Distributions and compositions of old and emerging flame retardants in the rhizosphere and non-rhizosphere soil in an e-waste contaminated area of South China

Plant selective uptake of halogenated flame retardants at an e-waste recycling site in southern China

“…Concentrations measured in this study were lower than those found in eucalyptus foliage (0.45e16.7 ng g À1 ) and pine needles (0.51e51.9 ng g À1 ) at another e-waste site, but close to those measured in plant samples from the reference site (0.09e2.46 ng g À1 ) , which indicated that DPs were not the dominant contaminant at this e-waste recycling site. This was also confirmed by the relatively low concentrations of DPs in the corresponding soils described in our previous study (Wang et al, 2016). Previous studies (Tian et al, 2012 reported that concentrations of DBDPE were lower than those of BDE 209 in pine needle and air samples around e-waste contaminated sites.…”

“…In this study, the values of f anti (ratio of anti-DP to total DPs) ranged from 0.48 to 0.67 (mean ¼ 0.57) in shoots and 0.46 to 0.75 (mean ¼ 0.61) in roots (Table S1), lower than the values in a commercial DPs product (0.75e0.8) (Qiu et al, 2007), but higher than those reported in rhizosphere soils (ranging from 0.47 to 0.61, with an average of 0.53) (Wang et al, 2016). This was an indication that DPs in the study area may not originate from raw commercial DPs products, and anti-DP and syn-DP underwent different environmental processes.…”

“…Higher proportions of TBPH and TBB were found in roots than in shoots. Meanwhile, TBE, TBB, and TBPH were found to be concentrated selectively in roots in comparison, with concentrations in the corresponding rhizospheric soil reported previously (Wang et al, 2016). It is clear that lower brominated flame retardants were prone to uptake by plant roots.…”

“…A relatively low proportion of BDE 209 (mean ¼ 33%) was found in shoots, while a predominance of BDE 209 in roots was found in most samples, with a mean value of 60.9%. However, the proportions of lower brominated PBDEs (BDEs 28 and 47) in vegetable roots were much higher than those in the corresponding rhizosphere soils, as shown in our previous study (Wang et al, 2016). In addition, our previous result showed that lower brominated PBDEs were acropetally translocated preferentially from roots to shoots, in comparison with higher brominated PBDEs, after growing on e-waste contaminated soils for 60 days (Wang et al, 2015a).…”

“…ssp., P11), snow peas (Pisum sativum, P12), sweet potato (Ipomoea batatas (L.) Lam., P13), and lettuce (Lactuca sativa, P14) were sampled. In addition, the corresponding rhizosphere soils were also collected, and the detail descriptions can be found in our previous study (Wang et al, 2016). Each sample was composed of at least three subsamples collected from the same type of vegetable around the sampling site.…”