The Effects of Chronic Lifelong Activation of the AHR Pathway by Industrial Chemical Pollutants on Female Human Reproduction

Environmental chemicals, such as heavy metals, affect female reproductive function. A biological sensor of the signals of many toxic chemical compounds seems to be the aryl hydrocarbon receptor (AHR). Previous studies demonstrated the environmental of heavy metals in Taranto city (Italy), an area that has been influenced by anthropogenic factors such as industrial activities and waste treatments since 1986. However, the impact of these elements on female fertility in this geographic area has never been analyzed. Thus, in the present study, we evaluated the AHR pathway, sex steroid receptor pattern and apoptotic process in granulosa cells (GCs) retrieved from 30 women, born and living in Taranto, and 30 women who are living in non-contaminated areas (control group), who were undergoing in vitro fertilization (IVF) protocol. In follicular fluids (FFs) of both groups the toxic and essential heavy metals, such as chromiun (Cr), Manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), cadmium (Cd) and lead (Pb), were also analyzed. Higher levels of Cr, Fe, Zn and Pb were found in the FFs of the women from Taranto as compared to the control group, as were the levels of AHR and AHR-dependent cytochrome P450 1A1 and 1B1; while CYP19A1 expression was decreased. The anti-apoptotic process found in the GCs of women fromTaranto was associated with the highest levels of progesterone receptor membrane component 1 (PGRMC1), a novel progesterone receptor, the expression of which is subjected to AHR activated by its highest affinity ligands (e.g., dioxins) or indirectly by other environmental pollutants, such as heavy metals. In conclusion, decreased production of estradiol and decreased number of retrieved mature oocytes found in women from Taranto could be due to chronic exposure to heavy metals, in particular to Cr and Pb.     

Trace elements in children with autism spectrum disorder: A meta-analysis based on case-control studies

Autism spectrum disorder (ASD) is a common childhood neurodevelopmental disorder that may be related to trace elements. However, reports on the relationship between them are still inconsistent. In this article, we conducted a meta-analysis on this issue. We searched the PubMed, EMBASE, and Cochrane databases as of November 15, 2019. A random-effects model was used, and subgroups of studies were analyzed using samples of different measurements. Twenty-two original articles were identified (18 trace elements, including a total of 1014 children with ASD and 999 healthy controls). In autistic children, the overall levels of barium (Ba), mercury (Hg), lithium (Li), and lead (Pb) were higher. There were significant differences in the levels of copper (Cu) in the hair and serum between autistic children and the control group. The levels of Hg, Li, Pb and selenium (Se) in the hair of autistic children were higher than those of healthy children, while the levels of zinc (Zn) in the blood were lower. Excessive exposure to toxic heavy metals and inadequate intake of essential metal elements may be associated with ASD. Preventing excessive exposure to toxic metals and correcting poor dietary behaviors may be beneficial for the prevention and treatment of the disease.     

Metallothionein induction in human peripheral blood lymphocytes by heavy metals

Human peripheral blood lymphocytes have the capacity to produce metallothioneins (MTs) as a protective response to cadmium exposure. To define the range of metal species inducing lymphocyte MTs, cellular proteins synthesized after exposure to each of 11 heavy metals were analyzed by gel electrophoresis. Toxic metals such as cadmium, mercury and silver were found to induce thioneins (apoproteins of MTs) at relatively low concentrations (maximum at approximately 10 microM), whereas less toxic metals such as zinc, copper and nickel were inductive at relatively high concentrations (maximum at approximately 200 microM). Tin, lead, iron, cobalt, and manganese did not induce thioneins. The heavy metal specificity of MT induction in the lymphocyte resembles that in the liver, and the regulatory mechanism of MT production seems to be similar in both of these tissues. In the cells exposed to highly toxic metals such as cadmium and mercury, expression of cytotoxicity (represented by decline of cysteine uptake) was remarkable at the metal concentrations higher than those saturating thionein induction, supporting the protective role of MTs against heavy metals.     

