Environmental impact and site-specific human health risks of chromium in the vicinity of a ferro-alloy manufactory, China.

Previous studies often neglected the direct exposure to soil heavy metals in human health risk assessment. The purpose of this study was to assess the environmental impact and site-specific health risks of chromium (Cr) by both direct and indirect exposure assessment method. Results suggested that total Cr was shown a substantial buildup with a significant increase in the industrial and cultivated soils (averaged 1910 and 986 mg kg(-1), respectively). The Cr contents of vegetables exceeded the maximum permissible concentration by more than four times in every case. Human exposure to Cr was mainly due to dietary food intake in farming locations and due to soil ingestion in both industrial and residential sites. Soil ingestion was the main contributor pathway for direct exposure, followed by inhalation, and then dermal contact. The highest risks of vegetable ingestion were associated with consumption of Chinese cabbage. The results also indicated that plant tissues are able to convert the potentially toxic Cr (VI) species into the non-toxic Cr (III) species. The analyses of human health risks indicated that an important portion of the population is at risk, especially in the industrial site.