Effects of gestational cadmium exposure on pregnancy outcome and development in the offspring at age 4.5 years.

The objective of the present study was to evaluate the potential effect of maternal cadmium exposure on pregnancy outcome and development in the offspring at age 4.5 years. Between November 2002 and December 2003, 109 normal pregnant women were enrolled in our cohort from Da-Ye Country, Hubei Province in Central China. The placental, whole blood, and cord blood levels of cadmium were determined by inductively coupled plasma mass spectrometer (ICP-MS). The 106 children at 4.5 years of age given birth by the aforementioned women were followed up and the following rate was 97.25%. Detailed questionnaire surveys, anthropometric measurements were performed, and IQ development was evaluated by Wechsler Preschool and Primary Scale of Intelligence Revised Edition (WPPSI-R). Multiple linear regression analysis indicated that cord blood cadmium level was significantly negatively correlated with fetus development. Low birth weight (less than 2,500 g) occurred significantly more frequently in infants with higher cord blood cadmium than in those exposed to lower levels of cord blood cadmium. Significantly negative correlation was found between cord blood cadmium exposure and WPPSI-R IQ full score after controlling for confounding variables. It was concluded that cord blood cadmium concentration was a factor that influenced fetus growth and later IQ development.

Chromosomal aberrations and DNA damage in human populations exposed to the processing of electronics waste.

BACKGROUND, AIM, AND SCOPE: It has been known that the pollutants of electronic wastes (E-wastes) can lead to severe pollution to the environment. It has been reported that about 50% to 80% of E-wastes from developed countries are exported to Asia and Africa. It has become a major global environmental problem to deal with 'E-wastes'. E-waste recycling has remained primitive in Jinghai, China. This not only produces enormous environmental pollution but also can bring about toxic or genotoxic effects on the human body, threatening the health of both current residents and future generations living in the local environment. The concentration of lead in the blood of children in the E-waste polluted area in China is higher than that of the control area. But little is known about the cytogenetic effect to human beings caused by the pollution of E-wastes. In the present study, experiments have been performed to investigate the genetics of permanent residents of three villages with numerous E-waste disposal sites and to analyze the harmful effects of exposure to E-wastes. MATERIALS AND METHODS: In total, 171 villagers (exposed group) were randomly selected from permanent residents of three villages located in Jinghai County of Tianjin, China, where there has been massive disposal of E-wastes. Thirty villagers were selected from the neighboring towns without E-waste disposal sites to serve as controls. Chromosomal aberrations and cytokinesis blocking micronucleus were performed to detect the cytogenetic effect, dic + r (dicentric and ring chromosome), monomer, fragments (acentric fragments, minute chromosomes, and acentric rings), translocation, satellite, quadriradial, total aberrations, and micronuclear rate were scored for each subject. DNA damage was detected using comet assay; the DNA percentage in the comet tail (TDNA%), tail moment (TM), and Olive tail moment (OTM) were recorded to describe DNA damage to lymphocytes. RESULTS: The total chromosome aberration rates (5.50%) and micronuclear rates (16.99%) of the exposure group were significantly higher than in the control group (P = 0.000). The percentage of DNA in the comet tail, tail moment, and Olive tail moment detected by comet assay showed that there was a significant difference in DNA damage in the exposure group (P = 0.000). The chromosome aberration, micronucleus rate, and DNA damage observed in women were significantly higher than those in men. Chromosome aberration and micronuclear rates of both smokers and non-smokers in the exposure group are obviously higher than that in the control group (P = 0.000). DISCUSSION: The use of outdated (and unsafe) ways to deal with E-wastes can lead to exposure to a variety of substances harmful to human health. The components of pollution may enter the human body through the air, drinking water, and food chain to damage human genetic material, resulting in genomic instability. The rates of chromosomal aberration, micronucleus formation, and the degree of DNA damage in women in the group exposed to electronic waste were significantly higher than in men. The reason for this may be concerned with the traditional lifestyle of the local residents or the difference of sensitivity to the exposure to E-wastes or any others. Further investigations are needed to provide evidence to demonstrate this. CONCLUSIONS: Here, we report the obviously cytogenetic toxicity to the exposure population by the E-waste pollution for the first time. E-waste pollution may be a potential agent of genetic mutation, and may induce cytogenetic damage within the general population exposed to the pollution. These findings need to be considered, and steps should be taken to protect the current population and future generations from the effects of pollution with E-wastes. RECOMMENDATIONS AND PERSPECTIVES: The above results remind us that the impact of E-waste recycling on environmental quality of Jinghai should be evaluated soon. Moreover, it is urgent for the government to prohibit E-waste import and its processing by outdated ways. The future studies such as pollutant details of drinking water, air, and soil in the area as well as epidemiological investigations on the harmful effect to children must be performed eagerly. All the data available do provide a compelling case for immediate action in both countries to address workplace health and safety and waste management.

[Factors related to Glycophorin A mutation frequency of workers exposed to benzene.].

