Cumulative exposure characteristics of vegetable farmers exposed to Chlorpyrifos in Central Java - Indonesia; a cross-sectional study.

BACKGROUND: Agriculture is a major economic sector in Indonesia. Chemical pesticides are widely being used in agriculture for controlling pest. There is a growing concern that pesticide exposure, particularly chlorpyrifos (CPF) exposure, combined with other occupational characteristics that determine the level of exposure, can lead to further health impacts for farmers. Our objective was to evaluate the cumulative exposure characteristics among farmers exposed to CPF by using a validated algorithm. METHODS: We conducted a cross-sectional study of 152 vegetable farmers aged 18-65 who actively used CPF for at least 1 year in Central Java, Indonesia. Subject characteristics were obtained using a structured interviewer-administered questionnaire, addressed for sociodemographic and work-related characteristics. The cumulative exposure level (CEL) was estimated as a function of the intensity level of pesticide exposure (IL), lifetime years of pesticide use and the number of days spraying per year. CEL was subsequently classified into two groups, high and low exposure groups. The difference in characteristics of the study population was measured using Chi-square, independent-t or Mann-Whitney test. Association between CEL and its characteristics variables were performed by multiple linear regression. RESULTS: Seventy-one subjects (46.7%) were classified as the high exposure group. The use of multiple pesticide mixtures was common among our study population, with 94% of them using 2 or more pesticides. 73% reported direct contact with concentrated pesticides product, and over 80% reported being splashed or spilt during preparation or spraying activity. However, we found that the proportion of proper personal protective equipment (PPE) use in our subjects was low. Higher volume of mixture applied (p <  0.001) and broader acres of land (p = 0.001) were associated with higher cumulative exposure level, while using long-sleeved clothes and long pants (p <  0.05) during pesticide spraying were associated with lower cumulative exposure after adjusted for age and gender. CONCLUSIONS: These findings indicate an inadequate knowledge of using pesticides properly. Thus, we recommend comprehensive training on pesticide usage and encourage proper PPE to reduce the exposure level.

The determinants of thyroid function among vegetable farmers with primary exposure to chlorpyrifos: A cross-sectional study in Central Java, Indonesia.

Objectives: Occupational pesticide exposure, chlorpyrifos (CPF) in particular, may adversely affect the thyroid. The purpose of this study was to evaluate the determinants of thyroid function as indicated by the serum concentration of thyroid-stimulating hormone (TSH) among Indonesian vegetable farmers with primary exposure to CPF. Methods: A total of 151 vegetable farmers participated in this study. The sociodemographic and occupational characteristics of the participants were obtained using a structured interviewer-administered questionnaire. A validated quantitative method was used to estimate the cumulative exposure level (CEL). Serum TSH, thyroglobulin (Tg), free thyroxine (FT4), and urinary iodine excretion (UIE) were measured in the laboratory. The difference in TSH concentrations according to CEL and other characteristics were analysed using the Mann-Whitney U test. A multiple linear regression model was used to evaluate the potential determinants of TSH. Results: The mean age was 50 (SD 9.4) years. The median concentrations of TSH, FT4, and Tg/FT4 ratio were 1.46 mIU/L, 1.17 ng/dL, and 6.23 × 102, respectively. We observed that higher TSH concentrations were found among those with a higher Tg/FT4 ratio, were classified as high CEL, and had lower UIE or FT4. Conclusions: Our findings show that Tg/FT4 ratio, CEL, FT4, UIE concentrations, and post-spraying days were determinants of TSH concentrations among farmers with primary exposure to CPF. These results indicate that farmers are exposed to agents with thyroid-disrupting properties, thus supporting previous evidence showing the potential for thyroid disorders in agricultural populations exposed to pesticides.

The Role of CYP2B6*6 Gene Polymorphisms in 3,5,6-Trichloro-2-pyridinol Levels as a Biomarker of Chlorpyrifos Toxicity Among Indonesian Farmers.

