Having lived in Manhattan for 7 years, and Hong Kong for 9, I'm pretty sure the air quality inside the Hong Kong MTR is better than the NYC subway. Air in the

Having lived in Manhattan for 7 years, and Hong Kong for 9, I'm pretty sure the air quality inside the Hong Kong MTR is better than the NYC subway. Air in the stations in Hong Kong is air conditioned and filtered. Not that feeling is the best measure, but the feeling of the air in a lot of the NYC stations is just not great. Outdoor air quality in Hong Kong was pretty rough a few years on either side of 2014, but it has either gotten better lately or I've stopped noticing the bad days.