Heavy Metal Contaminated Food Crops Irrigated with Wastewater in Peri Urban Areas, Zambia

Studies on peri urban farming in Zambia have not adequately tackled the issues pertaining to heavy metal contaminated wastewater irrigation farming. The study investigated heavy metal contamination of water, soils and crops at two peri urban areas in Zambia. Two study sites were New Farm Extension in Mufulira Town in the Copperbelt Province and Chilumba Gardens in Kafue Town in Lusaka Province. The heavy metals investigated were lead, copper, cobalt, nickel and chromium. These heavy metals were found to be higher than acceptable limits in wastewater used to irrigate crops and there are potential human health risks associated with consumption of heavy metal contaminated food crops which have implications on the livelihoods of people. Samples of water, soil and crops were collected and analysed for lead (Pb), copper (Cu), chromium (Cr), cobalt (Co) and nickel (Ni) using the Atomic Absorption Spectrometer (AAS). The data on heavy metals was analysed using mean, standard error and T-test. The results indicated that the levels of heavy metals in wastewater, soil and food crops were above acceptable limits at two study sites. It can be concluded that there was heavy metal contamination of wastewater, soil and food crops at the two peri-urban areas in Zambia. The study highlighted the actual levels of heavy metal contaminant uptake in food crops consumed by the peri urban population. The information from this study can be used by the relevant authorities to develop appropriate measures for monitoring and control of heavy metal contamination in wastewater irrigation farming systems in peri urban areas inZambia.

Analysis of Heavy Metal Content in Food Crops Planted Along the Shaanxi Inner Mongolia Expressway

To understand the effect of the running of Shaanxi Inner Mongolia Expressway on food crops planted along the sides, we determined the heavy metal contents(Zn, Pb, Cu and Cb) in the digestion solutions of the root, stem and leaf from rice and corn. The results showed that highway promoted the accumulation of heavy metal elements in corn and rice. Compared with the CKs(crops produced where no highway extend), contents of heavy metal elements in two crops tested from two sampling sites were both over standard. This indicates that food crops planted within 100 m away from the highway are been polluted by heavy metals, which is directly related with the running of Shaanxi Inner Mongolia Expressway. Based on this, the areas within 100 m away from the highway are not suggested to cultivate food crops.

Trends of Laboratory-Detected Heavy Metals in Children: Solutions for Heavy Metal Contamination in Infant Food Products

In 2019, an investigation by the U.S. House of Representatives revealed major infant food conglomerates had products with high levels of arsenic, lead, cadmium, and mercury, posing concerns for infants’ vulnerability to the neurotoxic effects of these metals. Trends of laboratory-detected heavy metals were analyzed in children aged zero to five from 1999-2020, providing insights on heavy metal contamination in infant food products. Utilizing National Health and Nutrition Examination Survey (NHANES) data, mean heavy metal levels in children were calculated, considering gender, race, and income-to-poverty ratio as proxies for assessing associations with increasing heavy metal rates in infant food. Findings indicated an overall decrease in mean concentrations over time, though remaining elevated. Black children exhibited higher lead levels than the overall average, while the Asian subgroup displayed higher levels of total blood mercury and cadmium levels. Lack of internal standards in regulatory bodies, particularly the FDA, exacerbates the issue, with no legally enforceable guidelines or strict maximum levels for heavy metals in infant foods. Urgent FDA interventions are needed, addressing contamination at the sources of raw materials, implementing transparent and extensive product testing, and comprehensive manufacturer labeling to inform consumers about elevated heavy metal levels in infant products.

