Contribution of anthropogenic and natural sources to the levels of trace elements in two costal sites in campeche, mexico

Abstract

The influence of anthropogenic and geochemical sources on trace metal levels in wet deposition was studied in two coastal sites – Isla del Carmen and San Antonio-Cardenas – both located in the State of Campeche. Simultaneous samplings of precipitation were carried out by automatic samplers from June 1 to October 31, 2004. A total of 52 samples were collected to determine trace metals (Al, Fe, Mn, Cu, Zn, Pb and Ni). A mean pH value of 4.64 was found for San Antonio-Cardenas, whereas in Isla del Carmen this value was 5.38, indicating levels of acidity in rainwater in San Antonio-Cardenas while Isla del Carmen showed a natural buffer capacity to neutralize the acidity. The influence of the crustal was evident in both sampling sites, specifically for Al, Fe and Mn. In both sites, high percentages of dissolved fractions were found for Cu, Pb, Zn and Ni. However, these percentages were more significant in San Antonio-Cardenas, suggesting that these trace elements had an anthropogenic source.