Study: Pavement covers 40% of Phoenix

New research from the Arizona State University reveals that 40% of the city of Phoenix is covered in pavement. According to an article by Joanna Allhands for ASU News, this is enough to cover the entire city of San Francisco four times over.

Researcher Elham Fini decided to assess an overlooked impact of asphalt: "volatile organic compounds that escape from bitumen, the black, sticky petroleum byproduct that holds asphalt together." As these compounds escape from pavement during warm days, they form ultrafine particles that worsen air quality and can cause dizziness and long-term damage to human lungs. "Tests and a modeling analysis also suggest that they can cause significant neurological damage in humans, particularly among women and the elderly."

Fini hopes research like hers will lead to better protections for workers and communities exposed to asphalt on a daily basis. "She has teamed up with Peter Lammers, chief scientist at the Arizona Center for Algae Technology and Innovation, to begin growing a strain of algae that could reduce VOC emissions using wastewater from a Phoenix treatment plant." The algae has been shown to reduce the toxicity of asphalt emissions by roughly 100-fold and can slow how quickly asphalt breaks down. 

According to Allhands, "Fini is exploring other binder options, including a product made from the leftover branches of forest-thinning projects, and working with Phoenix to pave a section of road with algae-infused asphalt."