Health risk assessment of trace metal(loid)s in agricultural soils based on Monte Carlo simulation coupled with positive matrix factorization model in Chongqing, southwest China

This study aimed to investigate the pollution characteristics, source apportionment, and health risks associated with trace metal(loid)s(TMs) in the major agricultural producing areas in Chongqing, China. We analyzed the source apportionment and assessed the health risk of TMs in agricultural soils by using positive matrix factorization(PMF) model and health risk assessment(HRA) model based on Monte Carlo simulation. Meanwhile, we combined PMF and HRA models to explore the health risks of TMs in agricultural soils by different pollution sources to determine the priority control factors. Results showed that the average contents of cadmium(Cd), arsenic (As), lead(Pb), chromium(Cr), copper(Cu), nickel(Ni), and zinc(Zn) in the soil were found to be 0.26, 5.93, 27.14, 61.32, 23.81, 32.45, and 78.65 mg/kg, respectively. Spatial analysis and source apportionment analysis revealed that urban and industrial sources, agricultural sources, and natural sources accounted for 33.0%, 27.7%, and 39.3% of TM accumulation in the soil, respectively. In the HRA model based on Monte Carlo simulation, noncarcinogenic risks were deemed negligible(hazard index <1), the carcinogenic risks were at acceptable level(10^(-6)<total carcinogenic risk ≤ 10^(-4)), with higher risks observed for children compared to adults. The relationship between TMs, their sources, and health risks indicated that urban and industrial sources were primarily associated with As, contributing to 75.1% of carcinogenic risks and 55.7% of non-carcinogenic risks, making them the primary control factors. Meanwhile, agricultural sources were primarily linked to Cd and Pb, contributing to 13.1% of carcinogenic risks and 21.8% of non-carcinogenic risks, designating them as secondary control factors.

Spatiotemporal simulation and predication of heavy metal(loid) concentrations in coal chemical industrial areas with a soil environmental capacity model

Heavy metal (loid)(HM) accumulation in the soil and the HM spatiotemporal distribution have important implication for soil pollution prevention and remediation. The present study investigated the concentrations and spatiotemporal distributions of lead (Pb), mercury (Hg), cadmium (Cd), chromium (Cr) and arsenic (As) in the topsoil of a coal chemical plant in Ningxia Aulonomous region (Ningxia), China. Topsoil samples (/?= 153) were obtained using the checkerboard method, and the HM concentrations were determined. The soil residual rates of the five HMs were measured with leaching experinients and were applied in a soil environmental capacity model to predict the quarHitiHive variation of the HM concentrations. The predicted results were employed to estimate the HM spatiotemporal distribution within 2() years with the Kriging technique. The number of sampling sites, where all five HM concentratio ns exceed their corresponding background values in Ningxia, would be increased from 0 to 90% within 1() years of the plant operation. In addition, Pb and Cd were distributed along the traffic routes. Mercury and As were distributed near fuel gas emission vents. Chromium was mainly accumulated in slag dumps. The study may provide the theoretical and practical foun d at ion for future HM pollution control in coal chemical plants.

Microbial Remediation of Heavy Metal(loid)Contaminated Soil: A Review

Because of the rapid development of industrial processes, increased urban pollution and agricultural chemicals applied in recent years, heavy metal(loid) pollution in soil has been very serious, and there is an urgent need for fast and efficient removal of heavy metal(loid) pollution. Currently, environmental microorganisms are always used to perform biological alteration or improvement of soils and sewage. Using functional microorganisms that are resistant to toxic heavy metal(loid) ions for alteration and transformation of heavy metal(loid)s in ionic form is an effective measure for microbial remediation of heavy metal(loid)contaminated soil. This paper reviewed the microbial remediation mechanism of heavy metal(loid) contaminated soils, and the approaches for breeding bacteria those can be used for highly efficient removal of heavy metal(loid)s, as well as the application examples of microbial remediation and transformation of heavy metal(loid) contaminated soil, and finally described the future trends and further research work of heavy metal(loid) contaminated soils by microbial remediation.

