Spatio-temporal assessment, sources and health risks of water pollutants at trace levels in public supply river using multivariate statistical techniques. (November 2021) - Sales de Carvalho, Vanessa
Abstract: The Joanes River is located in the northeast of Brazil, crosses the Camaçari Petrochemical Complex, the largest integrated industrial complex in the Southern Hemisphere, which has over 90 companies in the chemical and petrochemical industry. The present study aims to evaluate spatial distribution, seasonal variation and identify possible sources of trace metal contamination in surface water samples of the Joanes River. Samples were collected in the dry (December 2018) and rainy (August 2019) seasons. Analysis of trace elements (As, Cd, Cr, Cu, Ni, Mn and Pb) were performed by ICP-MS. A total of 60 water samples were obtained. Samples were analyzed using exploratory techniques such as principal component analysis (PCA) and cluster analysis (CA). It was possible to characterize the samples according to the seasonal variation. The formation of two groups was observed. Among these, samples from the rainy season presented the higher levels of metals in relation to the samples of the dry season. Natural and anthropic sources of metal contamination were identified using CA. Similarity was shown in the relationship between the metals As–Pb and Ni–Cd–Cr–Cu in the dry season, and Cd–Ni and Pb–As–Cr–Cu in the rainy season. Dermal absorption (HQderm) and ingestion hazard quotients (HQing) routes exhibited values of less than one for all the elements analyzed for adults and children, in both rainy and dry seasons. This indicated that the pollutants analyzed posed little or no health risk over a lifetime of exposure. According to international guidelines (US EPA), the values of Cu, Pb and Cr were above the limit established. Highlights: First evaluation of trace metals pollution in Joanes River water were conducted. In this region that concentrates the Brazil's largest industry complex. The CA and PCA analyses were effective to identify the water pollution sources. CA suggested that As, Cr, Cu, Cd, Ni and Pb were mainly anthropogenic sources. As showed the highest values for HQing for adults in the dry and rainy periods.