Unhealthy air for region this week due to ozone and Canadian wildfire smoke

Long Islanders who are very sensitive to air pollution should consider limiting outdoor activities Tuesday because of ozone pollution, authorities said, though by late Monday the region was not subject to the air quality health advisories covering New York City and parts of the rest of the state.

Those advisories were issued because of smoke from Canadian wildfires. While Canadian and U.S. federal monitoring showed plumes from those fires impacting much of the northeast United States including Long Island, the Environmental Protection Agency's AirNow air quality portal showed real-time and forecast readings for Long Island that were better than those for most of the rest of the state.

Shortly before 6 p.m. Monday, the AirNow portal showed an index of 105 for Melville in central Long Island, with a Tuesday forecast of 100. New York City was at 119 with a Tuesday forecast of 110. The index converts all pollutant levels into a single number. The lower the number, the better. Anything below 50 is classified as "healthy." Fifty to 100 is "moderate," while 100-150 is unhealthy for "sensitive groups."

On Monday, levels of the pollutant ozone made outdoor activity potentially unhealthy for some people on Long Island and in New York City, authorities said. Suffolk County Health Commissioner Dr. Gregson Pigott on Monday morning warned all residents, especially young children, seniors, people with health conditions or those who exercise outside, to "limit strenuous outdoor activity." Levels of ozone, the principal compound of smog, produced when sunlight hits air contaminants from car exhaust and other sources, are often highest on hot, sunny afternoons, according to the county health department.

Smoke from the wildfires was set to drift south into the metro area Monday, according to the National Weather Service, possibly giving the sky a milky appearance, according to meteorologist James Tomasini, but not significantly impacting visibility.

FireSmoke Canada, a portal for information about wildland fire weather and smoke operated by the Canadian government, showed plumes of smoke from fires in the central part of that country extending into the American Midwest and Northeast, including Long Island.

By July 30, according to the Canadian government, the number of wildfires countrywide was slightly behind the 10-year average but the area burned was far ahead: 15.3 million acres for the year so far, versus the average 6.7 million acres.

Tomasini said prevailing winds would likely clear smoke from the Island by the end of the week.

Dr. James V. McDonald, the state's health commissioner, told reporters at a Monday briefing, conducted online, that New Yorkers can probably expect air quality alerts to be a regular summer occurrence in years to come. "The climate has changed, and I think this is part of the new normal," he said.

Monday's ozone warning came less than a week after the federal Environmental Protection Agency proposed rescinding the 2009 finding that carbon dioxide and other greenhouse gases threaten public health and rescinding limits on tailpipe emissions.

Should the new EPA rules be implemented, "I think we could expect that to contribute to increased ozone," said Amanda Lefton, commissioner of the state's Department of Environmental Conservation, at the Monday briefing. The proposed rule change "ignores 15 years or more of progress in science," she said.

The EPA said its proposal would reinstate consumer choice while decreasing the cost of living.

"Many stakeholders have told me that the Obama and Biden EPAs twisted the law, ignored precedent, and warped science to achieve their preferred ends and stick American families with hundreds of billions of dollars in hidden taxes every single year," EPA Administrator Lee Zeldin said, announcing the proposal.

The Associated Press contributed to this story.

By Nicholas Spangler

nicholas.spangler@newsday.comspanglernewsday

Nicholas Spangler is a general assignment reporter and has worked at Newsday since 2010.