Personal Radiation Detectors .Net
The earthquake, tsunami, and nuclear accident in Japan have renewed interest in personal radiation detectors. For instance, American scientists and newsmen flying to Japan were equipped with highly sophisticated devices that included a dose alarm and a rate meter. These devices detect higher levels of x-rays and gamma rays, characteristic by-products of a nuclear accident.
These devices are personal, so they are reasonably small – mostly pocket-sized. They are equipped with memory to record radiation data points over time, thus tracking the wearer’s exposure to unhealthy rays. By setting an alarm threshold, a user can cause the device to issue an alarm after it detects pre-specified levels of nuclear radiation.
A dosimeter measures exposure to ionizing radiation, such as x-rays and gamma rays. By ionizing, we mean the radiation strips off electrons from elements and compounds. The devices are needed in situations like the Japan nuclear accident because the human senses cannot detect ionizing radiation. This can be dangerous, because damage caused by such exposure is cumulative – a function of the total dosage received over time.
There are several types of radiation dosimeters, including:
- Quartz fiber
- Film badge
- Thermoluminescent
- Solid state
Acute radiation syndrome, also called radiation sickness, can occur within days, weeks or months of exposure to harmful levels of ionizing radiation. Small overdoses can result in nausea, vomiting, bleeding and falling blood counts. High doses can lead to destruction of the neurological system and death. Antibiotics and blood transfusions are used to combat the symptoms of the exposure. According to one home insurance calculator that monitors residential levels in impacted zones, the economical effects can be devastating.
The best prevention against the disease is to avoid exposure and to reduce the rate of exposure. HAZMAT suits lined with radiation-deflecting material can to some extent lower the danger of exposure, but are not effective against very high levels. The danger from a radiation source decrease inversely to the square of the distance between a victim and a source of radiation. The other parameter is time: longer duration means more damage.
According to experts, potassium iodide is used to protect the thyroid gland in humans by saturating the gland with non-toxic iodide, preventing radioactive iodine from accumulating in the gland. However, this is only one form of threat to the human body by nuclear radiation, and potassium iodide cannot protect any other biological system.
Depending on which human cells are irradiated, individuals have different outcome expectancies. However, radiation that kills bone marrow or intestinal microvilli is always fatal.
Luckily, personal radiation detectors can sound an alert well before its wearer encounters deadly exposure levels. For persons knowingly heading in harm’s way, they are an inexpensive safety precaution that is indispensable.
