cyhalothrin and carbendazim

The concentration of pesticide residues in 105 green tea samples grown in Hangzhou area were investigated. Of the 14 pesticides analysed using gas chromatography-tandem mass spectrometry and the 27 pesticides analysed using liquid chromatography-tandem mass spectrometry, only 18 were detected in the tea samples. The most frequently detected pesticide residues were imidacloprid (35.2%), acetamiprid (26.7%), carbendazim (21.0%), bifenthrin (21.0%), and cyhalothrin (19.1%). Carbofuran was the only pesticide which exceeded in one sample the maximum residue limit. The concentrations of the analytes in tea samples ranged from below the limit of detection (LOD) to 2.64 mg/kg. Their mean concentrations were all below the LOD, except for imidacloprid, acetamiprid, carbendazim, bifenthrin and cyhalothrin. Based on a preliminary long-term exposure assessment, the hazard quotient values of the detected pesticides varied in the range 0.47 × 10

Topics: Food Contamination; Gas Chromatography-Mass Spectrometry; Humans; Pesticide Residues; Pesticides; Risk Assessment; Tea

Pesticide mixtures can often be found on crops and in the natural environment due to the usage of multiple pesticides in crop production. However, the toxicity of pesticides is mostly evaluated individually but not jointly. Many studies have pointed out that pesticide mixture may have elevated toxicity compared with its individual counterpart, therefore, it is important to quantify the change in toxicity. Such quantification can provide invaluable information for environmental and ecological risk assessment, and further support risk management to develop appropriate means to mitigate the risk. The objective of this study is to quantify the ecotoxicity of pesticide mixtures composed of different combinations of four pesticides (i.e., Acetemiprid, Carbendazim, Chlorpyrifos, Cyhalothrin) to (1) understand if the co-presence of multiple pesticides will affect the toxicity and (2) to quantitatively approximate the change in toxicity. We first conducted acute toxicity testing and avoidance response testing using earthworms to obtain dose-response data for two different endpoints; then the benchmark dose (BMD) methodology was applied to estimate the toxicity values for the active ingredients of these four pesticides and their mixtures. The BMD analysis results suggest that the ecotoxicity of the active ingredients of the pesticides is very likely to increase when two or more pesticides are used simultaneously, highlighting the importance to consider toxicity of mixtures in the regulatory decision making process. This study demonstrates that the benchmark dose methodology can be a useful tool to quantify the toxicity of chemical mixtures and support cumulative risk assessment accordingly.

Topics: Animals; Benzimidazoles; Carbamates; Chlorpyrifos; Neonicotinoids; Nitriles; Oligochaeta; Pesticides; Pyrethrins; Risk Assessment; Soil Pollutants; Toxicity Tests, Acute

The dissipation of six pesticides (carbendazim, thiabendazole, procymidone, bifenthrin, λ-cyhalothrin, and β-cyfluthrin) in shiitakes from cultivation to postharvest drying process was investigated, and the dietary exposure risk was estimated thereafter. The field trial study indicates that the half-lives of carbendazim, thiabendazole, and procymidone were much shorter than those of bifenthrin, λ-cyhalothrin, and β-cyfluthrin. Furthermore, the effects of two drying processes on the residues and processing factors (PFs) were investigated. The results showed that hot-air drying resulted in higher residues than sunlight exposure drying. Both drying processes led to pesticide residue concentration (with PF > 1), except for thiabendazole upon sunlight exposure treatment. The estimated daily intakes (EDIs) ranged from 0.06% of the acceptable daily intake (ADI) for thiabendazole to 42.43% of the ADI for procymidone. The results show that the six pesticide residues in dried shiitakes are still within acceptable levels for human consumption on the basis of a dietary risk assessment.

Topics: Benzimidazoles; Bridged Bicyclo Compounds; Carbamates; Diet; Environmental Monitoring; Food Contamination; Humans; Nitriles; Pesticide Residues; Pyrethrins; Reproducibility of Results; Risk Assessment; Shiitake Mushrooms; Thiabendazole

Little research has been performed on the impact of pesticides on earthworms under tropical conditions. Taking into consideration the often-limited resources in tropical countries, simple screening tests are needed. Therefore, it was investigated whether three pesticides relevant for the Brazilian Amazon (benomyl, carbendazim, lambda-cyhalothrin) affect the avoidance behavior of the earthworm Eisenia fetida. The tests were performed for two days according to ISO guideline 17512 but were adapted to tropical conditions (i.e. test substrate, test organism and temperature). The results indicate that this test gives reproducible and reliable results. Toxicity values (NOEC, EC50) are lower than those determined in 14 day-acute mortality tests and are approximately in the same range such as those found in 56 day-chronic reproduction tests with the same earthworm species, which were performed in parallel. Therefore, the use of the earthworm avoidance tests is recommended as a screening tool for the risk assessment of pesticides.

Topics: Animals; Avoidance Learning; Behavior, Animal; Benomyl; Benzimidazoles; Brazil; Carbamates; Fungicides, Industrial; Lethal Dose 50; Nitriles; No-Observed-Adverse-Effect Level; Oligochaeta; Pesticides; Pyrethrins; Risk Assessment; Soil; Toxicity Tests; Tropical Climate