Human health risk assessment and environmental distribution of trace elements, glyphosate, fecal coliform and total coliform in Atlantic Rainforest mountain rivers (South America)

Abstract

Trace elements (Ag, Al, As, Ba, Be, Cd, Co, Cr, Cs, Cu, Fe, Ga, Mn, Ni, Pb, Se, Sr, Ti, U, V and Zn), glyphosate and fecal (FC) and total coliform (TC) bacteria in surface water samples in 24 rivers from southern Atlantic rainforest (South America) were analyzed. The potential health risk of these trace elements, glyphosate and coliform to local population were assessed. Trace elements' (TE) concentrations were determined by ICP-MS, while the glyphosate was analyzed by HPLC. Determination of coliform was performed by dilution method and incubation. The results were then compared to national and international guidelines to diagnose the environmental situation. Only the Fe and Mn concentration were above the recommended limits by USEPA (Mn=500μgL−1) (USEPA, 2009) and WHO (Mn=400μgL−1). Based on TE concentrations, the Hazard Quotient and Hazard Index were calculated. The resulting indices suggest no risk to population. Glyphosate was below 200μgL−1 in all sites, except San Antonio River, where the concentration was 1600μgL−1. According to the USEPA, the glyphosate could present a low risk for children, but only in the San Antonio River during extreme floods. Based on the mean concentration of FCs, three of the 24 rivers were classified as high risk (CFU 100ml−1>1000) while the other study sites were intermediate (100>CFU 100ml−1>1000ml). Inter-trace element correlation revealed the natural origin of Ba, Cu, Fe, Mn, V and Zn. Principal component analysis and factor analysis revealed that high levels of coliform were associated with urbanization and changes in land use.