An improvement in Beijing’s air quality last year compared with 2014 may have had more to do with weather patterns than with a decline in emissions, environmental experts say.
The Municipal Environmental Protection Bureau said the average concentration of PM2.5 particles — used as a proxy for measuring air quality — at 81 microgrammes per cubic metre, was down
6 per cent from 2014’s average of nearly 86 microgrammes and 10 per cent from 90 in 2013. The World Health Organisation’s standard for safe air is an annual mean of 10 microgrammes.
您已閱讀26%（542字），剩余74%（1532字）包含更多重要信息，訂閱以繼續探索完整內容，并享受更多專屬服務。