Status and health risk assessment of farmland soil heavy metal contamination in Hebei province

Objective To analyze the status and health risk of farmland soil heavy metal contamination in Hebei province.Methods Totally 2 700 farmland soils samples were collected with stratified random sampling in Hebei province in 2014;then contents of lead,cadmium,and chromium in the soil samples were determined.The health risks related to the soil heavy metal contaminations were estimated using health risk assessment model recommended by the United States Environmental Protection Agency.Results The average content of lead,cadmium,and chromium were 18.52,0.4,and 39.63 mg/kg,respectively.The content of cadmium in 13.74% of soil samples exceeded the national secondary standard;while the content of lead and chromium did not exceed the national standard.The range of non-carcinogenic risks related to the soil heavy metal contamination was from 1.7 10^-6 to 8.25 10^-4;the health risks related to the contamination of the three metals decreased in an order of chromium,lead,and cadmium and were all less than the thresholds of 1.The range of carcinogenic risk of cadmium and chromium contamination was from 4.40 10^-9 to 4.34 10^-5,which was within the range of acceptable risk (10^-6-10^-4).The life expectancy loss due to soil cadmium contamination ranged from 0.03 minute to 1.17 minutes and that due to chromium contamination ranged from 29.22 minutes to 269.77 minutes.Conclusion There was farmland soil cadmium contamination but there were neither non-carcinogenic nor carcinogenic health risk related to the skin contact to farmland soil lead,cadmium,and chromium contamination in Hebei province.