Risk Assessment of Heavy Metals in Food Crops at Abandoned Lead-Zinc Mining Site at Tse-Faga, Logo, Lga, Benue State, Nigeria

Hundreds of children died in 2010 due to suspected lead poisoning from mining sources in Zamfara State among epidemiological concerns. Evaluating ecological and human health risks of heavy metals levels in sampled food crops harvested near two abandoned Lead-Zinc mining sites at Logo Benue State is crucial. Abelmoschus esculentus, Carica papaya, Manihot esculenta, and Zea mays were sampled, prepared, and analyzed for four heavy metals using the Atomic Absorption Spectrophotometric method. The mean data from the analysis of variance was subjected to ecological and health risk models. Pb means value ranged from Carica papaya Peel 0.46 ± 0.011 mg/kg to 1.30 ± 0.01 mg/kg in Zea mays seed. Zn was highest in Carica papaya flesh 0.50 ± 0.01 mg/kg, and lowest in Manihot esculenta peels and its flesh 0.12 ± 0.000 mg/kg. Hg and Cd were below detectable levels. Zea mays seeds (1.001) had the highest Pd bioaccumulation factor. BAF of zinc and ecological indices were <1. Daily Intake of Metals were all <1, however, Hazard Quotient (HQ) of Pb was ≥1 in Manihot esculenta flesh 1.143 and Zea mays at 1714. Cancer Risks were within permissible range (10-4 - 10-6). Health Risk result indicates communities around the mining area may be at risk of lead poisoning therefore due to high contamination of samples, routine checks on heavy metals especially lead is recommended to prevent excessive bioaccumulation in the body.

Assessment of Dietary Exposure and Health Risk to Multiple Heavy Metals amongst Some Workers in Yaounde, Cameroon

This study reports on the dietary exposure of people in Yaounde, Cameroon to heavy metals： lead （Pb）, cadmium （Cd）, mercury （Hg）, copper （Cu） and zinc （Zn）. One hundred and fifty table-ready food, water and soft drink samples were collected from households and street restaurants in Yaounde and analyzed for heavy metals contents using atomic absorption spectrophotometer. Lead （93%, range 0.019-1.77 ppm）, Cd （70%, range 0.01-4.68 ppm）, Hg （81%, range 0.03-10.56 ppm）, Cu （90%, range 0.004-40.32 ppm） and Zn （87%, range 0.014-2,447.04 ppm） were detected in studied samples. Maximum level of each metal exceeded its corresponding European Commissions legislative limits. Samples from street restaurants were most tainted with heavy metals. The highest average daily intakes （ADIs） of Pb （0.96 mg/day） and Hg （1.84 mg/day） were through tap water, while Cd （1.15 mg/day）, Cu （5.42 mg/day） and Zn （601.6 mg/day） were through rice/peanut sauce mixed food. The ADI for Cd and Hg was each higher than its respective PTDI （provisional tolerable daily intake） as defined by JECFA （Joint FAO/WHO Expert Committee on Food Additives） and EVM （Expert Group on Vitamins and Minerals）. The estimated average daily exposure dose of each detected metal significantly （p = 0.001） exceeded its corresponding PTDI. However, the health risk index was 〈 1 for all studied samples and it was found to be safe, indicating there is a relative absence of health risks associated with the ingestion of contaminated foods, water and soft drinks. Notwithstanding, the detected levels and ADI being higher than legislative limits and PTDI respectively speculates need for awareness raising towards reducing exposure levels to heavy metals in Cameroon.

Strategies to manage the risk of heavy metal(loid) contamination in agricultural soils

Soil contamination with heavy metal(loid)sthreatens soil ecological functions, water quality and foodsafety;the latter is the focus of this review. Cadmium (Cd)and arsenic (As) are the toxic elements of most concern forfood safety because they are relatively easily taken up byfood crops. Rice is a major contributor of both Cd and Asintakes to the Chinese population. Contarmination and soilacidification are the main causes of high Cd levels in ricegrains produced in some areas of southern China. The riskof Cd and As accumulation in food crops can be mitigatedthrough agronomic practices and crop breeding. Liming iseffective and economical at reducing Cd uptake by rice inacid soils. Paddy water management can produce oppositeeffects on Cd and As accumulation. Many genes control-ling Cd and As uptake and translocation have beencharacterized, paving the way to breeding low accumulat-ing crop cultivars through marker- -assisted molecularbreeding or genetic engineering. It is important to protectagricultural soils from future contamination. L ong-termmonitoring of anthropogenic additions and accumulationof heavy metal(loid)s in agricultural soils should beundertaken. Mass-balance models should be constructedto evaluate future trends of metal(loid)s in agricultural soilsat a regional scale.

