Smart Air analyzed PM2.5 air quality data from the Berkeley Earth Project from 2014-2018. The air quality in Tangshan has significantly improved over the past 5 years. Each year, PM2.5 has dropped by 10% to 20%. From 2014 to 2018, Tangshan saw an overall 46% drop in PM2.5. Despite 2018 being Tangshan best year for air quality on record, the PM2.5 still averaged 54 micrograms, which is over 5 times the WHO annual limit.
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