Patrons at a restaurant in eastern China’s Jiangsu province got a surprise when they were handed a bill that included a charge for “air purification”, state media has reported. The eatery in Zhangjiagang had bought several air filtration machines recently and passed the operating cost along to the customer. A charge of 1 yuan (about 16 US cents or HK$1.2) was tacked onto the bill, for each diner, without warning, according to Xinhua. That didn’t digest well with customers, who complained to the city’s consumer pricing bureau. It launched an investigation and ordered the restaurant to fix its pricing system. Bureau staff were quoted as saying the supply of clean air was the responsibility of the restaurant management, and not a legitimate charge. But the idea of paying to breathe easy won support on social media. On Weibo, the Chinese version of Twitter, one commentator wrote: “I am willing to give an extra yuan [for purifying the air].” Another said: “They could have added the extra one yuan to the price of the dishes, but they didn’t ... there is nothing wrong with charging this extra fee. The kind of dining environment decides the kind of pricing.” Beijing was hit with intense smog last week, and the city saw its first red alert issued for air pollution. But drastic measures taken by authorties helped cut emissions by 30 per cent, bringing brief blue skies ahead of the past weekend although the air quality later deteriorated.