Persistent Toxic Substances in Agricultural Soils of Lishui County, Jiangsu Province, China

Abstract

The contamination status and distribution of PTS, including HCHs, DDTs, PCBs, and PAHs, were studied in the agricultural soil of Lishui County, one of China's nationally designated eco-demonstration region. The PTS was analyzed by GC, GC/MS, and HPLC coupled with microwave extraction. The concentrations of the sum of HCHs, DDTs, and PCBs ranged from <0.1 ng g(-1) to 133 ng g(-1), 93.8 ng g(-1), and 81.0 ng g(-1) (dry wieght), respectively; while the contents of the sum of PAHs ranged from 3.26 ng g(-1) to 91.0 ng g(-1) (dry wieght). The soil investigation revealed that there were no recent HCHs and DDTs pollution; none of the soil PCBs concentrations suggested a serious biological threat in the investigated area; the extent of pollution of PAHs was low compared to other investigations. In summary, levels of PTS contamination in the soil of the Lishui County were relatively low, but caution should be taken in industrial zone.

Contamination and Congener Profiles of Polychlorinated Biphenyls from different agricultural top soils in a county of the Tailake Region, China

“…Thus, the heavier homologues generally tend to be retained by the soil more than the lighter ones. The results in nearby regions that showed that the pentachlorinated and hexachlorinated PCBs were the dominant congeners in leaves and agricultural soil were consistent to the congener profiles in Taicang vegetable soil [3,11,13,14]. But the paddy field is often covered by water and less cultivated than the vegetable fields, which decreases the chance of PCBs atmosphere-soil exchange especially the lighter homologues with higher vapor pressure and increases the dechlorination of heavier chlorinated congeners.…”

“…Backe et al reported that PCB concentrations in soils of south Sweden showed a large variation between various sampling sites, and PCB congener composition was shown to differ between sites, with congener patterns almost site-specific [19]. The studies in nearby region Zhangjiangang, Changsu, and Lisui showed that PCB 118 had the highest concentration in all congeners of PCBs in soil [3,14]. But the study in Tai Lake, Hangzhou Bay and Shanghai City region showed the PCB 138 was the highest concentration congener in agricultural soil [13].…”

“…In general, the PCBs in our study was higher than that in Tai lake, Hangzhou Bay and Shanghai city region, ranged from 0.01 g kg −1 to 0.62 g kg −1 with not mentioning the numbers of congeners [13], but lower than those in Zhangjiagang and Changshu with a mean of 4.13 g kg −1 , ranged from ND to 32.83 g kg −1 including 13 congeners [3] and in Lishui with a median of 5.75 g kg −1 , ranged from ND to 81.0 g kg −1 including 20 congeners [14], and also lower than that of another result in industrial zone of Shanghai with a mean of 48.91 g kg −1 , ranged from 0.5 to 586.85 g kg −1 including 42 congeners [11]. The results were also lower than that in global background surface soils with a mean concentration of 5.41 g kg −1 consisting of 29 PCB congeners [15], but higher than that in Chinese average surface soil with a mean concentration of 0.515 g kg −1 consisting of 59 PCB congeners [16].…”

Polycyclic aromatic hydrocarbon concentrations in urban soils representing different land use categories in Shanghai

“…The mean concentrations of soil total PAHs in all districts were greater than 3000 lg/kg. Maliszewska-Kordybach (1996) developed a classification system of contamination of soils by PAHs (Table 2) based on studies of PAH concentrations in European soils, as well as from an estimation of risk of human exposure, and the classification has been widely accepted and cited (Morillo et al 2008;Hu et al 2009). According to the classification system all the sampling areas apart from an urban park can be considered to be heavily contaminated with PAHs.…”

Distribution of polychlorinated biphenyls in both products and by-products of a mussel shell incinerator facility

“…Ultrasound-assisted solvent extraction (UASE) (Errekatxo et al 2008;Rocco et al 2008), microwave-assisted extraction (MAE; Hu et al 2009), supercritical fluid extraction (SFE; Song et al 2002), and pressurized liquid extraction (PLE; Antunes et al 2009) have recently been used to circumvent the shortcomings of classical extraction methods for this purpose.…”