Why determining air quality in Los Angeles is so confusing right now

Air Now Fire map Includes data from PurpleAir sensors (represented by small circles on the map), and Watch Duty, a non-profit fire tracking appIt also displays PurpleAir data. But it is possible that due to different calculations and processing delays, the air quality index reported by the same sensors can vary significantly from one map to another. For what is known as PM2.5 pollution, or small inhalable smoke and dust particles, a PurpleAir sensor located south of Los Angeles International Airport simultaneously on Monday returned an air quality index of 28 on the AirNow website, 20 on WatchDuty, and 5 on the PurpleAir website. Official page.

Each of these values ​​generally indicates healthy air, but things can get more complicated when other types of data are added to the calculations. That’s exactly what companies like BreezoMeter and Ambee are doing in hopes of providing what they describe as “hyper-local” accurate estimates in the many miles between certain sensor locations.

BreezoMeter was founded in Israel and raised tens of millions of dollars in venture capital funding before being acquired by Google in 2022 for more than $200 million, according to Israeli media. (Google declined to comment on the value of the deal.) It supports the air quality data that appears in the weather app on Apple devices and the Google Maps app. Meanwhile, Indian startup Ambee is responsible for the air quality data in WeatherBug, which is among the most popular weather apps in the world.

Yael Maguire, Vice President of Geo-Sustainability at Google, says BreezoMeter Estimated air quality on an hourly basis across a wide range of pollutants and locations, generating more data than many government systems. To make its calculations, the company uses information gleaned not only from EPA and PurpleAir sensors, but also from satellites and other sources such as weather and traffic reports. Similar data is being incorporated into Ambee’s own algorithm, according to its CEO, Jaideep Singh Bachher. “We want to give people the right data whenever and wherever they need it,” he says.

Volkens says he does not trust these systems. He says the low-cost PurpleAir sensors they rely on, in part, aren’t well suited to the conditions they’re often deployed in the United States, including during wildfires. But he admits that although they tend to be wrong on raw numbers, these sensors can be accurate about 90 percent of the time in determining the advisory level — that green-to-maroon scale that’s often enough for people to make decisions. . On how to protect their health.

PurpleAir representative Andrew White says its sensors It was found to be accurate It does not control how other services perform calculations using its data. Google’s Maguire says the company “provides groundbreaking, highly accurate information on air quality,” including “even in areas with limited monitoring.”

The safest bet for anyone concerned about air quality is to trust the highest number or color level among different services, says Jennifer Richmond Bryant, an assistant professor of forestry and environmental resources at North Carolina State University who has studied PurpleAir sensors. “I have more confidence in AirNow’s numbers because I understand them,” she says. But “it never hurts to make a very conservative decision when it comes to protecting yourself.”

In countries that do not have sufficient government oversight, startups fill an important void. BreezoMeter and Ambee were founded by people concerned about their families’ exposure to harmful air particles at home in Israel and India, respectively. BreezoMeter offers data for over 40 countries, and Ambee offers data for over 100 countries.

This breadth of coverage also makes its services attractive to Apple and other global companies that want to incorporate air data, which includes pollen forecasts, into apps, product testing or marketing campaigns. Breezometer’s clients include companies in the automotive, health, fitness and beauty industries. Ambee’s includes healthcare companies such as Sanofi, which makes the allergy pill Allegra, which was launched last year tool To find walking and cycling routes with clean air.

BreezoMeter has let go of some of its staff under Google, although Maguire says the company is committed to providing reliable weather data. As demand for air quality data grows, researchers are racing to improve production of low-cost sensors and calling for the installation of different types of monitoring equipment, such as more pollen counting stations. What’s not foggy these days is that the air is It gets worseAnd we’re late in measuring this well, Folkens says.