Heavy metals toxicity in plants: An overview on the role of glutathione and phytochelatins in heavy metal stress tolerance of plants

Plants experience oxidative stress upon exposure to heavy metals that leads to cellular damage. In addition, plants accumulate metal ions that disturb cellular ionic homeostasis. To minimize the detrimental effects of heavy metal exposure and their accumulation, plants have evolved detoxification mechanisms. Such mechanisms are mainly based on chelation and subcellular compartmentalization. Chelation of heavy metals is a ubiquitous detoxification strategy described in wide variety of plants. A principal class of heavy metal chelator known in plants is phytochelatins (PCs), a family of Cys-rich peptides. PCs are synthesized non-translationally from reduced glutathione (GSH) in a transpeptidation reaction catalyzed by the enzyme phytochelatin synthase (PCS). Therefore, availability of glutathione is very essential for PCs synthesis in plants at least during their exposure to heavy metals. Here, I reviewed on effect of heavy metals exposure to plants and role of GSH and PCs in heavy metal stress tolerance. Further, genetic manipulations of GSH and PCs levels that help plants to ameliorate toxic effects of heavy metals have been presented.     

某污灌区重金属与两种持久性有机污染物(POPs)污染趋势评价

对某污灌区的土壤剖面进行采样分析,利用不同的评价方法进行评价,结果表明,土壤中金属元素Cr、As、HG、Cd、Cu、Pb、Ni、Zn和持久性有机污染物BHC、DDT含量有上升趋势,80%以上的表层土壤样品污染物含量超过土壤底层,85%以上的土壤样品污染物含量明显超过当地土壤的自然背景值.通过污染物在土壤中的残留模型预测,两种有机污染物和元素Cr、As、Hg、Cd、Cu会在土壤中累积,持续的污水灌溉可能使在土壤中累积的这些污染物进入地下水或食物链,对环境健康造成危害.     

Cd and Zn uptake in macrophyceae from Greek coasts

Summary In the frame of a project financed by the General Secretariat of Research and Technology, the Institute of Botany has undertaken to measure the degree of pollution in the marine area by means of physicochemical and biotic parameters. Bioaccumulation of heavy metals in the macrophyceae has also been examined. Since the latter are immobile, they form strong indicators of pollution for the respective biotopes. Comparing the measurements carried out in marine macrophyceae obtained from the Gulf of Kavala and Pylos, we have made the following conclusions. Seasonal variations were detected in the Cd and Zn content of nine marine macrophyceae species which had already been investigated. Cadmium, one of the toxic metals, was, in certain cases, present in a large number of species. Fluctuations in the quantities were seasonally detected, but more obvious differences were those between species from different classes of macrophyceae. In contrast, the amount of Zn was generally lower. When we compared the values of Zn to those of Cd in the same algal species, we detected an antagonism between them (i.e. higher values for Cd were accompanied by lower values for Zn). Finally, on comparing the biotopes, we found there was slightly more Cd in Pylos than in Kavala. In the harbour of Kavala, in particular, where there is strong evidence of domestic sewage, the amount of Cd is very low. It is well known that Cd is derived mostly from industrial waste waters; in the city of Kavala, the domestic waste does not include high quantities of heavy toxic metals.     

Heavy Metals and Neurodegenerative Diseases: An Observational Study

In this study, we evaluated the levels of some of the most investigated metals (Cu, Se, Zn, Pb, and Hg) in the blood of patients affected by the most common chronic neurodegenerative diseases like Alzheimer’s disease (AD) and multiple sclerosis (MS), in order to better clarify their involvement. For the first time, we investigated a Sicilian population living in an area exposed to a potentially contaminated environment from dust and fumes of volcano Etna and consumer of a considerable quantity of fish in their diet, so that this represents a good cohort to demonstrate a possible link between metals levels and development of neurodegenerative disorders. More specifically, 15 patients affected by AD, 41 patients affected by MS, 23 healthy controls, and 10 healthy elderly controls were recruited and subjected to a venous blood sampling. Quantification of heavy metals was performed by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). This technique has allowed us to establish that there is a concomitance of heavy metal unbalance associated with AD more than in other neurodegenerative pathologies, such as MS. Also, we can assess that the concentration of these elements is independent from the diet, especially from occasional or habitual consumption of fruits and vegetables, prevalence in the diet of meat or fish, possible exposure to contaminated environment due both to the occupation and place of residence.     

The Physiological Role of Boron on Health

Environmental factors have been implicated in the etiology of autism spectrum disorder (ASD); however, the role of heavy metals has not been fully defined. This study investigated whether blood levels of mercury, arsenic, cadmium, and lead of children with ASD significantly differ from those of age- and sex-matched controls. One hundred eighty unrelated children with ASD and 184 healthy controls were recruited. Data showed that the children with ASD had significantly (p < 0.001) higher levels of mercury and arsenic and a lower level of cadmium. The levels of lead did not differ significantly between the groups. The results of this study are consistent with numerous previous studies, supporting an important role for heavy metal exposure, particularly mercury, in the etiology of ASD. It is desirable to continue future research into the relationship between ASD and heavy metal exposure.     

