Air quality in Woodland Hills

How is the air quality in Woodland Hills?

Air quality in Woodland Hills is generally rated good to moderate by US Environmental Protection Agency (EPA) standards. In 2019, air quality index (AQI) levels for nearby Thousand Oaks varied from 18 (“good”) in February to 53 (“moderate)” in June.

The US AQI is a scale ranging from 0 to 500, where higher numbers convey pollution levels with higher health risk. The US EPA calculates an overall AQI by weighting 6 criteria pollutants in a formula. Fine particulate matter (PM2.5) and ozone are the two criteria pollutants that tend to be present at the most dangerous levels, and as a result, most commonly dictate overall AQI. This is particularly true in Woodland Hills, which shares much of the same air quality as Los Angeles, a city reputed for its high ozone and PM2.5.

In the United States, Los Angeles ranks as the most polluted city for ozone despite the metropolitan area’s efforts to limit emissions of precursor pollutants in recent decades.¹ Ozone is a highly irritating gas pollutant that, unlike other criteria pollutants, is not emitted directly into the air but rather is formed when heat transforms nitrogen dioxide (NO₂) and volatile organic compounds (VOCs) via chemical reactions into ozone. Vehicular traffic is often attributed to high ozone levels, as fuel combustion is the leading source of ambient NO₂. In Los Angeles, the second most populous city in the United States, traffic is common among major throughways and throughout the greater metropolitan area, and public transportation remains relatively unpopular. Traffic, in combination with a sunny and warm climate, create ideal conditions for ozone formation.

Although ozone levels in the Woodland Hills have fallen during the last twenty years clean air policies at the state level, sensitive groups such as children, the elderly, and those with heart and lung disease are still prone to experiencing adverse health effects as the region remains in federal non-attainment.

PM2.5, is another air pollutant of concern in Woodland Hills. Although monthly averages in 2019 show PM2.5 levels ranging from good to moderate, numerous days each year experience PM2.5 spikes. The American Lung Association (ALA) shows that short-term PM2.5 pollution, or 24-hour PM2.5 pollution, has been increasing since 2016. From 2014 to 2016, Los Angeles experienced an average of 10 days per year of high PM2.5 levels; from 2015 to 2017, 13.2 unhealthy days; and from 2017 to 2018, 13.8 unhealthy days. These latest increases coincide with increasingly severe wildfire seasons, which create high levels of particle pollution. Warmer temperatures and longer dry spells brought on by climate change are expected to worsen California’s wildfires, and the number of unhealthy PM2.5 days in Woodland Hills will also rise in the future if this is indeed the case.

Is there smoke in Woodland Hills?

2020 has proven to be the most catastrophic fire season on record for the state of California, with more than 4 million acres burned by October.² In addition to California’s warming temperatures and lengthening dry season, powerful Santa Ana winds that blow in from the Great Basin frequently fan flames, causing fires to grow rapidly.

Smoke in Woodland Hills during the 2020 fire season broke all-time records, as air quality in parts of Southern California reached 10 to 15 times federal health standards.³ The severity of the pollution spikes prompted public health officials to issue health warnings to residents about poor air quality throughout the San Fernando Valley and its surrounding mountainous areas.

As particulates in wildfire smoke settle close to the ground, they can pose severe health risks to residents. When these microscopic particles are inhaled, they can enter the bloodstream and cause widespread bodily harm. In 2020, frequent smoke advisories published by the Southern California Air Quality Management District (SCAQMD) warned residents in affected communities to avoid unnecessary outdoor activity.

Refer to Woodland Hills forecast air quality data and stay informed about ever-changing air quality levels to anticipate any wildfire smoke danger in your area. Use the IQAir air quality map of the Woodland Hills to pinpoint current active fires, and observe the direction that wind is moving wildfire smoke.

How does air quality in the Woodland Hills compare to other cities in Los Angeles County?

Overall, Woodland Hills pollution levels generally fare better than neighboring cities in Los Angeles County, according to the 2019 World Air Quality Report. This is a benefit of the Woodland Hills location, which is slightly removed from denser areas of the Los Angeles Basin. Sea breezes blowing in from the Pacific frequently deliver clean air to Los Angeles’ coastal areas, another benefit of the geographic location of the Woodland Hills.

In 2019, nearby Thousand Oaks averaged a PM2.5 concentration of 8.2 μg/m³ (“good”). Only two months, June and July, averaged air quality levels that exceeded US EPA “good” standards.

