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About Ozone

Picture of harmful ground-level ozone in NYC

What is Ground Level Ozone Pollution?

Ground level ozone is not emitted directly into the air, but is created in the air itself. Ozone forms on hot sunny days when pollution from cars, power plants, consumer products and other sources react with sunlight.

Health Effects of Ground Level Ozone

Ozone in the air we breathe can harm our health. People most at risk from breathing air containing ozone include people with asthma, children, older adults, and people who are active outdoors, especially outdoor workers. Breathing ozone can trigger a variety of health problems including:

  • Eye irritation
  • Chest pain
  • Coughing, shortness of breath and decreased lung function
  • Increased susceptibility to respiratory infections
  • Increased likelihood of asthma attacks
  • Inflammation of the lungs
  • Ozone can worsen bronchitis, emphysema, and asthma, leading to increased medical care.
Ozone over New York City
NYC - February 2005.

New York State Warns of High Ozone Levels

Public health officials caution against strenuous outdoor activity when ozone levels are high. To help people decide when to curtail activity, DEC forecasts ozone pollution and, in cooperation with the NYS Department of Health, posts warnings if dangerous conditions are expected to occur. These warnings are also aired through the media and are available on the toll-free Ozone Hotline at 1-800-535-1345.

Environmental Effects of Ground Level Ozone

Plant showing damage caused by ground-level ozone
Cotton plant showing damage caused by ground-level ozone.
Courtesy of USDA-ARS, Fitzgerald Booker
  • Damage to leaves, trees and other plants during the growing season.
  • Sensitive plants are at greater risk for disease, insect damage and other environmental effects.

How to Reduce the Formation of Ground Level Ozone

  • Choose a cleaner commute - car pool, public transportation, bike or walk when possible.
  • Combine errands and avoid extended idling.
  • Use environmentally safe paints and cleaning products whenever possible.
  • Avoid gasoline and chemical spills around the home.
  • Avoid using polluting chemicals during poor air quality days.
  • Conserve electricity. Consider setting your thermostat a little higher in the summer and lower in winter.

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