南极海洋生物持久性有机污染物:水平、传递与风险评价

尽管南极被认为是远离人类污染的净土,但近年来不断发现有机氯农药、多氯联苯、多溴联苯醚和全/多氟化合物等传统和“新型”持久性有机污染物(POPs)存在于南极的非生物及生物环境中,由此引发了全球各国对南极生态系统的不断关注。POPs性质稳定,能够久存于环境中,并具有毒性,易富集于生物体内并产生一定的健康风险。为了解南极和南大洋持久性有机污染物的生物地球化学过程及其对生物种群和生态系统产生的影响,本文以南大洋典型食物链为主线并结合南极海洋生物生活习性,综述了近年来国内外学者对南极海洋食物链不同营养级生物体内POPs的研究现状,并对南极海洋生态系统POPs研究前沿和热点提出了展望。研究显示,南极地区是世界上污染程度最低的地区,但过去几十年有关南极海洋生物中POPs的类型不断增加,表明该地区受到地区内/外活动的影响日益增加。零散的研究数据以及各异的技术方法使得目前仍无法阐析POPs沿食物链传递的机制。有关南极海洋生态系统POPs动态的长期监测与评估计划亟待建立。     

The present status of biological effects of toxic metals in the environment: lead, cadmium, and manganese

The number of reports concerning the chemical toxicology of metals which are released in the environment by natural as well as anthropogenic sources, have been increasing constantly. Lead, cadmium, and manganese have found a variety of uses in industry, craft, and agriculture owing to their physical and chemical properties. The environmental burden of heavy metals has been rising substantially by smelter emission in air and waste sewage in water. Further, organic compounds of lead and manganese used as antiknock substances in gasoline are emitted into the atmosphere by automobile exhaustion. Such environmental contamination of air, water, soil, and food is a serious threat to all living kinds. Although these metals are known to produce their toxic effects on a variety of body systems, much emphasis has been placed on their effects on the nervous system owing to apparent association of relatively low or "subclinical" levels of metallic exposure with behavioral and psychological disorders. Clinical and animal data on environmental exposure show that while lead and manganese are most toxic to the nervous system, cadmium exerts profound adverse effects on kidney and the male reproductive system. It appears that the consequences of exposure to lead in adults are less severe than the types of exposure associated with hyperactivity in neonates. Except for a few reports, hyperactivity has indeed been observed in animals exposed to either of these three metals. Experimental work has also shown that these metals produce behavioral changes by altering the metabolism of brain neurotransmitters, especially catecholamines. Recently, it is hypothesized that these metals exert their toxic effect by damaging biological defences which exist in the body to serve as protective mechanisms against exogenous toxins. A voluminous publication list with diverse opinions on the biological effects of metals is available and there is an urgent need to compile assessment of the existing literature to identify the future theme of research work. The problem of metal toxicity becomes even more complex owing to simultaneous or successive exposure of the general population to different physical, chemical, biological, and psychological factors in the environment. The net toxic manifestations produced by multiple exposure should, therefore, be different from those produced by a single factor as the result of their additive, synergistic or antagonistic action. Even though a metal may not exist in sufficient amounts to cause any disability, the toxicity could result when a second factor is also present.(ABSTRACT TRUNCATED AT 400 WORDS)     

Comparative Assessment of Essential and Toxic Metals in the Blood of Rheumatoid Arthritis Patients and Healthy Subjects

The present study deals with the comparative evaluation of essential and toxic metals in rheumatoid arthritis and healthy donors. Blood samples collected from rheumatoid arthritis patients and healthy subjects were analysed for selected essential and toxic metals (Ca, Mg, Fe, Zn, Cu, Co, Mn, Cr, Cd and Pb). The samples were digested in nitric acid and perchloric acid mixture, followed by quantification of the metals using atomic absorption spectrometry. Mean levels of Ca, Mg, Fe and Zn were significantly higher in the blood of healthy donors; however, elevated levels of Cd, Co, Cr, Cu and Pb were observed in blood of the patients. The correlation coefficients among the selected metals in the blood of arthritis patients were significantly different compared with the healthy counterparts. Multivariate cluster analysis revealed mutual apportionment of the essential and toxic metals in blood of the patients, whereas, in controls, the essential and toxic metals revealed diverse apportionment. Variations in the metal levels with gender, residence and smoking habits were also evaluated in both donor groups. Relative distribution, correlation and apportionment of the essential and toxic metals in the blood of the patients were significantly different than of controls.     