Heavy metal contamination in soils of greenhouse vegetable production systems in a cold region of China

Heavy metal(HM)contamination in soils of greenhouse vegetable production(GVP)systems has drawn increasing attention in terms of food safety.In the present study,64 surface soils were sampled,and the concentrations of select HMs were determined using atomic absorption spectroscopy.The results showed that the concentrations of cadmium(Cd),lead(Pb),zinc(Zn),copper(Cu),nickel(Ni)and chromium(Cr)in the soils were(0.2±0.2)mg/kg,(26.5±8.4)mg/kg,(101.4±43.2)mg/kg,(29.1±8.6)mg/kg,(24.5±3.3)mg/kg,and(56.5±6.3)mg/kg,and the corresponding accumulation index(AI)values were 2.30,1.10,1.43,1.45,1.07,and 0.97,respectively.The spatial distribution of the HMs suggested that Cd pollution displays a fractionation effect,which may be related to the source of Cd and its mobility.The concentration of Zn was significantly correlated with that of other HMs,implying that a comprehensive interactive effect might occur between Zn and other HMs.Furthermore,the values of the potential ecological risk index(RI)ranged from 41.23 to 185.91,meaning that attention should be paid to HM contamination of GVP soils to ensure food quality and safety.

基于荧光光谱技术的食品检测研究

本文简要介绍了荧光光谱技术的基本原理,并对其在食品检测领域的应用进行了综述,重点阐述了荧光光谱检测方法在几种常见食品污染物中的应用,包括农药残留、重金属污染、非法添加物等。通过对比传统检测方法,分析了荧光光谱技术的优势,如快速、灵敏、无损等。最后,展望了荧光光谱技术在食品检测领域的发展前景,并提出了进一步研究的方向和建议,以期为保障食品安全提供有力的技术支撑。

茶树枝生物质炭对农田土壤肥力与水稻镉吸收和转运的影响

开展受污染耕地治理技术探索,是确保耕地合理利用与缓解资源紧张的重要措施。该研究以茶树枝进行生物质炭烧制,在镉污染稻田中通过设置3种不同用量(3000、6000和9000 kg·hm^(-2))茶树枝生物质炭开展田间试验,探究茶树枝生物质炭对稻田土壤养分、有效态镉、水稻生长与镉吸收和转运的影响,结果表明,中用量生物质炭处理千粒重、株高、产量与空白对照处理相比分别增加5.04%、9.00%和3.77%,籽粒镉含量下降46.67%,显著降低镉在水稻体内的富集和转运系数。同时土壤pH值增加0.23,有机质含量、碱解氮含量、有效磷含量、速效钾含量分别增加11.41%、13.77%、8.28%、40.94%,土壤有效态镉含量下降13.04%。综合来看,采取茶树枝生物质炭6000 kg·hm^(-2)用量时,能够实现水稻增产与降镉,同步提升土壤肥力的目标,可作为安全利用技术措施进行推广应用。

荧光铜纳米团簇用于食品和环境中Cr_(2)O_(7)^(2-)的检测研究

重金属离子污染问题是食品和环境安全领域的一个重要课题,因此迫切需要开发科学灵敏的检测方法。文章使用4,6-二氨基-2-巯基嘧啶(DAMP)作为配体,在温和条件下,仅通过简单的搅拌,在10 min之内合成一种发射波长为590 nm的新型铜纳米团簇(copper nanoclusters,CuNCs)。鉴于该团簇对于重铬酸根离子(Cr_(2)O_(7)^(2-))高度的灵敏性和抗干扰能力,将其作为荧光探针,实现了对Cr_(2)O_(7)^(2-)的特异性和灵敏性检测,最低检出限为0.7μmol/L。通过加标回收试验,验证其在饮用水和湖水实际样品中对Cr_(2)O_(7)^(2-)的荧光检测能力,荧光变化显著,其加标回收率在94.3%~108.2%之间,相对标准偏差(relative standard deviation,RSD)均低于5%。结果表明该荧光探针对食品和环境中的Cr_(2)O_(7)^(2-)具有良好的检测效果。

