Greatest long-term health risks of cancer. Typically, when cells are damaged or deteriorated to a certain extent, they will be self-eliminated. When this self-elimination of the ability to disappear, the cells get "eternal life", you can continue to divide uncontrollably, which evolved into cancer. 

Our body has many mechanisms to prevent cancerous cells and replace damaged tissue. However, the damage caused by radiation can seriously disrupt the body of these mechanisms, so that greatly increased the risk of cancer. In addition, if the body does not bond well to repair radiation damage and changes brought about by our genes is likely to cause mutations. These mutations not only increase their risk of cancer, there may be passed on, so that the radiation effects in offspring who show up. These effects include small head and brain, eye developmental defects, slow growth and severe cognitive learning defects. 

Health extent of the damage depends on the produce ionizing radiation decay time of exposure to radiation and radioactive substances. It can break chemical bonds between atoms and molecules in human tissue, may have serious effects on human important biochemical structure and function. 

Our body tries to repair these injuries, but sometimes too much damage is too severe or organizations involved with organ that can not be repaired. 

Moreover, the body's natural repair process, is also likely to produce errors. Most easily injured by radiation part of the body including the gastrointestinal epithelial cells as well as those that generate blood cells in bone marrow cells. 

First, the dangers of nuclear radiation on human 

Affect the general situation of nuclear leakage performance of personnel in the nuclear radiation, also called radioactive substances, radioactive material through inhalation, skin wounds and gastrointestinal absorption into the body, causing the radiation, y radiation is absorbed by the body to penetrate a certain distance, so that personnel are external irradiation damage. 

The formation of internal and external irradiation of radiation sickness symptoms are: fatigue, dizziness, insomnia, skin redness, ulceration, bleeding, hair loss, leukemia, vomiting and diarrhea. Sometimes increased cancer, distortion, the incidence of hereditary disease, affecting the health of generations. Generally speaking, the radiation energy of the body to accept, the more severe their symptoms of radiation sickness, carcinogenic, teratogenic greater the risk. 

Mild injury, mild acute radiation sickness may occur, such as fatigue, malaise, loss of appetite. 

Moderate injury, can cause moderate acute radiation sickness, such as dizziness, weakness, nausea, vomiting, decreased white blood cell count. 

Severe injury, can cause severe acute radiation sickness, despite treatment, but 50% of the exposed person may die within 30 days, the remaining 50% can be restored. Showed repeatedly vomiting, may have diarrhea, decreased white blood cell count. 

Very severe injury, causing very severe radiological disease, high mortality. Repeated vomiting, diarrhea sharp drop, shock, white blood cell count. Nuclear accidents and nuclear radiation bomb explosion will result in immediate death or severe injury. Also cause cancer, infertility, and other freaks. 

The following is the amount of radiation suffered (unit: millirem) consequences: 

450000 ~ 800000:30 days will go moribund state; 

200000 ~ 450000: hair loss, a serious blood disease, some people died in 2-6 weeks; 

60000 ~ 100000: the emergence of various radiation sickness; 

10000: the possibility of cancer is 1/130; 

5000: a year of work of nuclear radiation suffered; 

700: Nuclear radiation brain scan; 

60: The amount of radiation in the human body; 

10: The amount of radiation when the plane suffered; 

8: Building materials radiation generated annually; 

1: The amount of radiation the leg or arm of the X-ray examination. 

(Note: This unit uses rem (rem), the existing units of the Greek (Sv) 1Sv = 100rem) 

Embryonic and fetal injury 

Fetal embryo and fetus are more sensitive to radiation, exposure to radiation in the pre-implantation embryo can increase the stillbirth rate; during organogenesis contact can increase the rate of fetal malformations, neonatal mortality rate is correspondingly increased. According to epidemiological investigations showed that in children irradiated in fetal life, the incidence of leukemia and certain cancers was higher than the control group. 

Long-term effects 

In the medium-or high-dose range, nuclear radiation carcinogenesis has been confirmed by animal experiments and epidemiological investigations. Acute and chronic exposure by the crowd, the leukocyte serious decline in the incidence of lung cancer, thyroid cancer, breast cancer, and other bone cancers increased with increasing dose. 

Affected by the aftermath of the nuclear radiation contamination after 

After six months of radiation contamination, the body will change, including lens opacities, cataracts, male testes and female ovaries affected cause permanent infertility, impaired bone marrow hematopoietic dysfunction appear, and by the emergence of various cancers. 

Another genetic effects also have to make germ cell gene or chromosome mutation, resulting in birth defects and other problems. 

Second, nuclear radiation symptoms 

Large doses of radiation damage caused by ionizing radiation in a short time, called acute radiation sickness. Longer than allowed dose of radiation damage, called chronic radiation sickness. The disease is common in staff received excessive radiation, the public and the victims of the explosion of nuclear weapons, the main trigger hematopoietic disorders, internal bleeding, tissue necrosis, infection and malignant transformation and so on. 

Among them, the body external beam radiation caused major damage in the early course of the disease typical of acute radiation sickness, nausea, vomiting, fatigue, fever and diarrhea. "Leave more of 'duration in patients with different lengths, the symptoms eased. To a very serious development of the infection, bleeding and gastrointestinal symptoms. After appropriate treatment the symptoms gradually ease. 

The injury is different according to local irradiation with doses affected, according to the site may be subject erythema, edema, dry and moist desquamation peeling, blisters, pain, necrosis, gangrene, or hair loss and other symptoms. Local skin injury usually lasts a few weeks to a few months, serious conventional methods are difficult to cure. However, external radiation is more common in nuclear power plant workers. 

Pollution caused by irradiation in vivo general no obvious early symptoms, unless a high intake, but this is very rare.