New York State Department of Environmental Conservation (DEC) Commissioner Amanda Lefton and State Department of Health (DOH) Commissioner Dr. James McDonald are updating the Air Quality Health Advisory in place for smoke enhanced fine particulate matter pollution to include ozone on Thursday, June 12, 2025, for the Long Island, New York City Metro, and Lower Hudson Valley regions. The advisory on fine particulate matter remains in effect for these regions due to the impact of smoke from wildfires in Canada. 

The pollutants of concern are: 

• Fine Particulate Matter
• Ozone 

The fine particulate matter advisory will be in effect from 12 a.m. through 11:59 p.m. 

The ozone advisory will be in effect from 11 a.m. until 11:59 p.m. 

The Air Quality Health Advisory regions consist of: Long Island, which includes Nassau and Suffolk counties; New York City Metro, which includes New York City, Rockland, and Westchester counties; and Lower Hudson Valley, which includes Dutchess, Orange, Putnam, Ulster, and Sullivan 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. 

Ozone

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 (NOx) and volatile organic compounds (VOCs) 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. 

Fine Particulate Matter
Fine particulate matter (PM) consists of tiny solid particles or liquid droplets in the air that are 2.5 microns or less in diameter. PM 2.5 can be made of many different types of particles and often come from processes that involve combustion (e.g., vehicle exhaust, power plants, and fires) and from chemical reactions in the atmosphere. 

Exposure can cause short-term health effects, such as irritation to the eyes, nose, and throat, coughing, sneezing, runny nose, and shortness of breath. Exposure to elevated levels of fine particulate matter can also worsen medical conditions such as asthma and heart disease. People with heart or breathing problems, and children and the elderly may be particularly sensitive to PM 2.5. 

When outdoor levels are elevated, going indoors may reduce exposure. If there are significant indoor sources of PM 2.5 (tobacco, candle or incense smoke, or fumes from cooking) levels inside may not be lower than outside. Some ways to reduce exposure are to minimize outdoor and indoor sources and avoid strenuous activities in areas where fine particle concentrations are high. Additional information on ozone and PM 2.5 is available on DEC's website and on DOH's website. 

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

• 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 such as smoking.  

Additional information on ozone and PM 2.5 is available on DEC's website and on DOH's website (PM 2.5) / DOH's website (ozone). A new DEC fact sheet about the Air Quality Index is available on DEC’s website or by PDF download https://dec.ny.gov/sites/default/files/2024-05/aqiweb.pdf.