Abstract
Attempts were made to assess the contributions of different pathways of heavy metal exposure to the carcinogenic and non-carcinogenic risks based on the field samplings and questionnaire surveys of children residing in an informal e-waste processing village and a reference village in Viet Nam. The results showed that the ingestion of cooked rice contributed the most (69.20 − 99.60%), followed by the ingestion of soil (0.32 − 29.53%), to the environmental health risks of exposure to a mixture of Pb, Cd, Cr, Ni, and As in children from the two villages. Ingestion of drinking water and dermal contact of soil, however, contributed negligibly. It was found that the non-carcinogenic risk of each heavy metal from four pathways was less than 1, with Ni (0.48), As (0.44), Cd (0.23), Cr (0.19), and Pb (0.14), meaning these heavy metals are unlikely to cause an adverse non-carcinogenic risk to a child. It was also found that the carcinogenic risks for each heavy metal, except that for dermal contact of soil to children were higher than the benchmark value of 10−6 set by USEPA, indicating the likelihood of carcinogenic risks to children, especially to those aged 8 − 10 years. Children whose parents were engaging in e-waste processing activities and those who lived in a distance less than 10 m from an e-waste processing site sustained greater carcinogenic and non-carcinogenic risks.
Acknowledgments
The authors acknowledge the valuable assistance provided by the volunteers; local authorities of Cam Xa Commune, My Hao District, Hung Yen Province, Viet Nam; staff of the NIOEH, Viet Nam; and the scientists and technicians at the laboratory of the Department of Medical Testing and Environmental Analysis, NIOEH. Special thanks go to Dr. Ha Thai Le and Dr. Binh Thi Ta at the NIOEH. Completion of this study would not have been possible without their assistance. The authors also acknowledge the financial support provided by the Thammasat University Research Fund under the Thammasat University Research Scholar, Thailand, Contract No. 75/2561.
Disclosure statement
The authors declare that there is no conflict of interest.