【作者】 胡冀；

【导师】 杨新文；

【作者基本信息】 中南大学 ， 劳动卫生与环境卫生学， 2010， 硕士

【摘要】 [目的]：探讨移动通信基站微波辐射对周围居民神经行为功能的影响及其环境低强度电磁辐射健康损害的早期生物标志,为环境暴露低强度微波辐射的健康风险预测和评估提供科学依据和监测指标。[方法]：(1)随机抽取长沙市内20个建有基站的居民小区和10个未建基站的居民小区,对小区居民生活内外环境中的微波辐射强度进行测量。(2)选择长沙市区内移动通信基站(900MHz)周围50m居住人群63名为观察组,对照组为非移动基站周围定居人群69人,采用自行设计的问卷,收集研究对象的基本情况以及相关信息,运用WHO-NCTB进行神经行为功能测试。(3)健康成年昆明受精雌性小鼠随机分为：孕期-生后均不辐射组(记为第1组,即对照组)、孕期辐射-出生后结束辐射组(记为第2组)、孕期不辐射-出生后辐射组(记为第3组)、孕期-出生后均辐射组(记为第4组),采用900MHz辐射源,孕期每天照射8小时,辐射强度为40±3.27uw/cm2,直至仔鼠出生；仔鼠每天照射8小时,辐射强度为40±3.27uw/cm2,共4周；对照组置于相同环境但不予以照射。辐射处理后：①黑白巷实验检测小鼠焦虑情况,平衡木、游泳、前肢悬挂时间实验检测仔鼠运动协调能力。②水迷宫实验测定仔鼠学习记忆功能。③HE染色观察仔鼠脑组织形态结构改变。④分光光度法检测仔鼠脑组织中SOD、GSH活性及LDH、MDA含量的改变。[结果]：(1)暴露小区微波辐射强度明显高于对照小区(p=0.000)；基站周围微波辐射强度在距基站10米左右出现一最高值,此后才随距离的增加而逐渐减弱；天线主瓣方向区域微波辐射不一定较高,付瓣方向区域微波辐射也不一定较低；同时存在两个基站时,两者所产生的电磁辐射在某一区域范围可产生电磁场叠加现象,使辐射强度增加；居民居室暴露窗口外的电磁辐射强度不但随距离变化,还随着楼层高度而有所增强；铝合金防盗网内的电磁辐射强度要明显低于网外的电磁辐射强度(p<0.05)；玻璃窗内、外电磁辐射强度几乎没有变化(p>0.05)。(2)观察组出现头晕症状明显高于对照组(P<0.05),紧张-焦虑和疲惫-惰性情感状态得分也显著高于对照组(P<0.05)。(3)观察组的视觉简单反应平均时、顺背和倒背得分、数字译码总得分、视觉保留记忆错误次数以及目标追踪错误次数与对照组相比差异具有显著性(P<0.05)。同时居住年限与简单反应平均时间、视觉保留记忆错误次数、目标追踪错误次数均呈明显正相关(P<0.05),与倒背得分呈明显的负相关(P<0.05)。居住处离基站的距离与顺背得分、倒背得分、译码总得分呈现明显的正相关(P<0.05),与简单反应平均时间、视觉保留记忆错误次数、目标追踪错误次数则呈现明显的负相关(P<0.05)。(4)各辐射处理组仔鼠与对照组相比,黑白巷结果、平衡木得分、游泳总时间、以及前肢悬挂时间改变不大(P>0.05)。出生后接受辐射的小鼠潜伏期时间明显延长(P<0.05),错误次数明显增加(P<0.05)。(5)孕期、出生后接受微波辐射照射均会导致MDA含量升高,GSH含量及SOD活性降低(P<0.05),但脑组织未见明显病理改变。[结论]：(1)本课题所调查的基站周围地面微波辐射功率密度均在《环境电磁波卫生标准》(GB9175-88)的一级标准内,但有部分居室暴露窗外微波辐射功率密度偏高,甚至个别居室窗内、外微波辐射功率密度远远超出一级安全范围。在环境监测中还进一步证实居室安装铝合金防盗网具有良好的微波电磁场屏蔽作用。(2)基站微波辐射对周围居民的情感状况、智力、记忆学习、感知和心理运动等神经行为能力有一定的负面影响。(3)小鼠在生长发育过程中暴露于900MHz移动通信电磁微波辐射,即使辐射剂量水平没有超出现行的卫生学标准,也可出现学习记忆能力下降和神经行为的改变。(4)小鼠在生长发育过程中暴露于900MHz移动通信电磁微波辐射,可导致脑组织抗氧化酶活性降低,氧自由基生成增多。提示SOD、GSH活性及MDA含量可作为电磁辐射引起神经元功能性损伤的早期指标。更多还原

