Rock quarries create invisible dust particles proven to cause silicosis—a progressive, incurable lung disease. Long-term exposure to particulate matter is strongly associated with heart disease, stroke, infertility, and pregnancy complications.


Proven Health Hazard

Dust created by gravel quarries is considered respirable crystalline silica, a type of particulate matter. Studies have established a strong link between these particles and the following health effects:

  • Silicosis
  • Pulmonary disease1
  • Reduction in lung function
  • Leukemia
  • Atherosclerosis and heart disease2
  • Dysrhythmia
  • Heart failure and cardiac arrest
  • Stroke and cognitive disorders3
  • Fertility problems
  • Miscarriage
  • Premature birth
  • Low birth weight4

Over 12,000 residents within five miles of the proposed quarry will be affected by cascading injurious events resulting from particulate matter carried by prevailing winds. Young children, the elderly, and those with respiratory illnesses such as COPD, emphysema, asthma, and progressive lung disease will be most impacted.

The San Antonio-New Braunfels metro area has pediatric asthma rates of 1 in 7 (nearly twice the national average) and Comal ISD already has over 2000 students with an asthma health alert on file. Particles produced by rock-crushing operations will increase air pollution and exacerbate this health risk for Comal ISD students.

Elderly woman struggling to breathe, lung disease
Particulate matter diagram showing sizes of PM2.5 and PM10 particle pollution released by limestone quarries similar to the proposed Vulcan Comal quarry

Invisible Toxins

You can’t even see it—but you’re certainly breathing it. Respirable crystalline silica is categorized and monitored as PM 2.5 (fine particulate matter 2.5 micrometers or smaller—less than 1/20 the width of a human hair) and PM 10 (10 micrometers or smaller). Both sizes are inhaled and can go directly to lungs and bloodstream.

Quarry blasting, crushing, and hauling operations emit high levels of carcinogenic particulate matter. Visible dust (larger particles) is also created by movement of front-end loaders, mining trucks, transfer conveyors, excavators, bulldozers, and utility vehicles.

Over 80 formal complaints have been filed against Vulcan in Texas alone. And over 35 violations occurred at a single Vulcan Materials plant (Loop 1604 in San Antonio).

Violations at Vulcan Plant in San Antonio

Krystal Henagan lived near the Vulcan Materials plant in San Antonio. Henagan traces ongoing family illnesses to air pollution and extensive permit violations by Vulcan Materials. (Fox San Antonio TV)

With Vulcan’s samples they found silica and manganese inside my home, and that’s unlike a typical household profile. Outside they found fly ash, which is very toxic. There are permit violations dating back all the way to 1991.

Noxious Gas & Air Pollution

Daily emissions of diesel exhaust from plant equipment and hundreds of gravel trucks generate nitrogen oxide, sulfur dioxide, carbon monoxide, and volatile organic compounds (VOCs).

Additionally, when these pollutants combine with sunlight, they create ozone. The San Antonio region’s air quality continues to worsen with higher and higher ozone levels exceeding the nation’s health-based standards. With these ozone violations predicted to mark us with a “non-attainment” status, by August 2018 we should expect the EPA to issue their ozone designation decision for eight counties in the San Antonio-New Braunfels Area.

The proposed quarry and the additional truck traffic would significantly impact regional air quality, even beyond a five-mile radius of the quarry site.

Dust created by blasting in rock quarry similar to planned Vulcan Materials quarry in Comal County
Exhaust from truck hauling gravel. Affected roadways in Comal County include SH 46, FM 3009, FM 1863, Beck Road, US 281, FM 311, FM 3159, and Loop 337.