Source and Health Risk Assessment of Some Heavy Metals in Non-Certified Organic Rice Farming at Nakhon Nayok Province, Thailand

Abstract

Heavy metals contamination in non-certified organic rice farming without buffering zone are affected by many factors. The monitoring and assessment in agricultural soils and rice grain are required to estimate the potential risk of organic products. The occurrence of heavy metals in agricultural soils and rice grain were in a ranking order of Pb > Mn > Zn > Cu > Ni and   Zn > Mn > Pb > Cu > Ni, respectively. However, Pb and Zn contents were more than exceeded the maximum permissible in rice grain.  The non-certified organic rice farming might cause health risk for consumers,  the high Health Index (HI) values of rice consuming  for adults male (5.10-35.09) and female (6.12-42.08) indicated that their adverse health effect still be serious problem for consumers by taking rice products from these non-certified organic rice farming. Basing on the person’s correlation analysis and principle components analysis indicated that Target Hazard Quotients (THQ) of Zn was positive correlated with Zn content in soil and Zn bioaccumulation in rice.  Highlights, contamination sources were identified that Zn and Mn mainly derived from main road and community activities, while, Pb and Cu contaminants mainly derived from paddy field activities. This funding will confirm awareness for health risk of non-certified organic rice farming.