the danger of radon gas in our homes - how to create a crawl space to evacuate the radon gas

radon test danger safety architecture construction illustration project drawing gas lung cancer illness concepts concept industry building activity inhaling radioactive contamination cracked residential home house testing mesothelioma soil ventilated cracks ventilation air pollution vent pipe duct natural floor flooring intake risk cross section radiation protection crawl space radonstop bedrock groundwater breathing our homes create evacuate