Question

1. Describe the health effects of "Radon Gas" and the mitigation strategies used to prevent exposure in homes and workplaces. (remember the exposure limits, geographical distribution in the US, measurement/detection, routes of exposure and mechanism of the health effects).
2. What are the health effects of radiation on an unborn baby? (Don't forget the effects at different stages of pregnancy)
3. What is the role of Potassium Iodide in "Radiation Emergencies/ Accidents"?

Answer 1

1) Radon is a gas that you cannot smell, taste or see. Radon forms naturally when uranium, thorium, or radium, (radioactive metals) breaks down in rocks, soil and groundwater. People can be exposed to radon primarily from breathing radon in air that comes through cracks and gaps in buildings and homes. Because radon comes naturally from the earth, people are always exposed to it.When you breathe in radon, radioactive particles from radon gas can get trapped in your lungs. Over time, these radioactive particles increase the risk of lung cancer. It may take years before health problems appear. Radon is the second leading cause of lung cancer after cigarette smoking.mainly side effects of radon gas exposure are

• persistent cough.
• coughing up blood.
• wheezing.
• shortness of breath.
• hoarseness.
• chest pain, especially when you cough or laugh.
• frequent infections such as bronchitis and pneumonia

the US EPA has set an action level of 4 pCi/L. At or above this level of radon, the EPA recommends take corrective measures to reduce exposure to radon gas. This does not imply that a level below 4.0 pCi/L is considered acceptable, as stated in the BEIR VI study .

2) Depending on the stage of fetal development, the health consequences of exposure at doses greater than 0.5 Gy can be severe, even if such a dose is too low to cause an immediate effect for the mother. The health consequences can include growth restriction, malformations, impaired brain function, and cancer

During the first 2 weeks of pregnancy, the radiation-related health effect of greatest concern is the death of the baby. The fetus is made up of only a few cells during the first 2 weeks of pregnancy. Damage to one cell can cause the death of the embryo before the mother even knows that she is pregnant. if the baby survive,means also will have birth defects related to the exposure.

Large radiation doses to the fetus during the more sensitive stages of development (between weeks 2 and 18 of pregnancy) can cause birth defects, especially to the brain. When a fetus is exposed to large doses of radiation the health consequences can be severe, especially to the brain.

Between the 18th week of pregnancy and birth, radiation-induced health effects (besides cancer) are unlikely unless the fetus receives an extremely large dose of radiation. In the 18- to 25-week stage of pregnancy,health consequences similar to those seen in the 8- to 17-week stage could occur, but only when the doses are extremely large.

After the 26th week of pregnancy, the radiation sensitivity of the fetus is similar to that of a newborn. At the 26th week of pregnancy, the fetus is fully developed though not fully grown. Unborn babies exposed to radiation in the womb during this stage of pregnancy are no more sensitive to the effects of radiation than are newborns.

3) KI (potassium iodide) is a salt of stable (not radioactive) iodine that can help block radioactive iodine from being absorbed by the thyroid gland, thus protecting this gland from radiation injury.

The thyroid gland cannot tell the difference between stable and radioactive iodine and will absorb both. KI works by blocking radioactive iodine from entering the thyroid. When a person takes KI, the stable iodine in the medicine gets absorbed by the thyroid. Because KI contains so much stable iodine, the thyroid gland becomes “full” and cannot absorb any more iodine either stable or radioactive for the next 24 hours.

KI cannot do

• KI cannot prevent radioactive iodine from entering the body.
• KI can protect only the thyroid from radioactive iodine, not other parts of the body.
• KI cannot reverse the health effects caused by radioactive iodine once damage to the thyroid has occurred.
• KI cannot protect the body from radioactive elements other than radioactive iodine.