Health risk assessment of heavy metal pollution in groundwater of a karst basin,SW China

To investigate the presence of metal elements and assess their health risk for the populace in the Nandong Underground River Basin(NURB),we conducted an analysis of eleven common heavy metals in the water body.A Health risk assessment(HRA)model was employed to analyze 84 water samples from the NURB.The detection results revealed the following order of heavy metals concentrations:Fe>Al>Mn>Zn>As>Cd>Pb>Cr>Ni>Cu>Hg.Correlation analysis indicated a certain similarity in material source and migration transformation among these eleven metal elements.Our study identified that the health risks for local residents exposed to metal elements in the water of NURB primarily stem from carcinogenic risk(10^(−6)–10^(−4)a^(−1))through the drinking water pathway.Moreover,the health risk of heavy metal exposure for children through drinking water was notably higher than for adults.The maximum health risks of Cr in both underground and surface water exceeded the recommendation standard(5.0×10^(−5)a^(−1))from ICRP,surpassing the values recommended by the Swedish Environmental Protection Agency,the Dutch Ministry of Construction and Environment and the British Royal Society(5.0×10^(−6)a^(−1)).The results of the health risk assessment indicate that Cr in the water of NURB is the primary source of carcinogenic risk for local residents,followed by Cd and As.Consequently,it is imperative to control these three carcinogenic metals when the water was used as drinking water resource.

SPATIAL-TEMPORAL VARIATION OF HEAVY METAL ELEMENTS CONTENT IN COVERING SOIL OF RECLAMATION AREA IN FUSHUN COAL MINE

Grid method is employed for sampling covering soil at the test field,whic h is reclamation area filled by coal mining wastes for cropland in th e Fushun coal mine,Liaoning Province,the Northeast China.The soil samp les are taken at different locations,inclu ding three kinds of covering soil,th ree different depths of soil layers a nd four different covering ages of covering soil.The s patial-temporal variation of heavy metal element content in reclamatio n soil is stud-ied.The results indicate that the co ntent of heavy metal elements is decreasing year after year;the determin ant reason why the content of heavy metal elemen ts at 60cm depth layer is higher than t hat at 30cm depth layer and surface is fertiliz-er and manure application;the metal elements mainly come from external environment;there is no metal pollut ion coming from mother material(coal mining wastes)in plough layer of covering soil.

Heavy metals accumulation effect in rabbit body fluids after smoking

Concentration of heavy metals in blood and urine of rabbit after inhaling three different kinds of cigarette was studied through the animal passive smoking pattern. The samples were prepared by nitric acid solution digestion and determination of seven kinds of heavy metals including Hg, Se, Sn, Pb, Cd, Ni and Cr was performed by inductively coupled plasma-atomic emission spectrometry （ICP-AES）. The ICP-AES method was established with good precision and accuracy, relative standard deviation （n=6） was between 2.9% and 5.9%, and the recovery was in the range of 95.0%-104.2%. Concentration of six heavy metals increases in some extent in blood and urine after period of smoking and the increasing of heavy metals in blood and urine all shows time dependence. Significantly higher heavy metal levels are observed in the blood and urine of the cigarette inhaling rabbits in the exposed group. The concentration of six kinds of heavy metals in the blood of the rabbit increases after 16 weeks exposing to cigarette smoking. Three times of rig, ten times of Se and trace amount ofPb, Cd, Ni and Cr are detected in the blood after 16 weeks of smoking. For urine samples, about three times of Hg, two times of Se, five times of Pb and trace amount of Cd are detected after 16 weeks of inhalation of cigarette. Comparatively, higher concentration of heavy metals are detected after inhaling of Nise cigarette.

