If you stacked all the pavement in Phoenix into one spot, it could cover San Francisco four times. That’s a lot of asphalt! In fact, paved surfaces take up about 40% of the city. This setup has a serious downside: it traps heat during the day and releases it at night, creating what’s known as the urban heat island effect. As a result, cities burn more energy.
Elham Fini, a senior scientist at Arizona State University, points out that we need to pay attention to how pavement affects our health, not just its carbon footprint. “For sustainability,” she says, “we can’t overlook human health.”
The Health Risks of Asphalt
Fini has spent years studying why asphalt degrades quickly. Her research has revealed that asphalt releases volatile organic compounds (VOCs). These chemicals give asphalt its distinctive smell and can worsen air quality. Two studies show that VOCs change at night, creating tiny particles that can damage the lungs and lead to dizziness or breathing issues, especially on hot days.
Long-term exposure to these fumes is linked to serious health risks, including lung cancer—particularly a concern for construction workers who lack proper protection.
Aging Pavement: An Increased Threat
Research shows that as pavement gets older, it can release more harmful VOCs. These chemicals are small enough to enter the bloodstream and can cause neurological damage, mainly affecting vulnerable groups like women and the elderly. Fini warns that rising temperatures exacerbate these emissions.
A Move Toward Safer Solutions
Fini is collaborating with Dr. Bruce Johnson from the Mayo Clinic to explore how these emissions affect health. Their goal is to develop safer asphalt formulations to protect construction workers and nearby communities.
One promising idea involves using algae grown with treated wastewater. Fini and scientist Peter Lammers are experimenting with this algae as a binder mixed into asphalt. Preliminary studies show that it can significantly reduce the most toxic VOCs released, making asphalt both safer and longer-lasting.
A study published in Clean Technologies and Environmental Policy noted that algae-infused asphalt could cut toxicity levels by about 100 times, offering a game-changing solution for road construction.
The Bigger Picture
In the U.S., there are around 4 million miles of roads. Fini believes they should do more than just connect places. New approaches in asphalt could enhance road durability, lessen health risks, and even reduce maintenance costs.
As cities like Phoenix continue to grow, addressing the health impacts of pavement should be a priority. For more research on this topic, check out studies published in the Journal of Hazardous Materials and Science of the Total Environment.
