title: Spatial distribution and temporal trends of farmland soil PBDEs: processes and crop rotation effects.
abstract: The concentration and temporal trend of PBDEs in farmland soil during a circle of crop rotation period within an e-waste dismantling area of South China were investigated. The averaged current concentration of total PBDEs in the farmland soil was averaged 19.1 ± 20.7 ng/g dry weight, which was much lower than the PBDE level in roadside soil and in topsoil near e-waste dismantling sites. Spatial distribution of total PBDEs concentration in the study area showed higher level at the field near e-waste workshops and lower at the distanced farmland area. Soil organic carbon content was significantly correlated with concentration of BDE209 (r = 0.704, p < 0.01), but not related with the sum concentration of other PBDE compounds (r = 0.097, p > 0.1). During the whole crop rotation circle, the temporal concentration of PBDEs in the farmland soil was highest (25.3 ± 11.4 ng/g dry wt.) in April when early paddy had been transplanted for 1 or 2 weeks. When the crop rotated to autumn peanut in August and the land is turning dry, the PBDEs concentration in farmland soil reached the lowest level which was 8.1 ± 1.2 ng/g dry wt. The temporal trend of PBDEs in farmland soil was not consistent with that of atmospheric PBDEs and soil total organic carbon (TOC) content during the rotation cycle. It was concluded that the dynamics of PBDEs in the farmland soil is influenced by multiple, interacting factors, and not clearly related to neither the atmospheric deposition nor the organic carbon content of the soil, but possibly related to the micro-environmental conditions changed by crop rotation process.
authors.affiliation: Key Laboratory of Ministry of Land and Resources for Eco-geochemistry, National Research Center for Geoanalysis, Xicheng District, 26 Baiwanzhuang Street, Beijing, 100037, China. jiaoxch@pku.edu.cn.
authors.forename: Xingchun
authors.initials: X
authors.lastname: Jiao
authors.affiliation: Key Laboratory of Ministry of Land and Resources for Eco-geochemistry, National Research Center for Geoanalysis, Xicheng District, 26 Baiwanzhuang Street, Beijing, 100037, China.
authors.forename: Qifeng
authors.initials: Q
authors.lastname: Tang
authors.affiliation: Key Laboratory of Ministry of Land and Resources for Eco-geochemistry, National Research Center for Geoanalysis, Xicheng District, 26 Baiwanzhuang Street, Beijing, 100037, China.
authors.forename: Shu
authors.initials: S
authors.lastname: Chen
authors.affiliation: Institute of Geographic Sciences and Natural Resources Research, Beijing, 100101, China.
authors.forename: Yajia
authors.initials: Y
authors.lastname: Deng
authors.affiliation: Institute of Geographic Sciences and Natural Resources Research, Beijing, 100101, China.
authors.forename: Hongying
authors.initials: H
authors.lastname: Cao
authors.affiliation: Key Laboratory of Ministry of Land and Resources for Eco-geochemistry, National Research Center for Geoanalysis, Xicheng District, 26 Baiwanzhuang Street, Beijing, 100037, China.
authors.forename: Guang
authors.initials: G
authors.lastname: Wang
authors.affiliation: Key Laboratory of Ministry of Land and Resources for Eco-geochemistry, National Research Center for Geoanalysis, Xicheng District, 26 Baiwanzhuang Street, Beijing, 100037, China.
authors.forename: Yongliang
authors.initials: Y
authors.lastname: Yang
mesh_terms: D000383:Agriculture; D002681:China; D004784:Environmental Monitoring; D000072480:Farms; D055768:Halogenated Diphenyl Ethers / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*; D013997:Time Factors
chemical_list: D055768:Halogenated Diphenyl Ethers; D012989:Soil Pollutants
keywords: Crop rotation; Farmland soil; Polybrominated diphenyl ethers (PBDEs); Spatial distribution; Temporal trend