Health effects

Much of the data about air quality in our area focuses on particulate matter (PM). That doesn't diminish issues like increased carbon emissions, VOCs and ozone, which contribute to climate change and cause other adverse effects on the environment. We are focusing on PM because the Midlothian cement industry already releases quite a bit of PM, and Holcim's permit request could push emissions closer to the maximum allowable limit.

PM is also a topic of rapidly growing research. Every month, more scientific studies are being released showing health risks associated with PM, even at levels below current EPA standards.

Particulate matter (PM)

What is it?

  • This is basically the "dust" in the air.

  • The smaller it is (i.e., PM 2.5), the more dangerous it is because it can easily enter the bloodstream from your lungs and travel anywhere in your body.

Documented health effects

    • Mental health problems (decreased IQ, dementia, suicide, autism, behavior problems)

    • Heart attacks/cardiovascular disease

    • Asthma, COPD and other breathing difficulties

    • Diabetes

    • Cancer

    • Pregnancy loss, low birth weight, NICU admission, birth defects

    • Early death

Threshold concerns

  • Recent data shows there is no truly safe threshold for PM. The higher the exposure, the higher the risk of all of the above, even when levels are within EPA standards.


"Our multicountry time-series analysis provides evidence on positive associations between short-term exposure to PM10 and PM2.5 and daily all-cause, cardiovascular, and respiratory mortality. This study indicated independent associations of PM10 and PM2.5 concentrations with daily mortality after adjustment for gaseous pollutants. Further, concentration-response curves for the effects of PM on mortality showed a consistent increase, with flattening of the slopes at higher concentrations, and the associations were still detectable at concentrations below the current air-quality guidelines and regulatory limits"

Link to full text of article


A cohort study of more than 4.5 million US Veterans showed that "99.0% of the burden of death due to nonaccidental causes and 99.0% of the burden of death due to non-communicable diseases was associated with PM2.5 levels below standards set by the US Environmental Protection Agency." This amounted to 195,868 deaths due to non-accidental causes and 186,597 deaths due to non-communicable diseases.

Link to full text of article

See the summary below for more details on recent studies

PM Research Summary 7-19 1.5 copy.docx

Summary of Midlothian area air quality: health consultation 2016

"Certain air pollutants may have caused harmful effects in both the past and present."