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1.
Heavy metals are important toxicants known to exert adverse effects in humans and animals, given sufficient exposure and accumulation in the body. This has a great concern both at personal and public health risk. Heavy metals are also known to interact with the essential trace minerals at the level of absorption and also during the metabolism. The adverse effects of the absorbed and accumulated heavy metals include neurological, reproductive, renal and hematological systems. Children are more sensitive than adults to the effects of lead. Efforts are made to understand the mechanism of the interactions of heavy metals with essential trace minerals at the level of absorption. With available sensitive and specific methodologies like Anodic Stripping Voltammetry for the evaluation of the levels of toxic heavy metals such as lead, cadmium, mercury etc., better understanding of heavy metal absorption is made possible. Due to the poor nutritional standards, risk of heavy metal exposure is still a major concern in developing countries. Studies carried out by the author have provided evidence towards the understanding of the prevailing mechanisms of metal-metal interaction at the intestinal level. During growth and development the demand for the essential minerals being at higher level, differentiation of various essential metals and heavy metals pose an inherent problem due to certain common properties shared by them. With this approach to the problem of heavy metal toxicity, it is preventable not only with environmental intervention but also by the nutritional management.  相似文献   

2.
Lead is one of the most widely scattered toxic metals in the environment and used by mankind for over 9,000 years. Lead in the environment may be derived from natural or anthropogenic sources. In humans, lead can cause a wide range of biological effects depending upon the level and duration of exposure. The purpose of this study was to find out the effect of lead exposure on systolic and diastolic blood pressure, serum calcium, ionized calcium, phosphorus, parathyroid hormone and vitamin D and examine the overall effect of all these parameters on the bone mineral density of battery manufacture workers. For this study ninety battery manufacture workers were selected and divided in three groups depending upon duration of lead exposure. Group I—workers with duration of lead exposure 1–5 years, Group II—workers with duration of lead exposure 6–10 years and Group III—workers with duration of lead exposure more than 10 years. Each group consisted of thirty workers. Thirty age matched healthy control subjects were taken for comparison. Demographic, occupational and clinical data were collected by using questionnaire and interview. The venous blood samples were collected from the study groups and normal healthy control group. At the time of blood collection random urine samples were collected in amber coloured bottles. The biochemical parameters were estimated by using standard assay procedures. Statistical analysis of the data was done using independent student‘t’ test for parametric variables. Values were expressed as mean ± standard deviation (SD). P values of 0.05 or less were considered to be statistically significant. The blood lead levels and urinary lead levels of all workers were significantly increased (P < 0.001) in proportion to the duration of lead exposure as compared to controls. Systolic and diastolic blood pressure were significantly raised (P < 0.001) in all three study groups of battery manufacture workers as compared to controls. Serum Calcium, Ionized calcium, phosphorus were significantly decreased (P < 0.001) in all the three study groups. Serum vitamin D levels were lowered (P < 0.01) and serum PTH was increased (P < 0.01) in workers as compared to controls. The results of this study clearly indicate that the absorption of lead is more in these workers which adversely affects blood pressure, disturbs calcium and phosphorus metabolism which further impairs mineralization of bone resulting in decreased bone mineral density observed in these workers. Lead toxicity is still persistent in battery manufacture workers though they are using sophisticated techniques in these industries. There is a need to protect the workers from the health hazards of occupational lead exposure.  相似文献   

3.
It is well known that chronic exposure of lead leads to adverse health effects. Workers for plastic industry are generally exposed to high concentration of lead as fume, dust, and additive that protect PVC. This study was done on them to find out the detrimental effects of chronic lead exposure on hepatic and hematological toxicity. Blood and 24 h urine sample was collected from 47 plastic industry workers and matched against 42 controls for various parameters. The study group shows significant increase in blood (p < 0.0001) and urinary level of lead (p < 0.0001). Hemoglobin levels were significantly decreased (p < 0.0001), and the liver enzymes like ALP, ALT, AST and y-GT were significantly increased (p < 0.0001) in all cases exposed for >10 years. Serum lipid peroxide by quantitative assay of thiobarbituric acid reactive substances was also found increased in the study group (p < 0.0001). The observations point towards the acute health risk faced by plastic industry workers, in whom chronic exposure to lead increases the absorption and accumulation, over a period of time, of this highly toxic element in their body. This increases oxidative stress, causes metabolic damage to RBC and cell membranes, and also suggests necrosis of liver cell, hepatocellular injury and presence of space occupying lesions. Considering the data immediate health and hygiene monitoring and proper rehabilitation for the suffering population seem to be of paramount need in plastic industry to minimize occupational hazards.  相似文献   

