Source analysis and risk evaluation of heavy metal in the river sediment of polymetallic mining area:Taking the Tonglüshan skarn type Cu-Fe-Au deposit as an example,Hubei section of the Yangtze River Basin,China

In this paper,25 sampling points of overlying deposits in Tonglushan mining area,Daye City,Hubei Province,China were tested for heavy metal content to explore pollution characteristics,pollution sources and ecological risks of heavy metals in sediments.A geo-accumulation index method was used to evaluate the degree of heavy metal pollution in the sediment.The mean sediment quality guideline quotient was used for evaluating the ecological risk level of heavy metal in the sediment.And a method of correlation analysis,clustering analysis,and principal component analysis was used for preliminary analysis on the source of heavy metal in the sediment.It was indicated that there was extremely heavy metal pollution in the sediment,among which Cd was extremely polluted,Cu strongly contaminated,Zn,As,and Hg moderately contaminated,and Pb,Cr,and Ni were slightly contaminated.It was also indicated by the mean sediment quality guideline-quotient result that there was a high ecological risk of heavy metals in the sediment,and 64%of the sample sites had extremely high hidden biotoxic effects.For distribution,the contamination of branches was worse than that of the main channel of Daye Dagang,and the deposition of each heavy metal was mainly influenced by the distance from this sample site to the sewage draining exit of a tailings pond.The source analysis showed that the heavy metals in the sediment come from pollution discharging of mining and beneficiation companies,tailings ponds,smelting companies,and transport vehicles.In the study area,due to the influence of heavy metal discharging from these sources,the ecotoxicity of heavy metals in the sediment was extremely high,and Cd was the most toxic pollutant.The research figured out the key restoration area and elements for ecological restoration in the sediment of the Tonglüshan mining area,which could be referenced by monitoring and governance of heavy metal pollution in the sediment of the polymetallic mining area.

Influence of serum adiponectin level and SNP +45 polymorphism of adiponectin gene on myocardial fibrosis

Adiponectin plays an important role in the development of hypertension, atherosclerosis, and cardio- myocyte hypertrophy, but very little was known about the influence of serum adiponectin or the adiponectin gene polymorphism on myocardial fibrosis. Our study investigates the influence of the SNP ＋45 polymorphism of the adi- ponectin gene and serum levels of adiponectin on myocardial fibrosis in patients with essential hypertension. A case-control study was conducted on 165 hypertensive patients and 126 normotensive healthy controls. The geno- types of adiponectin gene polymorphisms were detected by the polymerase chain reaction （PCR） method. Serum concentrations of procollagen were measured by a double antibody sandwich enzyme-linked immunosorbent assay （ELISA） in all subjects. The integrated backscatter score （IBS） was measured in the left ventricular myocardium using echocardiography. The serum levels of adiponectin in hypertensive patients were significantly lower than those in the normal control group （（2.69±1.0） μg/ml vs. （4.21±2.89） μg/ml, respectively, P〈0.001）. The serum levels of type-Ⅰ procoilagen carboxyl end peptide （PiCP） and type-Ⅲprocollagen ammonia cardinal extremity peptide （PIIINP） in the hypertension group were significantly higher than those in the control group. In the hypertension group, serum levels of adiponectin were significantly and negatively related to the average acoustic intensity and corrected acoustic intensity of the myocardium （t=0.46 and 0.61, respectively, P〈0.05 for both）. The serum levels of PICP and PIIINP were sig- nificantly different among the three genotypes of SNP ＋45 （P〈0.01）. Logistic regression analyses showed that sex and genotype （GG＋GT） were the major risk factors of myocardial fibrosis in hypertensive patients （OR=5.343 and 3.278, respectively, P〈0.05）. These data suggest that lower levels of adiponectin and SNP ＋45 polymorphism of the adi- ponectin gene are likely to play an important role in myocardial fibrosis in hypertensive patients.