Monday's explosion and fire at the Irving Oil refinery was heard and seen for miles around, but many people were left wondering what had happened and whether they were safe.

This week, civic officials in Saint John have been demanding answers about the flow of information to the public while thick plumes of black smoke rose to the sky over the Irving Oil refinery.

Others say the apparent shortcomings call for a provincial investigation as well.

“Address this issue of leaving residents and neighbours of the refinery in the dark for a long time when this was going on, leaving them fearful and what they should do,” said New Brunswick Green Party leader David Coon.

A handful of workers received relatively minor injuries in the blast and were treated in hospital or in doctor's offices.

There is concern that Monday's explosion and fire may have left more than physical scars, especially for those who were in close proximity to the explosion.

Irving Oil did not respond to our questions today, though in the immediate aftermath of the explosion, the company said counselling would be available.

“We do have employee assistance counselling for our own employees and for contractors as well, should anyone want to take advantage of that,” Kevin Scott of Irving Oil said on Monday.

Workers on the site could suffer symptoms typical of post-traumatic stress.

"Some people will develop anxiety symptoms (such as) worrying,” said Dr. Mike Simon. “They may develop dizziness or headache. They may be agitated, or be unable to sleep or their appetite goes down.”

These symptoms may not appear for weeks, or even months.

“Sometimes, you have a delayed reaction to a traumatic stressor,” said UNBSJ psychologist Dr. Mary Ann Campbell. “You may not have these symptoms right now, or at a high level right now, but after a couple of months, you may find that they're there, and you feel they're more intense than they should be for where you're at.”

The Boilermakers Local 73 has more than 600 people working on the turnaround maintenance project. A spokesman said today that its members have access to counselling and are being encouraged to use it, in the wake of Monday’s explosion and fire.

There's no word yet on when workers will be returning to work full time.

With files from CTV Atlantic’s Mike Cameron.