An Ozone Air Quality Advisory was in effect Monday for the New York City metro-area and Long Island. Ozone is a dangerous ground-level air pollutant and should not be confused with the protective layer of ozone in the upper atmosphere.

Ozone pollution is caused by auto exhaust and larger pollution sources, such as power plants which burn fossil fuels. Ozone levels are directly tied to higher temperatures.

Monday’s advisory applied to New York City, Westchester and Rockland counties, and Long Island, including Nassau and Suffolk counties. An advisory was also issued on Sunday for those areas and the Lower Hudson Valley.

New York State Department of Environmental Conservation (DEC) Commissioner Joe Martens and State Department of Health (DOH) Commissioner Howard Zucker issued Monday’s advisory, which was in effect until 10 p.m.

What is Ozone?

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.

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 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.

New York City has made major progress in reducing levels of particulate matter pollution. Reducing ozone levels, especially because they are partially caused by out-of-state pollution sources, remains a huge challenge.

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

DEC and DOH 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.