4.
Jewelry utilizes lead either directly or as a base metal. Costume jewelry requires lead before molding and plating the product with valuable metals. Therefore, such ornaments have a great potential to release heavy metals having health hazards. Also, jewelry makers engaged in preparing German silver, an alloy, apply lead in smelting, alloying, rolling and milling silver wires and pieces. The metal is taken up by blood, soft tissues and bone. The biological effects of lead are dependent upon the level and duration of exposure. Lead inhibits three enzymes of heme biosynthesis- δ-amino-levulinic-acid dehydratase (ALAD), coproporphyrin oxidase, and ferrochelatase, impairing heme synthesis and depressing serum level of erythropoietin resulting in decreased hemoglobin synthesis. Lead exposure also affects calcium metabolism and impair the synthesis of Calcitriol. In the present study, jewelry makers from Dhaka, Bangladesh, were shown to have significantly high levels of lead, protein, albumin, and parathormone in their blood, and significantly high amount of zinc-protoporphyrin and δ-amino-levulinic-acid in their urine. The control group, on the other hand showed significantly higher amounts of calcium (both total and ionized form) Vitamin D3 and non-activated erythrocyte ALAD in their blood, along with hemoglobin. It might be due to inhibition of 1-α-hydroxylase enzyme in renal tubules. Lead causes nephro-toxicity and inhibits 1-α- hydroxylase enzyme leading to decreased calcitriol synthesis resulting in impaired calcium absorption across gastro-intestinal tract and renal tubules. Low Vitamin D3 and significantly increased Parathyroid hormone (PTH) in study group has been found.  相似文献   

5.
Blood zinc protoporphyrin (ZPP), serum total protein (TP), and total cholesterol (TC) levels in automobile workshop workers in relation to lead toxicity were analysed. In the present study, automobile workshop workers (healthy male workers at an age between 28 and 35 from four major automobile workshops in Kottayam, Kerala State, India) and the control (male healthy adults at an age between 28 and 35 residing at Aymanam, a distant village at Kottayam District, Kerala having reduced or no chance of lead exposure) displayed significant difference in blood lead (BPb) and blood ZZP (BZPP) level. The mean value of BPb in automobile workshop workers was 15.76±0.33 μg/dl, while in the control it was 8.20±0.15 μg/dl. In automobile workshop workers, the mean value of BZPP was 34.2±0.62 μg/dl. The control group exhibited a mean of 11.5±0.22 μg/dl. Automobile workshop workers exhibited significant increase in BZPP was corresponding to the increase in BPb level. The total protein levels estimated in automobile workshop workers showed significant decrease compared to control individuals, but was within the reference range of healthy individuals. The mean value of TP level in automobile workshop workers and control was 6.9±0.13 g/dl and 7.71±0.18 g/dl, respectively. There was no significant difference in blood haemoglobin (BHb) level among the automobile workshop workers and control. The serum TC level in automobile workshop workers showed significant decrease compared to the control individuals, but was with in the reference range of healthy individuals. The mean level of serum TC in automobile workshop workers was 162.00±3.44 mg/dl and the same in control was 172.86±4.32 mg/dl. The present study affirms occupational lead toxicity in automobile workshop workers and its effect on serum protein and cholesterol levels.  相似文献   

