Chicago (Illinois), Minneapolis (Minnesota) and Detroit (Michigan) are three of the top ten cities with the worst air quality and pollution in the world, according to IQAir's ranking due to the smoke from more than 1,000 wildfires raging across Canada.

The National Weather Service (NWS) has already issued poor air quality alerts to millions of people in more than five states across the country.

Smoke from Canadian fires is seriously harmful and the greatest danger is due to the fine particulate pollutants it contains. People who are exposed to contaminated air may experience effects such as irritation of the eyes; nose and throat; coughing; sneezing; runny nose and difficulty breathing.

Worst fire season in Canadian history

According to the Canadian Interagency Wildfire Center, there are a total of 1,090 active fires (more than 670 are in the "out of control" category), with the majority of these in British Columbia (460).

Nearly 29 million acres of Canadian land has been affected by the fires (which is considered to be the worst in Canadian history). However, this forestry crisis had been in the offing for some time. At Voz Media we have reported statements from experts who claim that for years they have been warning the public about the need for greater investment to deal with fires.

Smoke from the fires coming from Canada has affected much of southern Canada and has spread as far as Europe.