Different working conditions shift the genetic damage levels of pesticide-exposed agriculture workers

Monitoring and environmental risk assessment of agricultural fungicide and insecticides in water, sediment from Kumkale Plain, Çanakkale-Turkey

This study was conducted to assess pesticide residues in 34 water and sediment samples taken from Kumkale Plain of Çanakkale-Turkey. Residue analyses were performed with the use of Quick-Easy-Cheap-Efficient-Rugged-Safe (QuEChERS)-liquid chromatography/tandem mass spectrometry (LC-MS/MS) procedure. For method verification, blank sediment and water samples were spiked at two limits of quantification (LOQ) levels of the pesticides. Overall recovery was 81.66% for sediment and 91.50% for water samples. In sediment samples, chlorpyrifos-M had the highest concentration, pyridaben was encountered in the majority of the samples (15 samples) and the highest number of pesticides (35) was seen in sample no. s13. In water samples, methoxyfenozide had the greatest concentration, metalaxyl was encountered in the highest number of samples (three samples) and the highest number of pesticide (8) was seen in sample no.w13. Sample no. s13 and w13 were taken from around the fountain basin. Pyraclostrobin and chlorantraniliprole residues exceeded the national limits set for water. In terms of hazard quotient (HQ), pesticides in sediment and waters were found to be safe. Despite the safe nature of pesticide on samples, greater attention has been paid on toxicity of the residues. It was concluded that authorities should put strict regulations on agrochemicals to reduce health risks of these chemicals.

Micronucleus assays with the human derived liver cell line (Huh6): A promising approach to reduce the use of laboratory animals in genetic toxicology

The inadequate representation of enzymes which catalyze the activation/detoxification of xenobiotics in cells that are currently used in genotoxicity testing of chemicals leads to a high number of false positive results and the number of follow up studies with rodents could be reduced by use of more reliable in vitro models. We found earlier that several xenobiotic drug metabolizing enzymes are represented in the human derived liver cell line Huh6 and developed a protocol for micronucleus (MN) experiments which is in agreement with the current OECD guideline. This protocol was used to test 23 genotoxic and non-genotoxic reference chemicals; based on these results and of earlier findings (with 9 chemicals) we calculated the predictive value of the assay for the detection of genotoxic carcinogens. We found a sensitivity of 80% and a specificity of 94% for a total number of 32 chemicals; comparisons with results obtained with other in vitro assays show that the validity of MN tests with Huh6 is higher as that of other experimental models. These results are promising and indicate that the use of Huh6 cells in genetic toxicology may contribute to the reduction of the use of laboratory rodents; further experimental work to confirm this assumption is warranted.

Glove performance in a warming climate: The role of glove material and climate on permeation resistance to organophosphate insecticides

Hands and forearms are the principal sites of dermal exposure to organophosphate insecticides, which makes glove use one of the most important components of an exposure control strategy. However, the selection of suitable gloves depends on issues such as task, type, and concentration of organophosphate as well as cost. In addition, chemical protection performance of gloves may be temperature dependent, which is of increasing concern in a warming climate. Two recommended reusable glove materials (polyvinylchloride and nitrile butadiene rubber) and one single-use glove (nitrile/neoprene) were tested for permeation resistance to actual formulations of organophosphate insecticides with active ingredients dimethoate and malathion. Chemical resistance parameters were measured using American society for testing and materials permeation test cells and compared across glove, organophosphate type, and temperature. The three gloves demonstrated comparable and adequate chemical resistance (less than one µg cm^-2min^-1 for up to 8 hr exposure; 25-60 °C) for dilute forms of dimethoate and malathion, used during spraying activities. However, the single-use nitrile/neoprene glove is not designed to fully cover the elbow which limits its suitability. In permeation tests that reflect "worst case" exposure scenario to concentrated (neat) organophosphate formulations, as in mixing/loading tasks, a significant variation in chemical resistance between gloves was observed. While polyvinylchloride offered the maximum resistance, physical degradation of nitrile butadiene rubber after 3 hr of continuous exposure makes it unsuitable for handling neat dimethoate. The single-use nitrile/neoprene glove material had considerably poorer permeation resistance (up to 155-fold greater permeation and 6-fold shorter breakthrough) against neat formulations. Overall, elevated temperature (>40 °C) was shown to result in significantly greater (P < 0.05) cumulative permeation of neat formulation insecticides. This work demonstrates the variation in glove performance and potential for greater exposure risk particularly when mixing concentrated pesticides at elevated temperature conditions such as an occluded human skin or hot greenhouses. Training and guidance on testing, selection, use, and storage of gloves should consider in-use exposure scenarios and temperature-induced reduction in chemical protective performance.