No abstract

The aim of this study was to evaluate the genotoxic effect of pesticides in exfoliated buccal cells of workers occupationally exposed in Guerrero, Mexico, using the comet assay and the micronucleus test. The study compared 111 agricultural workers in three rural communities (Arcelia 62, Ajuchitlan 13, and Tlapehuala 36), with 60 non-exposed individuals. All the participants were males. The presence of DNA damage was investigated in the exfoliated buccal cells of study participants with the comet assay and the micronucleus (MN) test; comet tail length was evaluated in 100 nuclei and 3000 epithelial cells of each individual, respectively; other nuclear anomalies such as nuclear buds, karyolysis, karyorrhexis, and binucleate cells were also evaluated. Study results revealed that the tail migration of DNA and the frequency of MN increased significantly in the exposed group, which also showed nuclear anomalies associated with cytotoxic or genotoxic effect. No positive correlation was noted between exposure time and tail length and micronuclei frequencies. No significant effect on genetic damage was observed as a result of age, smoking, and alcohol consumption. The MN and comet assay in exfoliated buccal cells are useful and minimally invasive methods for monitoring genetic damage in individuals exposed to pesticides. This study provided valuable data for establishing the possible risk to human health associated with pesticide exposure.

Calypso (thiacloprid), Poncho (clothianidin), Gaucho (imidacloprid), and Jade (imidacloprid) are commercial neonicotinoid insecticides, a new class of agrochemicals in México. However, genotoxic and cytotoxic studies have not been performed. In the present study, human peripheral blood lymphocytes (PBL) were exposed in vitro to different concentrations of the four insecticides. The genotoxic and cytotoxic effects were evaluated using the alkaline comet and trypan blue dye exclusion assays. DNA damage was evaluated using two genotoxicity parameters: tail length and comet frequency. Exposure to 9.5 × 10−6 to 5.7 × 10−5 M Jade; 2.8 × 10−4 to 1.7 × 10−3 M Gaucho; 0.6 × 10−1 to 1.4 × 10−1 M Calypso; 1.2 × 10−1 to 9.5 × 10−1 M Poncho for 2 h induced a significant increase DNA damage with a concentration-dependent relationship. Jade was the most genotoxic of the four insecticides studied. Cytotoxicity was observed in cells exposed to 18 × 10−3 M Jade, 2.0 × 10−3 M Gaucho, 2.0 × 10−1 M Calypso, 1.07 M Poncho, and cell death occurred at 30 × 10−3 M Jade, 3.3 × 10−3 M Gaucho, 2.8 × 10−1 M Calypso, and 1.42 M Poncho. This study provides the first report of genotoxic and cytotoxic effects in PBL following in vitro exposure to commercial neonicotinoid insecticides.

No abstract

The worldwide human population suffering from allergies continues to increase. Pollen grains are a major source of airborne allergens and significant cause of these diseases. Therefore, continuous monitoring of pollen grains released and transported in the air locally or regionally is required to determine the prevalence of various pollen types and identify intra-day and intraannual seasonal variations over time. In this study, we developed the first pollen calendar for Mexico City, which includes a large variety of taxa, many of which show a long Main Pollen Season which may last throughout the year. The analysis and comparison of daily, monthly and annual values showed that the occurrence and abundance of the main types of aeroallergenic pollen in the atmosphere were species of Fraxinus, Cupressaceae and Alnus, which occur during the periods from December through March, whereas airborne pollens of several species of Poaceae and Urticaceae occurred throughout the year. The variation in pollen concentration showed that the greatest intradiurnal variations occurred during the second half of the day. Regarding the relationship of pollen with bioclimatic factors, the increase in temperature favoured the presence of pollen in the air, whereas the increase in pluvial precipitation and relative humidity was associated with a decrease in airborne pollen. Large tracts of the Valley of Mexico have atmospheric conditions that are conducive to the accumulation of airborne particles, including pollen. Anomalous winds from the southeast dominated the surface wind variability during the first months of 2010. These patterns induced extreme values in wind convergence at the lower levels of the atmosphere, which resulted in high concentrations of pollen at our sampling site. We suggest that these conditions are related to the warm phase of the El Niño Southern Oscillation phenomenon (2009)(2010).