SLAVE LAKE, Alta. - The Alberta government says that test results from ash samples taken from the burned-out areas of Slave Lake show that contaminant levels do not present a risk to human health.
Alberta Health Services is still advising residents to use caution when entering burned-out areas, ensuring contact with the ash and debris is minimized.
Dr. Kathryn Koliaska, medical officer of health, says it's important for people to protect themselves from tripping and falling into the ash.
People returning to their devastated homes in Slave Lake had been told last week to sign waivers while the province checked for heavy metals and toxins in the fire-scarred town's soil.
Mayor Karina Pillay-Kinnee said at the time the waivers would shield the municipal government from blame if anyone was injured while visiting devastated neighbourhoods.
She said the intent was to ensure everyone understood how dangerous the sites were.
It's been nearly a month since nearly 7,000 people fled their homes in the face of a forest fire that levelled more than 400 homes and businesses, about one-third of the town.
People have since been allowed to return and many businesses and public services have resumed.
The provincial soil testing was the first time Alberta has done so in a residential area destroyed by a forest fire.
Studies done in California after major fires in 2003 and 2007 suggest what could be found. Research in the U.S. state found levels of lead, arsenic and antimony that exceeded Environmental Protection Agency guidelines. Potentially toxic hydrocarbon residues were also discovered.
Ash from the fires was also found to be so alkaline it was caustic, threatening eyes, noses and lungs -- as well as watersheds.
The province noted that many of the potentially hazardous compounds would have been in construction materials used in homes, while other compounds occur naturally after forest fires.
Alberta Health Services said it is expected the contaminant levels will decrease naturally over time.
Alberta Environment said testing will continue over the next six months.
