how to protect our homes from radon gas with depressurizing wells for buildings without the crawl space - concept

activity aerated air antiradon aspirations barrier barriers building buildings built concept condensation construction contamination cracked crawl crawlspace cross danger dangerous depressurization depressurizing domestic duct exhaust fan flooring foundation gas homes house how illustration industry intake life membrane mitigation natural our paving permeability pipe poisonous pollution pressure protect protection radiation radioactive radium radon risk safe section security shaft soil space structure subsoil suction symbol test tube uranium vapor vent ventilated ventilation ventilator warning water well wells