OBJECTIVE: To analyze related factors which affect GPA mutation frequency of workers exposed to benzene, with the Glycophorin A (GPA) mutation assay and explore the possibility of GPA mutation frequency as an index of predicting the risk of benzene poisoning. METHODS: The erythrocytes were bound with fluorescent-labeled monoclonal antibody after isolated and fixed from the peripheral blood, and then the GPA mutation assay was performed using the flow cytometry (FCM). The related factors of GPA mutation frequency were analyzed by statistical methods. RESULTS: The GPA mutation frequency of chronic benzene poisonings was significantly higher than that of their controls (P < 0.05). Significant direct correlation was found between age, length of service, accumulative exposure score and the GPA mutation frequency of workers exposed to benzene (P < 0.01). However, there was significantly inverse correlation between the 3AB index and the GPA mutation frequency (GPAN0: r(s) = -0.589, P < 0.01, GPANN: r(s) = -0.615, P < 0.01). In the multiple factor regression analysis on GPA mutation frequency, benzene exposure and individual susceptibility both entered model of multiple factors analysis, the coefficient of determination of benzene-exposed workers was 0.819. CONCLUSION: Exposure to benzene and individual susceptibility are the most important factors that affect GPA mutation frequency. GPA mutation frequency increases with the benzene exposure and individual susceptibility.

[The application of single-cell gel electrophoresis to the diagnosis of fanconi anemia].

OBJECTIVE: To explore the feasibility of single-cell gel electrophoresis (SCGE) as one of lab tests to examine DNA breakage for the diagnosis of Fanconi anemia (FA). Case Record A 4-year-and-10-month old boy presented with cryptorchism, deformities of both thumbs and esotropia of right eye. He developed thrombocytopenia and anemia when he was 3 year- and -2-month old. He was clinically diagnosed as FA. METHODS AND RESULTS: DNA breakage of peripheral white blood cells from the patient and his parents was examined with SCGE. The percentages of cells with chromosome breakage (comet-tail positive cells) were 100%, 90% and 52% for the patient,his father and mother, respectively, while that were only 2% and 5% in two normal same-age children (P <0. 001). The micronucleus-positive lymphocytes was 6.74% in the patient, being also much higher than normal value (0.40%). CONCLUSION: SCGE disclosed DNA breakage in the patient with FA, suggesting that it could be used as a test for determining DNA breakage of FA.

[Detection of DNA injury and repair with single cell gel electrophoresis radiation in biodosimetry].

OBJECTIVE: To explore the relationship between DNA repair in vitro and in vivo after irradiation, and to describe the curves of DNA repair which can improve the accuracy of radiation dose estimation. METHODS: The DNA double-strand break in lymphocytes of human and mouse was detected using neutral single cell gel electrophoresis (SCGE) after radiation and the curves of DNA repair individually were estimated, which were compared later. RESULTS: Along with the time lapsing, the DNA repair of human peripheral blood and mice increased significantly and the residual damage decreased gradually, which showed significant time-effect relationship. The curve of DNA repair in vitro of human lymphocytes presented the same log model as that of mouse DNA repair in vivo. The curve showed as followed respectively: Mice: Y(TM) = 55.8256 - 10.792 lnX (R(2) = 0.629, P < 0.01) and Y(OTM) = 25.4173 - 4.5273 lnX (R(2) = 0.661, P < 0.01); Human: Y(TM) = 30.242 7 - 7.383 6 lnX (R(2) = 0.686, P < 0.01) and Y(OTM) = 17.9772 - 3.9125 lnX (R(2) = 0.752, P < 0.01). CONCLUSION: The curve of DNA repair in vitro of human lymphocytes could be considered in biodosimetry estimation because the process of DNA repair in vitro could display the repair level and speed of DNA double-strand break in vivo.

Effect of environmental exposure to cadmium on pregnancy outcome and fetal growth: a study on healthy pregnant women in China.

The objective of the present study was to evaluate the potential effect of environmental exposure to cadmium on pregnancy outcome and fetal growth. Normal pregnant women were selected from Da-ye city of Hubei province, a cadmium-polluted area, from November 2002 through January 2003. Whole blood of pregnant women, cord blood, and placenta were collected and cadmium levels were determined by inductively coupled plasma emission mass spectroscopy. Incidence rate of preterm labor (gestational age < or = 37 weeks) and neonatal asphyxia, neonatal birth height, and birth weight were compared between lower and higher cadmium exposure level groups. Whole blood cadmium of 44 mothers ranged from 0.80 to 25.20 microg/L. Cadmium concentration in maternal blood was significantly higher than that in cord blood (t = 11.44, P < 0.01). Placenta cadmium ranged from 0.084 to 3.97 microg/g dry weight. After adjustment for maternal age, history of gestation, abortion and lactation, Logistic regression analysis showed that there was no significant association between cadmium exposure levels and pregnancy outcome (premature labor or neonatal asphyxia). Multiple linear regression analysis showed that, cord blood cadmium level, but not maternal blood cadmium and placenta cadmium, was significantly negatively associated with neonatal birth height (t= -2.33, P < 0.05). Compared with lower cord blood cadmium level (< or = 0.40 microg/L), higher level of cord blood cadmium (>0.40 microg/L) was associated with 2.24cm decrease in neonatal birth height. There was no significant association between cadmium exposure and birth weight. It was concluded that environmental exposure to cadmium significantly lower neonatal birth height.