6.
通过慢性暴露实验研究了菲律宾蛤仔在锌(Zn2+),铅(Pb2+)单一胁迫及联合胁迫下,消化腺和鳃内富集Zn2+和Pb2+及其金属硫蛋白水平随Zn2+、Pb2+暴露浓度的变化规律.结果表明, Zn2+50μg/L、Pb2+25μg/L联合胁迫时,消化腺和鳃内重金属的富集低于Zn2+、Pb2+单一胁迫,表现为拮抗作用;MT含量随着Zn2+、Pb2+暴露质量浓度变化而变化,比较发现消化腺中MT含量随Pb2+暴露质量浓度的变化最显著(p<0.01).  相似文献   

7.
Among the heavy metals, lead still remains the major toxic pollutant of the environment. Human exposure to lead can occur through numerous pathways including air, food, dust, soil, and water. In the present study 14 lead poisoned patients with non-occupational lead exposure were evaluated. They were followed up and compared against the controls with no history of lead exposure. The patients had high blood lead levels and symptoms of weakness, dizziness, abdominal pain, generalized body ache, loss of appetite, and anxiety. Repeated course of chelation therapy helped to bring down their body burden of lead. Alternative sources for lead exposure can cause severe lead poisoning in general population. Screening and medical management of such individuals is very important to identify and eliminate sources of lead. The treatment and management requires a thorough medical evaluation and environmental intervention.  相似文献   

8.
Lead ranks as one of the most serious environmental poisons all over the world amongst toxic heavy metals with no known biological function useful for the human body. A case of lead toxicity due to consumption of herbal medicine is being discussed. The case presented with gastrointestinal complaints and history of intake of herbal medicines for diabetes control for past 8 months. The analysis of the powdered herbal medicine procured from ayurveda practitioner was found to have high content of lead responsible for the lead toxicity. The patient is under regular followup. He has improved symptomatically on chelating therapy and blood lead levels have gradually improved. Regular awareness programs should be conducted in the population regarding possible exposure through home made herbal remedies so that general public can be made aware of the dangerous side effects of lead and other heavy metals on health.  相似文献   

9.
Heavy metals are natural elements in the Earth’s crust that can enter human food through industrial or agricultural processing, in the form of fertilizers and pesticides. These elements are not biodegradable. Some heavy metals are known as pollutants and are toxic, and their bioaccumulation in plant and animal tissues can cause undesirable effects for humans; therefore, their amount in water and food should always be under control. The aim of this study is to investigate the conditions for the bioremediation of heavy metals in foods. Various physical, chemical, and biological methods have been used to reduce the heavy metal content in the environment. During the last decades, bioremediation methods using plants and microorganisms have created interest to researchers for their advantages such as being more specific and environmentally friendly. The main pollutant elements in foods and beverages are lead, cadmium, arsenic, and mercury, which have their own permissible limits. Among the microorganisms that are capable of bioremediation of heavy metals, Saccharomyces cerevisiae is an interesting choice for its special characteristics and being safe for humans, which make it quite common and useful in the food industry. Its mass production as the byproduct of the fermentation industry and the low cost of culture media are the other advantages. The ability of this yeast to remove an individual separated element has also been widely investigated. In countries with high heavy metal pollution in wheat, the use of S. cerevisiae is a native solution for overcoming the problem of solution.This article summarizes the main conditions for heavy metal absorption by S. cerevisiae.How to cite: Massoud R, Hadiani MR, Khosravi Darani K, et al. Bioremediation of heavy metals in food industry: Application of Saccharomyces cerevisiae. Electron J Biotechnol 2019;37. https://doi.org/10.1016/j.ejbt.2018.11.003.  相似文献   

