Rural air pollution may be as hazardous as urban, study finds

Date:
January 27, 2022
Source:
University of Illinois at Urbana-Champaign, News Bureau
Summary:
New research shows that chemical reactivity, seasonality and
distribution of airborne particulate matter are critical metrics
when considering air pollution's impact on human health. Current
environmental regulations focus on the mass of pollutant particles,
and researchers are pushing to refocus regulatory efforts on more
regional and health-relevant factors.



FULL STORY ==========================================================================
New research shows that chemical reactivity, seasonality and distribution
of airborne particulate matter are critical metrics when considering air pollution's impact on human health. Current environmental regulations
focus on the mass of pollutant particles, and researchers at the
University of Illinois Urbana-Champaign are pushing to refocus regulatory efforts on more regional and health-relevant factors.


==========================================================================
A new study of air quality in the Midwestern U.S. found that measuring
the mass concentration of PM2.5 -- particles that are 2.5 micrometers in diameter or smaller -- does not correspond well with current methods for classifying particle toxicity. Additionally, the researchers found that
PM2.5 exposure may be just as hazardous in rural areas as in urban areas
-- evidence that challenges a common misconception that air pollution is
more toxic in urban areas than in than rural areas, the researchers said.

The findings of the study, led by civil and environmental engineering
professor Vishal Verma, are published in the Journal of Hazardous
Materials.

"The EPA classification of PM2.5 accounts for particle diameter and mass,
which are characteristics that are easy to measure," Verma said. "However,
not all particles that make up PM2.5 contribute to health equally."
PM2.5 poses a health risk because it can become embedded in lung tissue
when inhaled, the researchers said. Although chemically reactive fractions
of these particles are known to be toxic, a previous study by Verma's
group shows that the exact relationship between PM2.5 mass and toxicity
is unclear.

"Most air pollution studies have shifted focus from particle mass to
a property called cellular oxidative potential," Verma said. "Cellular oxidative potential describes the capability of the particles to generate reactive, oxygen-based chemicals that can lead to a variety of health
problems in the cells of lung tissue." To examine the influence of
oxidative potential more closely, the researchers collected PM2.5
samples weekly in the summer and fall of 2018 and in the winter and
spring of 2019. They chose three urban localities: Chicago, Indianapolis
and St. Louis; a rural location in Bondville, Illinois; and a roadside
location adjacent to an interstate highway in Champaign, Illinois.

Using an automated analytical technique developed in a previous study,
Verma's team analyzed the sample composition, oxidative potential and
mass. The team found that all locations shared similar levels of oxidative potental -- but saw a poor correlation between oxidative potential and
mass. That suggests that some of the lighter particles that make up
PM2.5 contribute more to tissue damage than others, the study reports.

"Our rural samples did have less mass than those in the urban settings,
but the oxidative potential was equal to samples from urban settings,"
Verma said.

"Additionally, the oxidative potential of the rural samples was higher in
the summer than in the winter, suggesting that summertime agricultural
activity can produce PM2.5 particles that are just as toxic as those
from urban settings." The team hopes this study brings attention to
these newly uncovered risks associated with PM2.5 in rural areas.

"The current methods used to measure PM2.5 oxidative potential are time- consuming and laborious, and we hope that our new methodology, combined
with these study findings, makes testing for oxidative potential more
appealing to environmental regulators and policymakers," Verma said.

The National Science Foundation supported this research.

========================================================================== Story Source: Materials provided by University_of_Illinois_at_Urbana-Champaign,_News_Bureau.

Original written by Lois Yoksoulian. Note: Content may be edited for
style and length.


========================================================================== Journal Reference:
1. Yixiang Wang, Joseph V. Puthussery, Haoran Yu, Yicen Liu, Sudheer
Salana,
Vishal Verma. Sources of cellular oxidative potential of
water-soluble fine ambient particulate matter in the Midwestern
United States. Journal of Hazardous Materials, 2022; 425: 127777
DOI: 10.1016/ j.jhazmat.2021.127777 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/01/220127104145.htm

--- up 7 weeks, 5 days, 7 hours, 13 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)