We Rep STEM aims to promote the work of inspiring people in the STEM community. Today, we’re checking in with Dr. David Gonzalez, an atmospheric chemist (UCLA) and a postdoctoral scholar in cardiology from the David Geffen School of Medicine at UCLA.

Dr. Gonzalez’ research focuses on the health effects of air pollution.

Here are six facts about air pollution, courtesy of Dr. Gonzalez.


1) Air Pollutants can be classified into gasses and airborne particulate matter. While both are of health concern, the health effects of particulate matter inhalation have been especially well documented.

(2) The size of airborne particles directly influences their toxicity. Inhalation of tiny airborne particles that are less that 2.5 micrometers (called PM2.5 or fine particles) pose the greatest health risk of all air pollutants. This is because these particles can penetrate deep into the lungs and potentially transport into the bloodstream.

(3) Airborne particles are not created equally! Particles can be made up of a cocktail of thousands of different chemicals depending on:

-Where the particles came from (ex: wildfire vs. vehicle emissions)

-Weather conditions (sunlight, humidity, clouds).

(4) According to the World Health Organization, indoor and outdoor air pollution is responsible for 7 million deaths per year, globally. This makes air pollution the number one environmental “killer.”

Unfortunately, the disease burden of air pollution disproportionately impacts the poor, marginalized people, children and the elderly. 

(5) Inhalation of unhealthy levels of PM2.5 has been associated with increased death, ER visits, heart disease, lung diseases, metabolic diseases, Alzheimer’s, dementia and even pregnancy risks. However, that vast majority of air pollution deaths and illnesses are due to heart disease.

(6) Although we have strong evidence for air pollution particles and their effect on human health—we still don’t understand WHAT in the particles makes people sick or HOW these particles are making people sick. This is a huge mystery that I, and several other researchers, are trying to figure out!

If this seems confusing, think about this. Humans long knew that poison ivy caused rashes. But just because you know something is “bad” or associated with negative effects doesn’t mean you know WHY your body is reacting that way. 

You can connect with Dr. Gonzalez on Twitter or visit his personal website to learn more about his research.


If you’d like to have your work featured on We Rep STEM, get in touch! We can be reached via email at werepstem@gmail.com.

EDITOR’S NOTE: Minor grammatical edits were made to the original text.

All photos courtesy of David Gonzalez.