radon_gas RADON GAS TEST (by David Lawyer, 1993) Radon gas is thought to be the major cause of lung cancer in the US for non-smokers. The ground is constantly emitting radon and thus radon is found everywhere. I recently (Sept. 1993) tested the sanctuary for radon gas. The radon level was found to be 0.6 pico-Curries/liter. This is a few times higher than the level found in outside "fresh" air but somewhat better (lower) than what is found in a typical house in the US. The danger level set by the EPA (and many think this level was set too high) is 4.0 pico-Curries/liter implying our 0.6 is at a safe level. Since I measured the level with the doors closed most of the time, opening the doors for ventilation well before the service would reduce radon. But it's not even clear that this is worth the effort as I estimated that the risk of being killed in an automobile accident on the way to church is typically many-many times greater than the risk of being killed by the radon gas in the sanctuary. In any case, it is planned to install door stops on the doors so that we will have the option of open doors. The air would also smell fresher but street noise would be louder. (Radon gas has no odor but we get other smells from the crawl space.) The design of the ventilation system makes our church a radon trap since the vents in the floors in the sanctuary go directly to the dirt crawl space underneath the building. I expected to find a much higher radon level. Luckily, the soil conditions here are such that the amount radon gas coming out of the ground must be well below average. Turning on the ventilation system recycles air using the crawl space as a return duct. Even if one opens the outside air intake vents in the basement, a substantial portion of the air is still recycled. (You can't get 100% fresh air from the vents.) 100% fresh air is possible by installing a huge damper in the basement to shut off the crawl space return duct during the warmer seasons. In view of the many other repairs needed and the low radon level, it's a low-priority item.