Radon is a naturally occurring, colorless, odorless and tasteless gas that is produced below the earths surface. Radon gas is always coming up through the ground and outside air is generally about 0.4 pCi/L. The concern is when radon gas accumulates inside the home. High radon levels (above 4.0 pCi/L) have been found in all 50 states and the EPA has a map that shows the highest risk areas and the lowest risk areas. Much of Kansas (including Johnson, Wyandotte, Douglas and Leavenworth counties) are rated Zone 1 on the map. Zone 1 is the EPA's highest radon potential areas and have a predicted average indoor radon screening level greater than 4.0 pCi/l. This map should not be used to determine if you should test your home. The only way to know if you have high radon is to test your home. For more information about radon, please visit the EPA website.