Polychlorinated naphthalenes, polychlorinated dibenzo-p-dioxins and dibenzofurans, and polychlorinated biphenyls in soils in an industrial park in Northwestern China: Levels, source apportionment, and potential human health risks.

Seventeen soil samples collected in an industrial park located in Ningxia Province, Northwestern China were analyzed for polychlorinated naphthalenes (PCNs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and polychlorinated biphenyls (PCBs). The PCN, PCDD/F, and PCB concentration ranges were 183-3340, 7.00-215, and 45.1-355 pg/g, respectively. Positive matrix factorization showed that secondary ferrous metal smelters and cement kilns contributed more than 70% of the total PCN concentration. Historical use of Halowax 1051 also affected the PCN concentrations in soil. Principal component analysis indicated that the PCDD/F concentrations in soil in the study area were mainly affected by thermal processes in secondary ferrous metal smelters. CB-209 was an important contributor to total PCBs in the study area, and likely originated from the phthalocyanine-type pigments used in a local recycled paper mill. Samples S10, S1, S17, and S6 had high ∑TEQ (PCDD/Fs + PCNs + PCBs) concentrations, and the carcinogenic risks of PCDD/Fs, PCNs, and PCBs for workers from these samples were 0.487 × 10-6, 0.234 × 10-6, 0.230 × 10-6, and 0.210 × 10-6, respectively. According to our results, the health risks of PCDD/Fs, PCNs, and PCBs for workers in this area should be given more attention.

Levels, profiles and potential human health risks of brominated and parent polycyclic aromatic hydrocarbons in soils around three different types of industrial areas in China.

Brominated polycyclic aromatic hydrocarbons (Br-PAHs) are an emerging class of persistent organic pollutants with toxicity similar to dioxins. Industrial thermal processes have been identified as major sources of Br-PAHs in the current environment. However, studies on soil contaminations with Br-PAHs around industrial areas were scarce. In this study, 18 Br-PAHs and 16 PAHs were analyzed in soils around an electronic waste dismantling area (EDA), an industrial area that mainly performed steel smelting (SSP), and an industrial area mainly performed secondary copper smelting (SCS). The mean concentrations of Br-PAHs and PAHs were 1362 pg/g and 1034 ng/g, 582 pg/g and 13,938 ng/g, and 307 pg/g and 2211 ng/g in the soil around EDA, SSP, and SCS, respectively. The order of Br-PAH concentrations among three industrial areas was inconsistent with that of PAHs, suggesting that there may be some differences in contamination characteristics of Br-PAHs in three types of industrial areas. The significant correlation between Br-PAHs and parent PAHs indicated that direct bromination may be the main formation pathway of Br-PAHs in soils in EDA. The result of principal component analysis further revealed that the congener pattern of Br-PAHs in soils around EDA is different from that of SSP and SCS. It was found that the ratio of 1-BrPyr and 3-BrFlu can be applied to identify environmental contamination with Br-PAHs from e-waste dismantling. The health risk assessment results showed that there were some soil samples with carcinogenic risks above the risk threshold in each industrial area, and deserve our concern.

SNPs discovery and CAPS marker conversion in soybean.

To discover new SNPs and develop an easy assay method in soybean, we compared the high-throughput pyrosequencing ESTs with whole genome sequences in different soybean varieties and identified 3899 SNPs. Transitions were found to be much more frequent than transversions in these SNPs. We found that SNPs were widely distributed in the soybean genome, targeting numerous genes involved in various physiological and biochemical processes influencing important agronomic traits. A set of 16 SNPs were validated in nine soybean varieties, and seven SNPs were converted into CAPS. From functional gene association analysis, the marker CAPS282 on the 3'-UTR of gene Glyma07g03490 was identified as associated with 100-seed weight in soybean. The SNP discovery and CAPS markers conversion system developed in this study is fast and cost effective, and holds great promise for molecular-assisted breeding of soybean.

Genome-wide identification of intron fragment insertion mutations and their potential use as SCAR molecular markers in the soybean.

Introns often have a high probability of mutation as a result of DNA insertions and deletions (indels). In this study, 503 introns with exon-derived insertions were identified using a comprehensive search of the soybean genome. Of the 375 pairs of PCR primer sets designed for the loci in question, 161 primer sets amplified length polymorphism among nine soybean varieties and were identified as soybean gene-intron-driven functional sequence characterized amplified region (SCAR) markers. These SCAR markers are distributed among all 20 of the soybean chromosomes, and they developed from numerous genes involved in various physiological and biochemical processes that influence important agronomic traits of the soybean. The development of these novel gene-driven functional SCAR markers was fast and cost effective, and their use will facilitate molecular-assisted breeding of the soybean.