The cold weather and the absence of wind allowed emissions across the whole of southeast England to build up over the weekend. Many other places across Britain were also suffering from high levels of pollution. According to the latest data from the Department for Environment, Food and Rural Affairs, by Monday evening eight regions of the UK were rated as having high or very high levels of air pollution, including the south-east, south-west, the east Midlands and Northern Ireland. The problem is expected to continue Tuesday. The forecast for Tuesday is that air pollution levels will remain unacceptably high in the capital with pollution levels expected to similarly persist in other areas across the country. Visibility at Heathrow had been reduced to roughly 100 meters (110 yards. Roughly 100 flights were cancelled and many more were delayed. As a consequence, travelers were advised Monday to check their flight status before going to the airport. “This is a particularly bad pollution episode,” said Timothy Baker of the environmental research group at King’s College London.