Dallas sits in EPA Zone 1, the highest risk classification for radon exposure in Pennsylvania. The Back Mountain's geological foundation consists of Devonian and Silurian bedrock formations deposited over 400 million years ago during ancient sea and tectonic activity. These ancient rock layers contain naturally occurring uranium deposits that continuously decay through a radioactive chain, ultimately producing radon gas that migrates upward through soil and bedrock fractures.
While Dallas's elevated terrain and mountainous setting might suggest protection from radon accumulation, the reality is more complex. The Back Mountain's bedrock fracture networks created by millions of years of geological stress actually facilitate radon transport from deep uranium-bearing formations directly to the surface. Natural joints, faults, and weathering patterns in the Devonian shale and sandstone create preferential pathways that concentrate radon in unexpected areas.
Seasonal variations significantly impact radon levels in Dallas homes. Winter's frozen ground and heating-induced negative pressure can increase indoor concentrations, while summer's warmer soil temperatures may reduce entry rates but not eliminate risk. The area's varied construction - from older stone foundations to modern basements - responds differently to these geological and seasonal factors, making professional location, or perceived drainage conditions.
Professional with average readings of 5.2 pCi/L - demonstrating that elevation provides no immunity from this invisible threat.