Migration of Heavy Metal Elements in Reclaimed Irrigation Water-Soil-Plant System and Potential Risk to Human Health

[Objectives]To study the impact of heavy metal pollution of soil and plants during the process of reclaimed water for irrigation of green land in arid areas and the potential health risks to humans during use.[Methods]Taking Zhongwei City in Ningxia,a typical arid area,as the research area,the irrigation water,soil and green grass in the reclaimed water irrigation region and the original green water irrigation region were sampled,the heavy elements Hg,As,Zn,Pb,Cd,Cr were detected,and the Nemerow method,biological absorption coefficient,and health risk assessment were employed to evaluate the degree of soil pollution,plant absorption capacity,and human health risks.[Results]Compared with the original green water,the Hg,Cd,and Cr pollution of the reclaimed water irrigated green land was higher,the As,Zn,Pb pollution was lower,and the content of Hg and Cd was higher than the environmental background values of soil in Ningxia;the Cr content exceeded the risk intervention values of the first type of land in the Soil Environmental Quality—Risk Control Standard for Soil Contamination of Development Land(GB 36600-2018).Compared with the original green water irrigation region,it is found that the reclaimed water irrigation reduced the heavy metal pollution of the soil to a certain extent.The heavy metal content of tall fescue grass(Festuca arundinacea)in the reclaimed water irrigation region was Zn,Cr,Pb,As,Cd,and Hg from high to low;the order of the biological absorption coefficient was Cd>As>Zn>Pb>Hg>Cr;irrigation water exerted a certain effect on the content of heavy metals in plants and the biological absorption coefficient through the soil.Using the health risk assessment method recommended by Environmental Protection Agency of the United States of America(USEPA),it was found that the reclaimed water has the highest risk through the inhalation route,and the occupational population has a higher risk of skin contact with soil and plants.[Conclusions]This study is intended to provide data support and theoretical basis for the environmental safety risk research of the application of reclaimed water in arid areas to urban greening.

Evaluation on environmental quality for heavy metal elements of Xihe soil

According to "Environmental quality standard for soil" and using As,Cd,Cr,Cu,Hg,Ni,Pb,Zn elements as evaluation index,the author evaluated soil environmental quality in Xihe area of Shenyang.The results show that the soil in Xihe area is polluted rifely by heavy metal elements.The polluted areas are mainly distributed near the upstreams of Xihe River,Shenxin River and Shenliao irrigation canal.There exist large distinctions among the heavy metal elements to the pollution degree.Cd pollution area is the biggest and the most serious in pollution degree.

Annual Fluxes of Heavy Metal Elements in Atmospheric Dry and Wet Depositions in the Pearl River Delta Economic Region, Guangdong Province

There are 158 sampling points to be set up in the Pearl River delta economic region. The collecting period is mostly one year, namely, from July 2007 to July 2008. The eight heavy metal elements of Cr, Ni, Cu, Pb, Zn, As, Hg, and Cd in 474 dry and wet deposition samples were tested in terms of the standard procedures. Their average annual fluxes have no obvious difference between dry deposition and wet deposition. So these elements might be at an equilibrium or quasi-equilibrium state between dry deposition and wet deposition.

Determination of Harmful Elements and Analysis of Pollution Level in Lysimachia christinae

[Objectives]To detect content of Pb,Cd,Hg,As,Cu,Zn,and Cr in Lysimachia christinae,and to analyze the pollution level.[Methods]Seven kinds of elements in L.christinae were determined by Inductively coupled plasma mass spectrometry and analyzed by single index and comprehensive index.[Results]The seven heavy metal elements showed good linearity in their respective concentration ranges.The recoveries of the samples were 84.5%-109.5%,and the RSD values were 2.30%-5.10%.Comparing the measured results of heavy metal elements with the limit values stipulated in the 2020 edition of the Chinese Pharmacopoeia and other standards,the Cr element in 19 batches of samples exceeded the standard,and the Zn element in 7 batches of samples exceeded the standard.The exceeding rates were 100.0%and 36.8%,respectively;the content of other heavy metal elements did not exceed the standard.The order of individual index from large to small was Cr,Zn,Cd,Hg,Cu,As,and Pb,and the average comprehensive pollution level was mild pollution and above.[Conclusions]L.christinae was mainly polluted by Cr,followed by Zn;this study can provide basic data for drafting of the limit standard for heavy metal elements in L.christinae.