LC-MS在食品加工过程中重金属污染物检测中的应用

食品加工过程中出现的重金属污染问题严重威胁食品安全和公众健康。液相色谱-质谱联用技术因其高灵敏度、高选择性和多元素同时检测能力,被广泛应用于食品重金属检测。重金属污染的主要来源有原料污染、加工过程中的污染、包装材料和存储过程中的污染。液相色谱-质谱联用技术在水产品、蔬菜水果、谷物豆类检测的实际应用中展示出了高效、准确的检测能力。通过优化检测方法和降低成本,该技术将在食品安全监控中发挥越来越重要的作用,从而为保障消费者健康提供技术支持。

食品安全检测技术对食品质量安全的影响与对策研究

食品中微量元素铅、砷的污染对公众健康构成严重威胁。先进的检测技术在提高检测精度和可靠性、促进食品安全标准的制定与完善、增强消费者信心以及发现和预防食品安全隐患方面具有重要作用。本文探讨铅、砷的来源及危害,分析原子吸收光谱法、电感耦合等离子体质谱法和X射线荧光光谱法等检测技术对食品质量安全的影响与对策。

禹州市煤矿区周边土壤和农作物重金属污染状况及健康风险评价

为全面了解河南省禹州市煤矿周边土壤和农作物中的重金属污染现状.对禹州市的某3个典型矿区(下文称为A、B和C矿区)周围土壤和主要谷类农作物(玉米和小麦)进行了调研和采样分析,并采用电感耦合等离子体质谱仪(ICP-MS)测定其重金属含量,同时通过单因子指数法和内梅罗综合指数法评价了煤矿周围土壤的污染状况,并利用MMSOILS风险评价模型评价了食用当地谷类农作物对成人和儿童造成的重金属健康风险.结果表明:研究区土壤受到了重金属不同程度的污染,污染程度排序:小麦地>玉米地,且就单个重金属污染程度来说, Cd> Cu> Co> Ni> Zn> Cr;内梅罗综合污染指数分析结果表明,玉米地的污染程度为安全,小麦地的污染程度为重污染,均以Cd对污染指数P_(综合)值的贡献最大;研究区农作物玉米籽粒中Cr、Co、Ni、Cu、Zn和Cd的平均含量分别为25.03、0.54、2.87、21.52、118.68、1.97 mg·kg^(-1);小麦籽粒中Cr、Co、Ni、Cu、Zn和Cd的平均含量分别为1.04、0.11、1.17、9.55、61.51、0.06 mg·kg^(-1).Cr、Co、Ni、Cu、Zn和Cd富集系数大小的顺序均为玉米>小麦;健康风险评价表明,研究区农作物籽粒中存在高重金属污染风险,尤其以Cd最为明显,食用当地谷类农作物对人体造成健康风险的顺序依次为Co> Cd> Cu> Zn> Ni> Cr,其中Co、Cd对成人风险较高,Co、Cu、Zn、Cd对儿童风险较高,对儿童造成的健康风险要明显高于成人;土壤重金属含量与谷类农作物可食部分重金属含量间无明显相关性.

