Safety of Potato Consumption in Slovak Region Contaminated by Heavy Metals due to Previous Mining Activity

Abstract

Heavy metals are among the most serious environmental contaminants in mining districts. Soil, as one of the main components of the environment, is the place of heavy metal entry into plants and consequently into the food chain, too. Potatoes grown in the region of Middle Spis (Slovakia) may be a source of increased content of heavy metals and pose a health risk to the consumer. The contents of heavy metals (Cd, Pb, and Ni) in potato and soil samples were determined using the AAS method and compared with limit values set by the Slovak Republic and the European Union. The content of heavy metals was determined in 12 potato cultivars with different length of vegetation period (mid-early, very early, and early, resp.), which were grown in three localities with a highly disturbed environment. Total contents and mobile forms of heavy metals as well as physical and chemical properties were determined in soil samples which were collected from the same sampling sites. Only Pb content in potato tubers was higher than the hygienic limit value (0.1 mg kg−1 FM) in 15 sampling sites (interval was n.d. –0.2298 mg kg−1 FM). The contents of exchangeable forms (total content) of heavy metals in soil were ranged between the intervals: Cd 0.004–0.055 (0.94–1 56), Pb 0.023–0.295 (17.00–26.80), and Ni 0.019–0.475 (30.80–71.00) mg kg−1. At current average consumption levels of potatoes, tolerable weekly intake (TWI) or tolerable daily intake (TDI) for observed heavy metals was not exceeded.