RADIATION: BAD OR GOOD?

Radiation is a process in which energetic particles or energetic waves travel through a medium or space. To help you more understand about radiation, here are the things that produce radiation. The lights on your cellphone, computers, laptop, photocopy machines, cameras (especially the flash), x-ray machine and other same things produce radiation.Sun rays are radiation. Radiation creates a big effect on every living creature, mostly on humans.

The negative side

Radiation is measured by the unit rem, which stands for “roentgen equivalent in man”. Up to 100 rems have no immediate harmful effects. Radiation exposure of over 100 rems causes the first sign of radiation sickness. Doses over 300 rems can cause internal harm and hair loss. Radiation of over 450 rems will kill more than half of those exposed; doses of more than 800 rems are always fatal.

Radiation of 200 rems or more causes a combination of nausea, bloody vomiting, and diarrhea. Radiation destroys rapidly dividing cells in the body, killing cells of the gastrointestinal tract, and harming the DNA and RNA of remaining cells.

Inflammation of the sac around the heart, respiratory failure, and vision impairment are all possible symptoms of radiation exposure. Radiation over 300 rems damages nerve cells and the cells that line the digestive tract. Hemorrhaging also occurs as radiation reduces the production of blood platelets. White blood cells are dramatically lost, causing those affected by radiation to become extremely vulnerable to disease. Radiation also destroys reproductive-tract cells, causing victims to become sterile at exposure to just 200 rems.

There are two types of radiation, Ionizing and non-ionizing radiation. Ionizing radiation is a proven human carcinogen (cancer causing agent). The evidence for this comes from many different sources, including studies of atomic bomb survivors in Japan, people exposed during the Chernobyl nuclear accident, people treated with high doses of radiation for cancer and other conditions, and people exposed to high levels of radiation at work, such as uranium miners.

Most studies on radiation and cancer risk have looked at people exposed to very high doses of radiation in the settings above. It is harder to measure the much smaller increase in cancer risk that might come from much lower levels of radiation exposure. Most studies have not been able to detect an increased risk of cancer among people exposed to low levels of radiation. For example, people living at high altitudes, who are exposed to more natural background radiation from cosmic rays than people living at sea level, do not have noticeably higher cancer rates.

Still, most scientists and regulatory agencies agree that even small doses of ionizing radiation increase cancer risk, although by a very small amount. In general, the risk of cancer from radiation exposure increases as the dose of radiation increases. Likewise, the lower the exposure is, the smaller the increase in risk. But there is no threshold below which ionizing radiation is thought to be totally safe.

Although radiation exposure affects the occurrence of various types of cancer, it does not affect their aggressiveness (tendency to grow and spread).

The positive side

Radiation therapy uses high-energy radiation to shrink tumors and kill cancer cells (1). X-rays, gamma rays, and charged particles are types of radiation used for cancer treatment.The radiation may be delivered by a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy, also called brachytherapy).Systemic radiation therapy uses radioactive substances, such as radioactive iodine, that travel in the blood to kill cancer cells.About half of all cancer patients receive some type of radiation therapy sometime during the course of their treatment.

Radiation therapy kills cancer cells by damaging their DNA (the molecules inside cells that carry genetic information and pass it from one generation to the next) (1). Radiation therapy can either damage DNA directly or create charged particles (free radicals) within the cells that can in turn damage the DNA.Cancer cells whose DNA is damaged beyond repair stop dividing or die. When the damaged cells die, they are broken down and eliminated by the body’s natural processes.

Doctors and other scientists are conducting research studies called clinical trials to learn how to use radiation therapy to treat cancer more safely and effectively. Clinical trials allow researchers to examine the effectiveness of new treatments in comparison with standard ones, as well as to compare the side effects of the treatments.

Researchers are working on improving image-guided radiation so that it provides real-time imaging of the tumor target during treatment. Real-time imaging could help compensate for normal movement of the internal organs from breathing and for changes in tumor size during treatment. Researchers are also studying radiosensitizers and radioprotectors, chemicals that modify a cell's response to radiation.

Radiosensitizers are drugs that make cancer cells more sensitive to the effects of radiation therapy. Several agents are under study as radiosensitizers. In addition, some anticancer drugs, such as 5-fluorouracil and cisplatin, make cancer cells more sensitive to radiation therapy. 

Radioprotectors (also called radioprotectants) are drugs that protect normal cells from damage caused by radiation therapy. These drugs promote the repair of normal cells exposed to radiation. Many agents are currently being studied as potential radioprotectors. The use of carbon ion beams in radiation therapy is being investigated by researchers, but, at this time, the use of these beams remains experimental. Carbon ion beams are available at only a few medical centers around the world. They are not currently available in the United States. Researchers hope that carbon ion beams may be effective in treating some tumors that are resistant to traditional radiation therapy.