OBJECTIVES: One of the most widely used pesticides today is chlorpyrifos (CPF). Cytochrome P450 (CYP)2B6, the most prominent catalyst in CPF bioactivation, is highly polymorphic. The objective of our study was to evaluate the role of CYP2B6*6, which contains both 516G>T and 785A>G polymorphisms, in CPF toxicity, as represented by the concentration of 3,5,6-trichloro-2-pyridinol (TCPy), among vegetable farmers in Central Java, Indonesia, where CPF has been commonly used. METHODS: A cross-sectional study was conducted among 132 vegetable farmers. Individual socio-demographic and occupational characteristics, as determinants of TCPy levels, were obtained using a structured interviewer-administered questionnaire and subsequently used to estimate the cumulative exposure level (CEL). TCPy levels were detected with liquid chromatography-mass spectrometry. CYP2B6*6 gene polymorphisms were analyzed using a TaqMan® SNP Genotyping Assay and Sanger sequencing. Linear regression analysis was performed to analyze the association between TCPy, as a biomarker of CPF exposure, and its determinants. RESULTS: The prevalence of CYP2B6*6 polymorphisms was 31% for *1/*1, 51% for *1/*6, and 18% for *6/*6. TCPy concentrations were higher among participants with CYP2B6*1/*1 than among those with *1/*6 or *6/*6 genotypes. CYP2B6*6 gene polymorphisms, smoking, CEL, body mass index, and spraying time were retained in the final linear regression model as determinants of TCPy. CONCLUSIONS: The results suggest that CYP2B6*6 gene polymorphisms may play an important role in influencing susceptibility to CPF exposure. CYP2B6*6 gene polymorphisms together with CEL, smoking habits, body mass index, and spraying time were the determinants of urinary TCPy concentrations, as a biomarker of CPF toxicity.

Serum adiponectin and resistin in relation to insulin resistance and markers of hyperandrogenism in lean and obese women with polycystic ovary syndrome.

OBJECTIVE: The role of insulin resistance in polycystic ovary syndrome (PCOS) has been established. However the role of adiponectin and resistin in the relationship between insulin resistance as markers of obesity and PCOS has not been conclusive. This study aims to determine the influence of the serum levels of adiponectin and resistin on PCOS, and assess possible correlations with the hormonal and metabolic parameters of the syndrome and obesity. METHODS: This study continued a case control study that had finished recruiting 24 subjects of reproductive women with PCOS as a case group, and 24 subjects of normal ovulatory reproductive women without hyperandrogenism as a control group. Further, only 18 subjects of the control group had a body mass index (BMI) <25 kg/m(2) and were included the data analysis, whereas others were excluded. Therefore, these study data were divided into three groups. Twenty-four PCOS patients from the case group were allocated to two groups, A (n = 14) patients had PCOS + BMI ≥25 kg/m(2); B (n = 10) patients had PCOS + BMI <25 kg/m(2). Group C was the control group of 18 reproductive women without PCOS + BMI <25 kg/m(2). Blood samples were collected between day 3 and 5 of a spontaneous menstrual cycle, at 07:00 to 09:00, after overnight fasting. Serum levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), total testosterone, prolactin, sex hormone-binding globulin (SHBG), glucose, insulin, adiponectin and resistin were measured. RESULTS: Serum adiponectin levels were significantly decreased in group A compared with group B and group C. No significant difference existed in adiponectin between group B and group C. Homeostasis Model of Assessment-Insulin Resistance (HOMA-IR) value in group A was found to be significantly higher than group C, but no significant differences were found between group B and group C or between group A and group B. There was no significant difference in serum resistin between all groups, nevertheless the resistin-to-adiponectin (R:A) ratio was significantly decreased in group A compared with groups B and C. In a multiple regression model, BMI, testosterone and insulin resistance were the major determinants of hypoadiponectinemia. However, only BMI was the major determinant of the resistin represented by the R:A ratio. CONCLUSIONS: Serum adiponectin levels and the ratio of resistin to adiponectin levels are reduced in obese women with PCOS. These results suggest that, by reducing adiponectin serum level, hyperandrogenemia, together with nutritional status of obesity, might contribute to insulin resistance in the pathogenesis of PCOS.