Poor Air Quality is defined as the presence of high levels of pollutants in the atmosphere that can endanger human health and the environment. Despite significant improvements since the 1970 Clean Air Act, New York City (NYC) is one of many regions across the country that experience unhealthy pollutant levels, posing threats to both public health and delicate ecosystems. In light of ongoing environmental and climatic changes and the rapid implementation of greenhouse gas (GHG) emissions reductions strategies, tracking air quality over time and the impacts in New York City is crucial.
What is the Hazard?
Air Quality is the extent to which the air is pollution free. There are multiple pollutants that can contribute to air pollution, each one with distinct methods of measuring as well as federal standards. One way that air quality is represented by the Environmental Protection Agency (EPA) for ease of interpretation is by the Air Quality Index (AQI).1Environmental Protection Agency, “Air Data Basic Information,” Environmental Protection Agency. The AQI tells us how clean or polluted the air is, and what associated health effects might be of concern. The AQI runs from 0 to 500 — the higher the number, the greater the level of air pollution. An AQI of 101 or more is considered unhealthy for sensitive groups, and 201 or more is considered very unhealthy for anybody.
The EPA calculates the AQI for five major pollutants regulated by the Clean Air Act: ground-level ozone, particle pollution (particulate matter), carbon monoxide, sulfur dioxide, and nitrogen dioxide. Ground-level ozone and airborne particles are the two pollutants that pose the greatest threat to human health.
Clean air is important for health. While poor air quality affects us all, older adults, children, and people with heart and lung conditions are most at risk.
City, state, and federal agencies measure what is in the air and study how pollution can lead to health problems. Air quality is a crucial aspect of New Yorkers’ daily lives, and it is important to understand the elements that contribute to it. Exposure to fine particulate matter (PM2.5) and ground-level ozone are influenced by economic status as well as where you live and work.2American Lung Association, “Disparities in the Impact of Air Pollution,” American Lung Association. For more information on how and why economic status influences exposure to poor air quality, please check the Social Environment section of this Hazard Plan.
Severity
Understanding the Air Quality Index
Poor air quality can be caused by multiple factors. Vehicle exhaust, wood stove emissions, industrial emissions, wildfire smoke, windblown dust, and other sources can be harmful to health. In New York City, major sources include burning fossil fuels for building heating and in motor vehicles. All of these sources contribute to high levels of pollutants.3UW Emergency Management, “Outdoor Air Quality,” University of Washington. New York City’s Department of Health and Mental Hygiene (DOHMH) has tracked two primary sources of poor air quality, and the level of risk each has on the health of residents: Particulate Matter and Ground-Level Ozone. Throughout the year, the city may experience poor air quality due to a high level of fine particles in the air. Exposure to PM2.5 can worsen serious health problems.
PM2.5: Particulate matter consists of tiny particles in the air that are inhaled into the lungs. PM2.5 refers to particles with a diameter of 2.5 micrometers or smaller. These particles can come from various sources, including vehicle emissions, industrial processes, and construction activities. Long-term exposure to PM2.5 has been linked to the development or worsening of respiratory and cardiovascular problems. Short-term exposure can lead to sore throats and other minor issues for most people, but for individuals with cardiovascular and respiratory issues, even short-term exposures can result in acute health issues that can require medical treatment.
Ground-Level Ozone: Ground-level ozone is a major component of smog and is formed when pollutants from vehicles and industrial facilities react with sunlight. Stagnant atmospheric conditions trap humid air and pollutants, such as ozone, near the ground. This is a component of smog that can trigger serious respiratory problems. It is also a risk to participate in strenuous physical activity outdoors during elevated air quality readings. Breathing in ozone for small periods, like an hour, can lead to sore throats and other minor issues for most. But for individuals with cardiovascular and respiratory issues, even short-term exposures can result in acute health issues that can require medical treatment.
Inhaling particulate matter from any source can have negative health effects, but recent studies suggest that breathing in smoke from wildfires may result in even more harmful health outcomes than other particle sources. This is due to the chemicals that are aerosolized when structures are destroyed by fire — there are higher amounts of lead, zinc, and magnesium, as well as acetaldehyde, acrolein, formaldehyde and benzene.4AirNow, “Health Effects of Wildfire Smoke,” AirNow.
