Description of Radiation Hazard Scale Categories
Category 5 means that radiation doses are dangerously high and
High doses of radiation
can cause massive damage to organs of the body and kill the person. The exposed
person loses white blood cells and the ability to fight infections. Diarrhea
and vomiting are likely. Medical treatment can help, but the condition may
still be fatal in spite of treatment. At extremely high doses of radiation, the
person may lose consciousness and die within hours.
Category 4 means that radiation doses are dangerously high and can
make people seriously ill. Radiation doses are not high enough to cause death,
but one or more symptoms of radiation sickness may appear.
Radiation sickness, also known
as Acute Radiation Syndrome (ARS), is caused by a high dose of radiation. The
severity of illness depends on the amount (or dose) of radiation. The earliest
symptoms may include nausea, fatigue, vomiting, and diarrhea. Symptoms such as
hair loss or skin burns may appear in weeks.
Category 3 means that radiation doses are becoming high enough
where we may expect increased risk of cancer in the years ahead for people who
Leukemia and thyroid cancers can appear in as few as 5 years after
exposure. Other types of cancer can take decades to develop. Studies have shown
that radiation exposure can increase the risk of people developing cancer. This
increased risk of cancer is typically a fraction of one percent. The lifetime
risk of cancer for the population due to natural causes is approximately 40%.
The increase in risk of cancer from radiation depends on the amount (or dose)
of radiation, and it becomes vanishingly small and near zero at low doses of
Category 2 means that radiation levels in the environment are
higher than the natural background radiation for that geographic area. However,
these radiation levels are still too low to observe any health effects.
When radiation levels are
higher than what we normally have in our natural environment, it does not
necessarily mean that it will cause us harm.
Category 1 means that radiation levels in the environment are
within the range of natural background radiation for that geographic area.
Low amounts of radioactive
materials exist naturally in our environment, food, air, water, and
consequently in our bodies. We are also exposed to radiation from space that
reaches the surface of the Earth.These conditions are natural, and this
radiation is called the natural background radiation.