又一次冬天，又一次PM2.5来袭！面临北京冬天的PM2.5，我开始想：冬天PM2.5到底比夏天严重多少？
我分析了北京和上海美国大使馆近8年的PM2.5数据，结果冬天平均PM2.5比北京的夏天多30%。上海的冬天比夏天多60％。
这有多严重？世界卫生组织PM2.5的24小时上限是25微克（年上线是10微克！）。那么北京夏天平均PM2.5是上限的三倍多，在北京冬天是四倍多。
你不在北京或者上海住吗？其他城市的空气也不安全！
寒冬将至，做好准备！
寒冬将至
- Paddy Robertson
- Paddy Robertson
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The data from Mr. Cyr you cite is from May 2014. E.g. the Totobobo model used by him has been replaced by a newer model by now, which possibly performs differently. This is worth noting, I think.