Mental Health Disorders among Thai Farmers: Occupational and Non-Occupational Stressors.

This cross-sectional study aimed to identify occupational and non-occupational factors that impact levels of stress, depression, and anxiety among farmers located in the northern part of Thailand, including the potential psychological impacts of pesticide use. The participants (N=270) were interviewed with a survey adopted and modified from peer-reviewed articles and questionnaires. The survey consists of four parts, including demographic information and pesticide exposure; perceived farm stressors employing Farm Stressor Survey (FSS); mental health disorder utilizing Srithanya Stress Scale (ST5), Nine-Questions Depression- Rating Scale (9Q), and Depression Anxiety Stress Scale 21 (DASS21); in addition to COVID-related stress utilizing COVID Stress Scale (CSS). The participants were categorized into two groups i.e., Spray and No Spray based on their self-reported occupational use of pesticide spraying within the past year. No significant associations were observed between occupational pesticide exposures and mental health disorder scores. Being female, having a second job besides a farmer, having applied pesticides for greater than 20 years, and having a higher farm stressor perception showed a significant positive association with self-reported mental health disorders; while having a good agricultural practice and PPE use showed a significant negative association with those outcomes. This pilot study scrutinized expanded sources of stress in farm work and provided information for the development of more effective mental disorder intervention programs for Thai farmers.

Self-Assessed Threshold Temperature for Cold among Poultry Industry Workers in Thailand.

The self-assessed threshold temperature for cold in the workplace is not well known. We asked 392 chicken industry workers in Thailand what they regard as the cold threshold (CT) and compared subgroups of workers using linear and quantile regressions by CT sextiles (percentiles P17, P33, P50, P67, and P83, from warmest to coldest). The variables of interest were sex, office work, and sedentary work, with age, clothing thermal insulation, and alcohol consumption as adjustment factors. The mean CT was 14.6 °C. Office workers had a 6.8 °C higher mean CT than other workers, but the difference ranged from 3.8 °C to 10.0 °C from P17 to P83. Sedentary workers had a 2.0 °C higher mean CT than others, but the difference increased from 0.5 °C to 3.0 °C through P17-P83. The mean CT did not differ between sexes, but men had a 1.6-5.0 °C higher CT at P17-P50 (>20 °C) and a 5.0 °C lower CT at P83 (<10 °C). The CT was relatively high at warm (≥10 °C), dry (relative humidity <41%), and drafty (air velocity > 0.35 m/s) worksites. We conclude that office, sedentary, and female workers and those working at warm, dry, and draughty sites are sensitive to the coldest temperatures, whereas male workers are sensitive even to moderate temperatures.

Workplace Cold and Perceived Work Ability: Paradoxically Greater Disadvantage for More vs. Less-Educated Poultry Industry Workers in Thailand.

The association between worksite temperature and perceived work ability (WA) in various educational classes remains unknown. Therefore, we interviewed 286 poultry industry workers in Thailand about their WA and linked their responses to worksite temperature. WA was based on the self-assessment of current work ability compared with their lifetime best ability (scores 0-10). Education was classified as high (university or vocational school) or low (less education). Temperature was classified as cold (-22-10°C) or warm (10-23°C). WA and the occurrence of a low WA were regressed on worksite temperature, education, and their interaction with the adjustment for sex, age, job category, physical work strain, moving between cold and warm sites, thermal insulation of clothing, relative humidity, and air velocity. The average worksite temperature was 10°C for high- and 1°C for low-educated workers. The average WA score was 8.32 (SD, 1.33; range, 4-10) and classified as low (<8) in 23% of the workers. In highly-educated workers, the adjusted mean WA decreased from 9.11 in the warm areas to 8.02 in the cold areas and the prevalence of a low WA increased from 11 to 30%, while no significant change was observed in less-educated workers. The WA score was estimated to decline by 10% more (95% CI, 4-16%) in the cold areas for the more vs. less-educated workers and the prevalence of a poor WA was estimated to increase 3.09 times (95% CI, 1.43-5.45) more. Highly-educated workers in this industry are a risk group that should be given customized advice.

Disruption of the Diurnal Cortisol Hormone Pattern by Pesticide Use in a Longitudinal Study of Farmers in Thailand.

Alteration of the hypothalamic-pituitary-adrenal (HPA) axis hormones has been associated with a range of chronic metabolic and cardiovascular health conditions. This study evaluated whether type of farming (organic versus conventional) or the number of self-reported days of spraying pesticides in the past 8 months was associated with diurnal cortisol levels. Salivary cortisol levels were measured four times a day (waking, 30 min after waking, 6 h after waking and bedtime) longitudinally, 8 months apart during three rounds of data collection. Pesticide using (conventional) and organic farmers were recruited to participate. Pesticide use in the previous 8 months was determined as the number of spray days for each type of pesticide used (herbicide, insecticide, fungicide) from self-reported questionnaires. Estimates of cortisol levels at four time points, the cortisol awakening response (CAR), and the diurnal cortisol slope (DCS) were estimated with a longitudinal mixed model that accounted for the non-linearity of cortisol levels across the day. Conventional farmers had significantly lower cortisol levels at waking than organic farmers (3.39 versus 3.86 ng ml-1), 30 min after waking (5.87 versus 6.96 ng ml-1), 6 h after waking (1.62 versus 1.88 ng ml-1), and lower diurnal cortisol slope (-2.26 versus -2.51 ng ml-1). Farmers who frequently applied herbicides (90th percentile of the number of spray days in the past 8 months) had significantly lower waking, 30 min after waking, 6 h after waking, bedtime and diurnal cortisol slopes compared with those with no spray days of herbicide in the past 8 months (organic and some of the conventional farmers). Those who frequently applied insecticides in the past 8 months had significantly lower bedtime levels and diurnal cortisol slopes, compared with those with no spray days of insecticide in the past 8 months. There were no significant differences in cortisol hormones between those who frequently applied fungicides and those who did not spray fungicides. Repeated pesticide use appears to be disrupting the HPA axis and depressing the normal diurnal cortisol rhythm among conventional Thai farmers.

