Nature and use
Polychlorinated biphenyls (PCBs) are an industrial chemical with the following characteristics:
1. Strong heat transfer, but no power transmission.
2. It is not easy to burn.
3. The properties are stable and will not change chemically.
4. Insoluble in water, it is a fat-soluble substance.
Based on the above properties, the industry initially regarded PCB as a godsend, widely used as a dielectric, placed in electronic instruments such as capacitors and transformers, or used as a heat exchange liquid to adjust the working temperature of instruments.
People didn't know PCB was toxic at first, so they didn't take preventive measures. At the same time, many PCB wastes are dumped in the ocean. It was not until workers in the PCB industry began to get sick one after another, and environmentalists found that there was PCB in marine life that people began to pay attention to the problems caused by PCB.
How PCB enters human body
A large amount of PCB waste is piled up in landfill, which will release gas. Over time, these wastes will flow into lakes or oceans. Although PCBs are insoluble in water, they are soluble in oil, so they accumulate in marine organisms, especially larger organisms such as sharks and dolphins. When we eat this deep-sea fish, or eat other contaminated food, including dairy products, meat fat, grease, etc., we will inhale PCB. The ingested PCBs are mainly stored in human adipose tissue, which can be transmitted to the fetus through the placenta during pregnancy and released into human milk.
Effects of polychlorinated biphenyls on human body
Damage to liver and kidney
The skin has acne, redness and swelling, which affects the pigment.
Eye swelling and discomfort, increased secretion.
Nervous system is slow to respond, hands and feet are paralyzed and trembling, memory declines, and intellectual development is hindered.
Reproductive function interferes with hormone secretion and reduces the reproductive ability of adults. Newborn babies are prone to birth defects and grow slowly in the future.
Carcinogenesis, especially liver cancer. The International Organization for Research on Cancer has listed PCBs as possible carcinogens.
Control of printed circuit board
1976, the United States Congress legislated to prohibit the production, sale and distribution of PCB.
Since 1980s, many countries, such as the Netherlands, Britain and Germany, have imposed restrictions on PCBs.
However, even with restrictions, during the period of 1984-89, the global annual output was still 22 million pounds. It seems not feasible to stop PCB production globally.
conclusion
The pollution of PCB is the bad result accumulated for many years, which can be said to be global. Almost all food will be polluted to some extent, and it is really difficult to avoid it completely. What we can do is to pay attention to the food we eat, enhance our awareness and concern about environmental protection, and hope that policy makers can make appropriate controls.
Two transformers (10KV, 400KVA) newly built in our community are only 4m away from the residential building, and there is no wall in the middle (facing the master bedroom balcony). Does the noise and radiation produced have a great influence on people? I also looked up some information on the internet, and I don't know if it is reasonable. Please correct me. Is there any good way?
Information found:
Can the electromagnetic radiation pollution caused by transformer be treated by environmental protection?
Lawyer Yan:
With the renovation of dilapidated buildings, some new residential areas have been built in our city. Because the transformer in the community is only separated from the residential building by a wall, the noise disturbs the people. However, the monitoring results show that the indoor noise of residents basically meets the noise standard of factory boundary (residential cultural and educational area). However, some residents still report that the operation of the transformer makes them feel weak, have poor memory and have symptoms such as irritability, and strongly urge the environmental protection department to deal with them. We think this is a symptom caused by electromagnetic radiation pollution during the operation of transformer. I would like to ask: In addition to the noise standard, can the pollution caused by transformers be managed by the Administrative Measures for Environmental Protection of Electromagnetic Radiation? What standards apply to management? What means are used for management?
