In this study, two hormones 17β-estradiol (E 2 ) and 17α-ethynylestradiol (EE 2 ), and three phenolic compounds, bisphenol A (BPA), 4-N-nonylphenol (4-NP) and 4-tert-octylphenol (4-t-OP), were determined in surface water in the Cuautla River at the State of Morelos during the dry-season in Mexico. The endocrine disrupting compounds (EDCs) were extracted from water samples using solid-phase extraction (SPE) with end-capped C 18 , and then the extracts were chemically derivatized to TMS (trimethylsylane)-compounds and analyzed by gas chromatography coupled to mass spectrometry (GCMS). The most abundant compound was BPA (22.46 ± 30.17 ng L −1 ), followed by 4-t-OP (11.24 ± 11.76 ng L −1 ), 4-NP (7.53 ± 14.88 ng L −1 ), EE 2 (2.37 ± 4.36 ng L −1 ) and E 2 (0.97 ± 1.82 ng L −1 ). The residual amounts of target compounds could either reach stream surface water from direct domestic wastewater discharges, conventional wastewater treatment plant or can be a result from the use of agrochemicals in crop areas. The EDCs in Cuautla River exerted a high pressure on the aquatic ecosystem because their presences in surface water caused medium and high potential ecological risk. Besides, it was found that aquatic organisms were exposed to estrogenic activity.

. Spatial variations were found during the dry-warm season, which were attributed mainly to differing intensities of local traffic and less dispersion of air pollutants in Miravalle. Seasonal variations were associated with increases in rainfall (June-September) and differences in temperature (January-May and October-January). The benzo(a)pyrene-equivalent (BaPE) and BaP results suggest that exposure to PM 2.5 -containing carcinogenic PAHs (C-PAHs) in Miravalle during the warm-dry and cold-dry seasons can be seen as representing a serious risk to human health. The contributions from potential sources to PAHs in PM 2.5 were evaluated by the diagnostic ratios between PAHs and principal component analysis (PCA). In the whole sampling period, vehicular emission activity, probably related to light and heavy traffic, was found to be the predominant contributor to PM 2.5 -bound PAHs.

Polycyclic aromatic hydrocarbons (PAHs) are formed in natural processes during combustion of biomass (e.g., forest fires) and by anthropogenic activities at high temperatures. In according with the suggestion the major sources of PAHs in the environment. The main sources of PAHs come basically from heat and power generation (e.g., coal, gas, wood, and oil), industrial processes (e.g., coke production), refuse burning and vehicle emissions. Human exposure to airborne PAHs can result from these processes, as well as from emissions from other sources, such as cooking, smoking, and materials containing PAHs (e.g., petroleum products and fuels). The potential serious health effects resulting from acute and chronic human exposure to PAHs are of concern. For this reason, the identification and quantification of PAHs in airborne particles have been a real challenge, given the multiple impacts that these substances represent for human health. In the last decade, multiple technological developments have been implemented, ranging from sampling systems, extraction and analysis of these compounds with the aim of obtaining more accurate and reliable results. This chapter was prepared to describe and to assess the state of the art about the evolution and application of sampling, extraction and analysis methodologies for the determination of PAHs in airborne particles.

Atmospheric particles with an aerodynamic diameter less than or equal to 2.5 micrometers (PM2.5) were collected at two sites located in the urban area of the city of Cuernavaca (Morelos) during a season when a large number of forest fires occurred. Three dicarboxylic acids (malonic, glutaric and succinic) and levoglucosan were analyzed by liquid chromatography coupled with mass spectrometry (ESI-Q-TOF) and soluble potassium (K+) was analyzed by ion chromatography. The concentration of PM2.5 increased on the days when the highest number of forest fires occurred. A strong correlation was observed between levoglucosan and K+, confirming the hypothesis that both are tracers of biomass burning (r = 0.57, p < 0.05). Levoglucosan (average 367.6 ng m−3, Site 2) was the most abundant compound, followed by succinic acid (average 101.7 ng m−3, Site 2), glutaric acid (average 63.2 ng m−3, Site 2), and malonic acid (average 46.9 ng m−3, Site 2), respectively. The ratio of C3/C4 concentrations ranged from 0.5 to 1.2, with an average of 0.8, which suggests great photochemical activity in the Cuernavaca atmosphere. The ratio of K+/levoglucosan concentrations (0.44) indicates that open fires are the main source of these tracers. The positive correlations between PM2.5 and levoglucosan and succinic and malonic acids suggest that such compounds are contributing to secondary organic aerosol particle formation.