PORTLAND – Public safety workers are working unsustainable overtime hours as they respond to bioterrorism scares, patrol airports and give protection to potential terrorism targets.

The heightened vigilance and extra work of public safety workers is occurring nationwide.

But it is acute in Portland and the rest of Maine because two of the suspected hijackers began their trek of terror Sept. 11 by boarding a plane in Portland and flying to Boston before boarding another plane and flying it into one of the World Trade Center towers.

Police have been swamped with tips from people who believe they saw suspicious activity or one of the hijackers in Maine before the attacks. Local departments must do an initial assessment on each credible tip before forwarding it to the FBI.

Also, firefighters and police must respond each time a suspicious package is reported, and that is changing the way emergency workers view their job.

“Responding to an anthrax call or a terrorist incident wasn’t something that was initially on your everyday thought process,” said Portland Deputy Fire Chief Fred LaMontagne. “Having seen [the New York City attack] we realize there is nothing beyond the scope of possibility here, and certainly that affects the way [firefighters] feel about their job and every call. Nothing is seen as routine any more.”

Supervisors in several police departments are clamping down on how much overtime officers are working and are keeping alert for signs of burnout.

“We get to a point where we forget we need our rest,” said Police Chief Jerry Hinton in Brunswick, where the department has announced that officers are unavailable to work for some outside security details.

In Portland, however, the department waived a rule after the attacks that no officer can work more than 64 hours a week. That’s because of the increased demands for a police presence at places like the Portland International Jetport.

The Coast Guard has also been stretched as it tried to escort every cruise ship and oil tanker in the Port of Portland in the weeks after the terrorist attacks. Now it has adopted a more selective escort strategy so it does not overtax its limited personnel.