限制性片段长度多态性分析(ARDRA)方法对重金属污染土壤中细菌群落多样性的研究

限制性片段长度多态性分析(ARDRA)是用限制性内切酶消化扩增后的细菌16SrDNA,通过凝胶电泳分析微生物种群多样性的分子标记技术,该技术在微生物生态学领域有着广泛的应用.实验采用2种途径评价了这种方法应用于研究土壤中细菌种群多样性的可行性.通过对未污染土壤细菌16SrDNA的克隆,获得了经内切酶HaeⅢ消化的不同16SrDNA的ARDRA类型,并对测序的19个克隆子建立了系统发育树.此外,还对不同Cd和Pb污染水平的土壤微生物进行了群落水平上的ARDRA分析.结果表明,5mg·kg-1Cd和500mg·kg-1Pb污染对微生物群落组成有一定影响,但此范围内的重金属含量对微生物群落多样性没有相关性影响.

Accumulation of Pb,Cu,and Zn in native plants growing on contaminated sites and their potential accumulation capacity in Heqing,Yunnan

Phytoremediation is one of the cost-effective and environmental friendly technologies used to remove contaminants from contaminated soils,which has been intensively studied during the last decade.Presently,few economical and effective remediation methods are available for the remediation of Pb contaminated sites.This study was conducted to assess the potential of 19 plants growing on contaminated sites in Pb mine area.Plants and associated soil samples were collected and analyzed for total metal concentrati...

Potentially harmful metals,and health risk evaluation in groundwater of Mardan,Pakistan:Application of geostatistical approach and geographic information system

This study investigates the values of pH,total dissolved solids(TDS),elevation,oxidative reduction potential(ORP),temperature,and depth,while the concentrations of Br,and potentially harmful metals(PHMs)such as Cr,Ni,Cd,Mn,Cu,Pb,Co,Zn,and Fe in the groundwater samples.Moreover,geographic information system(GIS),XLSTAT,and IBM SPSS Statistics 20 software were used for spatial distribution modeling,principal component analysis(PCA),cluster analysis(CA),and Quantile-Quantile(Q-Q)plotting to determine groundwater pollution sources,similarity index,and normal distribution reference line for the selected parameters.The mean values of pH,TDS,elevation,ORP,temperature,depth,and Br were 7.2,322 mg/L,364 m,188 mV,29.6℃,70 m,0.20 mg/L,and PHMs like Cr,Ni,Cd,Mn,Cu,Pb,Co,Zn,and Fe were 0.38,0.26,0.08,0.27,0.36,0.22,0.04,0.43 and 0.86 mg/L,respectively.PHMs including Cr(89%),Cd(43%),Mn(23%),Pb(79%),Co(20%),and Fe(91%)exceeded the guideline values set by the world health organization(WHO).The significant R^(2)values of PCA for selected parameters were also determined(0.62,0.67,0.78,0.73,0.60,0.87,-0.50,0.69,0.70,0.74,-0.50,0.70,0.67,0.79,0.59,and-0.55,respectively).PCA revealed three geochemical processes such as geogenic,anthropogenic,and reducing conditions.The mineral phases of Cd(OH)_(2),Fe(OH)_(3),FeOOH,Mn_(3)O_(4),Fe_(2)O_(3),MnOOH,Pb(OH)_(2),Mn(OH)_(2),MnO_(2),and Zn(OH)_(2)(-3.7,3.75,9.7,-5.8,8.9,-3.6,2.2,-4.6,-7.7,-0.9,and 0.003,respectively)showed super-saturation and under-saturation conditions.Health risk assessment(HRA)values for PHMs were also calculated and the values of hazard quotient(HQ),and hazard indices(HI)for the entire study area were increased in the following order:Cd>Ni>Cu>Pb>Mn>Zn>Cr.Relatively higher HQ and HI values of Ni,Cd,Pb,and Cu were greater than one showing unsuitability of groundwater for domestic,agriculture,and drinking purposes.The long-term ingestion of groundwater could also cause severe health concerns such as kidney,brain dysfunction,liver,stomach problems,and even cancer.

Metals toxicity and its bioaccumulation in purslane seedlings grown in controlled environment

We aimed to find the toxicological impacts of Cd, Pb and Zn in single dozes and in combinations on Purslane (Portulaca oleracea) seedling. The Pursolane seedlings? grown in pots in a green house were treated with different soil treatments spiked (mg/kg) with Pb (300, 400 and 500), Cd (0.5, 1 and 1.5), and Zn (250, 500, 700) alone and then in specified combinations/concentrations i.e., Cd/Pb (0.5/300, 1/400, 1.5/500), Cd/Zn (0.5/250, 1/500, 1.5/700) and Pb/Zn (300/250, 400/500, 500/ 700). The results indicated that increasing concentrations of the studied HMs in seedlings tissues significantly (p P. oleracea seedling, compared to Pb and Zn. Roots of P. oleracea seedlings were more sensitive to the studied HMs in comparison with shoot. The uptake patterns showed antagonistic impacts on each other and were reflected in response to growth parameters. The combine toxicities of Cd, Pb and Zn (Cd/Pb, Cd/Zn and Pb/Zn) were more than the toxicity due to single dose of each element but less than their additive sums.

