The Nunavat government put out a public health advisory on Friday with the new warning for women in Iqaluit.
It says new air quality data indicates the total level of dioxins and furans — toxic chemicals released when hazardous waste is burned —exceed the health standard set by Ontario.
The advisory says while long-term exposure to high levels of dioxins is known to increase cancer risk, the levels of dioxins observed in Iqaluit are far below the health standard for cancer.
But the warning for women of child-bearing age has been issued because the Nunavut government says there is a possible risk that dioxins above the standard may lead to decreased fertility in male offspring.
Last month, the Nunavut Health Department warned those with heart and lung disease, the elderly and the very young to stay indoors as much as possible, with the windows closed.
"Based on the new information, women of child-bearing age should also limit their exposure to the dump fire smoke, as a precaution," the Nunavut government said in its advisory.
"These people should avoid the area around the dump fire and stay indoors as much as possible with the doors and windows closed."
Iqaluit residents have been living with the fire dubbed the "dumpcano" — a combination of dump and volcano — since it flared up May 20 from spontaneous combustion.
City officials say a lack of money and manpower prevents them from dousing the fire.
Nunavut mayors first asked the federal government for extra money to fix dangerous dumps and failing sewage lagoons in 2001. A 2004 report by the Conference Board of Canada made similar points, as did a 2010 consultant's study for Environment Canada.