For more information about the impact of ozone and PM2.5, check out the New York City Environment and Health Data Portal.
Probability
The EPA uses action days as a means of notifying the public about air quality issues, and these can be announced for a variety of issues ranging from PM2.5 to high pollen counts. Air quality action days, for people with weaker respiratory or cardiovascular systems, are announced when either ozone or PM2.5 levels are above 100, and for the general population when levels are above 150 (unhealthy).5Environment & Health Data Portal, “Air Quality Action Days,” City of New York. The number of action days issued by the EPA for PM2.5 has decreased since at least 2001.
Air Quality Data for NYC | Environment & Health Data Portal
This chart shows that the number of action days annually related to PM2.5 has fallen from between 5 and 15 for sensitive groups per year before 2008, to zero or one per year since 2012.6Environment & Health Data Portal, “Fine Particles (PM 2.5) Action Days,” City of New York.
New York City has seen remarkable reduction in the amount of PM2.5 in the last 20 years due to local, state, and federal regulations on sulfur in heating oil, coal-fired powerplants, and fuel standards for motor vehicles. While there has been a reduction in PM2.5, the city’s air can still be impacted for short periods of time by the world at large. Wildfires in California in 2021 and Canadian wildfires in 2023 caused the city brief, but severe, drops in air quality. The impact that fires in Canada and the U.S. West Coast can have is very hard to forecast. It depends on the severity of the fires, large scale wind patterns, atmospheric chemistry, and localized weather. The impact external factors play on short-term air quality in NYC and the challenges in forecasting — along with the prediction of increasing drought in wildfire-prone areas — make tracking wildfire smoke-related air quality events over time essential.
For example, in June of 2023, NYC experienced historic highs of poor air quality.
Fine Particulate Pollution at Seven Locations in New York City
In the chart titled Fine Particulate Pollution at Seven Locations in New York City, the level of pollution was higher than the worst daily average record in San Francisco — which was on Nov. 16, 2018, when wildfires were blazing in Northern California. At its peak, it approached average pollution levels recorded in Portland, Oregon, on Sept. 13, 2020, during the worst of its pollution from nearby wildfires.7Environment & Health Data Portal, “The New York City Community Air Survey,” City of New York. Coincidentally, the poor air quality exhibited in the graph was caused by the wildfires in Canada, which is north of NYC. Please read the specific case study later in the report for more information.
Ozone levels in the city fluctuate but are highest during the summer when warm weather and strong sunshine accelerate chemical reactions that produce ozone. This means that ozone levels will be highest in the city during the summer when the sunlight hitting the city is strongest. With increasing temperatures, there will be more days of high ground-level ozone.
Location
The New York City Community Air Survey, an extensive air quality monitoring program, lets us understand neighborhood-by-neighborhood differences in air quality and pinpoint neighborhoods with the worst air quality. Concentrations of NO2 (Nitrogen Dioxide), NO (Nitric Oxide), and PM2.5 are higher in industrial zones with more diesel truck traffic, neighborhoods with large numbers of restaurants, and areas of higher traffic and building density.8https://nychazardmitigation.com/documentation/hazard-profiles/poor-air-quality/#_edn8
The maps titled NYC Fine Particles (PM2.5) by Neighborhood show the measure of the seasonal average of PM2.5 throughout the city in the summer of 2021 and the winter of 2020 to 2021.9Environment & Health Data Portal, “The New York City Community Air Survey,” City of New York. These maps show that higher measurements of PM2.5 are found in densely populated and industrial zones of the city. Comparing the two maps also shows that the time of year is an important factor in the amount of PM2.5 present in the city’s air. The high rates of traffic reflect an increased number of heavy vehicles used in construction in the city during the summer, which results in higher overall PM2.5.
NYC Fine Particles (PM2.5) by Neighborhood
Source: DOHMH
Because other pollutants emitted by vehicles can combine with ozone rapidly, higher ozone levels are more likely to occur in areas of the city that are far from high volumes of traffic. The impact of this can be seen in the map showing ozone (O3) levels by neighborhood in New York City. The New York City Community Air Survey found that ozone levels were highest on the Rockaway Peninsula, one of the lowest density areas in the city, and mostly isolated from the rest of the city by Jamaica Bay.
