Organophosphorus pesticide exposure decreases sperm quality: association between sperm parameters and urinary pesticide levels.

Several studies have suggested that human semen quality has declined over the past decades and some of them have associated it with occupational exposure to pesticides. However, most of these studies have not been associated with a reliable exposure level and have been designed mostly as cross-sectional studies. The present work evaluates, in a longitudinal follow-up study, the effect of organophosphate pesticides (OP) at three occupational exposure levels on semen quality. In addition, the study examined the association between OP urinary levels and sperm parameters in exposed and unexposed workers. A total of 139 semen samples from 52 volunteers were assessed. Urinary OP levels were measured by gas-liquid chromatography. The results revealed that the poorest semen quality was found among the subjects with the highest OP exposure and the highest urinary OP levels. Seasonal variations in sperm concentration and sperm count were registered. The results showed a significant decrease in total sperm count among subjects with the highest exposure to OP. Further studies assessing the effects of OP on male reproductive health should be controlled by the variability in human sperm parameters, sperm seasonality, spermatogenesis time and the changing OP exposure level in men highly exposed to OP.

Micronuclei induced by airborne particulate matter from Mexico City.

Particulate air pollution is an important environmental health risk. In the present study, we have investigated the ability of chemically characterized water and organic-soluble extracts of PM(10) from two different regions of Mexico City to induce micronuclei in a human epithelial cell line. We also evaluated the association between the chemical characteristics of the PM and its genotoxicity. The airborne particulate samples were collected from an industrial and a residential region; a Hi-Vol air sampler was used to collect PM(10) on glass fiber filters. PM mass was determined by gravimetric analysis of the filters. One section of each PM(10) filter was agitated either with deionized water to extract water-soluble compounds or with dichloromethane to prepare organic-soluble compounds. The chemical composition of the extracts was determined by ion and gas chromatography and atomic adsorption spectroscopy. A549-human alveolar epithelial cells were exposed to different concentrations of PM(10) extracts and the cytokinesis blocked micronucleus assay was performed to measure DNA damage. Even though the industrial region had a higher PM concentration, higher amounts of metals and PAHs were found in the residential area. Both industrial and residential extracts induced a significant concentration-related increase in the micronuclei frequency. The PM(10) water-soluble industrial extract induced significantly more micronuclei than the one of the residential region; inversely, the organic residential extract induced more micronuclei than the one from the industrial region. The association between the induction of micronuclei and the chemical components obtained by the comparative analysis of standardized regression coefficients showed that cadmium and PAHs were significantly associated with micronuclei induction. Data indicate that water-soluble metals and the organic-soluble fraction of PM(10) are both important in the production of micronuclei. Effects observed, point to the risk of PM exposure and shows the need of integrative studies.

Effect of chemical composition on the induction of DNA damage by urban airborne particulate matter.

Airborne particulate matter (PM) contains a large number of genotoxic substances capable of endangering human health. In the present study, we have investigated the ability of chemically characterized water-soluble and organic-soluble fractions of two particle sizes (PM2.5 and PM10) from different regions of Mexico City to induce DNA damage in a human lung epithelial cell line. We also evaluated associations between the physicochemical parameters of the PM and its genotoxicity. The airborne particulate samples were collected from four regions of the city; a HiVol air sampler was used to collect PM10 on glass fiber filters and a tapered element oscillating system coupled to an automatic cartridge collection unit was used to collect PM2.5 on teflon filters. PM mass was determined by gravimetric analysis of the filters. Filters containing PM2.5 and one section of each PM10 filter were agitated either with deionized water to extract water-soluble compound, or with dichloromethane to prepare organic-soluble compounds. The chemical composition of the extracts was determined by ion and gas chromatography and atomic adsorption spectroscopy. A549 human type II alveolar epithelial cells were exposed to different concentrations of the PM2.5 and PM10 extracts, and alkaline single cell gel electrophoresis or the Comet assay was performed to measure DNA damage and repair. These analyses indicated that soluble transition metals and the organic-soluble PM fractions are crucial factors in the DNA damage induced by PM. PM composition was more important than PM mass for producing genotoxicity. The results of this study showed that the constituents of the water-soluble PM extract are more likely to induce DNA damage than the organic compounds.