Spatiotemporal variability of pesticides concentration in honeybees (Apis mellifera) and their honey from western Mexico. Risk assessment for honey consumption.

The study conducted in the state of Colima, western Mexico, aimed to assess the 1) occurrence, 2) temporal variability, 3) spatial variability, and 4) potential risk for honeybees and human consumption of pesticide-contaminated honey. For that purpose, 48 pesticides were determined in bees and their honey during both dry and wet seasons. The research considered two variables: land use categorization (irrigated agriculture, rainfed agriculture, grassland, and forest area) and location (coastal, valley, and mountain). Bee and honey samples were collected, pre-treated using solid-phase extraction (SPE), and analyzed using LC-MS/MS and GC-MS techniques. Occurrence: of the total number of pesticides, 17 were detected in the bee samples and 12 in the honey samples. The pesticides with the highest concentrations in the bee samples were glufosinate ammonium, picloram, and permethrin, while in the honey samples, picloram, permethrin, and atrazine were the most prevalent. Temporal variability: analyses revealed significant differences between dry and wet seasons for glufosinate ammonium and DEET in bee samples and only for glufosinate ammonium in honey samples. Spatial variability: analyses showed a trend in the number of detected pesticides, with irrigated agriculture areas having the highest detection and grassland areas having the least. The human potential risk assessment of contaminated honey consumption indicated no risk. The bee's potential risk for consumption of pesticides contaminated honey revealed chronic effects due to permethrin in a general scenario, and carbofuran, diazinon and permethrin in the worst scenario, and potential risk of acute effects by permethrin. The findings of this study contribute to understanding the contamination levels of pesticides in bees and their honey, emphasizing the importance of monitoring and mitigating the adverse effects of pesticide exposure on bee populations and environmental health.

Capture and accumulation of perchlorate in lettuce. Effect of genotype, temperature, perchlorate concentration, and competition with anions.

Various studies have evaluated the accumulation of ClO4(-) in lettuce (Lactuca sativa), but very few have dealt with the variables that can interfere with its capture. The present study evaluates the transfer of ClO4(-) in two L. sativa varieties: butter head (L. sativa var. capitata) and cos lettuce (L. sativa var. crispa) under hydroponic conditions. The ClO4(-) concentrations used correspond to levels (1 and 2mgL(-1)), measured in irrigation water in the Iquique region in the north of Chile. Results indicate that the capture of ClO4(-) is dependent on its concentration, lettuce genotype, and temperature. The butter head variety accumulates the highest perchlorate concentrations. Anion competition involving NO3(-) (16 and 48mM), Cl(-) (23 and 56mM), and SO4(2-) (10 and 20mM) was evaluated, being NO3(-) (48mM), the most significant competition reducing the concentration of ClO4(-) in tissues of L. sativa varieties.