Hold Your Breath! Air Pollution Measured

As truck after truck barreled through New Haven’s industrial port district Monday afternoon, the asthma-inducing particulate matter in the air at the corner of Connecticut Avenue and Alabama Street reached 29.5 micrograms per cubic meter (μg/m³).

That compared to 16.4 outside Mitchell Library and 28 outside Tweed Airport and 21 by the Hill South police substation at the exact same time.

City government is now collecting and making public that data through 11 recently installed air quality sensors, which shine a light on just how much hazardous haze New Haveners take in with every breath.

Mayor Justin Elicker, City Engineer Giovanni Zinn, and city Health Director Maritza Bond discussed those sensors and the air quality they measure during a 1 p.m. press conference at the intersection of Connecticut and Alabama.

Zinn said that, over the past six months, his office has installed PurpleAir Flex air quality monitors at 11 locations across New Haven: at Connecticut and Alabama in the port district, at Tweed New Haven Airport, the Hill South substation, 424 Chapel St., 200 Orange St., the transfer station on Middletown Avenue, the Q House in Dixwell, the Morris Creek tidal gates, College Woods, the Boathouse, and Mitchell library in Westville.

These sensors shine a ​“solid state laser” into a chamber with a fan blowing air in, Zinn said. The sensor counts the particles that come in and measures the intensity of the reflection of light off those particles. That measurement is translated into a number, in micrograms per cubic meter, which is then fed in near real time (with a few minute delay, Zinn cautioned) to this city air quality monitoring webpage.

These sensors are for ​“information-only” purposes, Elicker and Zinn stressed. The city is not the regulatory agency for air quality. That work falls to the federal Environmental Protection Agency (EPA), which uses particulate matter as one of six factors to determine the air quality and pollution.

The Health Department already sends out alerts through the city’s emergency messaging system when the air quality is so poor that elderly and infirm New Haveners should stay inside when possible, like when the Elm City was blanketed last year by Canadian wildfire smoke.

Elicker and Zinn did not identify any one particular policy these new particle sensors will inform. They also said the data collected over the past six months has shown, somewhat mystifyingly, that air quality readings at these 11 disparate city locations tend to track one another; rarely do you see a spike in one spot that is also not seen in another. Elicker hypothesized that these citywide similarities reveal how ​“a lot of our air quality is impacted much more by what’s happening outside of the city.”

Zinn described the installation of these new sensors — which cost roughly $280 apiece — as akin to ​“pure science” at this point: the city is collecting data and presenting it to the public. What that data will show and what local policies it might inform are still TBD.

What is certain, Elicker and Bond stressed during the press conference, is just how relatively poor New Haven’s air quality is, given that the city sits at the intersection of a number of transportation hubs, including the highways, rail yard, airport, and port.

As a result, New Haven has some of the highest incidences of asthma in the state, and country, with Black and Latino residents suffering at disproportionate rates. According to DataHaven, 21 percent of New Haven adults have asthma, compared to 17 percent across Connecticut. Particles in the air — as emitted by everything from cars to planes to power plants — can lead to reduced lung function, asthma, strokes, and premature death, Elicker said.

With these new sensors, Elicker and Zinn said, the city will at least have a better sense of the state of the city’s air, which is a necessary first step to pushing for a cleaner place to live and work and breathe.