Organic and Inorganic Mercury in Biological Samples of Flouresecent Lamp Industries Workers and Health Risks

Objective The present study aims to investigate the concentrations of Hg and its aspects methyl mercury(Me-Hg)and inorganic mercury(I-Hg)in the biological samples(BSs)of fluorescent lamp industries workers(FLIWs).Methodology Different BSs including red blood cells(RBCs),plasma,urine,hair and nails were collected from the workers exposed to Hg and unexposed persons were selected as control group to measure both the T-Hg concentration as well as its species in different biological samples through quantitative analysis.Health data was collected through questionnaire survey.Results The mean concentrations of T-Hg(31.9μg/L),Me-Hg(27.7μg/L),and I-Hg(5.36μg/L)in RBCs were found significantly(P<0.001)higher among the workers(n=40)as compared to the control group(n=40).Similarly the mean Hg concentrations in plasma,urine,hair and nails were also significantly higher among the workers than the control group.The statistical relation between Hg concentration and demographic characteristics observed that workers experience and fish consumption has increased the Hg concentration while age,weight and smoking found no significant effect on Hg concentration in the BSs.Conclusion The study observed that the workers were highly exposed to high concentration of Hg and they are at a high health risk.

<i>Ex Utero</i>intrapartum treatment (EXIT)

The anesthesia ex utero intrapartum treatment (EXIT) procedure is a specialized surgical procedure used to deliver babies who have airway compression due to cystic adenomatoid malformation, bronchopulmonary sequestration, cervical teratomas, or other congenital conditions. EXIT is erroneously known as a routine cesarean section (CS), but is rather an extension of CS with discernible differences. The procedure creates an opening in the anesthetized abdomen of the mother and uterus. Once EXIT is complete, the remainder of the CS proceeds. EXIT is much more complex than a routine CS, as it requires coordination between the mother and a multidisciplinary team of surgical and neonatal personnel. This review highlights current anesthetic concepts during the EXIT procedure.

Health risks associated with heavy metals in the drinking water of Swat,northern Pakistan

The concentrations of heavy metals such as Cd, Cr, Cu, Mn, Ni, Pb and Zn were investigated in drinking water sources （surface and groundwater） collected from Swat valley, Khyber Pakhtunkhwa, Pakistan. The potential health risks of heavy metals to the local population and their possible source apportionment were also studied. Heavy metal concentrations were analysed using atomic absorption spectrometer and compared with permissible limits set by Pakistan Environmental Protection Agency and World Health Organization. The concentrations of Cd, Cr, Ni and Pb were higher than their respective permissible limits, while Cu, Mn and Zn concentrations were observed within their respective limits. Health risk indicators such as chronic daily intake （CDI） and health risk index （HRI） were calculated for adults and children separately. CDIs and HRIs of heavy metals were found in the order of Cr 〉 Mn 〉 Ni 〉 Zn 〉 Cd 〉 Cu 〉 Pb and Cd 〉 Ni 〉 Mn 〉 Cr 〉 Cu 〉 Pb 〉 Zn, respectively. HRIs of selected heavy metals in the drinking water were less than 1, indicating no health risk to the local people. Multivariate and univariate statistical analyses showed that geologic and anthropogenic activities were the possible sources of water contamination with heavy metals in the study area.

Transfer of Heavy Metals from Soils to Vegetables and Associated Human Health Risks at Selected Sites in Pakistan

Contamination of the food chain with heavy metals is considered as one of the major environmental pathways of human exposure to metals leading to potential health risks. This study aimed to investigate the concentrations of heavy metals such as copper （Cu）, zinc （Zn）, chromium （Cr）, nickel （Ni）, and manganese （Mn） in agricultural soils and food crops （fruit, leaf, and root vegetables）, and their associated health risks to the local population in selected southern districts of Khyber Pakhtunkhwa Province, Pakistan. The concentrations of the selected metals in soil varied over a wide range, in the following decreasing order： Mn 〉 Zn 〉 Cr 〉 Ni 〉 Cu. The bioaccunmlation of metals in vegetables was within the permissible risk limits, except for Cr which showed higher contamination in all the tested food crops. The trend of metal transfer factors for different vegetables was in the order of Cu 〉 Ni 〉 Cr 〉 Mn 〉 Zn, while the calculated daily intake of metals （DIM） in adults and children through consumption of food crops was in the decreasing order of Mn 〉 Zn 〉 Ni 〉 Cr 〉 Cu. The health risk index （HRI） values for the heavy metals for both adults and children were less than 1. Therefore, no significant health risk is anticipated for the local consumers through ingestion of these food crops.