NYC Ozone (O3) by Neighborhood
Surveying the City’s Air
DOHMH surveys air pollution at about 100 city locations during each season.10NYC Department of Health and Mental Hygiene, “New York City Community Air Survey,” City of New York. Routine sites are spread around the city to capture different neighborhood characteristics, including in residential, commercial, and industrial areas. Other sites are selected because they are near potentially high-emission locations. To better understand potential sources of emissions in low-income neighborhoods, an additional 15 environmental justice sites are also included.
Every survey site is monitored for a two-week period during each season. Monitors are mounted 10 to 12 feet off the ground on public light poles, on utility poles along streets, and in some parks.
The monitors use a small battery-powered pump and filters to collect air samples. After each two-week period, monitors are collected and taken to a laboratory for analysis.
Historic Occurrences
In the mid-1900s, air quality was especially poor due to the coal era. New York City air quality was absolutely disastrous during the 1960s.11Marco Margaritoff, “The Story of the New York City Smog of 1966 That Killed 200 People,” All That’s Interesting, October 2, 2021. Throughout this time period, deaths from pulmonary emphysema and chronic bronchitis began to skyrocket, linked to widespread smoking and how dirty the air was overall. Power plants, factories, cars, and lack of environmental knowledge led to the inception of the Clean Air Act.
But the 1966 New York City pollution episode was especially awful — so much so that it killed some 200 people. Varying reports estimate that smog killed anywhere from 169 to 400 people throughout that year. The pollution was formerly known as “smaze” — smoke and haze pre-dated the term of “smog.”
Poor readings for 2001 occurred after 9/11. The major contribution to poor air quality in NYC was due to the smoke and aftermath of a terrorist attack. Similar to the case study below, Canadian wildfires similarly influenced NYC’s air quality in 2002 and 2003.
In 2021 and 2017, air quality spikes (greater than an AQI of 200) were observed in July, specifically July 5 for both 2017 and 2021. This coincidence of poor air quality is tied to the over-release of fireworks and its direct effect on air quality.12Jeff Masters, “July 4 Fireworks Create Unhealthy Levels of Air Pollution,” Weather Underground, July 5, 2017.
Case Study
During the summer of 2023, smoke from wildfires in Canada drifted across the United States and drastically impacted the air quality of New York City.13NYC Emergency Management, “NYC Emergency Management and New York City Department of Health and Mental Hygiene Urge New Yorkers to Take Precautions and Prepare for Poor Air Quality,” City of New York, July 17, 2023. Levels ranged between 100 and over 200 AQI in certain areas. At the time of the incident, there were reports of close to 400 active wildfires across Canada’s West Coast.14Emily Mae Czachor, “Canadian Wildfire Maps Show Where Fires Continue to Burn across Quebec, Ontario and Other Provinces,” CBS News, July 19, 2023. Toward the east, Alberta had the second-highest number of active fires with 126, Quebec with 126, and New England with 106. The map titled Air Pollution in the United States illustrates the smoke travel pattern experienced by NYC in the summer of 2023.15Emma Newburger, “Air Quality in NYC Could Gradually Improve Friday as U.S. Chips in to Fight Canada Wildfires,” CNBC, June 9, 2023.
Air Pollution in the United States
As previously mentioned in the report, there is a slightly greater probability of short-term air quality events in the summer in NYC. Peak wildfire season in Canada is NYC’s summer. Globally we are seeing longer and longer wildfire seasons — a result of rising temperatures and decreased precipitation. With climate change, wildfire frequencies are projected to continue rising, suggesting that New York City is likely to experience similar air quality events in greater numbers in future years.16Grace Rauh, “New York City Must Prepare Against Future Air Quality Threats; Here’s How,” Gotham Gazette, June 15, 2023.
As the climate in NYC continues to change, we need to reduce the emissions that cause global climate change. We must consider the impacts on air quality from local activities like driving, and from distant events like wildfires. You can find out more information of our air quality history through the Hazard History and Consequence Tool.
