Human health risk assessment of toxic metals

The environmental research carried out in the village of Gyongyosoroszi has documented increased concentrations of arsenic and heavy metals in the soil of vegetable gardens. The differences between the metal contents of flooded and non-flooded vegetable gardens were significant, which confirm that the floods of Toka creek spread the contamination over the flood-plain of the village. The source of pollution is the tailing dump and the flotation plant.;The metal contents of vegetables were low and the arsenic content was under the detection limit in every case. The sorrel cultivated in flooded gardens has the highest metal content. Significant differences were also found between the flooded and non-flooded vegetable gardens. The vegetable concentration results further support the view that soil metals are not always absorbed as well as soluble forms, therefore use of default bioconcentration factors in assessing human health risk may overestimate the hazard. In our study, all of the bioconcentration factors were under 0.25 and the mobile elements were cadmium and zinc. Generally, the bioconcentration factors of non-flooded vegetable gardens were higher; the sorrel was the most accumulating vegetable.;In the pot experiment the BCFs were higher, but the tendencies were the same. The most accumulating vegetable was sorrel and the most mobile element was cadmium and zinc. The arsenic contents were also immeasurable.;Site-specific exposure parameters and a newly created equation for ingestion of vegetables were applied in risk assessment process. The site-specific exposure factors were generated from the results of questionnaire survey in the village, while the equation was based on the cultivation habits of homegrown vegetables.;The outcome of risk assessment has indicated acceptable risk in the village of Gyongyosoroszi, both in flooded and non-flooded vegetable gardens. The risk assessment process with default exposure parameters overestimated the risk. In contrast with previous study in the area, home gardening does not increase the risk for inhabitants at present. The most relevant exposure route was ingestion of homegrown vegetables. It is possible to further reduce the risk of human exposure to soil metal contamination by selecting leafy vegetables such as sorrel in home gardening.