Distribution characteristics, risk assessment, and relevance with surrounding soil of heavy metals in coking solid wastes from coking plants in Shanxi, China.

Heavy metal concentrations represent important pollution evaluation indices, and it is necessary to assess the potential environmental and health risks from heavy metals associated with coking wastes from coking plants. In this study, coking sludge (CS), tar residue (TR), coke powder (CP), and sulfur paste (SP) from three coking plants (Plant A, Plant B, and Plant C) in central, western, and southern Shanxi Province and from soils surrounding Plant A were selected as the research objects, and the distributions of Cu, Ni, Pb, Zn, Mn, Cd, and Cr were determined. The results showed that Cd in the four solid wastes far exceeded the soil background value by a factor of 16~195, and the contents of Pb in TR (three plants) and CS (Plant C) exceeded the soil background values 19.70-, 23.57-, 14.46-, and 12.56-fold, respectively. Similarly, the concentrations of Cu, Ni, Pb, Zn, and Cd in soils were higher than the background values by factors of 31.18, 8.35, 34.79, 29.48, and 3.43, respectively. In addition, the Cu, Ni, Pb, and Cr in the four solid wastes and soils mainly existed in the residual state. As depth increased, the overall Ni, Pb, Mn, and Cd concentrations in soils increased. The high ecological risks associated with the four solid wastes were mainly due to the enrichment of Cd. Workers in coking plants face certain Cr health risks. This study provides theoretical support for the coking industry with respect to the treatment, disposal, and management of solid wastes.

Spatial variability and risk assessment of heavy metals in the soil surrounding solid waste from coking plants in Shanxi, China.

Heavy metal pollution in the soil surrounding solid wastes from coking plants poses potential threats to human health and has attracted widespread attention. This study is the first to assess the spatial variability and risks of heavy metals in the soil surrounding solid waste from coking plants. The results showed that the concentrations of Cu, Ni, Pb, and Cd in the soil were much higher than the background value of the soil. Solid waste had a clear influence on the contents of Ni, Cd, Mn, Pb, and Cr in the soil. The ecological risk assessment of heavy metal pollution demonstrated that the pollution degree of Cu, Pb, and Cd was more serious than others, and the ecological risk of heavy metals was mainly caused by Cd in the soil. The human health risk assessment showed that adults and children near coking plants might face carcinogenic risk from exposure to Cr. This study can provide a theoretical basis for the prevention and management of soil heavy metal pollution surrounding solid waste in coking plants.

Quantitative assessment of the association between XRCC6 C1310G polymorphism and cancer risk.

X-ray cross-complementing group 6 (XRCC6) plays an important role in the DNA double-strand breaks repair and the maintenance of genomic integrity. XRCC6 C1310G polymorphism may be involved in the development of cancer through increasing genomic damages. However, studies investigating the relationship between XRCC6 C1310G polymorphism and cancer risk yielded contradictory results. To shed some light on these inconsistent findings, a meta-analysis was performed to clarify the effect of XRCC6 C1310G polymorphism on the susceptibility of cancer. A systemic literature search of PubMed, EMBASE, and China National Knowledge Infrastructure databases was conducted from their inception to September 26, 2012. The association between XRCC6 C1310G and cancer risk was assessed by the pooled odds ratio (OR) with 95 % confidence intervals (95 % CI) calculated by meta-analysis. A total of 15 eligible studies (4,642 cancer cases and 6,059 controls) were identified. Overall, there was obvious evidence for an association between XRCC6 C1310G polymorphism and increased risk of cancer under two genetic comparisons (GG vs. CC: fixed-effect OR 1.35, 95 % CI 1.10-1.66, I (2) = 17.0 %; GG vs. CG/CC: fixed-effect OR 1.25, 95 % CI 1.02-1.53, I (2) = 0.0 %). Subgroup analysis indicated that the association was significant in Asians (G vs. C: random-effect OR 1.13, 95 % CI 1.01-1.26, I (2) = 51.3 %; GG vs. CC: fixed-effect OR 1.43, 95 % CI 1.14-1.81, I (2) = 0.0 %; GG vs. CG/CC: fixed-effect OR 1.37, 95 % CI 1.09-1.72, I (2) = 0.0 %), but not in Europeans. Data from the current meta-analysis support the existence of an association between XRCC6 C1310G polymorphism and cancer risk in Asians. Studies with larger sample size are needed to further evaluate the influence of XRCC6 C1310G polymorphism on susceptibility of various cancers.

[Safety value of contaminant in water pollution accident based on human health risk].

The acute human health risk assessment of contaminant in water pollution accident is a new study field of environmental sciences. This study established a model for calculating acute safety value of contaminant in water pollutant. The acute safety value of contaminant in mainly water pollution during 2000-2010 was calculated by this model. The safety value of sodium cyanide, cadmium, formaldehyde, ammonia, toluene, nitrobenzene, microcystin-LR were 0.1, 0.6, 8, 20, 6, 0.07, 0.004 mg x L(-1), respectively. The differences of safety value calculate methods between acute and chronic exposure were compared from the following aspects, the toxicology exposure end-point, allocation of intake, exposure sensitive subpopulation.