What is the Risk?
Air Quality Data
Survey monitors check pollutants that cause health problems, such as fine particles, nitrogen oxides, sulfur dioxide, ozone, and elemental carbon (a marker for diesel exhaust particles).
It is important to note that the New York State Department of Environmental Conservation (NYS DEC) runs the regulatory monitoring for compliance with the Clean Air Act and issues the air quality alerts during events. New York City Community Air Survey (NYCCAS) is the DOHMH survey that looks at neighborhood differences and includes a few real-time PM2.5 monitors. However, it does not collect data for the purpose of issuing air quality alerts.
New York City’s air quality is improving, but DOHMH’s health impact estimates from 2015 to 2017 found that fine particle pollution alone each year caused:
- At least 2,000 deaths,
- About 1,400 hospital admissions for lung and heart conditions, and
- 3,750 emergency department admissions for asthma.17Environment & Health Data Portal, “Asthma Emergency Departments Visits Due to Ozone,” City of New York.
For more information about the survey, outdoor air quality, or health impacts of air pollution, refer to the Air Quality Hub on the Environment & Health Data Portal, which includes information from the survey — such as PM2.5 data feed and data stories.
Neighborhood Air Quality reports are made available by the New York City Community Air Survey.
Social Environment
The high number of renters in NYC also results in many residents being at risk from low air quality, including those who may be sensitive to poor air quality, those with cardiovascular or respiratory disease, those experiencing poverty, those who lack access to health care, and those who live in an environment that does not allow them to make substantial improvements to their homes. Furthermore, this may also be an issue of poor housing quality and poorly maintained housing. This prevents residents from being able to build a sealed barrier that retains clean air in the event of prolonged periods of poor air quality.
In New York City, the following poor air quality–related health impacts were recorded by the Environment and Health Data Portal:
- Estimated Annual (age 30+) Deaths due to PM2.5: 1,971
- Estimated Annual (age 30+) Cardiac and Respiratory Deaths due to Ozone: 410
- Estimated Annual (age 20+) Respiratory Hospitalizations due to PM2.5: 779
- Estimated Annual (age 40+) Cardiovascular Hospitalizations due to PM2.5: 659
- Estimated Annual Asthma Hospitalizations due to Ozone:
- Age 18+: 262
- Under Age 18: 351
- Estimated Annual Asthma Emergency Department Visits due to PM2.5:
- Age 18+: 2,358
- Under Age 18: 1,395
- Estimated Annual Asthma Emergency Department Visits due to Ozone:
- Age 18+: 3,298
- Under Age 18: 1,817
Built Environment
Emissions from buildings and construction are a substantial source of air pollution in New York City. As the city continues to grow, we need to make certain that the buildings we build and live in operate in ways that support our quality of life.
Even with the rapid construction of New York City, many of the rented spaces are not built with central air-conditioning or with air-conditioning with air filters — with the exception of newer construction. As a result, many renters may have to run a window-based air-conditioning unit in the summer to keep cool, even when doing so comes at the cost of blowing unhealthy air into their homes.
The growing popularity of heat pumps may be a way for residents to see substantial improvements in their homes’ air quality. Heat pumps allow for indoor temperature control without needing to sacrifice indoor air quality.
The average person spends 90 percent of their time indoors.18NYC Department of Health and Mental Hygiene, “Indoor Air Quality,” City of New York. Young children, older adults, and those with chronic health conditions tend to spend even more time indoors and are more likely to be affected by indoor air quality problems, such as poor air filtration — which may be exacerbated by poor outdoor air quality.
While the built environment impacts air quality through factors like emissions and construction activity, air quality does not substantially impact the built environment.
Natural Environment
Poor air quality can occur during heat waves when stagnant atmospheric conditions trap pollutants in urban areas. Ozone, a major component of smog, is created when pollutants emitted by cars, power plants, industrial boilers, and other sources chemically react in the presence of sunlight. Hot weather can increase ozone levels, causing or worsening people’s respiratory problems.19Alejandra Borunda, “Extreme Heat Makes Air Quality Worse — That’s Bad for Health,” National Public Radio, September 6, 2023.
