The health toll of

fossil fuels

Nitrogen oxide (NOx) pollution from coal power plants contributed to the brown, hazy skies that once blanketed the Four Corners region.

NOx irritates the lungs and worsens asthma on its own — and in sunlight and heat, it reacts with VOCs (volatile organic compounds, carbon-based chemicals that evaporate easily from sources like fuel and exhaust) to form ground-level ozone smog, layering smog on top of the visible haze. That’s why ozone peaks during the hot summer months, when the reaction is strongest.

In San Juan County, oil and gas operations and coal-fired power plants are the main sources of both pollutants. At the height of regional fossil fuel activity, the two sectors released an estimated 40,200 tons of NOx and 65,100 tons of VOCs in 2017 — with oil and gas responsible for the majority of both, and coal contributing a significant share of the NOx total.

What Coal Leaves Behind

Coal combustion adds another threat: fine particulate matter small enough to lodge deep in the lungs and even enter the bloodstream. Long-term exposure to these particulates is linked to reduced lung function, heart disease, and premature death.

And the pollution difference isn’t small. Per megawatt-hour of electricity produced, coal emits roughly 2,257 pounds of CO2 — more than double natural gas’s 976 pounds, and worlds apart from solar’s essentially zero.

Who is Affected?

Youth

Children are especially vulnerable to air pollution: their lungs are still developing, they breathe more air relative to their body size, and active kids spend more time outdoors — especially in summer, when ozone peaks. Early exposure to coal and gas pollution is linked to slower lung development and higher lifetime asthma risk.

Miners

The toll didn’t start at the smokestack, either. Long before coal reached the power plant, it took a toll on the miners who extracted it and the communities living downwind of the mine — long-term coal dust exposure is linked to black lung disease and other chronic respiratory conditions.

Indigenous Communities

Indigenous communities have carried a disproportionate share of this burden. Navajo Nation lands sit closest to the wells, mines, and power plants driving the region’s pollution, and residents have long raised concerns about the health effects of living alongside decades of extraction.

Our skies have improved! Use the slider tool to compare:

Nitrogen oxide (NOx) pollution from coal power plants contributes to the brown, hazy skies that once blanketed the Four Corners region. It matters because NOx irritates the lungs, worsens asthma and other respiratory conditions, and reacts in sunlight to form ground-level ozone smog — on top of the visible haze. In 2011, monitors near the region’s coal-fired power plants (Four Corners Power Plant and San Juan Generating Station) recorded NOx concentrations at over twenty parts per billion (ppb). By 2026, ambient NO2 readings in Farmington have dropped to under 1 ppb, thanks to the retirement and partial shutdown of nearby coal units. You can literally see the difference and breathe easier!

Did You Know?

  • A recent study shows that a staggering 460,000 U.S. deaths between 1999 – 2020 are attributable to air pollution from coal plants alone. 
  • Impacts are widely distributed – on average, just two percent of deaths from coal-fired power plant emissions occur in the county where the plant is located, and just under a quarter of deaths even occur in the same state.

Learn More

San Juan Citizens Alliance created this website as an educational hub — a place to understand the region’s shift away from coal and gas, grounded in real data on jobs, health, water, and climate. We track this the Four Corners Clean Energy Transition closely and work to make sure it happens fairly, transparently, and in the community’s interest. Our goal is simple: the more people understand what this transition means for their community, the stronger public support and engagement will be in making it just and equitable for everyone who calls the Four Corners home.

Thank you to EcoFlight and Benjamin Hunter for their aerial images, and to Creative Geckos for other photos and design.

To learn more about the Four Corners Clean Energy Transition, what San Juan Citizens is doing, and how you can get more involved, contact us at info@sanjuancitizens.org.