Radionuclides
Alpha emitters.



Certain minerals are radioactive and may emit a form of radiation known as alpha radiation. Some people who drink
water containing alpha emitters in excess of  EPA's standard over many years may have an increased risk of
getting cancer.

Beta/photon emitters. Certain minerals are radioactive and may emit forms of radiation known as photons and beta
radiation. Some people who drink water containing beta and photon emitters in excess of EPA's standard over
many years may have an increased risk of getting cancer.

Combined Radium 226/228. Some people who drink water containing radium 226 or 228 in excess of EPA's
standard over many years may have an increased risk of getting cancer.

Radon gas can dissolve and accumulate in underground water sources, such as wells, and in the air in your home.
Breathing radon can cause lung cancer. Drinking water containing radon presents a risk of developing cancer.
Radon in air is more dangerous than radon in water.

http://www.epa.gov/safewater/hfacts.html#Volatile