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.

The abundance,distribution,and enrichment mechanism of harmful trace elements in coals from Guizhou,Southwestern China

Coal seams can enrich a variety of harmful trace elements under specific geological conditions.The spatial distribution of harmful trace elements in coal is extremely uneven,and the distribution characteristics of each element content are different.The harmful elements released in the process of coal mining and utilization will cause serious harm to the environment and the human body.It is of great resource significance to study the geochemistry of coal that affects the enrichment and distribution characteristics of harmful trace elements.Based on the domestic and foreign literature on coal geochemistry in Guizhou published by previous investigators,this study counted 1097 sample data from 23 major coal-producing counties in Guizhou Province,systematically summarized the relevant research results of harmful trace elements in the coal of Guizhou,and revealed the overall distribution and enrichment characteristics of harmful trace elements in the coal of Guizhou.The results show that the average contents of Cd,Pb,Se,Cu,Mo,U,V,As,Hg,and Cr in coal of Guizhou are higher than those in Chinese coal and world coal.A variety of harmful trace elements in the coal of Guizhou have high background values,especially in Liupanshui,Xingyi and Qianbei coalfield.The enrichment of various harmful trace elements in the Late Permian coal in Guizhou is mainly related to the combined action of various geological and geochemical factors.The supply of terrigenous debris and sedimentary environment may be the basic background of the enrichment of harmful elements in western Guizhou,while low-temperature hydrothermal activity and volcanic ash deposition may be the main reasons for the enrichment of harmful elements in southwestern Guizhou.

Assessment of pollution of potentially harmful elements in soils surrounding a municipal solid waste incinerator, China

We assessed the contamination levels of Mn, Zn, Cr, Cu, Ni, Pb, As and Hg and the risks posed by these potentially harmful elements in top-soils around a municipal solid waste incinerator （MSWI）. We collected 20 soil samples, with an average pH of 8.1, and another fly ash sample emitted from the MSWI to investigate the concentrations of these elements in soils. We determined the concentrations of these elements by inductively coupled plasma-optical emission spectrometer （ICP-OES）, except for Hg, which we measured by AF-610B atomic fluorescence spectrometer （AFS）. We assessed the risks of these elements through the use of geoaccumulation index （/geo）, potential ecological risk index （R/）, hazard quotient （HQi） and cancer risk （Riski）. The results showed that concentrations of potentially harmful elements in soil were influenced by the wind direction, and the concentrations of most elements were higher in the area northwest of the MSWI, compared with the area southeast of the incinerator, with the exception of As; these results were in accordance with those results acquired from our contour maps. According to the I^o values, some soil samples were clearly polluted by Hg emissions. However, the health risk assessment indicated that the concentrations of Hg and other elements in soil did not pose non-carcinogenic risks to the local populations. This was also the case for the carcinogenic risks posed by As Cr and Ni. The carcinogenic risk posed by As was higher in the range 6.49 × 10 -9.58 × 10 -6, but this was still considered to be an acceptable level of risk.

Distribution Characteristics of Sulfur and the Main Harmful Trace Elements in China's Coal

To promote the rational development and use of clean coal resources in China, data on the regional and age distribution of sulfur, arsenic and other harmful elements in Chinese coal was broadly collected, tested for content, and analyzed. Coal in northwestern China is characterized by low to extremely low levels of sulfur; the coal of the Taiyuan Formation in northern China mainly has high-sulfur content; that of the Shanxi Formation is mainly characterized by low sulfur coal; and the Late Permian coal in southern China has overall higher sulfur content; other regions have low sulfur coal. The average content of harmful trace elements in the bulk of China＇s coal is similar to the corresponding content in the coal of the North America and the rest of the world, whereas the content of various elements （Hg, Sb and Se） is different in magnitude to the corresponding percentage in the crust. The average content of the elements Cr, Se, Co, Be, U, Br in Late Permian coal in S China ranks first in the country whereas the average content of Hg and CI in the coals of Late Carboniferous to Early Permian age in N China are the highest. The average content of Mn in Early and Middle Jurassic coal is higher in NW China. The high content of harmful elements in some coal should cause particular concern both in the development and utilization of coal.

Trace heavy metals and harmful elements in roots and rhizomes of herbs:Screening level analysis and health risk assessment

Objective:Heavy metal and harmful element contamination are frequently reported in Chinese herbal medicines(CHMs),and roots and rhizomes parts showed a higher content than other parts.To investigate the residue level and assess the potential human health risk of heavy metals and harmful elements in roots and rhizomes,720 batches of the sample representing 20 species of herbs from different sources were collected.Methods:The content of Pb,Cd,As,Hg,and Cu in the digests was determined using ICP-MS.The chronic hazard index estimate based on non-cancer hazard quotient(HQ)was applied for potential health risk assessment of Pb,Cd,As,Hg,and Cu via consumption of CHMs.Results:Compared with the Chinese limit standard(Chinese Pharmacopoeia Commission,2020 edition)of Pb,Cd,As,Hg,and Cu in Ginseng Radix et Rhizoma,the exceedance percentage of Pb in total samples was 14.1%,which were generally far higher than Cd,As,Hg,and Cu.Health risk assessment results based on hazard quotient calculating showed that total HQ of Cu,Pb,As,Cd,and Hg in Pulsatillae Radix and Clematidis Radix et Rhizoma exceeded 1,with the value of 1.543 and 1.235.Besides,Arsenic had the highest HQ value(0.957)in Pulsatillae Radix.Conclusion:Consuming raw materials of Pulsatillae Radix and Clematidis Radix et Rhizoma may pose a potential risk and Arsenic residues in Pulsatillae Radix deserved special attention.

