Efforts by a local health care firm to level a sloped area in the parking lot of its proposed medical office building on Main Street have brought criticism from many Wakefield residents.

They object loudly to the way that slope would be eliminated: with blasting.

About 230 neighbors signed a petition asking the town’s Zoning Board of Appeals to deny Hallmark Health permission to blast, citing “potential damage to our homes, the safety of our pets, our elderly, and our peace of mind.’’

Despite neighbors’ objections, the board voted unanimously Wednesday to approve the variance, special permit, and site plan the project needed.

The vote came after Hallmark pledged to offer pre-blast surveys to any home requesting one (state rules require surveys only to homes within 250 feet), to hold a community meeting on the plan, and to distribute fliers and post information on a website, according to the Building Department.

Board members also advised neighbors that the fire chief is responsible for granting blasting permits.

But Kevin R. Sullivan, a leader of the petition drive, said neighbors were disappointed with the board’s decision and are likely to file an appeal.

“I think their attitude about the petition and our concerns was very dismissive,’’ he said of the board, adding that the commitments made by Hallmark did not leave residents reassured about the blasting. “It doesn’t take away the anxiety we feel.’’

Rob Brogna, a Hallmark spokesman, said, “We appreciate the zoning board’s thorough and thoughtful process and we look forward to working with the town of Wakefield and the neighbors.’’

Hallmark, a nonprofit that owns Melrose-Wakefield Hospital in Melrose and Lawrence Memorial Hospital in Medford, wants to construct the 30,000-square-foot medical facility on the site of a former Subaru dealership.

The firm wants to blast a portion of ledge to eliminate a slope at the rear of its parking lot, according to Hugh Kelleher, Hallmark’s vice president of support and ancillary services. One to three blasts daily would occur over 20 days.

“We are working to bring the grade down to a level where it’s safe not only for our patients but for our employees and the physicians working in the building,’’ Kelleher said, citing the risk that someone could slip on the sloped area on an icy winter day.

Hallmark needs the variance because the building is within 15 feet of an adjacent residential zone, and a special permit because the project provides slightly less than the required number of parking spaces. Site plan approval is needed for all new developments, according to building inspector John Roberto.

Fire Chief Michael J. Sullivan said Hallmark has advised him of its proposal to blast, though it has not yet applied for a blasting permit it is required to obtain from him.

The proposed facility would include doctors’ offices, imaging and physical rehabilitation services, and a lab for collecting samples.

“We are excited about having a presence in the town,’’ Kelleher said. “We have Melrose-Wakefield Hospital, and now we will be in Wakefield so we can proudly represent the community.’’

John Laidler can be reached at laidler@globe.com.