10.
Lead is found in small but appreciable quantities in air, soil drinking water and food. Exposure to such amounts of lead does not cause acute lead toxicity, but produces subtle effects, particularly in children. The CDC advocates “safe” or “acceptable” levels of blood lead up to 10 μg/dl, while OSHA declares blood lead levels up to 40 μg/dl as “safe” or “acceptable” in the occupationally exposed. The objective of the study was to see if blood levels considered “safe” can cause changes in the biogenic neurotransmitters in the developing brain which may cause neurobehavioral defects like hyperactivity and other cognitive disorders. Albino Wistar rats were divided into the control and lead-treated groups. The control group was given unleaded water, while the lead-treated group was fed with 50 ppm lead acetate in drinking water. On day 45 the animals were subjected to a passive avoidance test, their blood analysed for ZPP and lead. They were then sacrificed and the neurotransmitters—Norepinephrine (NE) and its metabolite—methoxyhydroxyphenylglycol (MHPG) estimated in the brain areas associated with learning and memory—the frontal cortex, hippocampus and the striatum by HPLC-ECD. Our results showed significant increases in blood lead, NE and MHPG, while ZPP increase was insignificant. The rats showed neurobehavioral abnormalities as assessed by the passive avoidance test. We concluded that low blood levels of lead cannot be considered “safe” or “acceptable” as it causes neurotransmitter alterations. Increased NE turnover is implicated in hyperactivity disorders such as ADHD and Tourette syndrome.  相似文献   

11.
A total of 75 healthy male dry cell industry workers exposed to carbon for 5, 8 and 10 years were compared with 48 controls matched for age and economic status with respect to free radical generation, lipid peroxidation and antioxidant levels. Lymphocytes were seperated from the whole blood and used for estimation of free radicals and antioxidants. Plasma lipid peroxidation products were estimated in the form of thiobarbituric acid reactive substances. Significant increase in free radical generation and lipid peroxidation products were observed in carbon exposed population than controls, and the increase was found to be significant with increase in the period of exposure. The levels of antioxidants i.e., superoxide dismutase (SOD) and catalase were found to decrease with the increase in exposure to carbon in industrial workers. These results suggest that exposure to carbon augments free radical generation, lipid peroxidation and promotes decline in antioxidant enzymes.  相似文献   

12.
Awareness about the toxic effects of non-essential metals is still lacking in developing countries. Lead is one among them, which ranks second in the Agency for Toxic Substances and Disease Registry’ s top 20 lists of toxic metals. Some of the herbal medicines prepared from certain roots and leaves are known to contain this toxic metal at alarming levels. We have a case of a person who suffered from the toxic effects of lead such as vomiting and colicky abdominal pain after consuming a herbal remedy for Jaundice treatment. This went unrecognized initially because of the presence of multiple problems like Malaria and Renal calculi. Lead poisoning as causative factor for anemia, vomiting and colic were confirmed only when blood lead concentration was estimated. A combination of chelation therapy and nutritional supplementation was found to be useful in reducing the body lead burden.  相似文献   

13.
杭州市居民区土壤重金属形态和酸可溶性研究   总被引：10，自引：0，他引：10  
研究了杭州市50个居民小区土壤重金属元素(Cd、Co、Cr、Cu、Ni、Pb、Zn、Mn和Mo)的含量、形态和酸可溶性。结果表明，与农业土壤相比，该市居民区土壤中Cd、Cr、Cu、Ni、Pb、Zn、Mn和Mo均有不同程度的积累；除Cr、Mo外，居民区重金属的积累一般低于该市商业区；土壤重金属元素的积累量随居民区建成时间的增加而增加．居民区土壤中Cd、Co、Cr和Ni主要以稳定的残余态为主；而Cu、Pb、Zn和Mn则以可提取态为主。除Zn、Mn外，重金属的酸可提性组分均较低．土壤重金属的稀酸提取量主要与提取平衡液的pH有关，随pH下降而增加，但大部分土壤中酸可提取的重金属量较低，因此杭州市居民区土壤在正常条件下不会有较多的重金属释放。  相似文献   

