haikou tops the 168 key chinese cities in terms of the air quality last year, followed by lhasa, huangshan, zhoushan and fuzhou, according to the ministry of ecology and environment. from january to december in 2021, days of "a" and "b" classes accounted for 87.5 percent of the whole year in 339 cities above the prefectural level. the average pm2.5 concentration was 30 micrograms per cubic meter, down 9.1 percent year-on-year. however, linfen, taiyuan in shanxi province, and hebi in henan province presented relatively poor air quality. no 10 zhuhai in guangdong province no 9 huizhou in guangdong province no 8 shenzhen in guangdong province no 7 lishui in zhejiang province no 6 xiamen in fujian province no 5 fuzhou in fujian province no 4 zhoushan in zhejiang province no 3 huangshan in anhui province no 2 lhasa in southwest china's tibet autonomous region no 1 haikou in hainan province
|