Theoretical Research on the Import and Export of Iron Ore and Harmful Element Detection Method based on Microwave Digestion Inductively Coupled Plasma Mass Spectrometry Approach

In this paper, we conduct research on the import and export of iron ore and harmful element detection method based on microwave digestion inductively coupled plasma mass spectrometry approach. Our country gradually increased demand for iron ore, iron ore trade, in order to ensure that the quality of the iron ore and taste which must be tested for total iron content. At the same time it also increased the demand for iron ore, although China＇ s iron ore production has been greatly improved. Our proposed approach optimizes the traditional detection method which will be meaningful.

Artisanal Mining and Soil Quality in the Sudano-Sahelian Climate: Case of the Artisanal Mining Site of Yimiougou in Burkina Faso, West Africa

The majority of the population of Burkina Faso lives from agriculture and therefore depends on the land. The main objective of this study is to assess the quality of the soils in the area linked to artisanal mining activities. The methodology adopted consisted in sampling and characterizing the main types of soil. In order to assess the level of soil pollution by artisanal mining, parameters such as the geo-accumulation index (Igeo) and the contamination factor (CF) are calculated. A prediction of acid mine drainage (AMD) was also carried out on samples of mine tailings which are potential sources of pollution of these soils. The results obtained show that the soils in Yimiougou are of nil to low agronomic interest. The Igeo shows that for lead, copper, zinc and arsenic the levels found in the different morphological units are partly attributable to human action and specifically artisanal mining. The values of the contamination factor indicate contamination. Cobalt presents the lowest contamination. For cadmium, the different types of soil are moderately contaminated except for the FITLC type, which has a CF value of 0.50, therefore synonymous with low or absent contamination. The various morphological units studied are very heavily contaminated with zinc, copper, lead and arsenic. The pH and conductivity values indicate that the mine tailings samples are non-acidogenic, therefore not yet oxidized. As for the sulphide contents, they show that only samples S17, S22, S23 and S24 present values that are strictly above the threshold (0.3%) and therefore potentially acid-generating. The comparative study of the acid potential (AP) and the neutralization potential (NP) reveals that the neutralization potentials of the different samples are clearly higher than the acid potentials even for the samples which present a proven acidification potential (S17, S22, S23 and S24). These results show that the mine tailings have the natural capacity to neutralize any possible mine drainage, given the presence of acid-eating minerals such as the carbonates associated with the mineralization.

Evaluation on Quality and Utilization Value of Bupleurum falcatum Linne

[Objectives]This study aimed to evaluate the quality of Bupleurum falcatum Linne interplanted with walnut in Ganluo and study the development and utilization value of other parts.[Methods]The contents of saikosaponins a and d were determined with RP-HPLC,and the contents of 7 kinds of harmful elements were determined by ICP-MS.The quality of B.falcatum Linne was compared with that of other Bupleurum species.[Results]The total saikosaponin content in Radix Bupleurum Falcatum(15.894 mg/g)was higher than that in Radix Bupleuri of other origins(8.748 mg/g).The total saikosaponin content in leaves of B.falcatum Linne(7.518 mg/g)is more than twice the limit promulgated by Chinese Pharmacopoeia.The contents of Al,Cr,Cu,As,Cd,Pb and Hg in B.falcatum Linne were all lower than the limits promulgated by the pharmacopoeia.In short,the quality of Radix Bupleurum Falcatum was better than that of Radix Bupleurum Marginatum(S3,S4)and Radix Bupleurum Sachalinense(S5).The leaves of B.falcatum Linne contained more saikosaponins and less harmful elements.[Conclusions]The method and technology of interplanting B.falcatum Linne with walnut in Ganluo are mature.The quality of the medicinal materials produced is superior,and the leaves are also rich in saikosaponins a and d,and can be used as the raw material for extracting saikosaponins a and d.This study provides a basis for further in-depth research on the cultivation of B.falcatum Linne in the domestic market.

Predicting the Bioaccessibility of Soil Cd,Pb,and As with Advanced Machine Learning for Continental-Scale Soil Environmental Criteria Determination in China

Investigating the bioaccessibility of harmful inorganic elements in soil is crucial for understanding their behavior in the environment and accurately assessing the environmental risks associated with soil.Traditional batch experimental methods and linear models,however,are time-consuming and often fall short in precisely quantifying bioaccessibility.In this study,using 937 data points gathered from 56 journal articles,we developed machine learning models for three harmful inorganic elements,namely,Cd,Pb,and As.After thorough analysis,the model optimized through a boosting ensemble strategy demonstrated the best performance,with an average R2 of 0.95 and an RMSE of 0.25.We further employed SHAP values in conjunction with quantitative analysis to identify the key features that influence bioaccessibility.By utilizing the developed integrated models,we carried out predictions for 3002 data points across China,clarifying the bioaccessibility of cadmium(Cd),lead(Pb),and arsenic(As)in the soils of various sites and constructed a comprehensive spatial distribution map of China using the inverse distance weighting(IDW)interpolation method.Based on these findings,we further derived the soil environmental standards for metallurgical sites in China.Our observations from the collected data indicate a reduction in the number of sites exceeding the standard levels for Cd,Pb,and As in mining/smelting sites from 5,58,and 14 to 1,24,and 7,respectively.This research offers a precise and scientific approach for cross-regional risk assessment at the continental scale and lays a solid foundation for soil environmental management.