The uncontrolled growth of cells in any part of the body is cancer. It is a group of disease. Cancer kills millions of people every year in our world. Few can be curable if diagnosed in the early stages. We can do a lot to minimize the risk of cancer. The hereditary risk factor is only about 5% to 10%. The rest comes from our lifestyle, diet and environment. We see here the many ways to reduce the cancer risks.
Apart from the ultraviolet rays from the sun there are many other radiations that can affect our health and can cause cancers. Here we have to differentiate between ionizing and non-ionizing radiations.

Ionizing radiation is high-frequency radiation. It has energy to remove an electron from an atom or molecule. Thus it can damage the DNA and this may lead to cancer. The ionizing radiations include:

• X-rays
• Gamma rays
• High energy ultraviolet rays
• Protons
• Alpha particles

Non-ionizing radiation is low-frequency radiation. It cannot damage DNA as the energy is not enough to remove electrons.

The non-ionizing radiations include:

• Low energy ultraviolet rays
• Infrared rays
• Visible light
• Radio waves
• Microwaves

Low energy ultraviolet radiation is a known risk factor for cancers. In other cases the cumulative effect must also be considered. Lot of neutral research is still needed in these fields.

Radiations from atomic bombs or atomic power plants are ionizing radiations and therefore sure risk for cancers. Workplace ionizing radiation is also risky. It is know that even small doses of ionizing radiation can increase cancer risk. The cancers caused by ionizing radiation include:

• Leukemia
• Thyroid cancer
• Lung cancer
• Skin cancer
• Breast cancer
• Stomach cancer
• Multiple myeloma

Leukemia can occur few years after radiation exposure and the other cancers can result after 10 to 15 years. Moreover, the radiation exposure to a particular part of the body or organ can cause cancer there.

Children are more sensitive and vulnerable than adults as they are growing.

The sources of ionizing radiation include:

• Natural radiation – cosmic rays, radiation in the earth and radon
• Radiation from medicine – CT scans, x-rays, radiation therapy, nuclear medicine tests. Radiation therapy doses are thousands of times higher than the x-rays
• Man-made radiation – Uranium mining, workplace radiations, from the already conducted atomic tests, accidents in the atomic power plants and the atomic waste depots

Tobacco products contain low levels of ionizing radiation. Smoke detectors and some building materials can also have low levels of ionizing radiation.

The whole body scanner in the airport uses very weak x-rays.

The non-ionizing radiation types include:

• Few ultraviolet rays
• Visible light
• Infrared rays
• Radio waves
• Microwaves
• Electromagnetic fields

Cell phones, heaters and all electrical devices emit non-ionizing radiation. Very little is known about the non-ionizing radiation and cancer risk. The non-ionizing radiation cannot damage DNA, but may affect the cells in other ways. Lot of long-term research is needed.

Cell phones and cell phone towers are not good to children below 12 years old. There are many studies to prove this. More long-term research is needed for adults.

Electromagnetic fields from the power lines and electrical devises may be the reason for increased leukemia and brain tumor in children. More studies are required for adults.

Television and computer screens produce many radiations. Here also more long-term research is needed.

Very high levels of microwaves are used to heat foods through microwave ovens. As long as it is used according to instruction there is no problem. High levels of microwaves can lead burns and it is dangerous to eyes too.

More research can only bring more light in this difficult field. It is better to avoid radiations if it is possible. It is always important to understand the difference between ionizing and non-ionizing radiation.