Sarnia, Ontario has just over 72,000 inhabitants, but over 60 chemical plants and oil refineries sit in a 15-mile-wide section outside town that’s come to be known as “Chemical Valley.”

The smokestack-filled skyline used to be a point of pride for Ontarians, a symbol of production, economy, and modernity. The chemicals produced there went into plastics, gasoline, pesticides, fertilizer and other important products. Now, the air quality is paying the price. In 2005 there was a record high of 46 smog days when school was cancelled because of the dangerously high concentration of pollutants in the air, which the World Health Organization has called “the worst in Canada.”

The most at-risk place in Sarnia is the Aamjiwnaang First Nations Reserve, home to a few hundred Chippewa, which is surrounded by petroleum refineries. The close quarters mean that factory accidents come at a high cost. Daycares, schools, workplaces, and public parks have all seen waves of illnesses that residents blame on refinery spills.

Authorities from groups like Dow Chemical, Sunoco, and Shell have dismissed health and quality of life complaints as anecdotal and unrelated to their plants on the edge of town. Environmental groups from Sarnia continue to protest and petition the petrochemical industry in an effort to clean up the town they love. In recent years the air quality index has improved, with only five smog days in 2009.