Radiation Dose Effects

Humans are exposed to radiation on a daily basis. Radiation exists in our environment, our bodies and the foods we consume, naturally occurring radiation in the air and from outer space. Radiation is measured in units called millirems, also known as mrems or rems. The average dose humans are exposed to is roughly 360 mrems per year. People who work in or around radioactive chemicals are exposed to 5,000 mrems per year. The biological effects radiation has on a human are measured in rems. Rem stands for "Roentgen equivalents in man."

Hair

• At 200 rems or higher, hair begins to fall out in large clumps. Hair loss occurs because hair follicles are extremely sensitive to radiation. Hair loss may be temporary or permanent depending on how much radiation a person is exposed to. Hair on the scalp is particularly affected by radiation. The scalp will become itchy, dry, pink and inflamed after exposure to radiation and it may resemble a sunburn. Hair loss may also occur on the whole body. Hair loss can occur in the face, arms, legs, underarms and pubic area. Hair may also thin out during exposure to radiation. If re-growth occurs, the hair will have a different texture and thickness.

Brain

• Brain cells do not reproduce and will not be damaged unless the rems measure at 5,000 or higher. Radiation kills nerve cells and small blood vessels. Exposure to 5,000 rems or higher can result in seizures or immediate death. Some effects that may go away with time or become permanent in some cases are dermatitis, alopecia and otitis media. Chronic, severe long-term effects include atrophy, leukoencephalopathy, radiation necrosis, neurological deterioration and dementia.

Blood System

• At around 100 rems the blood's lymphocyte cell count decreases, which makes the body more susceptible to infection. At this time, a person is considered as having mild radiation poisoning. Early symptoms of radiation poisoning mimic the flu and can go untreated unless a blood count is done. Symptoms can last up to 10 years and a person with mild radiation poisoning has an increased risk of long-term leukemia and lymphoma.

Gastrointestinal Tract

• At 200 rems radiation can damage the intestinal tract lining. This will cause nausea, abdominal pain, bloody vomiting and bloody diarrhea. The radiation can also destroy the cells in the body that divide rapidly. Cells divide rapidly in the gastrointestinal tract, reproductive cells and hair cells. Radiation exposure also destroys DNA and RNA. Other chronic damage such as scarring and obstructions in the small intestine may not appear until months or years after the exposure. Radiation exposure can also cause the formation of small abnormal blood vessels in the colon and rectum that can bleed easily.

Conclusion

• Though radiation is a normal and naturally occurring substance on earth, it is important to avoid severe or prolonged exposure to it. Radiation, even in small amounts, can cause serious sickness and conditions. Radiation can be beneficial when used in radiation therapy, but its side effects are still devastating and may be chronic. Exposure to natural radiation on a daily basis does not cause serious damage and is safe. However, extreme amounts of exposure to high doses of radiation can be painful and lethal.