Air quality snapshots: special findings from 10 years of NYCCAS

For 10 years, the New York City Community Air Survey (NYCCAS) has measured air quality at 100 locations around NYC. We’ve combined these measurements with data on things related to air quality - like traffic, building emissions, green space, and much more - to model seasonal air quality in every New York City neighborhood.

Our full findings are available in our annual report - but here are a few other interesting things we've found along the way.

Additional health threats of traffic volume

Traffic is a part of life in New York City and urban areas around the world. While transportation is critical to a healthy, functioning city, it can also contribute to poor health and quality of life for both commuters and residents.

NYCCAS air monitoring data shows that traffic is associated with higher levels of harmful pollutants: NO2, PM2.5 and black carbon (BC).

In addition, studies show that traffic is associated with two more health threats: air toxics and noise.

Air toxics

Air toxics are air pollutants that increase the risk of cancer and other serious health effects. A study by the Environmental Protection Agency found that 49% of New York City residents live in census tracts that exceed a common benchmark for cancer risk because of exposure to benzene and formaldehyde, compared with 4.8% of the population nationwide.

To further understand New Yorkers’ exposure to these air toxics, we measured air toxics - including benzene, formaldehyde and other compounds - at 70 sites across the city in 2011.

We found that average levels of benzene and formaldehyde varied across NYC, with some sites showing two, three or even six times more air toxics than cleaner sites - mostly due to traffic volume, congestion, and fuel-burning buildings.


City residents are exposed to significant environmental noise. A Health Department survey showed that one in five adult New Yorkers experience noise that disrupts sleep and other home life three or more times per week - and some high-poverty neighborhoods experience even greater rates of noise disruption.

Noise is more than an annoyance - it can cause stress, increase blood pressure and the risk of heart disease, and interfere with cognitive development in children.

To measure noise levels, we collected week-long sound pressure measurements at 56 sites across the city by mounting small sound-level meters on lampposts in 2012.

We found that for weeklong average values:

  • All sites exceeded noise guidelines set by the EPA and World Health Organization to protect health and quality of life (55 dBA).
  • Over half of sites exceeded EPA noise guidelines to prevent hearing loss (70 dBA).

The highest noise levels were recorded during the daytime hours of weekdays, in areas where there was a lot of traffic within 100 meters. It’s no surprise that where there are high levels of noise, there are also high levels of air pollution from vehicles.

Reducing emissions of both noise and air pollution from vehicles and other sources would improve health and quality of life in many of our most burdened neighborhoods.

The benefits of cleaner heating fuel

With cold weather and high population density, the Northeast is the nation’s largest consumer of heating oil. We use these fuels year round in building boiler systems for heat and hot water.

New York City has been phasing out the dirtiest heating fuel with high amounts of sulfur through recent City and State regulations. These heating fuel regulations will be fully implemented by 2030.

NYCCAS data shows that neighborhoods with higher proportions of buildings that burn high-sulfur heating oil have worse air pollution.

So how can we estimate the public health benefits of cleaner heating fuel? To estimate the impact of those heating oil regulations, we used model simulations. Here’s what we did:

We gathered emissions data using boiler permits and other buildings and emissions data to see how boiler emissions changed after the regulations were put in place.

We estimated the resulting change in PM2.5 concentration using a complex air quality computer model that combines emissions information, meteorology data, and simulations of atmospheric chemical reactions.

This map shows estimated reductions in PM2.5 by neighborhood, from 2008 (before the regulations took effect) to 2030, when the regulations will be fully implemented:

Then, we estimated the health benefits of reduced exposure to air pollution. We gathered neighborhood-level population and health outcome data, and we estimated the health events (like asthma, deaths, and more) that New Yorkers avoided due to this cleaner air. Here's what we found:

Mortality reductions in areas with the worst air quality: Cleaner fuels will save the most lives in areas with the greatest reduction in PM2.5, and areas with the highest rates of baseline premature mortality. These are the neighborhoods that already have poor air quality and high rates of death - including the Upper East and West Sides and Northern Manhattan.

Fewer adverse health events throughout the city: Cleaner fuels will result in reductions in other health events throughout the city, notably in the Bronx and Brooklyn. Even in neighborhoods with better air quality, hospitalizations and emergency department visits for cardiovascular disease, asthma emergency department visits, and respiratory diseases will go down as PM2.5 levels drop.

In other words, reducing PM2.5 benefits areas that have high PM2.5, but also communities with lower PM2.5 but high rates of respiratory diseases. You can explore these findings in the maps below.

Special monitoring for environmental justice

Across public health research, we see that communities with higher concentrations of poverty have higher rates of a variety of health conditions - including health conditions that are sensitive to air pollution. This makes people in these communities more vulnerable to harm from air pollution.

We make sure that our monitoring network accurately models air quality in high-poverty neighborhoods with supplemental monitoring at 15 environmental justice (EJ) sites. We placed monitors in high-poverty neighborhoods with lower than average density of air quality monitors, or near important emissions sources, starting in 2014.

Previously, our network of air quality monitors at 60 core sites gathered data that we used to model air quality across the entire city. With these 15 EJ sites, we can assess how well the model predicts air pollution levels in these communities with greater risk of air quality-related health impacts.

To do this, we compared the modeled estimates to the actual measured levels at these locations. Here’s what we found:

Only small differences between predicted estimates and monitored values. We found no meaningful (statistically significant) difference in the winter, summer, fall and annual average levels of PM2.5 or NO2.

Lower average concentrations of pollutants at 15 EJ sites. The 15 environmental justice sites measured, on average, 4% less PM2.5 than the citywide average of the 60 core sites, and 6% lower average NO2.

But like other sites citywide, there was variation in the levels measured at the new sites.

Additional confidence in our model. These findings show that the original model, based on the 60 core monitoring sites, is useful for predicting PM2.5 and NO2 levels - even in high-poverty neighborhoods that previously had fewer monitors. They offer additional confidence in our air quality monitor network and model, and tell us that NYCCAS does a good job of describing pollution levels in all NYC neighborhoods, even locations without monitors.

For more information about NYCCAS and our findings over 10 years of air quality monitoring, visit the Air Quality Hub.

Banner image:
Mayoral Photography Office
Published on:
April 21, 2020