14.
The purpose of this study was to find out the effect of lead exposure on systolic and diastolic blood pressure, heme biosynthesis related and hematological parameters of automobile workers. For this study 30 automobile workers were selected and compared with 30 age matched healthy control subjects. Significantly increased blood lead (364%, P < 0.001) and urinary lead (176%, P < 0.001) levels were observed in automobile workers (study group) as compared to controls. Systolic blood pressure (5.32%, P < 0.05) and diastolic blood pressure (5.87%, P < 0.05) were significantly increased in the automobile workers as compared to controls. The significantly decreased non-activated erythrocyte δ-aminolevulinic acid dehydratase (δ-ALAD) (−18.51%, P < 0.01) and activated δ-ALAD (−13.29%, P < 0.05) levels were observed in automobile workers as compared to normal healthy control subjects. But the ratio of activated/non-activated δ-ALAD was significantly increased (43.83%, P < 0.001) in automobile workers as compared to controls. Excretions of δ-aminolevulinic acid (83.78%, P < 0.001) and porphobilinogen (37%, P < 0.001) in urine were significantly increased in the study group as compared to the controls. In automobile workers heamoglobin (−11.51%, P < 0.001), hematocrit (−4.06%, P < 0.05), mean corpuscle volume (−3.34%, P < 0.05), mean corpuscle hemoglobin (−5.66%, P < 0.01), mean corpuscle hemoglobin concentration (−7.67%, P < 0.001), red blood cell count (−14.6%, P < 0.001) were significantly decreased and total white blood cell count (11.44%, P < 0.05) increased as compared to the controls. The results of this study clearly indicate that the absorption of lead is more in automobile workers and it affects on blood pressure, heme biosynthesis and hematological parameters observed in this study group.  相似文献   

15.
Our study aimed at comparing lead and zinc protoporphyrin (ZPP) levels in capillary and venous blood samples in a small population and to employ an easier method of sample collection for a major screening program in school children in major Indian cities. An awareness program on lead and its effects was conducted in two different schools. A total of thirty urban school children from South India, with an age group between 4–12 years consented for dual blood sampling and reported for the study. Venous and capillary blood samples were obtained simultaneously. Blood lead and zinc protoporphyrin (ZPP) levels were estimated using ESA Lead Analyzer and Haematofluorometer respectively. A significant correlation between capillary and venous ZPP (r=0.98) and lead (r=0.99) was observed. Rank sum test showed that there is no statistically significant difference between capillary and venous ZPP (P=0.891) and lead (P=0.672) values. This pilot study recommends that screening for lead may be done using capillary blood samples since significant correlation is observed between capillary and venous blood measurements. Obtaining samples using this mode is a non-invasive, less expensive, quick and easy method in children. Appropriately performed capillary sampling may be considered as an acceptable alternative to venipuncture for screening of blood for lead poisoning both in children and adults.  相似文献   

16.
镉(Cd)是一种剧毒重金属元素,可引起呼吸系统、肾损伤等多种疾病,对人体毒性极高,可通过多种途径暴露于人体,危害人体健康。土壤-植物-食品-人的迁移途径在人类对环境镉的暴露中占主导地位。近年来,Cd通过饮食途径对人体健康造成的风险日益引起人们的关注和重视。本文在对研究区不同土地利用类型下土壤和作物进行大规模采样调查的基础上,对其蔬菜、水稻、旱地、果园等4种土地类型土壤及其种植作物中镉含量积累进行了研究。结果表明,菜地和水稻地有明显的污染超标现象,其中菜地土壤镉含量最高。根据不同土地利用类型下各作物镉富集系数,进行聚类分析,比较其对镉富集能力的差异,结果表明水稻地稻米镉的富集能力最高,单独划为一类。利用定性风险分析技术,对不同土地利用类型下土壤镉对人体健康的风险商值进行了计算,结果表明不同土地类型下,作物镉风险商值为水稻>深色蔬菜>浅色蔬菜>水果>玉米。镉对个人致癌年风险的计算结果表明,水稻个人年致癌风险为0.6270×10-4/年,高于防护委员会(ICRP)推荐的最大可接受年风险水平0.5×10-4/年,为不可接受水平,居民面临较大的致癌风险,应采取积极措施对研究区土壤镉污染进行治理和修复。  相似文献   

