Radon is a radioactive gas formed from the natural decay of uranium, which is found in varying amounts in soil, bedrock, stone, and water sources. As a gas, radon circulates through small cracks and gaps in the foundation and floors of buildings or exposed soil in crawl spaces. If left untreated, indoor radon levels can concentrate to dangerous levels.
Prolonged radon exposure leads to lung cancer in non-smokers and smokers alike. However, to best protect your employees and customers from the threat of radon, it’s important to understand the sources from which radon is derived.
Cracks and Gaps in Foundations and Floors
Any cracks or gaps in concrete slab floors or basement and crawlspace foundations provide direct access for radon gas to rise indoors from the soil. Radon can even penetrate solid concrete over time. Expansion joints, cracks from settling, construction joints, and openings around pipes, wires, floor drains, and sumps are common entry points. Faulty foundation seals also increase infiltration. Floor drains, holes, and perforations enable radon to migrate up from underlying soil and bedrock.
Radon in Well Water
Sites utilizing well water drawn from underground aquifers can introduce radon through the water itself. As water travels through radon-rich soil and rock formations, the gas gets absorbed and dissolved. Once pumped up and brought indoors, dissolved radon gets aerated out of water from agitation and heating. As released, water-borne radon enters air. It then spreads to other areas through ventilation systems, pipes, and drains. Bathrooms and kitchen areas often have higher exposures.
Southwestern Geology Drives Radon Concerns
The varied geology and soil profiles of the Southwest contain natural deposits of elements that decay into radon gas, such as uranium and thorium. Granite formations, phosphate deposits, volcanic rock, and cracking clay soil all harbor these radioactive signatures to some degree. Consequently, the EPA classifies most of New Mexico and West Texas as Zone 1 areas with the highest predicted indoor radon levels. Due to their size and often complex design, larger commercial buildings in these high-risk zones could contain astronomically high levels of indoor radon without testing or mitigation.
Porosity in Caliche Soil – Caliche, also called hardpan, refers to the cemented deposits of calcium carbonate that form substantial soil layers commonly found in the Southwest. Typically found during new construction, this hardened subsurface has considerable porosity despite its cement-like stiffness. Unfortunately, those pores and voids provide ideal channels for soil-based radon to rise up and seep through foundations if not properly excavated. Any commercial property lacking vapor barriers or proper seals along caliche soil invite radon intrusion.
Networks of Subterranean Limestone Caverns – The unique karst landscapes marking areas of the Southwest such as the Guadalupe Mountains in New Mexico also play a role in geologic radon release. Subsurface limestone formations get etched over time by mildly acidic groundwater, carving out extensive caverns, sinkholes, and underground streams. With abundant pores, cracks, and tunnels through the soluble bedrock, radon travels through these hidden channels before entering buildings built atop karst surfaces. This is especially problematic in larger sprawling facilities such as schools and hospitals.
Uranium Mining Residuals – While no active uranium mines currently operate in the Southwest, the legacy of past uranium mining and processing activities in New Mexico has left a mark regarding radon concerns. With over 1,100 abandoned uranium mine sites across the state, unearthed raw uranium ore continues emitting radon gas as a byproduct of its radioactivity. Although mines closed decades ago, uncontrolled mining waste with uranium content lingers along with associated radon production.
Commercial Radon Testing & Mitigation
Workplace radon safety requires proactive testing and mitigation. With heightened risks to worker health, the EPA recommends all commercial property owners routinely have their facilities tested for radon at least once every two years. If elevated levels exist, Southwest Radon Eliminators can install effective radon mitigation systems. On top of that, we can also help property owners and onsite maintenance techs develop an effective Operation, Maintenance, and Monitoring Plan for your commercial facility!