TORONTO - Liberal Leader Dalton McGuinty is defending his party's plans to erect hundreds of wind turbines in the province amid new concerns about the health risks involved for those who live near the giant windmills.

"The science in fact is there," McGuinty said Thursday during a campaign stop at a Toronto hospital.

"We've also funded a university chair so that we can conduct our own longitudinal study here in Ontario, in addition to those that have been conducted in other parts of the world, to make sure we're being safe. It's really important that we rely on the science."

McGuinty's comments come after a report that the province's Ministry of the Environment received hundreds of complaints over negative health effects of the turbines, which it downplayed.

A southwestern Ontario family also announced this week it was suing over a wind farm they claimed was damaging their health, saying they have suffered vertigo, nausea and sleep disruption because of the Kent Breeze wind farm.

The wind farm began operating in May and includes eight turbines, the closest of which is 1,146 metres from the Michaud's property.

The lawsuit comes a week after another southwestern Ontario couple went to court saying they were being blocked in their efforts to determine if wind turbines cause any adverse health effects.

The Liberals also faced some criticism while visiting eastern Ontario for the annual plowing match on Tuesday, especially from farmers who live near the windmills and complain of a range of health problems they associate with the energy projects.

McGuinty acknowledged the controversy that day, but said there were also many farmers who had applied to earn extra cash from the government's generous payments for wind and solar power by applying for their own green energy projects.

The Liberal leader spent much of last week touting green jobs, but mostly visited solar panel plants, not wind turbine makers. The only exception was a stop at the CS Wind plant in Windsor, which makes wind turbine towers.

Progressive Conservative Leader Tim Hudak has promised a moratorium on wind turbines and has said he'd allow local municipalities to have a say over such projects.

"I think Dalton McGuinty's policies of forcing industrial wind turbines like pins in a pin cushion across the province is wrongheaded," said Hudak.

"I think it's causing damage to communities and it's awfully expensive, driving up our hydro bills."

The New Democrats have yet to take a clear position on wind turbines, but leader Andrea Horwath said she hasn't been waffling on the issue.

"We've been very clear that we are supportive of renewable energy and adding new renewable energy to our grid," she said.

"But where I think the Liberals have fumbled the ball quite seriously is in cutting out community from the discussion, and I think this is why we're in such a bad situation."

Horwath said she wasn't "particularly convinced" that wind turbines made people sick, adding "it's not something that the medical evidence is showing."

"But I'm not to judge, I don't live beside a wind turbine, I don't have one on my property," she said.

"I'm sympathetic to the fact that every human experiences things in a different way."

McGuinty made his comments while promising an expansion project for Mount Sinai Hospital in Toronto,which will include the renovation of the emergency ward and a new surgical suite with 19 operating rooms.

He used the hospital stop, which was one of several this week, to attack the Progressive Conservatives' health record, saying they cut funding to that particular hospital by $12.5 million a year when Mike Harris was premier.

The Tories shot back, saying that between 1995 and 2003 the party increased Mount Sinai's budget by $78 million or 69 per cent.

The party has also promised to boost health-care spending by $6.1 billion if elected.

McGuinty, they said, "needs to stop lying to Ontario families" by claiming the PCs would cut investments in health care.