Heavy metal accumulation by panicled goldenrain tree(Koelreuteria paniculata) and common elaeocarpus(Elaeocarpus decipens) in abandoned mine soils in southern China

Phytoremediation can be used as a sustainable technology for mine spoil remediation to remove heavy metals. This study investigated the concentration of 7 heavy metal contamination in soil and plant samples at an abandoned mine site. We found that, after vegetation remediation at the abandoned mine site, the reduction rates for 7 heavy metals were in the range of 4.2%-86%, where reduction rates over 50% were achieved for four heavy metals （Zn, Mn, Cd, Ni）. Transfer coefficients of the panicled goldenrain tree （Koelreuteria paniculata Laxm） and the common elaeocarpus （Elaeocarpus decipens） for Zn, Mn, Ni, and Co were more than 1. Enrichment coefficients of both trees for Mn were higher than 1. Our results suggest that the panicled goldenrain tree and the common elaeocarpus tree may act as accumulators in remediation. Moreover, the woody vegetation remediation in abandoned mining areas play an important role in improving scenery besides removing heavy metal from contaminated soil.

Influence of Soil Geochemistry to the Quality of Winter Jujube in Zhanhua

[Objective] The aim was to investigate the effects of soil geochemistry on the quality of winter jujube.[Method]Based on the data of ecological geochemical survey in lower Yellow River Basin,the relevance of the geochemistry environment in top soils and the quality of winter jujubes was analyzed.[Result]Cd,Ni and other heavy metals in the soil more obviously affected the nutrition of winter jujubes.[Conclusion]B,Mn,MgO,Cd,Zn,K2O and other elements in the root soil played an important role in the enrichment of Cr and Hg of winter jujube fruit.And the absorption of heavy metals in winter jujube root could be interfered by improving fertilization method,to reduce the enrichment of harmful elements in jujube fruit.

用电感耦合等离子体质谱法测定中草药中的重金属元素

In this paper,the determination of six heavy metal ions (arsenic,lead,cadmium,chromium,mercury and nickel) in the Chinese Herb by inductively coupled plasma-mass spectrometry (ICP-MS) was studied.The samples were digested by nitric acid and hydrogen peroxide in a microwave oven.The Sc,Y,In,Bi were added as internal standards to eliminate the matrix interferences.The results show that most of the relative standard deviations of these trace elements were below 3.5%,the standard recoveries of these elements were in the range of 91%-107%,and the detection limits were in the range of 0.001-0.006 μg·L-1. This method is accurate,rapid,convenience,and can be applied to the determination of arsenic,lead,cadmium,chromium,mercury and nickel in Chinese Herb with good results.

Contamination and health risk assessment of heavy metals in road dust in Bayan Obo Mining Region in Inner Mongolia, North China

The objective of this study was to investigate the concentration and spatial distribu- tion patterns of 9 potentially toxic heavy metal elements （As, Cd, Co, Cr, Pb, Cu, Z.n, Mn, and Ni） in road dust in the Bayan Obo Mining Region in Inner Mongolia, China. Contamination levels were evaluated using the geoaccumulation index and the enrichment factor. Human health risks for each heavy metal element were assessed using a human exposure model. Results showed that the dust contained significantly elevated heavy metal elements concen- trations compared with the background soil. The spatial distribution pattern of all tested met- als except for As coincided with the locations of industrial areas while the spatial distribution of As was associated with domestic sources. The contamination evaluation indicated that Cd, Pb, and Mn in road dust mainly originated from anthropogenic sources with a rating of ＂heav- ily polluted＂ to ＂extremely polluted,＂ whereas the remaining metals originated from both natural and anthropogenic sources with a level of ＂moderately polluted＂. The non-cancer health risk assessment showed that ingestion was the primary exposure route for all metals in the road dust and that Mn, Cr, Pb, and As were the main contributors to non-cancer risks in both children and adults. Higher HI values were calculated for children （H1=1.89）, indicating that children will likely experience higher health risks compared with adults （H1=0.23）. The cancer risk assessment showed that Cr was the main contributor, with cancer risks which were 2-3 orders of magnitude higher than those for other metals. Taken in concert, the non-cancer risks posed by all studied heavy metal elements and the cancer risks posed by As Co, Cr, Cd, and Ni to both children and adults in Bayan Obo Mining Region fell within the acceptable range.