【Abstract】 [Objective]:To explore the effects of microwave radiation from mobile phone base stations on the neurobehavioral functions of the surrounding residents and to find the early damage biomarkers of health lesion which caused by the low-intensity electromagnetic radiation, then to provide scientific basis? and monitoring indicators for health risk prediction and evaluation of low intensity microwave radiation environmental exposure.[Method]:(1) Randomly selected 20 residential areas where built base stations and 10 residential areas where no base stations are built as a control. Measured the intensities of microwave radiation inside and outside of the residential living environment.(2) Select 63 people living 50 m around the mobile phone base station (900MHz) to be the observation group and select 69 people living in non-mobile phone base station to be the control. Using the questionnaire to collect basic information, tests neurobehavioral function by using WHO-NCTB.(3) The fertilized adult female Kunming mice were randomly divided into four groups:pregnancy-after birth no radiation group (denoted as Group 1, the control group), pregnancy radiation-after birth no radiation group (denoted as group 2), pregnancy no radiation-after birth radiation group (denoted as group 3), pregnancy-after birth radiation group (denoted as group 4), using 900MHz radiation, exposured 8 hours per day during pregnancy, the radiation intensity was 40±3.27 uw/cm2, until the fetus was born; offspring exposured 8 hours per day, the radiation intensity was 40±3.27uw/cm2, total 4 weeks. The control was placed in the same environment, but no radiation. After that:①the balancing beam, swimming, forelimb hanging time for the motor coordination of offspring s, black and white Lane for anxious in mice.②measured learning and memory function of offspring by water maze.③to observe the morphological changes of offspring brain tissue by HE staining.④Detected SOD, GSH activity and LDH, MDA changes in offspring brain tissue by spectrophotometric. [Results]:(1) The intensities of microwave radiation in the exposure residential districts were obveriously higher than the control (p<0.05); There was a peak at about 10m from the station, then intensity would gradually weakened with the increase of the distance.The level of microwave radiation in antenna main lobe direction is not necessarily higher than the side lobe direction, and the side lobe direction also is not lower. At the same district, where there were two base stations, the electromagnetic field nestification would take place.The intensities of microwave radiation outside the exposure windows in the resident room not only changed with distance but also with the height of the floor. The intensities of microwave radiation inside the aluminum alloys security net were much lower than those of outside the aluminum alloys security net (p<0.05), but the inside or outside of glass-window appears almost no change (p>0.05).(2) The dizziness symptoms were significantly higher in the observation group (P<0.05), also the POMS scored of tension-anxiety and fatigue-inertia were significantly higher (P<0.05).(3) The SRT, DSp,SAMD, DS,BVR,PA of observation group were significant difference compared with the control group (P<0.05). While the time limit of habitation were positively correlated with the SRT, BVR, PA (P<0.05), but were negatively correlated with the DSp (P<0.05). The distance from the base station were positive correlated with DSp and DS (P<0.05), but negative correlated with BVR and PA (P<0.05).(4) Compared with control group, the black and white Lane results, motor coordination, total swimming time and forelimb hang time of the radiation treatment group had no change (P> 0.05); exposure radiation after the birth, the latency period was significantly prolonged (P<0.05) and the number of errors increased significantly (P<0.05).(5) Exposure to microwave radiation during pregnancy and after birth, both would lead to MDA content increased, GSH content and SOD activity decreased (P<0.05), but no significant pathological changes in brain tissue. [Conclusion]:(1)Although all the measure dates on the ground around the base station could be below the "environment electromagnetic wave hygienic standard" (GB9175-88), there were still a minorities of windows which exposed to the base station were higher, and the outside and inside of a few window was even higher beyond the safe level defined standard. The aluminum alloys security net can partly shield the microwave radiation from the mobile phone base station.(2)The microwave radiation from base station has some negative impact on the emotional status, intelligence, memory, learning, perception and psychomotor of surrounding residents.(3) The mice exposed to 900MHz microwave radiation during period of the growth and development, even if the level of radiation dose did not exceed the existing standards of hygiene, the learning and memory declined and the neurobehavioral changed.(4) The mice exposed to 900MHz microwave radiation during period of the growth and development can lead to antioxidant enzyme activities decreased, oxygen free radicals increase in brain tissue. That hinted SOD, GSH activity and LDH, MDA content can be used as an early indicator of neuronal function injury caused by electromagnetic radiation.更多还原