PORTLAND — The United States Environmental Protection Agency is forecasting poor air quality in the region Tuesday.

Poor air quality, which is caused by high amounts of ground-level ozone, will affect coastal Maine from Acadia National Park to points south, according to a release issued by the EPA.

“We predict that Tuesday will be an unhealthy air quality day in parts of New England,” said Curt Spalding, Administrator of EPA’s New England office. “On these hot, humid and smoggy days, EPA and the medical community suggest that people limit their strenuous outdoor activity.”

EPA officials said poor air quality is also expected to affect coastal Connecticut, Rhode Island, southeastern Massachusetts including Cape Cod and offshore islands.

Exposure to elevated ozone levels can cause breathing problems, aggravate asthma and other pre-existing lung diseases and make people susceptible to respiratory infection.

When ozone levels are elevated, people should refrain from outdoor activity, especially sensitive populations such as children and adults with respiratory problems.