An extensive epidemiological
literature relates PM2.5 to adversehealthimpacts. Latterly,theWorld Health
Organization’s International Agency for Research on Cancer (IARC)
officially classified air pollution mixing with suspended particles
in the air as a level 1 carcinogen. It stated that there is “sufficient
evidence” that exposure to outdoor air pollution causes lung cancer
and also linked it with an increased risk of bladder cancer. Such
exposure has increased significantly in China (IARC, 2013). Since
the ventilation systems need to regularly draw outdoor air into
buildings, hotel guests who staying indoor still have to breathe the
polluted outdoor air if there is no air filtration equipment in hotels.
Therefore,travelers whoplanto come toChina are increasingly concerned
about air quality. According to the China National Tourism
Administration, from January to June in 2013, the total number of
foreign arrivals dropped by 5% to just under 13 million compared
with the same period in 2012 (Watt, 2013).