Minerals and trace elements in a long term paddy soil-rice system in the north of Iran: Human health and ecological risk assessment

We determined concentrations of 52 elements in 480 paired rice and soil samples from northern Iran in June and October. The contamination factor, enrichment factor and geoaccumulation index indicated that bromine (Br), cadmium (Cd), cesium (Cs), germanium (Ge), indium (In) and selenium (Se) were enriched in soils from both June and October. Copper (Cu), molybdenum (Mo), potassium (K) and Zinc (Zn) showed more movement from soils to rice than other trace elements (TEs). For rice consumption, the target hazard quotient values of each element of both months were lower than one. Carcinogenic risk (CR) values of Arsenic (As) and Cd and total CR values for both cultivation months showed significant carcinogenic health risks for consumers. Estimated daily intakes of barium (Ba), lithium (Li), and strontium (Sr) through consumption of rice were higher than the recommended tolerable daily intake. In summary, our results revealed TEs are elevated in soil and rice in the north of Iran and consumption of rice poses a health risk to consumers.