"The main pollutants of concern in the UK are particulate matter (PM), oxides of nitrogen, and ground level ozone and ammonia. Road transport, large fuel-burning plants such as power stations, and agriculture are key sources for one or more of these pollutants. The economic cost from the impacts of air pollution in the UK is estimated at £9-19 billion every year. This is comparable to the economic cost of obesity (over £10 billion)." (Quoted from article)