The New York State Department of Environmental Conservation and Department of Health have issued an air quality health advisory for Monday, June 23, for ozone in the Long Island and New York City regions.

The advisory will be in effect from 11 a.m. through 11 p.m.

The Air Quality Health Advisory regions consist of all of Long Island, New York City, Rockland, and Westchester counties.

DEC and DOH issue Air Quality Health Advisories when DEC meteorologists predict levels of pollution, either ozone or fine particulate matter (PM2.5), 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.

High ozone levels

Summer heat can lead to the formation of ground-level ozone, a major component of photochemical smog. Automobile exhaust and out-of-state emission sources are the primary sources of ground-level ozone and the most serious air pollution problems in the northeast. This surface pollutant should not be confused with the protective layer of ozone in the upper atmosphere.

Ozone is not a direct emission, and is produced indirectly when sunlight chemically reacts with nitrogen oxides and volatile organic compounds from automobile exhaust and industrial emissions. High ozone is not as visible as PM2.5 because it is a colorless gas, but will produce hazy skies and reduce visibility in high concentrations.

People, especially those with cardiovascular disease and those who have respiratory disease (such as asthma), young children, the elderly, those who exercise outdoors, and those involved in vigorous outdoor work should 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 exposure. Individuals experiencing symptoms such as shortness of breath, chest pain, or coughing should consider consulting their personal physician.

Ozone levels generally decrease at night and can be minimized during daylight hours by curtailment of automobile travel and the use of public transportation where available.

New Yorkers also are urged to take the following energy-saving and pollution-reducing steps: