1: central nervous system influence
The central nervous system is sensitive to RF microwave electromagnetic radiation, so researchers pay attention to it, especially the epidemiological investigation on the influence of occupational population exposed to RF microwave electromagnetic radiation on the nervous system has been reported in China. The harm of radio frequency microwave electromagnetic radiation to health is mainly manifested as neurasthenia syndrome, and its symptoms mainly include headache, dizziness, memory loss, inattention, depression and irritability [1-4]. Wang Shaoguang et al [2] reported that 293 people exposed to pulsed microwave were investigated. The microwave exposure frequency was 400-9400MHz, the power density was 0.07-0. 18mW/cm2, and the incidence of neurasthenia syndrome was 40.3%. Among 348 continuous microwave occupational contacts, the microwave exposure frequency was 3400-8600MHz and the power density was 0.06-0. 15mW/cm2. The incidence of neurasthenia syndrome is 37.65438 0%, while that of the control group is only 5.65438 0%, which indicates that microwave electromagnetic radiation can significantly increase the number of neurasthenia syndrome patients in the exposed population. Ding Chaoyang et al. [1, 4] also reported that exposure to microwave would reduce sleep quality. Zhao Qingbo et al [3] reported that the incidence of neurasthenia syndrome was 765,438 0.8% when the microwave frequency was 3500-4200MHz and the field strength was less than 0.050 mW/cm2 (usually 0.0 10-0.030 mW/cm2), which was significantly higher than that of the control group (/kloc-0). Feng et al. [5] reported that the incidence of headache and alopecia in an occupational group exposed to 0.30 mW/cm2 was significantly higher than that in the control group. There is no significant difference in other symptoms such as dizziness, fatigue, insomnia and memory loss. Guo Baoke [6] and others think that there is no significant difference in the incidence of neurasthenia syndrome such as general weakness, headache, dizziness, insomnia and dreaminess. Compared with the control group, the pulsed microwave field intensity was 65,438 0.75 MW/cm2 and the continuous wave field intensity was 0.05mW/cm2, but it had significant effects on vision, lens injury and eye symptoms (such as dryness and fatigue).
In recent years, there are many reports about the influence of RF microwave on human neurobehavior [4, 5, 7, 8]. Feng et al. [5] tested the core behavior of 74 people exposed to microwave (average field strength: 0.053 mW/cm2). The results showed that the indexes of neurobehavioral function of occupational people exposed to microwave with a daily dose of 0.3 MW h/cm2 had no obvious effect compared with the control group. However, Zhu Qixing and others [7] conducted behavioral tests on 38 people exposed to low-field microwaves, and concluded that even in the environment where the power density of microwave electromagnetic field exposure is less than 0.0 1 mW/cm2, workers may have neurobehavioral effects such as emotional instability, decreased attention, reaction speed, hearing and memory, visual perception movement speed and psychological movement stability, and these effects are negatively correlated with the length of service. Long et al. [8] tested the core behavior of 50 workers exposed to microwave, and found that under the environment of low-intensity microwave (0.035mW/cm2), workers showed obvious changes in emotional state characteristics, among which, except for the intensity and activity index, other indicators were significantly different from those of the control group; After work, the number span and simple reaction time were significantly different from those of the control group, while other items had no significant changes.
Many laboratory studies believe that environmental electromagnetic radiation is a non-thermal effect with low intensity and long-term effect, which has been confirmed by animal experiments. Liu Zunyong et al. [82] reported that microwave radiation can double the oxygen consumption rate of rat brain tissue, weaken the oxygen metabolism ability of rat brain tissue and reduce the oxygen consumption ability. Yao Gengdong et al. [9] reported that under the conditions of microwave frequency of 3 GHz, electromagnetic field intensity of 1mW/cm2 and 5mW/cm2, the ultrastructural changes of mouse hypothalamus can be observed after microwave irradiation for more than one month, mainly showing the damage of mitochondrial structure. Liu Qiaobao et al. [10] irradiated rats 100 days with different doses, and found that the RNA and DNA of single cerebral cortex cells and whole brain tissues irradiated with doses less than 1mW/cm2 only showed meaningless reduction; When the microwave intensity reached 5mW/cm2, it was significantly lower than that of the control group. The author believes that continuous exposure to this dose will damage brain cells and tissues, leading to dysfunction of the central nervous system. At the same time, the author uses infrared radiation as a control. When infrared radiation raises the body temperature by about 5mW/cm2, it will not cause damage. Therefore, the author thinks that the biological effects of infrared thermal effect and microwave thermal effect are completely different. Pu Jingsui et al. [1 1] exposed mice to 3GHz and 5mW/cm2 for 7 consecutive days, and found that the total amount of EEG in some brain regions decreased, and the peak energy of EEG decreased significantly. The content of succinate dehydrogenase in hypothalamus and hippocampus decreased obviously, which was basically consistent with the results reported by Jianghuai et al. [12] with newborn mice. However, it has also been reported that when the power density is lower than 2W/cm2(9370MHz), it will not cause brain and eyeball damage.
Tao et al. [13] irradiated rats 1 hour with a microwave therapeutic apparatus at power densities of 20 mW/cm2, 10mW/cm2 and 1mW/cm2. Under the electric environment, it was observed that the brain neurons of the two groups had different changes, among which the mitochondria changed obviously. Mitochondria swelling, fusion and deformation; Crest defect, fracture and cavitation, etc. Sparse and dissolved nucleoli can be seen in the three experimental groups. The author thinks that microwave with low power density has certain influence on the ultrastructure of cerebral cortex cells in rats. When the frequency is 4GHz, the power density is 0.5-3mW/cm2, and it is irradiated for 3 hours every day for 365,438+0 days, the content of 5-HT in the whole brain of mice decreases obviously [65,438+04].
2. Effects of microwave on eyes
There are a lot of reports about eye damage caused by microwave in China, whether it is epidemiological investigation of occupational exposed people or animal experiments. Many reports believe that high-intensity microwave irradiation can cause cataracts [770], and animal experiments also have the same report [17,20-23], but whether the chronic effects of low-intensity microwave can cause eye damage (especially lens opacity and cataracts) is still inconclusive [15-18,20,24].
The biological effects of microwave have thermal effect and non-thermal effect, which are harmful to all human systems. The lens of the eye is the main target organ [19]. It is generally believed that the lens itself has no vascular tissue, so it becomes a sensitive part of microwave thermal damage. However, at present, there is no recognized clinical specific morphological characteristics of microwave-induced cataract, so there is controversy about the judgment of clinical microwave-induced cataract in human eyes [15,25].
It has been reported that working in a microwave environment with a certain intensity for a long time can make the lens of the eye turbid, dense and vacuous, and it is related to the contact time. The shape and position of lens opacity have no certain regularity, and the shape is a little bit like a sheet, a strip, a net, a brittle shape and so on. , with posterior capsule, posterior cortex, posterior pole, equator and anterior cortex [15- 17,19,25-29,33]. In addition, microwave also causes damage to other parts of the eye, such as conjunctiva, cornea, iris and fundus, including fatigue [19,30,31] and decreased vision [15,/kloc-0,6,24,32,33]. Old macular degeneration [27], weak response to light [20, 33], spasm and bleeding of small blood vessels in the fundus [17, 26], tiny retinal hemorrhage [19, 2 1, 33, 34,] and so on.
Dai et al. (1994) reported that 142 radar operators were investigated, and their exposure power density was 100-300 m w/cm2. The results showed that the incidence of lens opacity in the microwave irradiation group (76.05%) was significantly higher than that in the control group (48.78%), and the degree of opacity between the two groups was also significantly different. The forms of turbidity are mostly punctate and flaky under the posterior bundle, and the speed of turbidity progress is also significantly different (compared with 6 years ago). There was no significant difference in fundus changes between the contact group and the control group, and no abnormal changes were found in optic disc, cornea and iris [29].
Sichuan College of Occupational Prevention (1982) reported that 296 occupational contacts were investigated. The microwave power density is 10- 100 m w/cm2. The results showed that the incidence of vision loss in the microwave group (32.65%) was significantly higher than that in the control group (15.75%), and the posterior lens cortex was found.
