It's the material chosen by the Charlestown Citizens Alliance (CCA) for a vanity project
By Joanna Allhands, Arizona State University
Edited by Sadie Harley, reviewed
by Robert Egan
 |
| In Charlestown, we have "Faith's Folly," a lasting monument to the Charlestown Citizens Alliance's hypocrisy and cronyism. Despite opposing asphalt use elsewhere in Charlestown, the CCA allowed tons of asphalt to be used on a bike path pushed by CCA founding member Faith LaBossiere. LaBossiere sold the project to the CCA-controlled Town Council claiming it would only cost $7000 (see below). The actual cost turned out to be $266,927 plus interest on the bond leading to a cost over-run of 4,000%. |
If you piled all of Phoenix's pavement into one spot, it would be enough to cover San Francisco four times over. Roads, parking lots, and other paved surfaces blanket a lot of land—an estimated 40% of Arizona's capital city.
 |
| From the Power Point presentation shown the Council by Faith Labossiere. |
But for Elham Fini, a senior scientist affiliated with the
Julie Ann Wrigley Global Futures Laboratory at Arizona State University,
pavement's potential impact on our health deserves as much attention as its
carbon or energy footprint.
"To make something truly sustainable," she said,
"you cannot ignore the human side of it."
Asphalt fumes can be hard on health
Fini—a faculty member in ASU's School of Sustainable
Engineering and the Built Environment—spent years studying why asphalt breaks
down so quickly.
Suliman Rashid, a graduate teaching associate in the School
of Sustainability at Arizona State University, moves samples of an asphalt
binder made from leftover forest-thinning material. Credit: Joanna Allhands
That work pointed her toward the volatile organic compounds
that escape from bitumen, the black, sticky petroleum byproduct that holds
asphalt together.
Two studies in the Journal of Hazardous Materials and Science of the Total Environment shed light on how
the compounds that give asphalt its trademark scent change after sunset and
form ultrafine particles, which can worsen air quality.
These carbon-based vapors are continuously released but
become more noticeable on hot, sunny days. They can cause dizziness and difficulty breathing in the short
term.
Long-term exposure also can elevate the risk
of lung cancer, a major concern for construction workers who regularly
breathe these fumes without a respirator.
Aging pavement emits toxic vapors
And the impacts could get worse as pavement ages. Research
from Fini and others shows that asphalt begins releasing different, more toxic
strains of VOC as bitumen breaks down in sunlight and heat.
These toxic, often odorless VOCs are small enough to work
their way into arteries and organs.
Tests and a modeling analysis also suggest that they can
cause significant
neurological damage in humans, particularly among women and the
elderly.
"Heat is worsening the situation," Fini said.
"It's exacerbating the emissions from asphalt."
More study is needed to understand what level of
asphalt-emitted VOC exposure is unsafe. But what we know so far should raise
alarm bells for hot, car-centric cities such as Phoenix.
Goal: Safer asphalt, healthier workers
Fini is working with Dr. Bruce Johnson via a partnership
with Mayo Clinic to better understand how asphalt emissions impact respiratory
health.
She hopes that their studies will lead to stronger
protections for construction workers and surrounding communities, as well as
less toxic, lower-emitting asphalt formulations.
Fini has a head start on the latter.
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.
"It's a great setup," said Lammers, a research
professor in the School of Sustainable Engineering and the Built Environment,
"because we use water that's far too high in nitrogen and phosphorus to be
released anywhere. And instead, we reuse it to grow more algae."
Fini then bakes that algae at high temperatures without much
oxygen into a binder that can be easily mixed into asphalt.
Algae can capture the worst VOCs
A study in the journal Clean Technologies and Environmental Policy found
that while algae-infused asphalt doesn't significantly reduce total VOC
emissions, it can effectively keep the most toxic compounds from escaping.
In fact, tests showed that it reduced the toxicity of
asphalt emissions by roughly 100-fold.
Algae can slow how quickly pavement breaks down—which could lower
construction and maintenance costs and make its inclusion in asphalt even more
attractive for cities and paving companies.
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.
Because VOCs from pavement are often left out of air quality
assessments, these real-world tests are critical to evaluate pavement
performance and its long-term environmental impact.
"We have 4 million miles of roads in America,"
Fini said. "We should make those 4 million miles do more for us than just
get from A to B."
Publication details
Prasanna Kumar Bej et al, VOC emissions from asphalt:
Laboratory oxidation, ultrafine particle formation, and urban air quality
implications, Journal of Hazardous Materials (2026). DOI:
10.1016/j.jhazmat.2026.141713
Saba Shariati et al, Humidity: A hidden driver of toxic
emissions and asphalt decay in a changing climate, Science of The Total
Environment (2026). DOI:
10.1016/j.scitotenv.2026.181729
Elham H. Fini et al, Selective removal of toxic VOCs by
algae-derived biochar dramatically reduces the toxicity of asphalt
emissions, Clean Technologies and Environmental Policy (2026). DOI:
10.1007/s10098-026-03482-z
Journal information: Science
of the Total Environment , Journal
of Hazardous Materials