Contamination and human health risk assessment of heavy metal(loid)s in topsoil and groundwater around mining and dressing factories in Chifeng,North China

Chifeng is a concentrated mining area for non-ferrous metal minerals,as well as a key prevention and control area for heavyduty enterprises.This situation necessitates an efective ecological and human health risk assessment of heavy metal(loid)s driven by the wide distribution of metal ore processing,mining,and smelting factories in Hexigten Banner and Bairin Left Banner.We conducted surveys to assess the levels of heavy metal(loid)s(Cr,As,Pb,Cd,and Hg)in the topsoil and groundwater of the areas.The results indicated that the concentrations of As,Cd,and Pb in partial soil samples exceeded the environmental quality standards of Grade II.Based on contamination assessments,such as geoaccumulation indices and pollution indices,we inferred that Cd,Pb,and As were primary pollutants in topsoil.Potential ecological risks when considered as part of the average risk indices(RI)are up to 1626.40 and 2818.76,respectively,in the two areas.Comparative analysis revealed that Cd posed a very high potential ecological risk,followed by As.Moreover,the evaluation showed that the three exposure pathways of carcinogenic and non-carcinogenic risk followed a descending order:inhalation>ingestion>dermal contact,except for Pb.Arsenic in topsoil posed a potential non-carcinogenic risk to human health,while there were no adverse efects of As in groundwater.In addition,the average total carcinogenic risk for As in the two areas,as well as the risk of Pb in the topsoil of Bairin Left Banner and all the fve heavy metal(loid)s in groundwater,exceeded human tolerance.Pb–Zn mines caused higher human health risks.In addition,the tandem contamination of heavy metal(loid)s in soil and groundwater was not obvious.This research study provides a basis for pollution remediation to control heavy industry-induced ecological and health risks of heavy metal(loid)s.

Multiple assessments, source determination, and health risk apportionment of heavy metal(loid)s in the groundwater of the Shule River Basin in northwestern China

Global ecosystems and public health have been greatly impacted by the accumulation of heavy metal(loid)s in water.Source-specific risk apportionment is needed to prevent and manage potential groundwater contamination with heavy metal(loid)s.The heavy metal(loid)s contamination status,water quality,ecological risk,and health risk apportionment of the Shule River Basin groundwater are poorly understood.Therefore,field sampling was performed to explore the water quality and risk of heavy metal(loid)s in the groundwater of the Shule River Basin in northwestern China.A total of 96 samples were collected from the study area to acquire data for water quality and heavy metal(loid)s risk.There was noticeable accumulation of ferrum in the groundwater of the Shule River Basin.The levels of pollution were considered to be moderately low,as evaluated by the degree of contamination,heavy metal evaluation index,heavy metal pollution index,and Nemerow pollution index.The ecological risks were also low.However,an assessment of the water quality index revealed that only 58.34%of the groundwater samples had good water quality.The absolute principal component scores-multiple linear regression model was more suited for this study area than the positive matrix factorization model.There were no obvious noncarcinogenic or carcinogenic concerns for all types of receptors according to the values of the total hazard index and total carcinogenic risk.The human activities and the initial geological environment factor(65.85%)was the major source of noncarcinogenic risk(residential children:87.56%;residential adults:87.52%;recreational children:86.77%;and recreational adults:85.42%),while the industrial activity factor(16.36%)was the major source of carcinogenic risk(residential receptors:87.96%;and recreational receptors:68.73%).These findings provide fundamental and crucial information for reducing the health issues caused by heavy metal(loid)s contamination of groundwater in arid areas.