我国农作物的重金属污染及其防止对策

在参考国内有关资料的基础上，分析了我国农作物重金属污染的原因，其中，污水灌溉、乡镇企业的“三废 ”污染、汽车尾气等是造成我国农作物中重金属污染的主要原因；针对不同的污染原因，提出了防止农作物重金属污染的控制对策，保护农业生态环境是防止农作物重金属污染的根本途径。

污染谷物中重金属的分布及加工过程的影响

对污染水稻、小麦和玉米籽实中 Cd、Pb、Cu的分布及加工过程的去除进行了研究 .结果表明 ,Cd、Pb、Cu在水稻、小麦和玉米籽实各形态结构中的浓度分布不均 ,胚中浓度显著高于胚乳 ,且皮层和颖壳中浓度也较高 .但从单位重量籽实中的 Cd、Pb、Cu总量分布看 ,胚乳中占据绝对优势 .稻、麦籽实中 3种元素的浓度随样品加工浓度的升级去除率增加 ,水稻中 Cd、Pb、Cu的去除率可达 2 4 .1 0 %、56.93%和 41 .0 0 % ,小麦分别为 61 .66%、81 .2 7%、78.37% .

云南个旧市郊农作物重金属污染现状及健康风险

通过现场采样及室内分析,对云南个旧市郊鸡街镇的土壤和农作物重金属污染现状进行野外调查,并进行健康风险评价。结果表明,土壤Pb、Zn、Cu和Cd含量均超出《土壤环境质量标准》(GB15618—1995)二级标准,Pb、Cu和Cd的二乙三胺五乙酸(DTPA)提取态与总量呈极显著正相关(P<0.01),Zn则呈显著正相关(P<0.05)。农作物中除萝卜、甘蓝、花椰菜和甘蔗Pb含量未超出对应的食品安全限量标准外,其余作物均超标,Pb超标率达80%,其中薄荷Pb含量最高,平均值为3.28mg.kg-(1鲜重),超标9.93倍;朝天椒、土豆、大米和玉米Cd含量均超标,Cd超标率为20%,其中大米Cd含量最高,平均值为0.446mg.kg-1,超标1.23倍;Cu和Zn在所采的农作物中均未超标。薄荷对Pb和Cu、莴苣对Zn和Cd的富集系数高于其他农作物。豌豆尖、蚕豆、甘蓝、花椰菜、葱、朝天椒、甘蔗、韭菜、厚皮菜、白菜、萝卜、青花菜、土豆和金丝菜对Pb、Zn、Cu和Cd吸收能力较低,适合在污染区继续种植;薄荷、莴苣和青菜对4种重金属吸收能力较高,不适合在污染区继续种植。根据单因子评价方法,农作物受Pb轻度、中度、重度污染分别占50%、10%和20%,受Cd轻度、中度污染各占10%。对于不同种类农作物,不同重金属的综合污染指数为Pb>Cd>Zn>Cu。居民经食用蔬菜途径日摄入Pb、Zn、Cu和Cd量分别为0.204、2.336、0.376mg.d-1和0.028mg.d-1,分别占暂定每日耐受摄入量(PTDI)的101.78%、7.08%、5.79%和39.29%。因此,经蔬菜途径摄入Pb对当地居民健康构成潜在威胁。

云南个旧多金属矿区农田土壤-作物系统重金属污染现状——以乍甸镇为例

对云南个旧市乍甸镇农田土壤和农作物重金属污染现状进行了野外调查及评价。结果表明:农田土壤Pb、Zn、Cu、Cd、As质量比均超出GB 15618—1995《土壤环境质量标准》二级标准,Hg未检出,该地区农田呈现以As、Cd为主多种重金属复合污染。Pb、Zn、Cu、Cd、As土壤有效态质量比与土壤全量呈极显著正相关(p<0.01)。农作物中Cu、As质量比与土壤有效态Cu、As质量比无显著相关,Zn质量比与土壤有效态Zn呈极显著负相关(p<0.01),Cd、Pb质量比与土壤有效态Cd、Pb呈显著正相关(p<0.05)。89%的农作物As超标,油菜籽(Brassica napusL.)As质量比最高,均值达(23.04±14.33)mg/kg(鲜重,下同)。Pb超标率达72%,油菜籽Pb质量比最高,平均为(5.55±2.53)mg/kg。Zn、Cd超标率均为11.11%,超标最严重的油菜籽Zn质量比为(46.65±13.61)mg/kg,Cd质量比为(0.24±0.10)mg/kg。Cu超标率为5.55%,油菜籽Cu质量比最高,达(16.02±2.75)mg/kg。油菜籽对As、Pb、Zn、Cu、Cd的转移系数(农作物可食部分重金属质量比(鲜重)与土壤重金属质量比的比值)远高于其他作物。农作物对Pb、Zn、Cd、As的转移顺序依次为果实类、叶菜类、根茎类,对Cu的转移顺序为果实类、根茎类、叶菜类。农作物以As、Pb污染为主,总体属重度污染。聚类分析得出:油菜籽、青蒜(Allium ampeloprasumL.)和生菜(Lactuca sativaL.var.ramosaHort.)重金属污染严重,不适合在该地区继续种植和食用。

