The New York and Pennsylvania state department of transportation officials say Saturday is an Air Quality Action Day, a day when air quality will be unhealthy, especially for children, seniors and people with asthma and other respiratory ailments, due to forecast high levels of ground-level ozone pollution.
This alert is issued for parts of the New York downstate metropolitan region -- the five boroughs of New York City, Long Island and lower Hudson Valley -- and these residents are asked to leave their cars at home and/or stay indoors as much as possible.
In Pennsylvania, air quality action day predicts Saturday to have unhealthy pollution levels for sensitive people in the Liberty-Clairton region in Allegheny County; the Philadelphia region; the Susquehanna Valley region of Cumberland, Dauphin, Lancaster, Lebanon and York counties; and the Lehigh Valley region of Berks, Lehigh and Northampton counties.
Pennsylvania officials say ground-level ozone -- which forms when pollution from vehicles, industry, households and power plants "bakes" in the hot sun -- makes it hard for some to breathe.
New York officials also ask these residents to:
-- Use public transportation.
-- Refuel after dark because this prevents some pollutants from being emitted into the air and reacting with sunlight.
-- Avoid operating gas-powered gardening equipment such as lawn mowers.
Notable deaths of 2014 [PHOTOS]