Biochemical changes and adaptive strategies of plants under heavy metal stress

Heavy metal contamination of soil, aqueous waste stream and ground water causes major environmental and human health problems. Heavy metals are major environmental pollutants when they are present in high concentration in soil and show potential toxic effects on growth and development in plants. Due to unabated, indiscriminate and uncontrolled discharge of hazardous chemicals including heavy metals into the environment, plant continuously have to face various environmental constraints. In plants, seed germination is the first exchange interface with the surrounding medium and has been considered as highly sensitive to environmental changes. One of the crucial events during seed germination entails mobilization of seed reserves which is indispensable for the growth of embryonic axis. But, metabolic alterations by heavy metal exposure are known to depress the mobilization and utilization of reserve food by affecting the activity of hydrolytic enzymes. Some plants possess a range of potential mechanisms that may be involved in the detoxification of heavy metals by which they manage to survive under metal stress. High tolerance to heavy metal toxicity could rely either on reduced uptake or increase planned internal sequestration which is manifested by an interaction between a genotype and its environment. Such mechanism involves the binding of heavy metals to cell wall, immobilization, exclusion of the plasma membrane, efflux of these toxic metal ions, reduction of heavy metal transport, compartmentalization and metal chelation by tonoplast located transporters and expression of more general stress response mechanisms such as stress proteins. It is important to understand the toxicity response of plant to heavy metals so that we can utilize appropriate plant species in the rehabilitation of contaminated areas. Therefore, in the present review attempts have been made to evaluate the effects of increasing level of heavy metal in soils on the key behavior of hydrolytic and nitrogen assimilation enzymes. Additionally, it also provides a broad overview of the strategies adopted by plants against heavy metal stress.     

植物重金属转运蛋白研究进展

土壤中的有毒重金属不仅对植物有害,也可通过食物链危害人类和动物的健康.重金属转运蛋白在植物吸收、抵抗重金属的复杂机制中起着关键作用.植物重金属转运蛋白分为吸收蛋白和排出蛋白,其中,吸收蛋白转运必需重金属进入细胞,同时也会因为必需重金属的缺乏或离子之间的竞争而运载有毒重金属;排出蛋白是一类解毒蛋白,可将过量的或有毒的重金属逆向转运出细胞,或区室化于液泡中.目前,细胞内多种重金属转运蛋白基因的转录水平与重金属离子积累之间的联系已被揭示,并分离克隆出诸多相关蛋白家族成员.本文综述了近年来发现并鉴定的主要重金属转运蛋白的金属亲和性、器官表达特异性及细胞内定位等的研究进展.     

微生物与重金属间的相互作用及其应用研究

从多方面阐述了微生物与重金属二者间相互作用,指出微生物在生长代谢过程中能淋滤、吸收和转化重金属,对重金属有一定的抗性和解毒作用;但是,一定浓度的重金属对微生物过程及其种群具有较大的毒性。影响微生物在环境介质中的活动,矿业工程生产工艺已充分利用微生物能淋滤,吸收和转化重金属等特性来处理低品位难浸矿石,环境保护领域也积极利用微生物对重金属的抗性和解毒作用来实现工业废弃物的处理以及被重金属污染土壤的修复。利用微生物的生物量及其活性可以评价环境中不同介质的重金属污染水平。     

太湖水体典型重金属镉和铬含量及其生态风险

2010年9月使用电感耦合等离子体质谱仪(ICP-MS)对太湖水体中典型重金属镉和铬的暴露水平进行监测,在分析重金属暴露特征及其对太湖水生生物慢性毒性效应的基础上,采用安全阈值法进行生态风险评估.结果表明:镉和铬在太湖水体中均有检出,它们的平均暴露浓度分别为0.85和40.04μg·L-1;与铬相比,太湖水生生物对镉更敏感;铬的安全阈值＞1,镉的安全阈值略＜1,表明铬已对太湖水生生物造成一定的生态风险,而镉尚未对太湖造成明显生态风险.镉和铬的生态风险评估结果表明,毒性相对较低的铬,在高浓度环境暴露下会对生态环境造成较大风险,应给予足够重视.     