17.
The problem of pesticides is not new and its exposure to human due to indiscriminate use is largely associated with the health related problems including neurotoxicological alterations. High levels of pesticide residues and their metabolites in the dietary constituents, food materials, maternal blood, cord blood, placenta breast milk have been reported and linked to alterations in birth weight, crown heel length, head circumference, mid-arm circumference and ponderal index of the neonates. Epidemiological studies have suggested that exposure of pesticide to human could be a significant risk factor for neurological disorders, including Parkinson’s disease, Alzheimer’s disease and multiple sclerosis. Cholinergic and non-cholinergic dysfunctions in pesticide exposed population, especially in children have also been frequently reported in recent years. Developmental neurotoxicity is another concern in the area where pregnant are more prone towards its exposure and which results in the abnormalities in the fetus. In view of the increasing risk of human health through pesticide exposure, the present review has been focused on the studies pertaining to pesticide induced neurochemical alterations and associated behavioral abnormalities in farm workers which could establish a possible link between the its exposure and associated health hazards.  相似文献   

18.
周雯婧  贺惠 《科教文汇》2013,(12):102-103
近年来,我国重金属污染日趋严重引起了人们广泛关注。本文概括了我国农田土壤重金属污染来源及特点,为我国农田重金属污染防治提供依据。  相似文献   

19.
Activated carbon fabrics (ACF) mask prevents the absorption of lead and reduce its adverse effects of human health. Aim of this study to know the blood lead level and its effects on heme biosynthesis and hematological parameters after using 2 months activated carbon fabric mask of battery manufacturing workers (BMW). Blood lead level, heme biosynthesis and hematological parameters were measured by using standard method. Blood lead level (P < 0.001, − 13.5%) was significantly decreased, activated δ-aminolevulinic acid dehydratase (P < 0.001, 11.97%) and non-activated δ- aminolevulinic acid dehydratase (P < 0.001, 23.17%) enzyme activity were significantly increased, however, the ratio of activated to Non-activated δ- ALAD (P < 0.001, − 10.13%) was significantly decreased, urinary excretion of δ- aminolevulinic acid (P < 0.001, − 10.49%) and porphobilinogen (P < 0.001, − 7.38%) were significantly decreased after using 2 months ACF mask as compared to before using mask of BMW. Hematological parameters i.e Hb (P < 0.05, 13.42%), PCV (P < 0.05, 7.23%), MCV (P < 0.05, 1.9%) were significantly increased and total WBC count (P < 0.05, − 5.18%) was significantly decreased after using 2 months ACF mask as compared to before using mask of BMW. Two months using ACF mask reduces the blood lead level and improves the δ-ALDH activity and hematological parameters, decreases the urinary excretion of δ-ALA, PBG of battery manufacturing workers. Therefore, the regular using of ACF mask is beneficial to prevent the lead absorption and its adverse effects on human health.  相似文献   

20.
印度芥菜BjPCS1基因的表达提高烟草对重金属的抗性   总被引：4，自引：0，他引：4  
在植物体内植物络合素(PC)可与重金属螯合,并进一步转运至液泡贮存,使细胞质的重金属浓度降低,从而达到解毒效果。PC不是基因的直接翻译产物,而是以谷胱甘肽(GSH) 为底物由植物络合素合酶催化而成。将来源于重金属超富集植物印度芥菜(Brassica juncea)的植物络合素合酶基因BjPCS1转入烟草,PCR和Northern结果表明,该基因已经整合到烟草基因组中,并在转录水平上表达。在3种重金属(200mmol/L CdCl2、400mmol/L ZnCl2、200mmo/L NiCl2)胁迫条件下,转基因烟草植株的脯氨酸含量、可溶性糖含量、丙二醛含量、相对电导率和叶绿素含量等指标均优于未转化的对照植株,表明转化BjPCS1基因提高了烟草对3种重金属的抗性,其中转基因烟草抗Cd能力最强,并且转基因烟草的T1代种子在Cd处理的情况下萌发状况明显优于对照。这些结果说明BjPCS1基因在利用基因工程改良植物抗重金属能力和净化环境污染方面,具有良好的应用前景。  相似文献   

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