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Increasing e-waste has become a major problem for global environment and public health. In the process of dismantling and recycling of disordered electronic waste, heavy metals such as lead and brominated flame retardants and organic substances are released into environmental media such as air, soil, dust and water, which is harmful to the health of local residents. Taking an e-waste dismantling area in Guangdong Province as an example, this paper reviews exposure levels of heavy metals and organic matters in e-waste recycling areas in China, as well as the health effects of local residents. Previous studies have found that e-waste recycling activities led to serious environmental pollution and high exposure levels of heavy metals and organic matters in local residents, which has a certain impact on the physiological functions of various human systems. The establishment of a centralized dismantling zone can effectively reduce the load level of various pollutants.
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Objective@#To study the pollution status of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCB), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in cord blood of newborns in an e-waste dismantling area of Guangdong Province.@*Methods@#We recruited 20 eligible mothers and newborns who could meet the inclusion criteria in local hospitals of Guiyu in 2007. The inclusion criteria included directly engaged in dismantling e-waste during pregnancy and within 1 year before pregnancy; living in the e-waste dismantling workshops or the distance between living place and the e-waste dismantling areas was ≤200 m; the father of newborn was directly engaged in electronic waste dismantling for more than 1 year; the frequency of visiting the e-waste dismantling workshop during pregnancy was ≥3 times in a week. Questionnaires and physical examinations were performed on maternal and neonatal, and cord blood was collected from newborns to detect PCDD/Fs, PCB and PBDE. The concentration level of organic pollutants was corrected by the blood lipid content, and the total toxicity equivalent was calculated. The correlation between three compounds was analyzed by Spearman correlation.@*Results@#The mothers of the 20 newborns were (23.45±3.27) years old and lived for more than 5 years. The number of one parent engaged in e-waste dismantling, the mother or father smoking, and parent engaged in e-waste dismantling work were 3, 13, 15 and 19, respectively. The weight of newborns ranged from 2.5 to 3.6 kilogram and the Apgar score was 10 points. No adverse birth outcomes such as preterm birth, malformation or stillbirth were found. The median (maximum, minimum) concentration of PCBs, PCDD/Fs and PBDEs in cord blood were 263.22 (328.29, 244.19), 38.42 (147.49, 12.68), 39.33 (265.11, 14.81) pg/g lipid, respectively. The median (maximum, minimum) of toxic equivalence concentrations of PCDD/Fs and PCB were 3.94 (9.24, 2.69) and 15.95 (26.64, 9.28) pg TEQ/g lipid. PBDE, the proportion of PBDE, PCB and PCDD/Fs in cord blood was 50.41%, 49.25% and 0.34%, respectively. PCBs and PBDEs were positively correlated (r=0.733, P=0.039).@*Conclusion@#The high concentrations of PCDD/Fs, PCB, and PBDE were detected in the e-waste dismantling area. It is recommended that the risk of such substances on the health of local people should be assessed in a timely manner.
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Objective To explore the effect ofα-phenyl-N-tert-butylinitrone (PBN) on expression of nerve growth factor (NGF) in se-rum and spinal cord tissue in rats after spinal cord injury (SCI). Methods 174 female Sprague-Dawley rats were randomly assigned to fol-lowing groups:normal control group (n=54), normal saline control group (NS group, n=60, intrathecally injected normal saline 15 μl), and PBN group (n=60, intrathecally injected PBN, 3 mg, 15 μl). The model was established with New York University blow device (150 kDyne, 1 s dwell time). PBN was intrathecally injected into the damaged areas 30 min after operation, then once a day for 7 days. The Basso-Beattie-Bresnahan (BBB) Locomotor Rating Scale was used to assess the rats 3 days and 1 day before, and 1 day, 5 days, 10 days, 15 days, 20 days, 25 days, 30 days and 35 days after SCI. NGF in the injured spinal cord tissue and serum was measured 1 h, 12 h, 24 h, 48 h, 3 days, 7 days, 14 days and 21 days after SCI. Results NGF increased in serum but not in spinal cord. The ratio of NGF/total protein in serum rose and peaked 48 h after SCI, and the ratio was higher in NS group (0.92%±0.02%) than in PBN group (0.77%±0.05%) (P=0.021). BBB scores in-creased from the 9th day, and PBN group improved better than NS group (P<0.01). Conclusion PBN could reduce the expression of NGF in the SCI rats, and promote the recovery of neurol function.
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Tissue plasminogen activator(tPA) had been used clinically as a choice drug for the therapy of ischemic shock.Evidence in animal experiments suggests that tPA may play a neurotoxic role in central nervous system(CNS) via the induction of microglial activation,degradation of laminin matrix and enhancement of the N-methyl-D-aspartate(NMDA) receptor-mediated signaling in neurons,other reports imply tPA could protect rat neuronal cells from zinc-induced toxicity.
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Present studies have proved that tumor in-situ is infiltrated with plenty of macrophages (M?), M? may contribute up to or more than half of a tumor’s mass. It’s frustrated that as the main component of immune system, M? promote the tumor growth, and create a suitable microcircumstance to promote the progression of tumor as well. The furtherknowledge of the mechanism mentioned focusing on finding the new way to anti-tumor clinical research were reviewed.
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Brominated flame retardants (BFRs) are widely used industrial chemicals. Several BFRs were found to be at detectable level in the wildlife as well as in human, however, up to now there were few related papers which could be found for the adverse effects of BFRs on the wildlife, especially, on human. The recent research works on the biological effects of polybrominated diphenyl ethers (PBDEs), tetrabromobisphenol A (TBBPA) or derivates, hexabromocyclododecane (HBCD) and polybrominated biphenyls (PBBs) are reviewed in the present paper.
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Objective To understand the health of the electronic waste (e-waste) treatment workers and the adverse effects of e-waste on the workers engaged in e-waste dismantlement.Methods Health states were assessed by questionnaire investigation on 226 e-waste dismantlement workers and 172 non e-waste dismantlement workers (control group).Results The prevalence rates of headache/vertigo(47.7%),tetter /itch (15.0%),nausea(11.1%),insomnia(9.7%),hypomnesia (5.3%),nasal obstruction(5.3%),and conjunctiva congestion(4.8%) in e-waste dismantlement workers were significantly higher than that in the control group,and it seemed that the severity of the symptoms was strongly related to the type of work.Furthermore,there was a tendency that rate of insomnia raised with the length of service in the circuit boards dismantlement group.Conclusion E-waste dismantlement will produce adverse effects on health of the employed workers.