Organochlorine Pesticides in Karst Soil: Levels, Distribution, and Source Diagnosis.

Excessive reclamation and improper use of agrochemicals in karst areas leads to serious non-point source pollution, which is of great concern and needs to be controlled, since contaminants can easily pollute groundwater due to the thin patchy soil and developed karst structures. The occurrences of organochlorine pesticides (OCPs) in karst soil were investigated by analyzing 25 OCPs in the karst soils near the Three Gorges Dam, China. The total concentrations of OCPs ranged 161-43,100 (6410 ± 9620) pg/g, with the most abundant compounds being p,p'-DDT and mirex. The concentration differences between the orchard and vegetable field and between upstream and downstream presented the influences of land-use type and water transport on the OCP spatial distributions. Composition analysis indicated the possible fresh inputs of lindane, technical DDT, aldrin, endrin, mirex, and methoxychlor. Their illegal uses implied an insufficient agrochemical management system in undeveloped karst areas. Principal component analysis with multiple linear regression analysis characterized the dominant sources from current agricultural use and current veterinary use in the study area. OCPs in the soils might not pose significant cancer risk for the residents, but they need to be controlled due to their illegal uses and bioaccumulation effect via the food chain.

Rapid transport of organochlorine pesticides (OCPs) in multimedia environment from karst area.

Karst groundwater is crucial, but particularly vulnerable to contaminants. Anthropologically derived pollutants on the surface-environment in karst areas could easily and rapidly enter groundwater through highly developed transmissible structures and threaten water safety. To investigate such transport, we analyzed 24 organochlorine pesticides (OCPs) in the multimedia environment from the Zigui karst area of China, where agriculture is the predominant human activity. OCPs were frequently detected with the total OCP concentrations ranged from 228 to 7970 pg/g, 300 to 32,200 pg/L, 318 to 2250 pg/L, 149 to 2760 pg/g, and 752 to 12,000 pg/g in the soil, spring water, river water, spring sediment, and river sediment, respectively. HCB and p,p'-DDT were the most dominant OCP species. Isomeric and metabolic ratios indicated fresh inputs of Lindane, technical DDT, and Aldrin, although they have been banned in China. The spatial distributions, correlation analysis, and regression analysis suggested rapid OCP transport from the soil to the spring water, and from the soil and spring water to river water. OCPs in the soil and springs explained 92.3% and 89.0% of those in the spring water and river water, respectively. The solid transport with the fast-moving water was predominant for OCPs in sediments. Highly dynamic water systems and rapid OCP transport in the intro- and inter-medium suggested by our results substantiate the groundwater's vulnerability in karst areas. More studies on levels and transport of organic contaminants in karst systems and policy for protecting the karst groundwater are urgently required to control contaminant sources and ensure groundwater sustainability, since the karst water resources may suffer a potentially bleak future consisted of the decreased groundwater quantity and low water quality.

Evaluation of Bayesian approaches to identify DDT source contributions to soils in Southeast China.

Dicofol application may be an important source to elevate the dichlorodiphenyltrichloroethane (DDT) residues to soils in Fujian, Southeast China, after the technical DDT was banned, which left DDT residues from the historical application. The DDT residues varied geographically, corresponding to the varied potential sources of DDT. In this study, a novel approach based on the Bayesian method (BM) was developed to identify the source contributions of DDT to soils, composed with both historical DDT and dicofol. The Naive Bayesian classifier was used basing on the subset of the samples, which were determined by chemical analysis independent of the Bayesian approach. The results show that BM (95%) was higher than that using the ratio of o, p'-/p, p'-DDT (84%) to identify DDT source contributions. High detection rate (97%) of dicofol (p, p'-OH-DDT) was observed in the subset, showing dicofol application influenced the DDX levels in soils in Fujian. However, the contribution from historical technical DDT source was greater than that from dicofol in Fujian, indicating historical technical DDT was still an important pollution source to soils. In addition, both the DDX (DDT isomers and derivatives) level and dicofol contribution in non-agricultural soils were higher than other agricultural land uses, especially in hilly regions, the potential cause may be the atmospheric transport of dicofol type DDT, after spraying during daytime, or regional difference on production and application.

[Association of eight single nucleotide polymorphisms of chromosomes 20 and X with androgenetic alopecia among ethnic Han Chinese from Yunnan].

OBJECTIVE: To assess the association of 8 single nucleotide polymorphisms (SNPs) from chromosomes X and 20 with androgenetic alopecia among ethnic Han population from Yunnan province. METHODS: An eight-SNP co-amplification protocol was developed for the genotyping with a SNaPshot platform. A case-control study was carried out for the 8 SNPs from chromosomes X and 20 in 115 androgenetic alopecia cases and 125 healthy controls. Statistical analysis was conducted with SPSS17.0, Haploview4.2, SHEsis and MDR software. RESULTS: No association was found between the two groups with regard to the 4 SNPs located on the X chromosome. The genotypic frequencies of rs2180439, rs913063 and rs1160312 were significantly different between the two groups (P < 0.05). The frequency of T allele of rs2180439 was significantly higher in the case group (P < 0.05). The frequencies of A alleles of rs913063 and rs1160312 were significantly higher in the case group (P < 0.05). The haplotypes of C-T-C-G, T-C-C-G and T-T-A-A based on rs6137444-rs2180439-rs913063-rs1160312 showed significant difference between the two groups (P <0.05). rs6137444, rs21804393 and rs1160312 have a strong association with androgenetic alopecia. CONCLUSION: The 4 SNPs located on chromosome X were all monomorphic among ethnic Hans from Yunnan. The rs6152, rs16990427, rs1352015, rs1385699 SNPs located on chromosome 20 are associated with androgenetic alopecia in the same population. Individuals with T allele of rs2180439 and A allele of rs913063 and rs1160312 are more likely to develop androgenetic alopecia.

[Association study of CNR1, GAD1 and BDNF polymorphisms with male heroin dependence in the Dai population in Yunnan].

In order to analyze the association of CNR1(Cannabinoid receptor 1), GAD1(Glutamate decarboxylase 1), and BDNF(Brain-derived neurotrophic factor) polymorphisms with male heroin dependence in the Dai population in Yunnan Province, an eight-SNP co-amplification protocol was established to genotype on the SNaPshot platform. A case-control study was performed with 8 SNPs from CNR1, GAD1, and BDNF genes in 165 heroin-dependent males and 170 healthy males of the Dai population. Statistical analyses were conducted with SPSS17.0, Haploview4.2, PHASE2.1, and MDR software. We found that: (1) the genotype frequency of rs13306221 was significant in the case group (P<0.025); (2) the A allelic frequency of rs6265 was significantly higher in the case group; (3) the haplotypes of T-A-C, C-C-C, C-C-T, and T-C-C based on rs1978340-rs3791878-rs11542313 and haplotype A-G based on rs6265-rs13306221 were significant (P<0.05); (4) the haplotype frequencies of T-A-C, C-C-T, and A-G were significantly higher in the case group. These results indicate that the linkage between rs1978340 and rs3791878 in GAD1 has a strong association with heroin dependence. Furthermore, polymorphisms in CNR1 (rs1049353), GAD1 (rs1978340 and rs11542313), and BDNF (rs6265 and rs13306221) were associated with heroin dependence in the Yunnan Dai population, and individuals with the rs6265 A allele were more likely to be heroin dependent.