Chromosomal aberrations in humans as genetic endpoints to assess the impact of pollution

The chromosomal aberration assay with peripheral blood lymphocytes has been used routinely during the last three decades to survey exposure of humans to various genotoxic agents. A large number of biomonitoring studies are based on this genetic endpoint. A great deal of data exists on occupational, life-style or medical exposure situations but less evidence of the validity of the assay is available with regards to environmental exposure. In the present paper we report our investigations on the impact of pollution in two different populations using chromosomal aberrations in human peripheral blood lymphocytes as a biomarker of chronic exposure to heavy metals and dioxins/furans for a long period and as a biomarker of acute exposure to accidentally released vinyl chloride in the air. In order to study genotoxic effects (chromosomal aberrations) of heavy metals and dioxins/furans, 52 exposed individuals from a polluted area were compared to 51 matched controls from a distant non-industrialized area. A statistically significant increase was observed in the frequency of chromosomal aberrations in peripheral blood lymphocytes from the exposed population (1.90% aberrant cells vs. 1.11% for the controls). In the case of the vinyl chloride accident, chromosomal aberrations were analyzed in peripheral blood lymphocytes from 29 potentially exposed and 29 non-exposed individuals (matched controls). The exposed group showed a statistically significant increase in the frequency of aberrant cells (1.47% vs. 1.07% for the controls).     

Removal of heavy metals from industrial wastewaters by adsorption onto activated carbon prepared from an agricultural solid waste

Activated carbon was prepared from coirpith by a chemical activation method and characterized. The adsorption of toxic heavy metals, Hg(II), Pb(II), Cd(II), Ni(II), and Cu(II) was studied using synthetic solutions and was reported elsewhere. In the present work the adsorption of toxic heavy metals from industrial wastewaters onto coirpith carbon was studied. The percent adsorption increased with increase in pH from 2 to 6 and remained constant up to 10. As coirpith is discarded as waste from coir processing industries, the resulting carbon is expected to be an economical product for the removal of toxic heavy metals from industrial wastewaters.     

Cadmium and copper inhibit both DNA repair activities of polynucleotide kinase

Human exposure to heavy metals is of increasing concern due to their well-documented toxicological and carcinogenic effects and rising environmental levels through industrial processes and pollution. It has been widely reported that such metals can be genotoxic by several modes of action including generation of reactive oxygen species and inhibition of DNA repair. However, although it has been observed that certain heavy metals can inhibit single strand break (SSB) rejoining, the effects of these metals on SSB end-processing enzymes has not previously been investigated. Accordingly, we have investigated the potential inhibition of polynucleotide kinase (PNK)-dependent single strand break repair by six metals: cadmium, cobalt, copper, nickel, lead and zinc. It was found that micromolar concentrations of cadmium and copper are able to inhibit the phosphatase and kinase activities of PNK in both human cell extracts and purified recombinant protein, while the other metals had no effect at the concentrations tested. The inhibition of PNK by environmentally and physiologically relevant concentrations of cadmium and copper suggests a novel means by which these toxic heavy metals may exert their carcinogenic and neurotoxic effects.     

Comparative Assessment of Selected Metals in the Scalp Hair and Nails of Lung Cancer Patients and Controls

Lung cancer is seriously threatening human health and exposure to trace metals is the most important aetiology for lung cancer. Selected essential/toxic metals (Ca, Mg, Na, K, Fe, Zn, Cu, Sr, Li, Co, Mn, Ni, Cr, Cd and Pb) are measured in the scalp hair and nails of lung cancer patients and controls by atomic absorption spectrophotometric method employing nitric acid-perchloric acid-based wet digestion. Average concentrations of Pb, Cd, Mn, Co and Cu are found to be significantly higher (p?<?0.05) in the scalp hair and nails of lung cancer patients compared with the controls, however, appreciably higher concentrations of Zn, Ca, Na, Mg and Cr are noted in the scalp hair of the controls. Most of the metal levels reveal higher dispersion and asymmetry in the scalp hair/nails of the patients compared with the controls. Average metal levels are also compared to investigate probable differences based on sex, abode, food and smoking habits. The correlation study shows significantly diverse mutual variations of the metals in the scalp hair and nails of the patients and controls. Considerable variations in the metal levels are also noted for various stages and types of lung cancer (adenocarcinoma, squamous cell carcinoma, large cell carcinoma and small cell lung cancer). Multivariate apportionment of the metals in the scalp hair and nails of the patients and controls are also significantly diverse. The study reveals considerably divergent variations in the metal levels in lung cancer patients in comparison with healthy subjects.