This week, Canada and parts of the United States have confronted unprecedented declines in air quality due to smoke from Canadian wildfires, but people elsewhere in the world have long had to adjust and adapt to living with hazardous pollution levels. In some cases, those levels have improved over time.
NPR correspondents Anthony Kuhn and Eyder Peralta and freelance reporters Shalu Yadav and Kate Bartlett share what it's like in Beijing, Seoul, New Delhi, Mexico City and Johannesburg.
