Abstract

ABURTO-MEDINA, Arturo et al. Microbial community and pollutantns survey in sediments of biologically important wetlands in Lerma, Mexico. Rev. Int. Contam. Ambient [online]. 2015, vol.31, n.1, pp.7-22. ISSN 0188-4999.

Wetlands pollution is of great concern given their importance to conservation and as water and food sources for the local population. Therefore, microbial and chemical investigations were carried out on the Lerma (Chimaliapan) and Almoloya del Río (Chiconahuapan; both Ramsar sites) wetland samples in Mexico for risk assessment purposes. 16S rRNA-based clone library analyses showed the prevalence of Entero-bacteriaceae, specifically the genus Shigella and E. coli species in both wetlands. While faecal coliform levels in both wetlands were below the accepted limit, higher total coliform counts (> 2400 MPN) were observed in ~ 40 % of the sampled sites at Lerma. Other microorganisms detected included organisms similar to those obtained from hydrocarbon-contaminated environments with alkanes and poly-aromatic hydrocarbons being detected in the sediments. Detected metals were below United States Environmental Protection Agency (USEPA) limits, decreasing in the sequence: Al > Fe > Mn >V> Zn > Pb > Ni > Cr > Cu > Co > Tl > As > Be (except Cr at Almoloya). However, Al concentrations were significantly above the permissible limits (2700 mg/kg) of the National Oceanic and Atmospheric Administration of the United States in both wetlands. This study therefore demonstrates that increased health risks and potential for metal biomagnification by edible species could be associated with the use of wetland water resources.

Keywords : microbial diversity; metals; semimetals; wetlands; conservation; marsh.

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