Report tallies number of days with elevated air pollution in Nevada

The Las Vegas metropolitan area experienced 96 days of elevated air pollution in 2020, according to a report from the Environment Nevada Research & Policy Center, Frontier Group, and the U.S. PIRG Education Fund.

In the report, “Trouble in the Air: Millions of Americans Breathed Polluted Air in 2020,” researchers reviewed Environmental Protection Agency records on the total number of days of elevated air pollution — when air pollution levels are above what the EPA considers “good” — for each urban area and rural county that reported air quality to the EPA in 2020.

In 2020, the Las Vegas metropolitan area saw 81 days with elevated ozone and 32 days with elevated PM2.5 pollution— fine particulate pollution that comes primarily from burning fossil fuels and, especially in recent years,  wildfires. 

“Even one day of breathing in polluted air is dangerous for our health,” said Eve Lukens-Day, Global Warming Solutions Associate with Environment Nevada Research & Policy Center. “96 days is unacceptable and we need to do more to deliver cleaner air for our communities.”

Clark County is experiencing growing ozone pollution after nearly a decade of declines, according to data from the county.

In 2012, Clark County saw 43 days when ozone levels exceeded EPA health standards, but thanks to tougher emission standards and more fuel efficient cars, ozone pollution has steadily decreased over the years falling to a low of three days of excess ozone in all of 2019.

However, that trend reversed recently, largely due to growing wildfires in the West resulting in ground-level ozone. The American Lung Association’s 2020 “State of the Air” report found Las Vegas ranked as the 9th for most polluted city in the nation for ozone.

The Las Vegas metropolitan area showed the most number of days with elevated ozone of any Nevada county. 

Risk of ground-level ozone forming is the highest on sunny days with low airflow, making dry Southern Nevada an ideal petri dish. Stagnant weather conditions and the topographic structure of the Las Vegas Valley help trap these pollutants, causing levels to rise.

Wildfires in Northern Nevada, however, increased the number of days of elevated particulate pollution in several counties in the north.

Reno experienced 45 days of elevated ozone and 53 days with elevated fine particulate pollution in 2020.

Carson City saw more days with elevated ozone levels than the city of Reno with 49 days of ozone exceeding EPA standards. Carson City also had 44 days with elevated particulate pollution.

The enclave of suburban homes in Douglas County, Nevada known as the Gardnerville Ranchos with a population of about 50,000 had 55 days with elevated fine particulate — more than any other county— brought on by wildfires.

“Every year, millions of Americans are exposed to levels of pollution that American public health groups and international agencies consider unhealthy,” reads the report.

In 2020, 237.6 million Americans – more than 70% of the population – were exposed to more than a month of elevated levels of ozone and fine particulate pollution. 

Air pollution causes hundreds of thousands of premature deaths every year and contributes to health problems ranging from asthma to dementia, according to the EPA.

The study’s researchers also noted that current EPA standards could be obscuring a larger air pollution problem. 

Levels of air pollution allowed under current EPA standards are beyond those allowed by the World Health Organization and other health organizations.  The EPA standard for ozone is 70 parts per billion (ppb) over 8 hours, while the WHO’s guidelines recommend 51 ppb. Fine particulate pollution allowed by the EPA’s standard is more than twice as high as the WHO’s 2021 guidelines for protecting public health.

Global warming is predicted to make air pollution worse in the years to come.  Higher temperatures can increase ozone levels and increase the frequency and severity of wildfires in the Southwest, according to climate scientists.

Those fires are even more demanding as fire season started unusually early this year. The U.S. Forest Service spent more consecutive days this summer at the agency’s highest level of preparedness for wildfires than in any previous year, according to federal officials.