When levels of ozone and/or fine particles are anticipated to exceed an AQI value of 100, NYS DEC and the New York State Department of Health (NYS DOH) issue an Air Quality Health Advisory to alert people with high sensitivity to take necessary precautions.20NYS Department of Environmental Conservation, “Air Quality Index (AQI) Forecast and Current Observations For New York State,” New York State. When ozone levels are projected to reach the unhealthy range, people are advised to limit vigorous outdoor physical activity during the afternoon and early evening hours.
Smoke from a fire contains a mix of gases, particles, and chemicals. When residents breathe in smoke, they may experience temporary eye, nose, and throat irritation. People with asthma or other cardiovascular or respiratory conditions may be more vulnerable to health effects from smoke exposure.
Future Environment
While the city’s air quality has improved in recent decades, air pollution causes 6 percent of annual deaths in the city each year, making it one of the most significant environmental health problems. Furthermore, air quality improvements will have significant and immediate health benefits at a scale second only to reductions in smoking rates, among recent City initiatives.21NYC Department of Health and Mental Hygiene, Air Pollution and the Health of New Yorkers: The Impact of Fine Particles and Ozone, City of New York.
To reduce the toll from air pollution, actions are needed to address important local sources, such as motor vehicle exhaust, building heating oil, and aging power plants with outmoded technology. As part of the City’s sustainability plan, PlaNYC, many emission reduction initiatives have been completed or launched — and others are planned.22NYC Mayor’s Office of Climate & Environmental Justice, PlaNYC: Getting Sustainability Done, City of New York. The steps needed will produce many benefits beyond health, such as reducing greenhouse gas emissions. However, investments and behavior changes are also needed, making it important for New Yorkers to understand the burden of air pollution on health, the health benefits of addressing it, and the costs of inaction.
To better fight inevitable climate change, it is highly recommended to enact legislation and activation that focuses on reducing the city’s carbon footprint and pollution activity.
How to Manage the Risk?
Regulations
Local Law 97 was passed in April 2019, implementing new energy efficiency and greenhouse gas emissions limit requirements for New York City buildings. This law was included in the Climate Mobilization Act, which was a part of Mayor Bill de Blasio’s New York City Green New Deal.
“Under this groundbreaking law, most buildings over 25,000 square feet are required to meet new energy efficiency and greenhouse gas emissions limits as of 2024, with stricter limits coming into effect in 2030. The goal is to reduce the greenhouse gas emissions produced by the city’s largest buildings by 40 percent by 2030 and 80 percent by 2050, thereby improving local air quality through reducing PM2.5 as buildings burn less fossil fuels. The law also established the Local Law 97 Advisory Board and Climate Working Groups to advise the City on how best to meet these aggressive sustainability goals.”
— NYC Department of Buildings (DOB)
Federal legislation on air pollution began with the Air Pollution Control Act of 1955 and has since evolved through the Clean Air Act of 1963, the Air Quality Act of 1967, the Clean Air Act of 1970 (1970 CAA), the Clean Air Act Amendments of 1977 (1977 CAAA), and the 1990 Clean Air Act Amendments (1990 CAAA). These laws enabled the federal government to study air pollution, including techniques to minimize it, and create new regulations and requirements to reduce emissions.
Environmental Protection Agency (EPA)
The Environmental Protection Agency (EPA) was created in 1970 to manage the federal government’s environmental responsibilities under one agency. These responsibilities related to environmental issues that the public had grown increasingly concerned with, including “deteriorating city air, natural areas littered with debris, and urban water supplies contaminated with dangerous impurities.”
In early 1970, President Richard Nixon presented the House and Senate a groundbreaking 37-point message on the environment. This was in response to heightened public concerns about deteriorating city air, natural areas littered with debris, and urban water supplies contaminated with dangerous impurities. These points included:
- Requesting $4 billion for the improvement of water treatment facilities,
- Asking for national air quality standards and stringent guidelines to lower motor vehicle emissions,
- Launching federally funded research to reduce automobile pollution,
- Ordering a cleanup of federal facilities that had fouled air and water,
- Seeking legislation to end the dumping of wastes into the Great Lakes,
- Proposing a tax on lead additives in gasoline,
- Forwarding to Congress a plan to tighten safeguards on the seaborne transportation of oil, and
- Approving a National Contingency Plan for the treatment of oil spills.”