Liu Jun Yinchuan environment supervision office
Comrade Liu Jun:
In the process of transformer operation, it will not only produce environmental noise, but also produce electromagnetic radiation. If this electromagnetic radiation exceeds the specified energy limit, it will form electromagnetic radiation pollution. Electromagnetic radiation pollution can cause many kinds of harm, among which the main harm to human body is autonomic nerve dysfunction, blood pressure and blood phase imbalance, and even damage to eyes. The symptoms mentioned in your letter, such as fatigue, memory loss and excitability, can be said to be common symptoms of electromagnetic radiation pollution to human body. In order to prevent and control electromagnetic radiation pollution, in addition to Article 24 of the Environmental Protection Law, which stipulates that units that produce environmental pollution and other public hazards must take effective measures to prevent and control the environmental pollution and harm caused by electromagnetic radiation generated in production, construction or other activities, the State Environmental Protection Bureau also issued the Administrative Measures for Environmental Protection of Electromagnetic Radiation on March 25th, 1997, which made more specific provisions on the prevention and control of electromagnetic radiation pollution. The "electromagnetic radiation" specified in Article 2 of the Administrative Measures includes "electromagnetic radiation generated in high-voltage power transmission and transformation", so the electromagnetic radiation pollution caused to transformers can be managed with reference to this method. The applicable management standard is the Regulations on Electromagnetic Radiation Protection (GB 8702-88) issued by 1988. Article 2 of the standard stipulates that the specific absorption rate (SAR) of the public exposed to electromagnetic radiation should be less than 0.02W/kg for any continuous 6 minutes in 24 hours a day. The "specific absorption rate" here refers to the electromagnetic radiation power absorbed by the organism per unit mass, that is, the absorbed dose rate. In order to facilitate monitoring, the standard also stipulates the derived limit of public exposure, that is, the average limit of environmental electromagnetic radiation field parameters for any continuous 6 minutes 24 hours a day. The radiation of electromagnetic radiation body (field) exceeds the standard limit, which means that there is electromagnetic radiation pollution, and units or individuals engaged in electromagnetic radiation activities should bear corresponding legal responsibilities.
According to the provisions of the Measures for the Administration of Environmental Protection of Electromagnetic Radiation, the main management measures of electromagnetic radiation pollution are:
(1) Units and individuals that require the construction or use of electromagnetic radiation construction projects or equipment listed in the Catalogue of Electromagnetic Radiation Construction Projects and Equipment shall implement the environmental impact assessment system, the "three simultaneities" system and the declaration and registration system.
(2) For the electromagnetic radiation construction projects completed or under construction before March 25th 1997, or the purchased electromagnetic radiation equipment does not meet the environmental protection standards and is seriously polluted, it is required to take remedial measures; If it is difficult to remedy, it shall be closed down or relocated according to law.
(3) The environmental protection department shall, jointly with relevant departments, investigate and deal with electromagnetic pollution incidents that affect the public's production or quality of life, or adversely affect public health, and order units that produce electromagnetic radiation pollution to take measures to eliminate the impact.
(four) those who have made remarkable achievements in the prevention and control of electromagnetic radiation pollution shall be commended and rewarded by the competent administrative department of environmental protection; Those who violate the law and cause or may cause electromagnetic radiation pollution shall be punished by the competent administrative department of environmental protection.
In addition, units and individuals polluted by electromagnetic radiation also have the right to require polluters to eliminate hazards and compensate for losses, and may request the competent administrative department of environmental protection to investigate and mediate disputes with polluters; If mediation fails, the parties may also bring a lawsuit to the people's court; Disputes arising from electromagnetic radiation pollution between the parties may also be brought directly to the people's court without mediation by the competent administrative department of environmental protection.
Lawyer Yan
I want to add one thing here:
The lawyer ignored one thing:
In addition to the thermal effect mentioned by lawyers, the environmental pollution of transformers,
And non-thermal effects:
I looked up the minutes of the 2002 global conference on radiation research.
Get a few summaries:
The influence of power frequency (50HZ) current on human body is different from that of high frequency (such as base station and microwave oven), mainly due to thermal effect. The former is a strong low-frequency magnetic field, but at present, the mechanism of low-frequency magnetic field on human body is not clear, and some theories think that it acts directly through the horizontal change of cell membrane; There is a theory that it is a catalyst, such as catalyzing cancer cells to produce white blood cells.
This measurement is not in mw/cm2, but in ut.
Most scientific experiments find that 0. 1 microtra is a threshold.
If it exceeds, the incidence of childhood leukemia will rise to 2-4 times, and the incidence of other diseases such as breast cancer will also increase to a considerable extent.
From 65438 to 0974, Nancy Wertheim, an epidemiologist engaged in the study of childhood leukemia, found many times that power transformers were often installed in the yard of children with leukemia. A joint survey from Canada and France shows that electromagnetic radiation is related to leukemia. Nowadays, people also have a * * * knowledge: working in front of a video screen or in a place with strong electromagnetic fields will make people more prone to neurasthenia symptoms such as fatigue, fatigue and forgetfulness.