace. Health education programs, control measures and organizational policies should be implemented to mitigate the hazards for healthcare workers in hospitals.

Urinary glyphosate biomonitoring of sprayers in vegetable farm in Thailand.

In Thailand, glyphosate is popular herbicide to control pests in the agricultural sector. This study aimed to measure glyphosate exposure concentrations through inhalation, dermal contact, and urinary glyphosate concentrations among 43 vegetable farmers spraying glyphosate in Bungphra Subdistrict, Phitsanulok Province. Four types of spraying equipment were used, manual pump backpack (n = 3), motorized spray backpack (n = 22), battery pump backpack (n = 16), and high pressure pump (n = 2). Breathing zone air samples were collected using glass fiber filters; dermal contact samples were collected using 100 cm2 cotton patches attached on 10 body locations and urine samples were collected at 3 time points: morning void urine the day before spraying, the end of spraying event, and the morning void urine the next day of spraying. The results showed that the geometric mean (GM; geometric standard deviation [GSD]) of breathing zone concentrations of glyphosate exposure were 9.37 (10.17) µg/m3. The GM (GSD) of total dermal patches exposure concentrations were 7.57 (0.01) mg/h. The legs, back, and arms were the most exposed body areas. The GM (GSD) of urinary glyphosate was found highest among vegetable farmers using manual backpack 46.90 (1.35) µg/g creatinine. Farmers should wear masks and boots to reduce glyphosate exposure by inhalation and dermal contact.

Genetic Polymorphisms of Pesticide-Metabolizing Enzymes and Transporters in Agricultural Workers and Thyroid Hormone Levels.

PURPOSE: Chronic exposure to pesticides has been associated with thyroid dysfunction owing to their endocrine disruption ability. Genetic variations in genes encoding phase I and II enzymes and phase III transporters are partly responsible for individual responses to chemical pesticides. This study investigated the association between variations in genes involved in pesticide metabolism and altered thyroid hormone concentrations. METHODS: We assessed thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) in organic agriculture workers (n = 216) and workers who used chemical pesticides (n = 229). A questionnaire was used to collect sociodemographic, pesticide exposure, and health status data. Blood samples were analyzed for TSH, FT3, and FT4. Genomic DNA was extracted and genotyped using the TaqMan real-time PCR genotyping assay and restriction fragment length polymorphism method for 15 metabolically related genes. RESULTS: Significant differences in the TSH (1.58 vs 1.12 µIU/mL) and FT3 (0.34 vs 0.31 ng/dL) concentrations between the chemical and organic worker groups were observed. The frequencies of all single nucleotide polymorphisms were in Hardy-Weinberg equilibrium and were mostly consistent with Asian populations. The findings showed the association between SNPs of enzymes and transporters and TSH, FT3, and FT4. The odd ratio and adjusted odd ratio (with sex, age, smoking status, alcohol consumption and exposure parameters) for subclinical thyroid disease by the variant alleles CYP1A1 rs1048943, CYP2B6 rs2279343, CYP2C19 rs4244285, NAT2 rs1799931, and PON1 rs662 in the chemical workers compared with the organic workers were found (P values < 0.05). CONCLUSION: This is the first study to assess gene-environment interactions in Thai agricultural workers by investigating disruptions of the hypothalamic-pituitary-thyroid axis. The investigated SNP profiles revealed several gene-thyroid hormone associations in which even low levels of pesticide exposure could disturb thyroid homeostasis. These findings provide a foundation for planning future studies investigating associations between complex diseases and occupational pesticide exposure.

Comparison of Thyroid Hormone Levels between Women Farmers and Non-Farmers in Banten Indonesia.

Pesticides are suspected of being endocrine disruptors. This cross-sectional study measured serum samples for levels of thyroid hormones including thyroid stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), free T3 (FT3), and free T4 (FT4) among Indonesian female farmers (n = 127) and non-farmers (n = 127). A questionnaire was used to collect information on demographics and risk factors including work characteristics and frequency, and the use of home and agricultural pesticides. Results showed that there were no significant differences in the distribution of the clinical categories of thyroid levels between farmers and non-farmers except for FT3 and T4. However, in multivariable regression controlling for confounders, FT3 and T4 were significantly higher for farmers compared to non-farmers. In addition, 32% of farmers had clinically low iodine levels and 49% of non-farmers had clinically high iodine levels. We conclude that pesticide exposure may not be as important as iodine intake in explaining these findings. We recommend counseling by health workers about the importance of using iodized salt for farmers and counseling about high iodine foods that need to be avoided for non-farmers.