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

Anna Margenat,Víctor Matamoros,Sergi Díez,Nuria Cañameras,Jordi Comas,Josep M Bayona

doi:10.1016/j.envint.2018.12.013

Abstract

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.

Highlights

The consumption of vegetables grown with peri-urban agriculture has grown exponentially due to the increase in urban demand (Olsson et al, 2016)
Recent studies have highlighted that vegetables cultivated in peri-urban areas are generally exposed to a higher concentration of chemical contaminants than those grown in rural areas (Christou et al, 2017b; Säumel et al, 2012)
The present study aims to expand on those results and assess the occurrence of these contaminants (16 trace elements (TEs) and 33 organic microcontaminants (OMCs)) in several vegetables, as well as to assess the potential risk to human health associated with the consumption of vegetables grown on peri-urban farms

Summary

Introduction

The consumption of vegetables grown with peri-urban agriculture has grown exponentially due to the increase in urban demand (Olsson et al, 2016). Recent studies have highlighted that vegetables cultivated in peri-urban areas are generally exposed to a higher concentration of chemical contaminants than those grown in rural areas (Christou et al, 2017b; Säumel et al, 2012). Concerns about the chemical contamination of vegetables grown on peri-urban farms have risen due to the potential human health risk implications of consuming contaminated vegetables (Augustsson et al, 2018; Huang et al, 2018). The main health risks associated with peri-urban horticulture include the contamination of vegetables with agrochemical residues and trace elements (TEs) such as heavy metals (Birley and Lock, 1999). It is important to notice that soil amending may result in a higher vegetable exposure to heavy metals (Antisari et al, 2015)

Methods

Results

Conclusion