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In recent years, the quality of male sperm has shown a downward trend year by year. The male infertility rate in China continues to increase. It has been found that the impacts of environmental factors on male semen quality are mainly negative. Inorganic metallic elements as environmental contaminants have become a class of chemicals that cannot be ignored, and their health impacts on human reproductive systems have been received widespread attention and research. They certainly play a significant role in impairing male reproductive ability and are relative to the lower and lower semen quality. This review focused on the relationship between exposure to environmental metallic elements and semen quality of humans and animals, as well as summarized specific results from epidemiological studies, animal trials, or molecular experiments to provide a theoretical basis for protecting male reproductive capacity.
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Exposure to environmental pollutants imposes important health risks to human beings. In recent years, emerging evidence has suggested that nutritional components may ameliorate the adverse health effects of environmental pollutants. Therefore, it raises great public health interests in protecting human health from environmental pollutants by nutrition interventions. Considering in vivo and in vitro experimental evidence, as well as epidemiological studies, this paper reviewed the possible mechanisms underlying how nutritional components counteract the adverse health impacts of environmental pollutants, which can provide directions for further studies on health risk assessment and nutrition intervention associated with environmental pollutant exposure.
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Toxicant metabolism and toxicokinetics are an integrated part of toxicology. They study the absorption,targeted distribution,metabolic detoxicification or bioactivation,excretion and elimination of toxic substances after the body′s exposure via different routes,and also evaluate the effects of various factors on the disposition of poisons. The results of the studies provide essential data on the relation?ships between exposure kinetics and toxicological effect and their mechanisms. They also help to find possible targets of intoxication or detoxicification pathways,which can lead to efficient countermea?sures. In this review,the author summarized the thirty years of progress and features of the research on toxicant metabolism and toxicokinetics in China.
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Increases in cardiovascular disease (CVD) in modern society are attributable to aging and lifestyle changes such as westernized diet and decreased physical activity. On the other hand, mounting evidence suggests that environmental pollutants such as persistent organic pollutants (POPs), bisphenol A (BPA) and phthalates are also related to the increases in CVD. POPs are a family of lipophilic stable chemicals that accumulate in adipose tissue and create a persistent toxic effect. The association between POPs and CVD is reported through epidemiologic, animal and in vitro studies. The association between BPA and CVD has also been established from many epidemiologic studies; however, a causal relationship remains uncertain. Exposure to POPs or BPA is also associated with the development of well-known CV risk factors such as type 2 diabetes mellitus, hypertension, hypercholesterolemia and obesity. Therefore, it is uncertain whether POPs and BPA are involved directly to the pathogenesis of atherosclerosis or indirectly associated with CVD. Additional longitudinal and experimental studies searching for the direct causal relationship and exact linking mechanisms should be conducted to investigate the effect of exposure to environmental pollutants such as POPs and BPA.
Subject(s)
Animals , Humans , Adipose Tissue , Aging , Atherosclerosis , Cardiovascular Diseases , Diabetes Mellitus, Type 2 , Diet , Environmental Pollutants , Hand , Hypercholesterolemia , Hypertension , Life Style , Motor Activity , Obesity , Risk FactorsABSTRACT
Objective To know the levels of polychlorinated dibenzo-p-dioxins(PCDDs),polychlorinated dibenzo-p-furan (PCDFs)and polychlorinated biphenyl(PCBs)in milk and milk powder.Methods From Feb.2007 to Jun.2007,the milk and milk powder samples were collected and PCDDs,PCDFs and PCBs were extracted from the samples by Soxhlet extraction,cleaned up by FMS and quantified by HRGC-HRMS,using isotope dilution methodology.Results PCDDrFs and PCBs were detected in all samples.The mean levels of PCDD/Fs and dl-PCBs TEQ in the milk powder were 0.43 pg/g lipid(median:0.34 pg/g lipid),and in the packed milk were 3.83pg/g)lipid(median:2.04 pg/g lipid).The mean levels of PCDD/Fs and dl-PCBs TEQ in all samples were 2.13 pg/g lipid(median:0.815 pg/g lipid).The levels of PCDD/Fs and dioxin-like PCBs in the detected samples were far below the limitation of EU except of two milk samples,and the levels of PCDD/Fs and dioxin-like PCBs were higher in the packed milk than those in the milk powder.Conclusion Some of the milk and milk powder in the investigated city has been polluted by polychlorinated dibenzo-p-dioxins(PCDDs),polychlorinated dibenzo-p-furan(PCDFs)and polychlorinated biphenyl(PCBs).