Assessment of the Level of Metal(loid)s Pollution and Bioactive Compounds Screening of Anthill Soil

The anthill soil is used by hypertensive elderly and teenagers from Oshikoto region (Namibia) and many of them testified stabilization of their blood pressure to normal after consuming the anthill soil-derived aqueous extracts. This study therefore investigated and/or assessed the physicochemical parameters, the contents of some metal(loid)s (and their associated potential health risks) and the qualitative composition of bioactive compounds of this anthill soil. The homogenous soil sample collected from various anthill soils in the Oshikoto region was used to obtain the measurements of physiochemical parameters. The elemental contents were determined (using an Inductively Coupled Plasma Optical Emission Spectrophotometer) after acid digestion in accordance with the EPA method 350B and their potential health risk assessments were performed. Methanol, aqueous methanol, and aqueous-based extracts were generated via maceration extraction process prior to the screening of bioactive compounds using standard diagnostic assays. The oxidation reduction potential (164.4 ± 16.6 mV) was the only physicochemical parameter whose value was within the World Health Organization limits for drinking water whereas, total dissolved solids (23 ± 5.5 mg/L), electrical conductivity (44 ± 10.1 uS/cm) and pH (5.35 ± 0.33) were out of specifications. Phenolic compounds, flavonoids, terpenoids, and cardiac glycosides were present in anthill soil (with respect to the extractants used) to which its antihypertensive properties can be attributed in addition to some of the studied mineral components. With respect to the pH, TDS and EC, and the contents of most metal(loid)s in relation to their health risk assessment values, the results suggest that aqueous extracts derived from this anthill soil can be deemed unsuitable for human consumption.

高地球化学背景地区重金属污染分布特征及源解析研究

广西壮族自治区作为我国典型重金属高地球化学背景地区及有色金属重要产地,其土壤存在重金属污染问题。本研究结合随机森林模型、GIS技术和实地采样调查对广西不同地貌类型区域(峰丛喀斯特、峰林喀斯特、孤峰残山平原)中的土壤重金属含量特征及其富集特征进行综合分析对比,识别区域尺度高背景地区土壤重金属的地球化学特征。结果表明:在广西三种地貌类型中,土壤Cd、Hg、Pb、Zn的平均含量均高于广西背景值,其中Cd的平均含量为背景值的4.51倍,且样品中有27.2%的Cd、30.9%的Hg、65.5%的Pb和37.8%的Zn含量超出背景值。喀斯特地貌区的重金属高值区域与岩溶区高度重合,主要受到碳酸盐岩成土过程中的次生富集和金属氧化物吸附的影响。孤峰残山平原区域的重金属含量较低,未显示明显的高地球化学背景特征。研究区内人为工业活动和农业活动的复合作用对土壤中As和Cu的富集有显著贡献;采矿冶炼活动会对金属冶炼工业区周边土壤Cd、Zn有显著贡献;公路运输对附近土壤Hg的富集有显著贡献,铁路运输对土壤Cu的富集有显著贡献;城市活动对土壤Pb的富集有显著贡献。研究显示,广西地区土壤重金属污染具有明显的区域差异性,其中喀斯特地貌区域受高地球化学背景影响显著,重金属的富集主要由自然因素主导,但也受到多种人为活动的显著影响,尤其是在As、Cu、Cd、Zn、Hg和Pb等元素的分布上体现出复杂的成因机制。该研究不仅深化了对广西地区土壤重金属地球化学特征的理解,还为区域重金属污染防治提供了重要的科学依据。

pH对铜冶炼烟尘中重金属浸出行为的影响及其矿物学控制机理

以某废弃铜冶炼厂收集的铜冶炼烟尘作为样本,采用TCLP毒性浸出和宽溶液pH(3~13)范围浸出实验,研究了铜冶炼烟尘中重金属的释放行为及其矿物学控制机制。结果表明,TCLP浸出液中As、Cd、Cu、Pb和Zn浓度分别是我国《危险废物鉴别标准浸出毒性鉴别》(GB 5085.3—2007)中相应元素限值的704倍、82.7倍、2.08倍、3.1倍和3.26倍。在整个溶液pH处理范围内,As的释放率高达26.0%~28.1%。在酸性条件下Cd、Cu和Zn的浸出率明显较高,而Pb在pH 13.0时释放率较高。地球化学分析表明,在pH 5.5~11.5的溶液处理下,As的溶解度部分受新形成的Ca、Cu、Pb和Zn砷酸盐控制,而Cd、Cu、Pb和Zn的溶解度主要受碱性条件下氢氧化物沉淀形成控制。BCR顺序提取和XRD分析表明,浸出液中Cd和Zn浓度较高与其在灰尘中赋存活性态比例高一致。研究结果为烟尘处理或处置防止重金属污染提供科学指导。

