The Nova Scotia Court of Appeal has struck down an attempt by Sydney residents to launch a class action suit against the Sydney Steel Corporation, saying if they want to sue, they will have to do so individually.

Approximately 400 people had signed on to the lawsuit, alleging they and their properties were damaged by the old steel plant. Although the residents gave up claims for personal compensation in an earlier court proceeding, they allege they are still being exposed to the contaminants.

The class action was certified by a justice with the Supreme Court of Nova Scotia in January 2012, but that was appealed by the governments of Nova Scotia and Canada.

That appeal was upheld by the three judges of the Nova Scotia Court of Appeal.

"We're disappointed because we saw this as the only real route for access to justice for people who have had their properties impacted by the operations of Sydney steel works," said Ray Wagner, the lead lawyer for the class action suit.

"The problem with individual actions is that the cost of litigation in an environmental case is very excessive. Really, the only way to reasonably access justice is to be able to group those cases all together and provide mutual support in terms of advancing the case in that particular fashion."

The judges of the Nova Scotia Court of Appeal ruled a class action was not the best way to deal with the issue and the members would be better off filing individual lawsuits.

"The respondents argue that the class members' claims, individually, are so small that it would not be worthwhile for them to pursue relief individually and their financial resources are such that they cannot afford to bring separate proceedings. We appreciate their position and have given their argument serious consideration," the ruling says.

"However, as we have explained, the determination of what constitutes a nuisance is so individualized that it would still be necessary for the individual claimants to pursue their own claims. Any costs they would incur in proving nuisance would not be significantly mitigated by certification of this proceeding."

Wagner said he and his team will review the ruling with their clients to decide whether to appeal the decision to the Supreme Court of Canada.

"The decision has broad implications, not only for the people that are directly impacted in Sydney and for Cape Bretoners and people in Nova Scotia, but also across the country," he said Wednesday.

"It could be a death knell to class actions in the environmental field in an era, in a time when environmental concerns are being heightened."