Acute Changes in Thyroid Hormone Levels among Thai Pesticide Sprayers.

The objective of this study was to investigate the relationship of acute pesticide exposures and acute changes in thyroid hormones among Thai farmers. We recruited 78 farmers, who were scheduled to spray insecticides (chlorpyrifos and/or cypermethrin) or herbicides (paraquat and/or glyphosate). On the day before spraying, farmers collected their first morning void urine and went for blood collection. On the spray day, urine samples were collected at end of the spraying event and they were interviewed with questionnaires. The next morning, the first morning void urine and blood samples were collected. Blood samples were analyzed for thyroid hormones. Urine samples were analyzed for the metabolites of the pesticide sprayed. The results showed that the thyroid hormones, free triiodothyronine (FT3) and total triiodothyronine (T3) were significantly reduced as urinary chlorpyrifos metabolite increased the day after spraying. Total thyroxine (T4) significantly increased as cypermethrin metabolites increased the day after spraying. T4 significantly increased as urinary glyphosate levels increased; however, FT3 and T3 decreased significantly as urinary paraquat levels increased the day after spraying. These findings suggest that acute exposures to the pesticides chlorpyrifos, cypermethrin, paraquat and glyphosate can produce acute effects on the hypothalamic-pituitary-thyroid (HPT) axis, acutely altering thyroid hormone levels.

A Microfluidic Paper-Based Analytical Device for Type-II Pyrethroid Targets in an Environmental Water Sample.

A detection method for type-II pyrethroids in an environmental water sample using a microfluidic paper-based analytical device (µPAD) is reported here. The detection approach is based on the formation of cyanide from the hydrolysis of type-II pyrethroids and the colorimetric detection of cyanide on a layer-based µPAD. Parafilm and inexpensive laminating pouches were used to create a hydrophobic barrier for the assay on the µPAD. This detection approach was selective to type-II pyrethroids in water for which an environmental water sample was tested. The calibration curves for cypermethrin, deltamethrin, cyhalothrin, and fenvalerate ranged from 2 to 40 µg/mL without sample preconcentration. The lower concentrations of type-II pyrethroids can be assessed by including a preconcentration step prior to the detection on a µPAD. This detection system provides an alternative platform for fast, semiquantitative testing for pesticide contamination in environmental surface water by allowing for portability, low reagent/sample consumption, and low-cost testing.

Paraquat exposure of backpack sprayers in agricultural area in Thailand.

Thai agriculturists heavily used paraquat in agricultural areas to control weed and grasses. This study determined paraquat exposure among backpack sprayers in Thailand and identified determinants of occupational exposure. Breathing zone air and dermal samples were collected from 57 backpack sprayers while spraying. Spot urine samples were collected on the day before spraying, end of spraying event and the next day after spraying. The subjects were interviewed about general demographics, agricultural activities, pesticide application and personal protective equipment used while applying paraquat. Paraquat concentrations in urine samples, air samples and dermal samples were determined by HPLC with a fluorescence detector. The median IQR of urinary paraquat concentrations on the day before spraying, end of spraying event, the next day after spraying were 2.51 (0.81-5.59), 8.23 (3.3-13.73) and 3.48 (1.03-8.19) µg/g creatinine, respectively. Concentrations of air samples and total dermal exposures were 5.15 (2.28-10.12) µg/m3and 92.66 (34.37-1647.46) µg/hr, respectively. Use of battery powered backpack sprayer and standing upwind effectively reduced inhalation exposures. Wearing a long sleeve shirt, long pants, boots, latex gloves and balaclava could reduce paraquat concentration on dermal exposure among backpack sprayers.

Paraquat Exposure of Pregnant Women and Neonates in Agricultural Areas in Thailand.

This study aimed to assess paraquat concentrations in the urine of women at 28 weeks of pregnancy, delivery and 2 months postpartum and in the meconium of neonates. In all, 79 pregnant women were recruited from three hospitals located in agricultural areas in Thailand. The subjects were interviewed about personal characteristics, agricultural activities and pesticide use patterns. Paraquat was analyzed in urine and meconium using high performance liquid chromatography equipped with a fluorescence detector. The geometric mean (GSD) of urinary paraquat concentrations at 28 weeks of pregnancy, delivery and 2 months postpartum were 2.04 (4.22), 2.06 (5.04) and 2.42 (5.33) ng/mL, respectively. The urinary paraquat concentrations at 28 weeks of pregnancy, delivery and 2 months postpartum between agriculturist and non-agriculturist were not significantly different (p = 0.632, p = 0.915, p = 0.57 respectively). The geometric mean (GSD) of paraquat concentration in the meconium was 33.31 (4.59) ng/g. The factors predicting paraquat exposures among pregnant women and neonates included working outside, living near farmland, having family members who work on a farm, drinking well water and using herbicides or paraquat.