Emission control for precursors causing acid rain(V): Improvement of acid soil with the bio-briquette combustion ash

The bio-briquette technique which mixes coal, biomass and sulfur fixation agent and bio-briquettes under 3—5 t/cm 2 line pressure has aroused people's attention in view of controlling the air pollution and the acid rain. In this paper, the physicochemical properties of bio-briquette and its ash were investigated. And the acid soil was improved by the bio-briquette combustion ash, which contained nutritive substances such as P, N, K and had the acid-neutralizing capacity(ANC). The pH, EC, effective nutrient elements(Ca, Mg, K, P and N), heavy metal elements(Al, Cu, Cd, Cr, Zn and Mn) and acid-neutralizing capacity change of ash-added soils within the range of 0—10%, were also studied. Specially, when 5% bio-briquette combustion ash was added to the tested soil, the content of the effective elements such as Ca, Mg and K rose by 100 times, 7 times and twice, respectively. The total nitrogen also increased by about twice. The results showed the oxyanions such as that of Al, Cu, Cd, Cr, Zn and Mn were not potentially dangerous, because they were about the same as the averages of them in Chinese soil. It is shown that the ANC became stronger, though the ANC hardly increases in the ash-added soil. On the basis of the evaluation indices, it is concluded that the best mixture ratio is to add 2.5%—8% of the bio-briquette combustion ash to the tested soil.

Growth, Metabolism and Yield of Rice Cultivated in Soils Amended with Fly Ash and Cyanobacteria and Metal Loads in Plant Parts

Soil amendment with fly ash（FA） and combined supplementation with N_2-fixing cyanobacteria masses as biofertilizer were done in field experiments with rice. Amendments with FA levels, 0, 0.5, 1.0, 2.0, 4.0, 8.0 and 10.0 kg/m2, caused increase in growth and yield of rice up to 8.0 kg/m2, monitored with several parameters. Pigment contents and enzyme activities of leaves were enhanced by FA, with the maximum level of FA at 10.0 kg/m2. Protein content of rice seeds was the highest in plants grown at FA level 4.0 kg/m2. Basic soil properties, p H value, percentage of silt, percentage of clay, water-holding capacity, electrical conductivity, cation exchange capacity, and organic carbon content increased due to the FA amendment. Parallel supplementation of FA amended plots with 1.0 kg/m2 N_2-fixing cyanobacteria mass caused further significant increments of the most soil properties, and rice growth and yield parameters. 1000-grain weight of rice plants grown at FA level 4.0 kg/m2 along with cyanobacteria supplementation was the maximum. Cyanobacteria supplementation caused increase of important basic properties of soil including the total N-content. Estimations of elemental content in soils and plant parts（root and seed） were done by the atomic absorption spectrophotometry. Accumulations of K, P, Fe and several plant micronutrients（Mn, Ni, Co, Zn and Cu） and toxic elements（Pb, Cr and Cd） increased in soils and plant parts as a function of the FA gradation, but Na content remained almost unchanged in soils and seeds. Supplementation of cyanobacteria had ameliorating effect on toxic metal contents of soils and plant parts. The FA level 4.0 kg/m2, with 1.0 kg/m2 cyanobacteria mass supplementation, could be taken ideal, since there would be recharging of the soil with essential micronutrients as well as toxic chemicals in comparative lesser proportions, and cyanobacteria mass would cause lessening toxic metal loads with usual N_2-fixation.

Biological Cycles of Mineral Elements in a Young Mixed Stand in Abandoned Mining Soils

Phytoremediation as a sustainable and inexpensive technology based on the removal of pollutants from the environment by plants is becoming an increasingly important objective in plant research. In this study, biological cycles of five nutrient elements （N, P, K, Ca, and Mg） and eight heavy metal elements （Fe, Cu, Zn, Mn, Cd, Ni, Pb and Co） were examined in young paniculed goldraintree （Koelreuteria paniculata Laxm） and common elaeocarpus （Elaeocarpus decipens） mixed stands in an abandoned mining area. We found that after vegetation restoration in abandoned mining areas, the organic matter and concentrations of nutrient elements were significantly increased and the heavy metal elements were significantly decreased, the annual retention, uptake and return were 75.0, 115.4, and 40.3 kg/hm^2 for nutrient elements, and 1 878.0, 3 231.0 and 1 353.0 g/hm^2 for heavy metal elements, respectively, with the utilization coefficient, cycling coefficient and turnover rate of 0.92, 0.35 and 0.32 for nutrient elements, and 1.24, 0.42 and 1.92 for heavy metal elements, respectively. Our results suggested that the vegetation restoration in abandoned mining areas had significant effects in improving environmental conditions, enhancing soil available nutrients, and ensuring human health.