Q. We are flying from Los Angeles to Hong Kong this December and have heard horror stories about air pollution. Is it really that bad? How does it compare to LA’s air quality?

A. According to Wikipedia, “Air pollution in Hong Kong is considered a serious problem. Visibility is less than eight kilometers for 30% of the year. Cases of asthma and bronchial infections have soared in recent years... The pollution comes largely from coal-fired power stations and traffic, although a significant contribution comes from the tens of thousands of factories in China.... Hong Kong is approaching the record of being the darkest capital city in the world with the least amount of sunlight hours, just after Edinburgh.” A very useful website to monitor air quality around the world is aqicn.org. Just add /city/(name of city) at the end of the URL to find a real-time air quality index. On November 1, Hong Kong’s air quality was an “unhealthy” 127 although Beijing was even worse at a “very unhealthy” 259 (300 and above is considered “hazardous”). In contrast, downtown Los Angeles on the same day was merely a “good” 42. If you have asthma or other health conditions when visiting Hong Kong, it’s wise to limit outdoor exercise and stay indoors as much as possible.

Beijing smog pic via Shutterstock