By comparison, other cities in Los Angeles County experienced higher annual averages, and more months averaging air quality that exceeded “good” standards:

• Malibu air quality averaged 10.6 μg/m³ (“good”) in 2019, with 4 months of “moderate” air quality (June, July, August, November)
• Los Angeles air quality averaged 12.7 μg/m³ (“moderate”) in 2019, with 6 months of “moderate” air quality (June, July, August, October, November, December)
• Pasadena air quality averaged 13.5 μg/m³ (“moderate”) in 2019, with 6 months of “moderate” air quality (January, May, June, July, August, November)
• Glendale air quality averaged 13.6 μg/m³ (“moderate”) in 2019, with 6 months of “moderate” air quality (January, February, May, June, July, August)
• Burbank air quality averaged 15.5 μg/m³ (“moderate”) in 2019, with 10 months of “moderate” air quality (January, February, April, May, June, July, August, October, November, December)

Smog levels in Central Los Angeles are generally improving. Certain areas of the metropolitan area, however, are experiencing rising smog conditions. The San Fernando Valley, for instance, which includes Woodland Hills, suffers high and worsening ozone levels. During 2018, L.A.’s West Side only reported two bad ozone days, while downtown Los Angeles reported 4. The San Fernando Valley, on the other hand, reported 49 days with bad air quality, and San Bernardino reported the highest, 102 days. Both the San Fernando Valley and San Bernardino haven’t reported this many unhealthy ozone days since the mid-1990s.⁴

Due to the dynamic nature of air quality, trends only depict typical air quality levels. Use IQAir’s real-time air quality map to compare air pollution levels in Los Angeles County, and greater abroad.

Is smog in Woodland Hills improving?

Smog has been easing across Los Angeles County in recent years.⁵ Since the 2000-2002 monitoring period, ozone has fallen by roughly 20 percent, while annual PM2.5 levels have fallen by 47 percent. These reductions were achieved through a combination of local, state, and national laws aimed at reducing emissions, increasing fuel-efficiency, and transitioning to cleaner energy, among a myriad of other policies targeting nearly every industry.

In recent years, however, air quality improvements have stagnated. Environmental Protection Agency (EPA) rollbacks led by the Trump administration as well as climate change are both considered obstacles that have resulted in the lack of recent progress. Short-term PM2.5 has also displayed a worsening trend due to the rising threat of wildfires.

According to a 2017 report published by the New York University School of Medicine and American Thoracic Society, California contains 4 of the 5 cities with the most pollution-related deaths.⁶ In the last decade (since 2010), Los Angeles and the surrounding metropolitan area have topped the list, reporting an estimated 1,322 extra deaths as a result of air pollution in the L.A. Basin.

Further eradicating air pollution in the Woodland Hills area is critical to preserving the health of residents. Currently, the transportation sector creates 80 percent of smog-forming pollution in California, representing the single greatest opportunity for driving down L.A. emissions. Moving towards electric and hybrid vehicles has the potential to deliver significantly improved air quality. In 2020, California state government announced that it will require sales of all new passenger vehicles to be zero-emissions by 2035.⁷ Additional opportunities include shifting toward renewable energy, further limiting industrial emissions, and reducing consumption and waste, among others.

What causes air pollution spikes in the Woodland Hills?

Woodland Hills is a small and affluent neighborhood near the Santa Monica Mountains in the San Fernando Valley. As a largely residential area, much of the air pollution in Woodland Hills is not created locally, but is rather carried in by wind from the greater Los Angeles metropolitan area. The mountains that surround the L.A. Basin trap dirty air and keep it from dissipating. Thermal inversions, in which warm air high in the atmosphere traps cooler air and low-lying pollutants in the lower atmosphere, are common in the area and further exacerbate this effect.

Air pollution sources in greater Los Angeles include motor vehicle emissions, demand for energy production through fossil fuels, household energy consumption, port activity, and wildfires.

Wildfires represent an increasingly significant source of air pollution in Woodland Hills, often attributable to otherwise unanticipated spikes, particularly as regulations drive down emissions from other sources. Often, wildfires are burning outside of the Woodland Hills geographic borders. Smoke, however, is able travel hundreds of miles as it’s carried by wind. During wildfires, Los Angeles AQI levels have observed jumps from 40 (“good”) to 153 (“unhealthy”).⁸

+ Article Resources

[1] American Lung Association. (2020). State of the Air report.
[2] Davis W. (2020, October 4). California wildfires have burned 4 million acres and the season isn't over yet. National Public Radio.
[3] Barboza T. (2020, September 10). Los Angeles suffers worst smog in almost 30 years. Los Angeles Times.
[4] Barboza T. (2019, July 1). Must reads: The war on Southern California smog is slipping. Fixing it is a $14-billion problem. Los Angeles Times.
[5] Austin P. (2019, July 1). Worsening smog hits San Fernando Valley disproportionately. Patch.
[6] Cromar K, et al. (2017). Trends in excess morbidity and mortality associated with air pollution above ATS recommended standards, 2008 to 2017.
DOI: 10.1513/AnnalsATS.201812-914OC
[7] Valdes-Dapena P. (2020, October 3). California's mandate to sell only zero-emissions vehicles by 2035 isn't as crazy as critics think. CNN.
[8] Evan S. (2020, September 12). California air quality skyrockets to some of the worst levels ever due to wildfires. California Globe.