October 2013, Geneva, Switzerland. In its recent report, Air Pollution and Cancer, the World Health Organization classifies air pollution and particulate matter as carcinogenic to humans, causing lung cancer and possibly contributing to other cancer types. Gasoline-powered leaf blowers and other maintenance equipment are a major source of toxic and carcinogenic emissions cited in the report. Increasingly, these emissions are being put into the air at our homes, schools, and public spaces. Shouldn’t we be concerned?