Pan Dayan et al. (1992) reported a survey on the health effects of 33 workers exposed to microwave power density of 75- 175m w/cm2, and found that the detection rates of conjunctival congestion, macular degeneration and lens opacity were (76.4%, 2 1. 1% respectively.
In addition, there are some reports that low-intensity microwave irradiation has no obvious effect on eyes. Zhou Congqin et al. (198 1 year) investigated 25/kloc-0 radar personnel in naval forces, and their power densities exposed to microwaves were 0-35 m w/cm2 and 77000m w/cm2 respectively. The results showed that the visual acuity, visual field, lens and lens of the contact group. Li Huanying et al. (1993) investigated 144 microwave communicators. The power density of microwave radiation is 10-450 MW/cm2. Among 144 people, 14 cases (9.72%) had lens opacity in different degrees, while 65436 people in the control group.
3. The influence of microwave on circulation system
The effects of low-power microwave radiation on the circulatory system have been widely reported in China, and the results are basically the same. The main manifestations are palpitation, precordial pain, chest tightness and other symptoms, the abnormal rate of ECG is increased, sinus tachycardia is relieved, and cardiac bundle branch block and so on. In addition, blood pressure, hemogram, cerebral blood flow and microcirculation will also change to varying degrees [20, 24, 3 1, 32, 36.
Jianghuai (1982) [3 1] exposure 1664 microwave power (power density
Pan Dayan et al. (1992) [20] investigated 33 workers exposed to microwave power density of 75- 175m w/cm2 in the microwave room, and found that compared with the control group, the palpitation symptoms in the microwave exposure group increased, but there was no statistical significance. The abnormal rate of ECG increased significantly; The detection rate of hypotension increased significantly; The average value of hemoglobin and red blood cells increased significantly.
4. Effect of electromagnetic radiation on immune system
The body's immune system plays a very important role in resisting the invasion of external pathogens and is closely related to the occurrence of tumors. In recent years, with the wide application of microwave, people pay more and more attention to the influence of microwave on immune function. It is generally believed that the influence of microwave on immune function is related to microwave frequency, power density and exposure time. Low-intensity short-term irradiation can stimulate immunity, while long-term or high-power irradiation often shows inhibitory effect on immune function [42].
It was found that [43] The mice were irradiated with microwave with frequency of 2450MHz and power density of 65438 0 MW/cm2 for 7 consecutive days, which could obviously improve the immune function of animals (P
5. Microwave reproductive effect
The reproductive system is sensitive to microwave electromagnetic radiation, and the damage of heating microwave to the reproductive system is obvious [50-53]. However, there are many reports about the harm of non-thermal microwave to reproductive system in China.
Morphological changes of 1
The effect of microwave on male reproductive system is consistent in China. It is generally believed that the temperature of epididymis or testis irradiated by 2450MHz microwave can change the ultrastructure of seminiferous epithelium, epididymal epithelium, periseminiferous tubule epithelium and seminiferous tubule epithelium, destroy the spermatogenesis process of testis, and lead to morphological abnormalities of primary spermatocytes and early and late spermatocytes [5 1-58]. Some scholars believe that microwave has cumulative effect on male reproductive system, but some studies have found that one exposure can also lead to a significant increase in sperm abnormality rate and a significant decrease in DNA content in mice [59, 60, 6 1].
It has been found that the non-thermal effects of low-intensity microwave radiation can also affect sperm cells. Human semen was irradiated at 2450MHz for 65438 0 hours with power densities of 3, 5, 7 and 9mW/cm2, respectively. It was found that microwave radiation of 5 mW/cm2 had a significant effect on human sperm motility, survival rate and egg penetration rate, while microwave radiation of 3 MW/cm2, 7 MW/cm2 and 9 mW/cm2 had no significant effect on the above indexes. It was also found that the chromosome abnormality rate of human sperm in the 7mW/cm2 group was significantly higher than that in other groups. The above research shows that the effect of microwave exposure on human sperm seems to have a power density window effect, but it has not been confirmed by other studies.