Organophosphate Pesticide Exposure: Effect on Farmers' Sperm Quality in the Mekong Delta, Vietnam.

OBJECTIVES: Using pesticides in the An Giang province is widespread. However, studies on the health effect of organophosphate pesticide have not been updated within the past 12 years. This study aimed to assess exposure to organophosphate pesticides and their effects on sperm quality among farmers in the An Giang Province, Mekong Delta, Vietnam. METHODS: During the winter - spring crop season of December 2021 to February 2022, a cross-sectional study was conducted on farmers aged 18 to 60 years-old based on seven communes' health checkup programs. The pesticide spray group included farmers who had sprayed pesticides in the previous week and had a history of working in agriculture for more than 2 years. The control group was defined as those who lived in the same community, had not worked in agriculture, and had never sprayed pesticides. Demographic characteristics and blood, urine, and semen samples were collected and analyzed. RESULTS: Data for 184 eligible participants were analyzed, including 116 farmers in the pesticide spray group and 68 non-farmers in the control group. Pesticide spray contributed to a decrease in the sperm quality index of 6.253 units (95% CI, 4.472-8.749). Increasing each pseudocholinesterase (PChE) unit (kIU/L) was associated with an increase of 1.181 units in the sperm quality index (95% CI, 0.757-0.947). CONCLUSIONS: Preventive methods for organophosphate pesticide exposure, such as administrative controls, engineering controls, substitution, and personal protective equipment should be applied to control health risks. In the An Giang setting, personal protective equipment is feasible, but most types of equipment are not used. The immediate priority is to determine the cause of personal protective equipment not being used and to find solutions to encourage people to use them.

Comparative regulation of major enzymes in the bile acid biosynthesis pathway by cholesterol, cholate and taurine in mice and rats.

These enzymes play important roles in the biosynthesis of bile acids. They are cholesterol 7alpha-hydroxylase (CYP7A1), the rate limiting enzyme in the classic pathway, sterol 12alpha-hydroxylase (CYP8B1), the key enzyme for synthesis of cholic acid (CA), and sterol 27-hydroxylase (CYP27), the initial enzyme in the alternative pathway. In the present study, the susceptibility of these three enzymes to dietary cholesterol and cholate, and the cholesterol lowering effect of taurine were determined in male C57BL/6 mice and Wistar rats. Both mice and rats were divided into 6 groups: control group (N), high cholesterol diet group (C), high cholesterol and cholate diet group (CB), and their 1% taurine-supplemented groups (NT, CT, CBT, respectively). After animals were fed with the respective diets for one week, the mRNA levels of CYP7A1 increased in the C-group compared with those of the N-group, and decreased in the CB-group compared with those of the C-group in both mice and rats. But the extent of decrease is different between the two species. CYP8B1 was also markedly repressed by cholate in mice, but not in rats. These results are consistent with the changes in serum and liver cholesterol concentrations. Taurine significantly increased CYP7A1 mRNA levels in the CBT-group compared with the CB-group in both animal models, with a subsequent decrease in serum and liver cholesterol levels and increase in fecal bile acid excretion. Up-regulated CYP8B1 was also observed after taurine supplementation in the CBT-group in mice. No increase in CYP7A1 was produced by taurine in the CT-group compared with that of the C-group in mice, although the changes of serum and liver cholesterol and fecal bile acids indicated taurine showed an efficient cholesterol lowering effect. In addition, CYP27 was induced in both C- and CB-groups of rats but not of mice, and no changes were produced by taurine. The overall results suggest that there are differences between mice and rats in susceptibility of the three enzymes to dietary cholesterol and cholate, and taurine induced CYP7A1 to produce its cholesterol-lowering effect only in the presence of cholate in the cholesterol diet.