Public health units across Ontario are raising concerns about a sweeping amalgamation of their services planned by the province, saying the changes could affect the delivery of programs and lead to layoffs.

Dr. Robert Kyle, president of the Association of Local Public Health Agencies, said the units have so far received only "high level" information from the government about the consolidation of 35 units into 10 in a process set to get underway later this year.

The planned transformation comes as the government lowers its public health spending, requiring municipalities to contribute millions more to their health budgets than anticipated.

By 2021-2022, the provincial cut is expected to be $200 million annually.

The situation has chief medical officers of health across Ontario worried about disruption to essential public health service delivery, Kyle said.

"While all of this is happening, we have to continue to provide programs and services," he said. "It's almost akin to having an auto mechanic fine-tuning a car that's still running."

Ontario's public health units co-ordinate services including vaccination programs, infectious disease outbreak investigations and restaurant inspections.

It's unclear if the amalgamation exercise will result in savings, but it could result in layoffs since frontline staffing makes up a significant portion of agency budgets, Kyle said.

The government has said it conducted a review of the province's public health units and believes the current structure does not allow for consistent service delivery.

Amalgamation will help strengthen the system, the Tories said, but the agencies and municipalities still have to work out the specifics.