Available in both long-term as well as temporary tracking, the examinations are easy to use as well as require minimal configuration. " The examination is low-cost and reliable-- it doesn't take rocket science," claims Bill Wehrum, an administrator at the EPA's Workplace of Air and Radiation. The EPA suggests doing a 2nd radon test if a preliminary temporary test signs up 4 picoCuries per litre (pCi/L) or greater. If a 2nd examination signs up over 4 pCi/L, consider taking actions to lower radon levels in your home, the EPA warns.