There were days in Hong Kong, when the wind was blowing from China that the pollution index would reach 200, or higher. Some days I could not see 1/2 a mile across the harbor. A day less than 125 was considered a clear day. Is it any wonder after living there 20 years, despite being a nonsmoker, I have stage 2 COPD?
Same pollution problem in Taiwan. Winds blow it over from china. Some days you can’t see 100 yards.