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Objective To understand whether Imarcaptoacetate dioctyltin(IMA) is a environmental endocrine disruptor or not. Methods The new born Wistar rats were randomly divided into six groups including positive control group, negative control group and four experimental groups. The rats in the experimental groups were given IMA at different concentrations (0.100 0, 0.010 0, 0.001 0, 0.000 1 ?g/10 g) 1/1 000 000 by hypodermic injection, the rats in the negative control group were treated with corn oil and those in the positive control group were treated with dibutyltin dilaurate(DBTD) at concentration of 0.001 ?g/10 g bw. The rats were injected one time each day for five consecutive days. After one and half months, the levels of T, LH and FSH in the blood, the weight of the testicles, ovaries and the sexual organ exponent were determined. The pathological examination on some samples was conducted. Results In both of female and male, the levels of T in IMA treated rats were significantly increased and showed an doge-effect relationship (P0.05). The exponents of the testicles were different among groups (P
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Asaprimarilyused plasticizerin polyvinyl chloride,d(i2-ethylhexy)lphthalate(DEHP)is extensively used in consumer products,flooring and wall coverings,food contact applications,and medical devices.Because DEHP has been detected in waters,soils and air,and its metabolites have also been detected in human urinary,sufficient evidences show that DEHP is ubiquitous in the environment worldwide.DEHP is already in the blacklist of priority pollutants in water in China.Many researches indicate that DEHP is one kind of endocrine disrupting chemicals in animals,with carcinogenicity,teratogenicity and mutagenicity.Based on the researches and review on DEHP,this paper principally discussed the environmental level,metabolism and biological markers of DEHP,as well as the research progress on human health effects.
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Perfluorooctanesulfonate(PFOS),a new kind of persistent pollutants,is one of the key research in 21 century.This paper collected PFOS data in water and human body from several countries and areas,analyzed the relationship between PFOS concentration in human body and the influencing factors,such as regional distribution,gender and age and the change of influencing factors was discussed in detail.
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Objective To explore the effects of gestation exposure to dibutyltin dilaurate (DBTD) on the activity of enzymes in the testis and the spermatogenesis function in the mature male offspring of Wistar rats. Methods The pregnant rats were treated with DBTD by gavage at the doses of 0, 10, 20 and 30 mg/kg for days, from 12th-20th days of gestation. On 70th postnatal day, 10 male offspring rats were selected randomly from each group for measurements of the viscera coefficient of testis and the sperm count in epididymis, the activity of enzymes of testis was determined by spectrophotometry. Results There were no significant differences seen in the body weight gain of pregnant rats from days 12-20 of gestation, litter size, sex ratio of fetuses and body weight of male offspring rats between the experimental groups and the control group. The testis weight and viscera coefficient of testis in 30 mg/kg group increased significantly compared with the control group(P
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As a kind of pesticide, fungicide and preservative, PCP had been used extensively in industry, agriculture and domesticity throughout the world. PCP contamination is generally associated with sediments or soil, it can also concentrate in organism. Regarding the character of high toxicity, long persistence and difficult to degrade, PCP has become a kind of conspicuous environmental pollutant because of widely use and inappropriate disposal. In the contaminated area, PCP can be detected in the water, soil and the body of organisms. PCP can affect human health through directly exposure or through food chain. The absorbed PCP can be stored in liver, kidney and fat,it can also increase the incidence rate of tumork, disturb the endocrine system, affect immune function,inhibit reproduction and development. PCP not only has a direct impairment on human body but also shows a potential impact in genetics.
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Objective To know the actual level of hair lead levels in children of Xi'an. Methods Hair samples were collected from 203 children aged 7-13 years of an urban primary school and a suburban one during April-June, 2001. The hair lead levels were measured with flame atomic absorption spectrophotometer. Results The geometric mean of hair lead levels of children in urban area was 4.69 ?g/g, while in suburban area it was 1.67 ?g/g. There was a significant difference between them (t=7.78, P=0.001). The younger group had a higher hair lead levels in urban area and suburban area. With age, hair lead levels showed a significant down trend. There was no significant difference had been seen between boys and girls living in the city, but the hair lead levels of rural boys(median 2.92 ?g/g) were higher than rural girls (median 1.52 ?g/g), P=0.02. Rate of high hair lead (13.2%)of urban children, based on the standard (≥10.0 ?g/g), was higher than rural children (1.2%) (?2=9.18, P=0.002). Conclusion The hair lead levels of the children living in urban districts are higher than that in the suburb area of Xi'an city. The rate of high hair lead of urban children was higher than that of the suburban children. The hair lead levels of children aged 7-13 years in Xi'an have showed a down trend with age. There is no significant difference between boys and girls in urban area, but the hair lead levels in suburban boys is higher than that of the suburban girls.
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Objective To assess the level of environmental hormone (EH) in Lanzhou reach of the Yellow River and to find the pollutant sources and pollution routes. Methods Solid phase extraction (SPE), gas chromatography-mass spectrophotometry (GC-MS) and gas chromatography (GC-FID) were employed to determine EH in the water samples. Results 10 kinds of EH were detected, of which 6 were the priority control pollutants determined by the American EPA and 6 were predominant pollutants in China. 10 EH detected in Lanzhou reach of the Yellow River included naphthalene, phenanthrene, DBP, DEHP and benzothiazole and the detection rates of the five EH were 40%, 60%, 100%, 100% and 20% respectively. Conclusion The predominant environmental hormone pollutants in Lanzhou reach of the Yellow River are PAEs, PAHs, heterocycles, phenols and the main source of these pollutants is the waste water of petroleum chemical industry.