工频电磁辐射对小学生健康指标的影响研究

发布时间：2018-07-08 11:52

本文选题：工频电磁场 + 小学生　；参考：《武汉科技大学》2014年硕士论文

【摘要】：目的工频电磁场已经被国际癌症研究所(IARC)归类为人类可疑致癌物（2B类）。目前，人类生活环境中的辐射背景值是相对较低的，但是这种相对低的环境背景值的工频电磁场是否会对儿童血清免疫指标和氧化应激指标产生影响仍存在争议。本研究通过某地500kV超高压输变电线廊附近小学实地检测，了解输变电线廊附近学校的工频电磁场暴露水平，探讨工频电磁场对小学生某些健康指标的影响，为今后开展同类研究提供本底资料。方法在500kV超高压输变电线廊附近的小学选取4-6年级学生共456名作为暴露组，在距高压线10公里外没有典型辐射源区域随机选取另一小学4-6年级学生272名作为对照组。检测并对比两组小学生所在学校典型位置的电磁场强度及每名学生的淋巴细胞计数、血清免疫球蛋白IgG和IgM水平、溶菌酶含量和血清中3个重要的氧化应激指标：总抗氧化物（T-AOC）、丙二醛（MDA）水平、超氧化物歧化酶（SOD）；以及四个血常规指标（白细胞WBC,红细胞RBC,血小板PLT,血红蛋白HGB）水平。结果两所学校工频电磁场强度现场监测结果：暴露组21个监测点的工频电场强度范围为522-3930mV/m，对照组30个监测点的工频电场强度范围为16-2919mV/m；暴露组的工频磁感应强度范围为171.5-357.8nT，对照组的工频磁感应强度范围为9.95-72.08nT，所测值均低于国际辐射保护协会规定的工频电场限值4kV/m和磁场限值100μT。经过两独立样本的非参数检验，暴露组的工频电磁场强度高于对照组，差异有统计学意义（P0.001）。暴露组和对照组免疫功能相关指标检查结果显示：暴露组血清中免疫球蛋白IgG、IgM水平均低于对照组，差异有统计学意义(P0.01)；两组小学生血液淋巴细胞数目和唾液溶菌酶含量的差异没有统计学意义(P0.05)。两组小学生之间的氧化应激指标进行比较，结果显示暴露组总抗氧化物含量显著高于对照组(P0.05)，但两组小学生的血清SOD和MDA含量均无统计学差异(P0.05)。血常规指标检查结果：暴露组小学生血红蛋白HGB显著高于对照组(P0.05)。多元回归结果显示以上差异与工频电磁场暴露具有统计学关联。结论暴露组小学生所在学校距离500kV高压输变电线94m，暴露组工频磁场暴露强度明显高于对照组，且暴露组所在小学工频磁场暴露最高强度接近流行病学资料证实的可引起儿童健康效应的限值0.4μT。暴露组小学生淋巴细胞数目增加，而IgG、IgM水平降低，提示工频电磁场可能对小学生的免疫功能有一定的影响作用。暴露组血清的总抗氧化物T-AOC水平比对照组要高，差异具有统计学意义（P0.05）。提示工频电磁场使小学生体内的总抗氧化物指标T-AOC升高。而对MDA和SOD等指标无影响。暴露组小学生血红蛋白HGB水平高于对照组（P0.05），提示工频电磁场的暴露可能使小学生血红蛋白水平升高。本研究属于横断面调查，为病因假设提供了可能线索，，要确证暴露与健康效应之间关联，尚需进一步大样本人群流行病学的研究，如队列研究等，同时结合细胞、动物实验进行工频电磁辐射作用机制的探讨。
[Abstract]:Objective power frequency electromagnetic field has been classified as a suspected human carcinogen (class 2B) by the International Institute of cancer research (IARC). At present, the background value of radiation in human living environment is relatively low, but whether the frequency electromagnetic field of the relatively low environmental background value still has a dispute on the influence of the serum immune index and oxidative stress index in children. This study, through a field test in a primary school near the 500kV ultra high pressure transmission line corridor, understands the exposure level of the power frequency electromagnetic field near the transmission line corridor, and discusses the influence of the frequency electromagnetic field on some health indicators of the primary school students, and provides the background information for the future research.
Methods a total of 456 students were selected as exposure group at grade 4-6 in the primary school of 500kV ultra high pressure transmission line corridor, and 272 students of another primary school 4-6 were randomly selected at 10 km away from the high pressure line. The intensity of electromagnetic field and each school in the typical school position of the two primary school students were measured and compared. Lymphocyte count, serum immunoglobulin IgG and IgM levels, lysozyme content and 3 important oxidative stress indicators in serum: total antioxidant (T-AOC), malondialdehyde (MDA) level, superoxide dismutase (SOD), and four blood routine indicators (leukocyte WBC, erythrocyte RBC, platelet PLT, hemoglobin HGB).
Results the field frequency field intensity monitoring results in two schools: the intensity range of power frequency electric field of 21 monitoring points in the exposed group is 522-3930mV/m, and the intensity range of power frequency electric field of 30 monitoring points in the control group is 16-2919mV/m; the frequency magnetic induction intensity range of the exposed group is 171.5-357.8nT, and the frequency magnetic induction intensity range of the control group is 9.95-72. 08nT, the measured values were lower than the limited value 4kV/m of the industrial frequency electric field and the 100 u T. of the magnetic field. The intensity of the power frequency electromagnetic field in the exposed group was higher than that of the control group, the difference was statistically significant (P0.001). The examination results of the immune function related indexes of the exposed and control groups showed that the exposure group was exposed. The level of serum immunoglobulin IgG and IgM was lower than that of the control group (P0.01). There was no significant difference in the number of blood lymphocytes and the content of saliva lysozyme in the two groups of pupils (P0.05). The ratio of oxidative stress between the two groups of pupils was compared, and the results showed that the total antioxidant content in the exposed group was significantly higher. In the control group (P0.05), there was no significant difference in serum SOD and MDA levels between the two groups of primary school pupils (P0.05). The results of blood routine index examination were significantly higher than that of the control group (P0.05) in the exposed group. The results of multiple regression showed that the above difference was statistically related to the exposure of the power frequency electromagnetic field.
Conclusion the exposure group of primary school pupils was located at the distance of 500kV high voltage transmission line 94m, the exposure intensity of exposure group was significantly higher than that of the control group, and the maximum intensity of the exposure group was close to the epidemiological data which was close to the epidemiological data. The number of children's lymphocytes increased in the 0.4 u T. exposure group. The level of IgG and IgM decreased, suggesting that the power frequency electromagnetic field may have a certain influence on the immune function of primary school students. The level of total antioxidant T-AOC in the serum of the exposed group is higher than that of the control group, and the difference has statistical significance (P0.05). It suggests that the frequency electromagnetic field can increase the total antioxidant index T-AOC in the primary school students. And the indexes of MDA and SOD are used. The level of hemoglobin HGB in the exposure group was higher than that of the control group (P0.05), suggesting that exposure to frequency electromagnetic fields may increase the hemoglobin level of primary school students. This study belongs to a cross-sectional study, which provides a possible clue to the hypothesis of etiological hypothesis. It is necessary to confirm the association between exposure and health effects, and further large sample population epidemiology is needed. Such as cohort study, and combining with cell and animal experiments to explore the mechanism of electromagnetic radiation induced by power frequency.
【学位授予单位】：武汉科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R725.9

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