The annual report of the Office of the Provincial Advocate for Children and Youth

Ontario's new advocate for youth and children says it's unacceptable that 90 children who were known to child protection services died in 2007.

The deaths include children in foster care, provincial custody or from families with open files with children's aid organizations.

The numbers were provided by the office of the chief coroner.

In his first report released Monday, 90 Deaths: Ninety Voices Silenced, Irwin Elman says some may argue that 90 deaths is a small number compared with the 26,260 cases currently at children's aid societies across the province.

But he rejects that, saying the figure is "too high by any standard."

"I was startled by the number. I had no idea that this many children in the system are dying. And from my understanding, this number has been pretty consistent over 10 years. So, just multiplying 90 by 10, it's just startling to think that 900 to 1,000 kids in 10 years that have been deemed in peril by the state in some way have died. That's startling," he said.

According to the 2008 coroner's report, most of these deaths were preventable.

"We need to recognize that such deaths occur each year and we need to say as a society that we cannot accept this," said Elman.

Where the manner of death is known, 45 per cent of the children who died were under one year of age, and 32 per cent were between 12 and 18.

Elman said efforts to investigate the cases have been hampered by various provincial ministries, citing privacy issues.