Iran shut primary schools in Tehran and other parts of the country on Sunday as thick smog blanketed the capital despite curbs on road traffic and industrial activity.
伊朗週日關閉德黑蘭及該國其他地區的小學，因為儘管對道路交通及工業活動加以管制，濃霧仍籠罩首都。
Local authorities late Saturday announced the closure of all primary schools in the province of Tehran, which is home to 14 million residents, except in two towns.
地方當局週六晚間宣布，除兩個鄉鎮外，德黑蘭省的所有小學都將關閉，該省居民達1400萬人。
Every year, Tehran suffers some of the worst pollution in the world when cool temperatures cause an effect known as "temperature inversion". The phenomenon creates a layer of warm air above the city that traps pollution from its more than eight million cars and motorbikes.
每一年，當冷溫引發被稱為「逆溫」的效應時，德黑蘭便飽受全球最糟糕污染之苦。這種現象在城市上方產生一層暖空氣，堵住來自逾800萬輛汽機車排放的污染。
Airborne concentration of fine particles（PM2.5） hit 185 microgrammes per cubic metre in the south of Tehran and 174 in its centre on Sunday morning, local authorities said. That is far above the World Health Organization recommended maximum of 25 microgrammes per m3 over a 24-hour period.
週日上午，德黑蘭南部空氣中的細懸浮微粒（PM2.5）濃度達到每立方公尺185微克，中部則達174微克。這遠超過世界衛生組織建議的24小時期間，每立方公尺最高濃度25微克的標準。
The microscopic particles lodge deep in the lungs and are harmful to human health. Authorities ordered mines and cement factories in Tehran province to close and reinforced traffic restrictions in the capital’s centre. They called on the elderly, children, pregnant women and people with heart problems to stay indoors.
細懸浮微粒可深入留於肺部，危害人體健康。當局下令德黑蘭省的礦業與水泥廠停工，並加強首都中心的交通管制。他們呼籲年長者、兒童、孕婦以及有心臟問題的民眾待在室內。
Source article: http://iservice.ltn.com.tw/Service/english/english.php?engno=1161756&day=2017-12-20