— US Environmental Protection Agency (EPA)
Best Practices for Preparedness
Prepare for Unhealthy, Very Unhealthy or Hazardous air quality by taking the following steps:
- Be mindful of current and projected weather and air quality conditions, and proactively reschedule or relocate activities or develop back-up indoor plans if possible.
- Make a plan with your family, friends, and coworkers to accommodate sensitive or special consideration individuals during air quality events, including personal leave time if necessary.
- Ensure your air-conditioning and filter units are clean and ready to help keep the indoor air safe. If you are unsure of what to do at work, log a customer service request.
- Do not add to indoor pollution and minimize activities which stir up dust and other materials into the air.
- Work with your doctor or medical professional if you are in the sensitive group category to make a proactive plan for managing respiratory health.
- Do not use bandannas or wet cloths as face coverings during poor air quality events, as these do not provide good protection. Work with your health care provider to determine whether wearing an appropriate mask is a good solution for your risks.23Division of Emergency Management and Homeland Security, “Air Quality,” Connecticut State.
Monitor and limit exposure to air pollution:
- Check current air quality by visiting AirNow.gov.
- Check forecasted air quality levels by visiting NYS DEC’s website, which provides daily updates and can send you alerts by email, text, or mobile app.
- Sign up for air quality alerts from Notify NYC.
- Look out for air quality alerts on the radio and TV.
- Limit the time you spend outside when air quality is poor. However, indoor air quality can be worse than outdoor air quality if someone is smoking cigarettes or hookah indoors.
- Plan outdoor activities for days when pollution levels are low.
For those with medical conditions that maybe be aggravated by poor air quality, make sure to plan and store critical supplies such as:
- Multiple days’ worth of food and water
- Important medications and medical condition management plans
- N95 or KN95 masks and air filters
- Other basic supplies needed to avoid going outdoors
Here are some tips for how you can help lower air pollution levels:
- Choose a cleaner commute. Ride the subway or bus or bike and walk to get around. If you have to drive, drive an electric vehicle.
- Follow the City’s car idling law.
- Support City initiatives to reduce pollution and promote energy conservation.
To improve the air quality in your home, remove or reduce pollutant sources and regularly bring in fresh clean air from outside. Air filters and portable air cleaners can also help improve air quality together with air pollutant control and ventilation.
For businesses, we recommend establishing a control strategy to mitigate the extent of potential pollution. You can find more informational material provided by the EPA.
For businesses in New York City, accommodating employees during poor air quality periods is a new issue. Experiences like the 2023 wildfire smog are likely to become more frequent. It is critical for the health of employees for businesses to be able to adjust practices to limit the impact of poor air quality on health. If your business has employees that work outdoors, consider options that can reduce employee exposure to poor air quality.
These are some of the recommended practices for employers to implement for outdoor employees:
- Ensure employees know how to find current air quality ratings.
- Create internal policies and procedures on how to adjust workplace practices to accommodate for poor air quality.
- Establish training and communication programs to inform employees of smoke exposure reduction protocols.
- Establish clear guidance for employees to report worsening air quality conditions and any health impacts they are experiencing from smoke.
- Determine whether on-site air quality ratings are needed and, if so, establish on-site measurement standard operating procedures.
- Reduce outdoor work wherever possible when air quality drops below recommended levels.
- Plan for poor air quality by allowing alternate indoor work locations, such as work from home.
- Provide employees working outside or in transitional settings with additional breaks in a setting with filtered air.
- Assure access to N95 respirators and encourage employees to use them.
- Establish a training program for the use and proper fitting of N95 respirators.
Employers should consider these recommendations to reduce poor air quality exposure for indoor employees:
- Use low-VOC office and cleaning supplies.
- Test your building’s HVAC system.
- Make sure the HVAC system does not draw in outdoor air.
- Install high-efficiency air filters.
- Keep doors and windows closed as much as possible.
- Use other options to keep employees in a safe setting, such as telework or reduced work schedules.
- Make sure to have a communication and action plan developed prior to a smoke event.