As temperatures climb, Ozone Air Quality Advisories have been issued two days in a row this week for the New York City metro-area and Long Island. Similar ozone advisories were issued two days last week.

Ozone is a dangerous ground-level air pollutant that should not be confused with the protective layer of ozone in the upper atmosphere. Ozone pollution is caused by auto exhaust and larger emission sources, such as power plants which burn fossil fuels.

Ozone pollution is also exacerbated by rising temperatures due to climate change.

Tuesday and Wednesday’s advisories this week apply to New York City, Westchester and Rockland counties, and Long Island, including Nassau and Suffolk counties.

New York State Department of Environmental Conservation (DEC) Commissioner Joe Martens and State Department of Health (DOH) Commissioner Howard Zucker issued the advisories, which are in effect each day until 11 p.m.

Higher Temperatures = More Ozone Pollution

Unlike other air pollutants, ozone is not directly emitted by pollution sources. Instead, this “powerful oxidant” is formed in the air itself during smog conditions.

High temperatures (over 80°F) and sunlight react with emissions from vehicles and smokestacks to form ozone. Hydrocarbons such as gasoline vapors and nitrogen dioxide – what the state calls “ozone precursors”- can help to trigger the gas.

According to the state, automobile exhaust and out-of-state emission sources (such as power plants) are the primary sources of ground‑level ozone.

As average temperatures rise across the U.S. (and the globe) due to climate change, ozone pollution is also expected to increase unless the emission of ozone precursors can be cut significantly.

Americans face the risk of a 70 percent increase in unhealthy summertime ozone levels by 2050, a 2014 National Science Foundation study found. According to the NSF:

“Even short periods of unhealthy ozone levels can cause local death rates to rise. Ozone pollution also damages crops and other plants….However, the research also showed that a sharp reduction in the emissions of certain pollutants would lead to dramatically decreased levels of ozone even as temperatures warm.”

A public health threat for New Yorkers

Ozone is one of the most serious air pollution problems in the northeast. The New York City-metro area is currently in “non-attainment” of 2008 federal ozone standards.

A recent analysis by the City of New York estimated that 2,700 “premature” deaths every year can be tied to ozone and fine particulate matter, two separate air pollutants. Roughly 1 in 10 emergency room visits for asthma in New York City are attributable to ozone pollution.

asthma patient 2
Young asthma patient. Photo credit:

New York State (and City) have made major progress in reducing levels of fine particulate matter pollution, which is released by combustion sources such as building heating systems, vehicle exhaust, power plant and industry emissions, and even wood burning.

Reducing ozone levels, because they are tied to rising temperatures and partially caused by out-of-state pollution sources, remains a huge challenge.

Failing grades for ozone pollution in the NYC metro area

According to the 2015 State of the Air report card released by the American Lung Association, Suffolk and Westchester counties, along with the Bronx, Queens and Staten Island, all received failing grades for ozone pollution.

Both Manhattan and Rockland County received a “D”. Data for Brooklyn and Nassau County was unavailable.

The grades were calculated by totalling the number of days (in 2011, 2012 and 2013) in which ozone levels surpassed public safety guidelines over an 8-hour period. Suffolk County experienced 24 days when ozone levels were “orange”, or dangerous for sensitive populations. Staten Island experienced 17 such days, and Queens experienced 15.

Take precautions- especially when ozone levels peak

People, especially young children, those who exercise outdoors, those involved in vigorous outdoor work and those who have respiratory disease (such as asthma) are being asked to consider limiting strenuous outdoor physical activity when ozone levels are the highest (generally afternoon to early evening).

When outdoor levels of ozone are elevated, going indoors will usually reduce your exposure. Individuals experiencing symptoms such as shortness of breath, chest pain or coughing should consider consulting their doctor, say state officials.

Ozone levels generally decrease at night. They can be minimized during daylight hours by the reduction of pollution from cars and other vehicles, for instance.

New Yorkers can help reduce ozone levels by using mass transit and conserving energy

State regulators are urging New Yorkers to:

  • use mass transit or carpool instead of driving, as automobile emissions account for about 60 percent of pollution in our cities;
  • conserve fuel and reduce exhaust emissions by combining necessary motor vehicle trips;
  • turn off all lights and electrical appliances in unoccupied areas;
  • use fans to circulate air. If air conditioning is necessary, set thermostats at 78 degrees;
  • close the blinds and shades to limit heat build-up and to preserve cooled air;
  • limit use of household appliances. If necessary, run the appliances at off-peak (after 7 p.m.) hours. These would include dishwashers, dryers, pool pumps and water heaters;
  • set refrigerators and freezers at more efficient temperatures;
  • purchase and install energy efficient lighting and appliances with the Energy Star label; and
  • reduce or eliminate outdoor burning and attempt to minimize indoor sources of PM 2.5 [fine particulate matter pollution] such as smoking.

More helpful info from state regulators

The state departments of Environmental Conservation and Health issue Air Quality Health Advisories when DEC meteorologists predict levels of pollution, either ozone or fine particulate matter, are expected to exceed an Air Quality Index (AQI) value of 100. The AQI was created as an easy way to correlate levels of different pollutants to one scale, with a higher AQI value indicating a greater health concern.

A toll‑free Air Quality Hotline (1-800-535-1345) has been established by DEC to keep New Yorkers informed of the latest Air Quality situation.

Further information on ozone and PM 2.5 [fine particulate matter pollution] is available on DEC’s web site and on the DOH website.