Human health risk due to consumption of vegetables contaminated with carcinogenic polycyclic aromatic hydrocarbons

Abstract

Purpose Polycyclic aromatic hydrocarbons (PAH) are persistent, toxic, and carcinogenic contaminants present in soil ecosystem globally. These pollutants are gradually accumulating in wastewater-irrigated soils and lead to the contamination of vegetables. Food chain contamination with PAH is considered as one of the major pathways for human exposure. This study was aimed to investigate the concentrations of PAH in soils and vegetables collected from wastewater-irrigated fields from metropolitan areas of Beijing, China. Origin of PAH, daily intake, and health risks of PAH through consumption of contaminated vegetables were studied. Materials and methods Soil samples were collected from the upper horizon (0-20 cm) of both wastewater-irrigated and reference sites and sieved (<2 mm mesh) and then followed by freeze-drying at −50°C and 123 ± 2 Pa. Standing vegetables were also collected from the same sites used for soil sampling and divided into roots and shoots, thoroughly washed with deionized water, and freeze-dried. PAH were extracted using the Soxhlet method with 200 mL DCM for 24 h, and the extracts were cleaned with silica adsorption chromatography prepared with silica gel, alumina, and capped with anhydrous sodium. The final concentrated extracts (soil and vegetable) were analyzed using gas chromatography-mass spectrometry (Agilent 6890). Bioaccumulation factors, daily intake of PAH, and carcinogenicity of PAH were calculated by different statistical equations. (BaP). The emission sources of PAH were both pyrogenic and petrogenic in nature. However, the total concentrations of PAH were lower than the permissible limits set by different countries like Canada, Denmark and Germany. Highest total PAH concentration was found in the shoots of Spinacia oleracea L., while lowest in the roots of Raphanus sativus. In this study, the values of total toxic BaP equivalent (TEQ) through consumption of vegetables were found in order of S. oleracea L.>Lactuca sativa L.> Brassica oleracea L.>Brassica napus>Brassica juncea L.>R. sativus L. The data indicate that the daily intake of BaP through consumption of vegetables for adults were lower than virtually safe dose set by the Dutch National Institute for Public Health and the Environment. Conclusions Our findings indicate that PAH concentrations in soil and vegetables were lower than their respective permissible limits set by different organizations. However, the highest intake of total PAH was estimated through consumption of S. oleracea L. for both adults and children.

Quantification of PAHs and health risk via ingestion of vegetable in Khyber Pakhtunkhwa Province, Pakistan

“…A conversion factor of 0.085 was used to convert fresh green vegetable weight to dry weight, as described by Rattan et al (2005). Average daily vegetable intake for adults and children were considered of 0.345 and 0.232 kg person −1 d −1 , respectively, while the average adult and children body weights were considered of 63.9 and 32.7 kg, respectively, as used in the previous studies (Ge, 1992;Wang et al, 2005;Khan and Cao, 2012).…”

Polycyclic aromatic hydrocarbons (PAHs) in soils and vegetation near an e-waste recycling site in South China: Concentration, distribution, source, and risk assessment

“…Numerous studies have demonstrated that vegetables can take up and accumulate PAHs from the contaminated environment (Wennrich et al, 2002;Zohair et al, 2006;Khan and Cao, 2012). The mechanisms responsible for the PAH transfer to plant tissues primarily include sorption from soil particles, uptake by the roots through transpiration, and absorption through the waxy leaf cuticle or through stomata (Wild et al, 2004;Meudec et al, 2006).…”

“…Thus, heavy pollution at an e-waste recycling area may result in an elevated uptake of PAHs into vegetables. Because diet is considered the major source of human exposure to PAHs (Phillips, 1999) and vegetables are the basic food in the Chinese diet, potential health risks might be involved in consuming these contaminated vegetables (Tao et al, 2004;Zhao et al, 2009;Khan and Cao, 2012). However, most previous studies have focused on contamination by PCBs and BFRs (Ma et al, 2009a;Zhao et al, 2009;Wang et al, 2011a), and few studies were performed on the accumulation, distribution, and potential health risk of PAHs, especially in vegetables grown near e-waste recycling areas.…”

Distribution, Sources, and Association of Polycyclic Aromatic Hydrocarbons, Black Carbon, and Total Organic Carbon in Size-Segregated Soil Samples Along a Background–Urban–Rural Transect

“…Studies have found that human exposure to PAHs occurs more prominently via soils than via air or water (Torre-Roche et al, 2009). PAHs in soils, once accumulated, lead to contamination of vegetables and other crops to enter the food chain as one of the key human exposure routes (Yap et al, 2010;Khan and Cao, 2011).…”