铅冶炼场地粉尘重(类)金属的迁移转化

粉尘是铅冶炼场地土壤重(类)金属的来源之一,但粉尘中重(类)金属的迁移转化机制尚不明确。本文系统研究了此过程中重(类)金属的地球化学行为和解离机制。实验结果表明,两类粉尘样品中Pb、Zn、Cd和As的总量和浸出均超过标准,其中,两类粉尘中约有80%的Pb、Zn为生物可利用态,底吹炉粉尘中70%以上的As为弱酸提取态,而还原烟化炉粉尘弱酸提取态的重金属为Cd,占比为60%。Pb同位素结果显示,表土中97.12%的Pb来自冶炼过程中排放的粉尘。XRD和MLA结果表明,粉尘中的主要矿物为PbSO_(4)、ZnSO_(4)和CdSO_(4),表土中的矿物主要是石英、方解石、白云石和白云母。利用地球化学模型对主要矿物进行拟合发现,在酸性条件下,Pb、Zn和Cd的解离主要依赖于硫酸盐矿物,而As的解离与氢氧化铁的吸附作用有关。

大米和杂米中元素对人体健康风险评价

为更科学评估大米和杂米中多种微量元素的摄入情况及其对人体的健康风险,采用生理原理提取法(PBET)研究烹饪前后大米和杂米中多元素(汞、砷、镉、铅、镍、铜、锌和硒)生物可给性,计算日均暴露量、危险商和癌症风险。结果表明,所有市售大米和杂米中有毒元素含量均未超过我国食品中污染物限量值;烹饪后大米和杂米中元素含量不同程度降低,平均降幅大小趋势为:汞(23%)>镍~硒(20%)>砷~铅(17%)>镉(11%)>铜(3%)>锌(2%),相对籼米和籼糯米,粳米影响更大;汞和铅生物可给性平均降幅最大(均下降23个百分点),锌最小(下降11个百分点)。研究表明,人体通过大米和杂米摄入有益元素低于推荐摄入量;烹饪利于降低大米和杂米中有毒有害元素健康风险,但部分样品中砷和镉对人体存在一定的致癌风险,需进一步跟踪和关注。

Distribution, Mobility, and Health Risks Assessment of Trace Metals in River Sediments from Intense Agricultural Activity Areas in West Africa

The economy of West African countries is mainly based on agriculture. However, the trace metal(loid)s contamination status in rivers is relatively unknown in the region. In this work, 45 surface sediments collected from the Bandama, Comoé, and Bia Rivers in south and south eastern Côte d’Ivoire (West Africa), were analyzed for total metal concentrations and chemical speciation. The results showed that the river sediments were considerably contaminated by Cd and moderately contaminated by As, Cu, Pb, and Zn. Significant spatial variations were observed among the stations but not between the rivers. Metals Cd and Cu were likely to cause more ecological risks. The speciation analysis unravelled that the metal(loid)s partitioned mainly in the residual fraction, with the potential mobile fraction varying from 14% to 28%. The study calls for establishment of strict policies relative to the application of fertilizers and agrochemicals and mining activities to protect the environment and human health risks.

