.pld Extension - List of programs that can open .pld files In the following table, you can find a list of programs that can open files with .pld extension.This list is created by collecting extension information reported by users through the 'send report' option of FileTypesMan utility.
According to a national residential radon survey completed in 1991, the average indoor radon level in the United States is 1.3 picocuries per liter (pCi/L). The average outdoor level is about 0.4 pCi/L. Excessive radon levels have been found in all of the 50 states.
To put your school's radon test results in perspective, outdoor air background levels of radon are about 0.4 pCi/L. Getting indoor levels below 2 pCi/L is difficult. The EPA recommends that steps should be taken to lower radon levels if they are 4 pCi/L or above.