Occurrence and human health implications of chemical contaminants in vegetables grown in peri-urban agriculture

Recent studies have proven that vegetables cultivated in peri-urban areas are exposed to a greater concentration of organic microcontaminants (OMCs) and trace elements (TEs) than those grown in rural areas. In this study, the occurrence and human health risk of chemical contaminants (16 TEs and 33 OMCs) in edible parts of lettuce, tomato, cauliflower, and broad beans from two farm fields in the peri-urban area of the city of Barcelona and one rural site outside the peri-urban area were assessed. The concentration of TEs and OMCs (on fresh weight basis) ranged from non-detectable to 17.4 mg/kg and from non-detectable to 256 μg/kg, respectively. Tomato fruits showed the highest concentration of TEs and OMCs. Principal component analysis indicated that the occurrence of chemical contaminants in vegetables depended on the commodity rather than the location (peri-urban vs rural). Risk assessment using hazardous quotient (HQ) and threshold of toxicological concern (TTC) approaches showed that the risk for the consumption of target vegetables in the peri-urban area was low and similar to that observed for the rural site. Total HQ values for TEs were always below 1, and a minimum consumption of 150 g/day for children and 380 g/day for adults is required to reach the TTC due to the presence of pesticides. Further studies are needed to estimate the combined effect of TEs and OMCs on human health. © 2018 The AuthorsThe authors gratefully acknowledge the financial support of the Spanish Ministry of Economy, Industry and Competitiveness (MEIC) through Project AGL2014-59353-R . A. M. and Dr. V. M. would also like to acknowledge an FPI fellowship ( BES-2015-075745 ) and a Ramon y Cajal contract ( RYC-2013-12522 ) from the MEIC . The authors would further like to greatly thank the officers and farmers of the Baix Llobregat Agrarian Park for their assistance, as well as Ms. Yolanda Rodríguez, Ms. Marta Turull, Ms. Rui You, and Mr. Manel Martín for their technical assistance with the sampling and sample preparation. Appendix APeer reviewe