金钗石斛生物总碱对脂多糖诱导大鼠学习记忆功能减退的改善作用

目的探讨金钗石斛生物总碱(DNLA)对脂多糖(LPS)诱导的大鼠学习记忆功能减退的改善作用及可能的作用机制。方法成年雄性SD大鼠经Morris水迷宫训练合格后,随机分为模型组和假手术组。模型组大鼠左侧脑室微量注射LPS(10.gL-1)5μL后分为LPS,LPS+布洛芬(Ibu,40 m.gkg-1),LPS+DNLA(20,40和80 mg.kg-1)组,假手术组左侧脑室注射5μL生理盐水。大鼠清醒后ig给予Ibu或DNLA,每天1次,连续14 d。用Morris水迷宫检测大鼠空间学习记忆能力;HE染色观察海马神经元形态改变;免疫组织化学法检测海马淀粉样β蛋白片段1-42(Aβ1-42)含量;实时荧光定量PCR检测海马半胱氨酸天冬氨酸蛋白酶(caspase)3/8 mRNA表达水平。结果侧脑室注射LPS后,大鼠水迷宫逃避潜伏期及搜索距离明显延长,海马出现神经元凋亡和坏死改变。Ibu和DNLA均能明显缩短模型大鼠水迷宫逃避潜伏期和搜索距离,减轻神经元凋亡和坏死,降低海马Aβ1-42含量和caspase 3/8 mRNA表达水平。结论DNLA可改善LPS诱导的大鼠学习记忆功能减退,其机制可能与降低海马caspase 3/8 mRNA表达、减少Aβ1-42产生有关。

大鼠口服泻心汤及其配伍组方中原小檗碱类成分尿排泄动力学

目的研究大鼠灌服泻心汤及其配伍组方中3种原小檗碱类生物碱（小檗碱、巴马汀、黄连碱）尿排泄动力学的变化。方法取SD大鼠20只随机分成黄连、大黄黄连、黄芩黄连、泻心汤4组，采集灌胃给药前及给药后不同时间段尿液，用HPLC法测定尿药浓度，由尿排泄-时间数据计算尿排泄动力学参数，采用方差分析比较各组中3种原小檗碱类生物碱尿排泄动力学参数的差异。结果3种原小檗碱类生物碱排泄速率常数相近，排泄半衰期为9～16h。与黄连组比较，泻心汤组、大黄黄连组、黄芩黄连组中黄连碱尿排泄量占给药量比值减少，其中泻心汤组与之比较差异具有统计学意义（P〈0.05）。结论3种原小檗碱类生物碱具有类似的尿排泄特征，大黄、黄芩和黄连配伍能减少黄连碱的尿排泄量。

蕤核叶片解剖结构和组织化学定位研究

采用解剖学和组织化学方法,研究了蕤核(Prinsepia uniflora Batal.)叶片的解剖结构,并对叶片中的黄酮类、生物碱类及多糖的组织化学定位进行了研究。结果表明:蕤核叶片上表皮有角质层,下表皮有气孔分布,气孔密度为278个·mm-2,近轴面栅栏组织细胞2～3层,排列紧密而整齐,含有许多晶体;叶片主脉木质部发达,由多列导管组成。上述特征说明蕤核叶片的解剖结构与环境之间的适应性。组织化学定位显示黄酮多分布于栅栏组织和厚角组织,生物碱含量少,多糖均匀分布于叶肉中。

士的宁和马钱子碱氮氧化物的研究

以士的宁和马钱子碱为母体，与过氧化氢反应，生成士的宁和马钱子碱氮氧化物，通过还原性试验证明，士的宁氮氧化物较马钱予碱氮氧化物稳定。

缬草镇静催眠的物质基础

缬草(Valeriana officinalisL.)为败酱科缬草属植物,具有镇静催眠活性,在欧美国家广泛用于治疗轻中度失眠。其镇静催眠的活性成分主要集中在挥发油、缬草素类、黄酮类以及水溶性氨基酸成分等。挥发油的特征性成分有乙酸龙脑酯、缬草烯酸,缬草素类成分主要有缬草三酯、二氢缬草素和乙酰缬草素。缬草素类和挥发油类之间可能存在协同作用。

