protection of buildings from radon gas with a polyethylene membrane barrier and ventilated crawl space

radon test gas mitigation architectural feature detail details domestic life home interior residential building house indoors danger permeable polythene construction barrier membrane safe safety block mesothelioma air pollution quality indoor protection polyethylene industry insulation pipe tube duct crawl space pipeline radioactive contamination aspirations depressurization permeability pressure activity natural ventilation dangerous radium cracked cross section radiation