The derivation of soil generic assessment criteria for polychlorinated biphenyls under the agricultural land scenario in Pearl and Yangtze River Delta regions, China

Abstract

The agricultural soils in China are suffered from serious polychlorinated biphenyls (PCBs) contamination, however, the valid management standards for farmland are absent to efficiently control the health risks of PCBs exposure. This study analyzed the contamination characteristics and main composition of PCBs in agricultural soils of the southeastern China from the published literature over the past 20 years, and derived the regional generic assessment criteria (GAC) using an exposure modelling approach for individual and total PCBs (∑PCBs) via multiple exposure pathways such as ingestion of soil and dust, consumption of vegetables, dermal contact with soil and dust, ingestion of soil attached to vegetables, and inhalation of soil vapour and soil-derived dust outdoors under the agricultural land scenario. It is identified that the averaged ∑PCBs concentration of 80.03 ng g−1 under the 95 % lower confidence limit with an unacceptable health risk of 4.8 × 10−6 has significantly exceeded the integrated generic assessment criteria (expressed as GACint) of 16.5 ng g−1. Accordingly, the exposure pathways from the consumption of agricultural produces and indirect ingestion of soil attached to vegetables contributed up to 62 %–88 % of the total exposure, followed by 11 %–33 % of the soil ingestion and 2 %–6 % of dermal contact. The derived GACint for ∑PCBs is extremely valuable to effectively assess and manage the PCBs contamination in agricultural soils of China.