大宝山矿水外排的环境影响:Ⅱ.农业生态系统

大宝山外排酸性矿水对周边农村地区农业生态系统具严重的负面影响,表现在:农田所用的灌溉水酸度很强,灌溉水中多种重金属含量高于国家农田灌溉水质标准,其中Cd超标约16倍;土壤严重酸化,pH值可低至3.9,总实际酸度平均达47mmol/kg,比水溶性酸度高147倍,表明由矿水带进土壤的无机酸通过土壤的缓冲作用暂时转化为非水溶态并在土壤中累积;土壤重金属含量超标,以Zn、Cu和Cd为甚;粮食和果蔬等作物重金属污染严重,其中尤以Cd最为突出,最高可超标近150倍。

煤矸石场附近3种粮食作物的重金属富集特征及污染评价

为深入认识煤矸石堆积对周围农作物的重金属污染危害,探讨矸石场附近土壤-作物系统中重金属元素的富集转运规律,以宿州桃园煤矿矸石场附近农田为例,通过布点采样和试验测定,探讨了重金属元素Cu、Pb、Cd和Cr在土壤和3种粮食作物(玉米、绿豆和大豆)中的质量比分布特征,对比分析了不同粮食作物的根部富集能力和籽实转运能力,并利用单因子及内梅罗污染指数法对农作物重金属污染状况进行了评价。结果表明:研究区土壤中Cd、Cr和Cu有明显积累,4种元素质量比均随与矸石场距离增加而逐渐下降;作物不同器官中重金属质量比从大到小为根、茎、籽实,但叶片中部分元素质量比明显偏高;作物根部对重金属元素的吸收能力以玉米最高,而向籽实中的转运能力以绿豆和黄豆最高,这主要是3种作物根系特征和秸秆高度的差异所致;3种作物的内梅罗污染指数从大到小为玉米、黄豆、绿豆,其中玉米为轻度污染,黄豆和绿豆处于警戒水平。

锰矿农作物恢复区土壤重金属污染模糊综合评价

对广西八一、荔浦、平乐、全州、板苏和下雷6个锰矿食用农作物恢复区土壤重金属进行含量测定，结果表明，土壤各元素含量为：Pb41．63～348．31mg·kg^-1、Cr48．12～287．29mg·kg^-1、Zn47．38～269．92mg·kg^-1、Cu12．71～138．03mg·kg^-1、Cd0．73-46．50mg·kg^-1、Mn676．7～41996．4mg·kg^-1。Mn和Cd最高含量分别为广西土壤背景值的243倍和754倍。采用模糊综合评价法对土壤重金属进行评价：从单因素决定模型看，恢复区土壤对环境质量三级标准的平均隶属度为0．4340．981；从加权平均模型看，土壤对三级标准的隶属度为0．366～0．974。除下雷矿区外，其余5个锰矿恢复区土壤对三级标准的平均隶属度〉0．7，各采样区重污染率为100％；其中，Cd含量对三级标准隶属度〉0．8，Cd重污染率达100oA，是恢复区土壤的首要污染因子。因此，在锰矿废弃地生态恢复初期，应避免采用种植食用农作物恢复模式。