Abstract

Las Ilusiones lagoon is located in Villahermosa city, Mexico. Lack of a steady source of water, contaminants inflowing lagoon through residual and pluvial water drain from populated areas that surround it, and garbage accumulated on banks of the lagoon, have caused an alteration in its auto-purification capacity, producing eutrophication of its waters. The aim of this study was to analyze metals dissolved in the water from this lagoon in order to generate reliable data for future ecotoxicology studies on native organisms, such as crocodile that inhabits it. Water samples taken from different sites in the lagoon were analyzed to determine the content of lead, chromium, manganese, nickel and zinc using atomic absorption spectroscopy. Results showed values significantly above the detection limits for some of these metals, namely lead and zinc. The presence of these metals can be explained by pluvial discharges from the city around the lagoon that wash rusted metal roofs and carry domestic discharges, paint and roof insulation debris from buildings as well as oils and combustion particles from automobiles combustion.

Key words: Lead, chromium, manganese, nickel, zinc, atomic absorption, spectroscopy,water, metals, lake, lagoon, Tabasco, México