HPLC法同时测定不同配伍比例黄连-吴茱萸药对中4种有效成分的含量

目的:建立同时测定黄连-吴茱萸药对中4种有效成分含量的方法,探讨该药对的合理比例。方法:采用高效液相色谱法。色谱柱为Welch XB C_(18),流动相为乙睛-1.5 mmol/L十二烷基硫酸钠溶液(磷酸调p H至5.0)(梯度洗脱),流速为1.0 mL/min,检测波长为265 nm,柱温为30℃,进样量为10μL。结果:盐酸小檗碱、盐酸巴马汀、吴茱萸碱、吴茱萸次碱检测质量浓度线性范围分别为2.24～44.80μg/m L(r=0.999 9)、1.26～31.50μg/mL(r=0.999 8)、2.70～81.00μg/mL(r=0.999 8)、1.65～49.50μg/mL(r=0.999 9);精密度、稳定性、重复性试验的RSD<3.0%;加样回收率分别为98.11%～100.73%(RSD=1.04%,n=6)、96.54%～103.47%(RSD=1.86%,n=6)、95.49%～102.36%(RSD=2.05%,n=6)、97.19%～103.24%(RSD=2.19%,n=6)。当黄连-吴茱萸比例(m/m)为2∶1时,各成分综合含量最高。结论:该方法操作简便,精密度、稳定性、重复性好,可用于不同配伍比例黄连-吴茱萸药对中4种有效成分含量的同时测定;该药对中黄连-吴茱萸比例(m/m)为2∶1较合理。

中国重金属污染耕地土壤安全利用存在问题与建议

中国耕地土壤重金属污染情况不容乐观,如何安全利用重金属污染耕地仍是当今亟需解决的农业和环保问题。本文综合分析了近几年不同污染程度耕地土壤的安全利用措施,提出重金属低积累作物种植、重金属钝化技术、农艺调控及种植结构调整为当前污染耕地土壤安全利用的主要手段,并指出污染源防控力度不足、土壤污染与作物安全性关系不明、原位钝化技术风险及低积累作物利用效果的局限性仍然是中国污染耕地土壤安全、高效利用面临的主要问题,建议进一步完善污染土壤评价标准、健全污染土壤防控体系、优化污染土壤安全利用技术,以推动重金属污染耕地土壤的安全、高效和可持续利用。

四逆汤中3种双酯型生物碱含量对比研究

采用LC-MS技术测定并比较了在四逆汤中附子与甘草配伍前后3种双酯型生物碱含量的变化.实验结果表明,缺甘草四逆汤中3种双酯型生物碱含量是四逆汤中3种双酯型生物碱含量的2倍或更多,且存在显著性差异(P<0.01),附子配伍甘草后,其主要毒性成分——3种双酯型生物碱的含量显著降低.

中国耕地重金属污染现状及其人为污染源浅析

重金属污染物对食品安全及人身健康有很大的危胁,耕地土壤重金属污染问题已越来越受到关注。为有效防止耕地污染进一步恶化及改善食品质量安全,有必要整体分析我国耕地重金属污染现状及主要人为污染源。通过搜集全国(未含港澳台地区)有关耕地土壤重金属污染调查数据的文献(2008~2018年),采用地积累指数法分析了各地区Cd、Pb、Cr、Hg、As、Cu、Ni 7种重金属累积含量及可能存在的风险,综合评价了重金属在我国各地区耕地表层土壤30年来的积累情况和主要人为污染源。结果表明,陕西、甘肃、新疆、广东、海南、湖南、河南、浙江、北京、山西、吉林、四川12个省(市、区)是我国耕地污染较为严重的地区,其中陕西、甘肃、新疆、广东和湖南尤其严重;耕地土壤重金属污染元素主要是镉和汞,受到中度污染及以上的省(市、区)分别有9个和5个;造成耕地土壤重金属污染的主要人为因素有冶矿产业、工业企业、城市建设、车辆交通、垃圾处理及农业生产等,污染严重程度依次为冶矿产业>电子垃圾拆解>城市建设>工业企业>城郊活动>车辆交通>生活垃圾处理>蔬菜(设施)生产>畜禽养殖。建议应严格控制污染强度较高的工矿企业和城市建设等污染物的排放,同时农业土壤中的镉和汞作为优先控制和治理的元素。