Concentration, uptake and human dietary intake of novel brominated flame retardants in greenhouse and conventional vegetables

Abstract

The possible adverse effects of organic pollutants entering vegetables have attracted increasing attention in recent years. However, research on the behavior of novel brominated flame retardants (NBFRs) in soil-vegetable systems is still limited. This work was initiated to investigate the uptake of seven representative NBFRs by vegetables from bulk soil and suspended soil particles under greenhouse and conventional conditions. The mean concentrations of the sum of seven NBFRs (Σ7 NBFRs) were 2.8 and 3.8 ng g−1 dw in greenhouse tomatoes and cucumbers, respectively, and 1.1 and 1.7 ng g−1 dw in conventional tomatoes and cucumbers, respectively. Greenhouse vegetables had higher concentrations of Σ7 NBFRs than conventional vegetables. The root bioaccumulation factors (RBCFs) of tomatoes and cucumbers in response to NBFRs ranged from 0.6 to 6.3. The range of fruit bioaccumulation factors (FBCFs) was 0.3–7.0. The bioaccumulation factors (BCFs) in greenhouse vegetables were significantly higher than those in conventional vegetables, indicating that greenhouses increased the uptake of NBFRs by vegetables. To address human dietary exposure to NBFRs, the estimated dietary intake (EDI) and the amounts available for human absorption (EDIba) were calculated using vegetable consumption and gastrointestinal absorption, respectively. The mean EDI values of NBFRs from greenhouse and conventional tomato consumption were 344 ng d−1 and 109 ng d−1, respectively. The mean EDI values of NBFRs from greenhouse and conventional cucumber consumption were 445 ng d−1 and 217 ng d−1, respectively. The higher EDI values of NBFRs implied that consuming greenhouse vegetables was associated with higher health risks than consuming conventional vegetables. The mean EDIba values of the DBDPEs were 68 ng d−1 and 46 ng d−1 for tomatoes and cucumbers, respectively, and were significantly different from the EDI values due to lower bioaccessibility. Gastrointestinal absorption should not be neglected during risk assessments of human exposure to pollutants.