Rutilio Ortiz

Presence of Polycyclic Aromatic Hydrocarbons (PAHs) in Semi-Rural Environment in Mexico City

The quality of the environment in big cities depends on its population and their domestic, transport, and industrial activities. In some places agricultural land use coexists with urban areas and as a result of this urbanization and the presence of infrastructure for services like water, electricity, drainage, and the use of fossil fuels etc, contamination problems in the atmosphere, soil and water (Wilcke, 2000), that lately lead some ills on organisms such as respiratory malaises, liver-lung-skin cancer, irritation on eyes and others discomforts. The growth of urban environments presents a major challenge. However, Mexico City as center of economic growth, education, technological advancement, and culture, large city also offer opportunities to manage the growing population in a sustainable way.

Residues levels of organochlorine pesticide in cow's milk from industrial farms in Hidalgo, Mexico

A survey was carried out from 2008 to 2010 to determine the concentrations of 16 organochlorine pesticide residues (OPRs) from Tizayuca, Hidalgo, Mexico. Organochlorine residue determinations were made from milk fat, using chromatographic cleanup and analysis by gas chromatography with an electron capture detector. The OPR concentrations found were from below the detection limit (DL) to 0.91 ng g−1 in 2008, DL to 0.38 ng g−1 in 2009 and DL to 0.59 ng g−1 in 2010. In general concentrations of organochlorine pesticides were higher in the wet season (3.37 ng g−1 and 4.79 ng g−1) than the dry season (1.92 ng g−1 and 2.71 ng g−1) for 2009 and 2010, due to control of pests in the pasture and sheds. According to Codex Alimentarius regulations, individual pesticides did not exceed the permissible limits, which for example were 10 μg kg−1 for alpha hexachlorocyclohexane (HCH) and endosulfan I, 20 μg kg−1 for p,p’-DDT, and 6 μg kg−1 for dieldrin, endrin and heptachlor. A reduction of organochlorine pesticide concentrations in cows milk was noted, indicating that the Mexican government has achieved reduction or elimination of some organochlorine pesticides in response to global agreements on persistent organic pollutants.