Radon education

Why Radon Is Common in New Mexico Homes

New Mexico sits on some of the most uranium-rich geology in the country. Combine that with dry, permeable soils and it becomes clear why testing matters here more than in most states.

The source: uranium in the rock

Radon is a decay product of uranium. New Mexico has a long, well-documented history of uranium-bearing geology — the Grants Mineral Belt in the northwest was one of the largest uranium-producing districts in the United States. Uranium is also present at lower but meaningful concentrations across much of the state's volcanic rock, granites, and sedimentary formations, including the basin fill of the Rio Grande rift that Albuquerque sits in.

You do not need a mine underneath you. Ordinary background concentrations of uranium in soil generate radon continuously, everywhere.

The pathway: dry, permeable soil

Radon has a half-life of about 3.8 days. Whether it reaches your house depends on how quickly it can travel through soil before decaying. Wet, dense clay slows it. The dry, sandy, gravelly soils common across the Albuquerque metro and the Rio Grande valley do the opposite — they are highly permeable, and soil gas moves through them easily.

  • Dry soil means open pore space and fast gas movement.
  • Fractured bedrock and volcanic formations create direct channels.
  • Backfill around a foundation is typically looser than surrounding soil, forming a preferential path straight to your slab.

The driver: your house is a chimney

Warm indoor air rises and escapes through the upper part of a building, which slightly depressurizes the lower part. That pressure difference — the stack effect — actively pulls soil gas through every crack and penetration in the foundation. New Mexico's large day-night temperature swings and cold winter nights make this effect strong. Running exhaust fans, a clothes dryer, or a fireplace increases it further.

Local building patterns that matter

FeatureEffect on radon
Slab-on-grade constructionNo buffer level; soil gas enters living space directly
Post-tension slabsCracking still occurs; changes where suction points can be cut
Caliche and compacted subgradePoor sub-slab communication; more suction points needed
Evaporative (swamp) coolersPressurize the home seasonally, masking real annual levels
Newer tight envelopesLess natural dilution of whatever enters

What this means for you

Radon varies house to house, so no county map or ZIP-level average tells you your number. It tells you the odds are worth taking seriously. In this region, the practical takeaway is simple: test the house, test it under closed-house conditions, and retest every couple of years.

EPA radon action levels

Scale shown in picocuries per liter (pCi/L).

0.4 outdoor avg1.3 US indoor avg2.0 consider action4.0 EPA action level10+

Green is at or below the typical US indoor average. Amber is the range where the EPA suggests considering mitigation. Red is at or above the 4.0 pCi/L action level, where the EPA recommends fixing the home.

Not sure where to start? Call and ask.

We will walk you through testing, what your result means, and what a system for your home would involve — no pressure either way.