The Nassau County Department of Health alerts residents that the ozone level exceeded Federal and State levels at the Health Department's Laboratory in Hempstead yesterday. This was the third day this year's readings have exceeded Federal and State standards. The ozone levels are expected to exceed these levels again today.

Ozone guidelines, which were established in 1998, state that when the average ozone concentration over an eight hour period is greater than 0.08 parts per million, persons at risk should take precautionary measures. The very young, the elderly, or persons with existing heart and/or respiratory ailments should reduce physical and outdoor activities. Heavy outdoor exercise by others should also be avoided.

Ozone is a health concern because high concentrations may irritate nasal, throat and bronchial tissues, and attack components of the body's defense system. Respiratory symptoms resulting from ozone exposure may include shortness of breath, chest pain, throat irritation, cough and wheezing.

Up-to-date ozone level reading will continue to be available by calling the Nassau County Department of Health Laboratories 24-hour line at 572-1200 weekdays. In addition, staff is available weekdays between 9:00-3:00 p.m. to answer questions.

In addition, the New York State Department of Environmental Conservation (DEC) constantly monitors ozone levels throughout the state and issues health advisories in cooperation with the New York State Department of Health when they predict elevated ozone levels. The advisories are aired through the media and available on the New York State DEC toll-free Ozone Hotline telephone number: 1-800-535-1345.