Air pollution in the United Kingdom has long been considered a significant health issue, and it causes numerous other environmental problems such as damage to buildings, forests, and crops. Many areas, including major cities like London, are found to be significantly and regularly above legal and recommended pollution levels. Air pollution in the UK is a major cause of diseases such as asthma, lung disease, stroke, cancer, and heart disease, and it costs the health service, society, and businesses over £20 billion each year. Outdoor pollution alone is estimated to cause 40,000 early deaths each year, which is about 8.3% of deaths.