Ecological risk assessment associated with five endocrine-disrupting compounds in wastewater treatment plants of Northeast Mexico.

The ecological risk associated with five endocrine-disrupting compounds (EDCs) was studied in four wastewater treatment plants (WWTPs) in Monterrey, Mexico. The EDCs, 17ß-estradiol (E2), 17α-ethinylestradiol (EE2), bisphenol A (BPA), 4-nonylphenol (4NP), and 4-tert-octylphenol (4TOP) were determined by SPE/GC-MS method, where EE2 and 4TOP were the most abundant in effluents at levels from 1.6 - 26.8 ng/L (EE2) and < LOD - 5.0 ng/L (4TOP), which corroborate that the wastewater discharges represent critical sources of EDCs to the aquatic environments. In this study, the potential risk associated with selected EDCs was assessed through the risk quotients (RQs) and by estimating the estrogenic activity (expressed as EEQ). This study also constitutes the first approach for the ecological risk assessment in effluents of WWTPs in Northeast Mexico. The results demonstrated that the effluents of the WWTPs represent a high risk for the organisms living in the receiving water bodies because the residual estrogens effect E2 and EE2 with RQ values up to 49.1 and 1165.2. EEQ values between 6.3 and 24.6 ngEE2/L were considered the most hazardous compounds among the target EDCs, capable of causing some alterations in the endocrine system of aquatic and terrestrial organisms due to chronic exposition.

Determination of black carbon in fine particles using a semi-continuous method at two sites in the city of Guadalajara, Mexico, during 2007.

The black carbon is a pollutant species primarily emitted from the combustion of fossil fuels (diesel). Their concentrations associated to PM2.5 were monitoring at two sites in the city of Guadalajara. From January to May (except April), downtown site shown 2.7, 2.6, 4.0 and 2.3 times higher monthly concentrations. The dry season two showed higher concentrations respect to at least one of the others seasons (p < 0.0001) at each site, probably due to atmospheric conditions less favorable for the dispersal of pollutants. During the 24 h period were observed at the year two peaks of concentrations: the highest morning peak and lower night peak, both probably related to anthropogenic activity.

Occurrence and seasonal distribution of five selected endocrine-disrupting compounds in wastewater treatment plants of the Metropolitan Area of Monterrey, Mexico: The role of water quality parameters.

Five endocrine-disrupting compounds (EDCs) were determined in four urban wastewater treatment plants (WWTPs) of the Metropolitan Area of Monterrey (MAM) in two seasonal periods (winter and summer). The MAM, one of the most urbanized areas in Mexico, is characterized by high industrial activity and population density, leading to extensive use of several EDCs. In the MAM, ∼90% of urban and industrial wastewater is treated in WWTPs, where EDCs can be partially eliminated. In this work, dissolved levels of 17ß-estradiol (E2), 17α-ethinyl estradiol (EE2), bisphenol A (BPA), 4-nonylphenol (4NP), and 4-tert-octylphenol (4TOP) in wastewater were determined. The EDCs' determination was carried out through solid-phase extraction (SPE) and gas chromatography coupled to mass spectrometry (GC-MS). High EDCs levels (0.4-450 ng/L) were found in the influents of WWTPs, while concentrations in the effluents ranged from 0.2 to 26.8 ng/L, with E2, EE2, and 4TOP being the most persistent. The Spearman correlation analysis revealed the association between E2 and EE2 (r = 0.4835, p < 0.05), and between BPA and 4NP (r = 0.5180, p < 0.05), suggesting that these EDCs have similar sources. Also, E2, BPA, and 4TOP were positively correlated with the chemical oxygen demand (COD), biochemical oxygen demand (BOD), and total suspended solids (TSS) (r = 0.4080-0.5694, p < 0.05), indicating the association of the EDCs with the organic matter in the wastewater. The factor analysis confirmed the significant correlation of COD, BOD, TSS, temperature, and pH with the high occurrence of 4TOP during the summer. It was also confirmed that summer warmer temperatures favored the removal of BPA and 4NP in the studied WWTPs. Finally, the studied sites were classified by cluster analysis in three groups, revealing the impact that seasonality has on the behavior of the selected EDCs.

Composition and mutagenicity of PAHs associated with urban airborne particles in Córdoba, Argentina.

The comet assay and micronucleous test were used to assess the genotoxicity of organic compounds associated with particulate material collected in the city of Córdoba, Argentina. Samples were collected on fiber glass filters and their organic extracts were analyzed by GC-MS. These extracts were used for the comet assay on human lymphocytes and for the MCN test with Tradescantia pallida. The concentrations of polycyclic aromatic hydrocarbons as well as some of their nitro derivates were higher during winter. Their composition suggested that their main emission sources were gasoline and diesel vehicles. We observed genotoxic effects of these organic extracts due to the presence of both direct and indirect acting mutagens. We found a good agreement between the two test systems employed, which encourages the further use of plant bioassays for air pollution monitoring, especially in developing countries, due to their flexibility, low cost and efficiency.