China has blamed fog for recent disruption in and around Beijing, but whether the issue is fog or pollution, it has stirred much debate in the country.The thick phenomenon has blanketed the Chinese capital and its international airport in recent days, restricting visibility, forcing cancellation of hundreds of flights and closing highways in northern China.Chinese officials say it is only a weather issue, combined with \"light pollution,\" the Los Angeles Times reported. However, the U.S. Embassy in Beijing, which has its own monitoring system, said Sunday the index of fine particulate matter had soared to 522 micrograms per cubic meter, noting a 300 to 500 measurement is considered \"hazardous,\" the newspaper said.Beijing residents have been stocking up on face masks, while ridiculing their government\'s air quality numbers online.\"They are treating citizens as idiots,\" said a man on Sina Weibo, a Twitter-like microblog, the Times said. Another wrote, \"The city looks like a fairyland but thanks to the government, it is only \'slight pollution.\'\"The Chinese government says air quality is improving in Beijing and air quality standards are met 80 percent of the time.Environmental consultant Steven Andrews, who has been monitoring Beijing air-quality reports since the 2008 Summer Olympics, said Chinese authorities have been understating the severity of pollution by moving monitors out of congested areas.\"Suffocating smog has been covering Beijing like a greasy quilt recently,\" the China Daily said in a recent editorial. \"All of the residents in the city are aware of the poor air quality, so it does not make sense to conceal it for fear of criticism.