What is another term for smog? What is Düsseldorf ranked as in Mercer's 2012 Quality of Living survey? To be #2, does a country need to have limited #1 days a year?
Düsseldorf
Mercer's 2012 Quality of Living survey ranked Düsseldorf the sixth most livable city in the world. Clean air is an important attribute for a livable city. Smog is a term for air pollution.
Place in North Rhine-Westphalia, Germany
Does Düsseldorf have only a small number of smoggy days each year?