1月19日，北京西站笼罩在雾霾之中。北京市气象局18日22时同时发布大雾黄色、霾黄色预警，空气质量再现六级严重污染。19日白天，北京平原地区有雾，南部地区能见度将小于500米。新华社记者 公磊 摄     On January 19,,Beijing west railway station shrouded in fog in the haze.The Beijing meteorological bureau and day and at the same time release the fog yellow/Haze yellow warning,Air quality reproduction six levels of serious pollution.19 the day,Beijing plain areas of fog,South visibility to less than 500 meters.Xinhua news agency reporter and lei perturbation