Fig. 1
Annual average BS in Glasgow, Edinburgh and annual average for multiple sites across the UK for 1970–2001. The Glasgow and Edinburgh BS time series are averages across representative background sites in each city (sites EDI 10, 12 & 14 and GLA 51, 68, 95 & 98) operated at different times during the period covered. The UK-average BS time series was computed from sites operational in that year. Also shown are the annual average urban centre ‘gravimetric equivalent’ TEOM PM10 data for Glasgow and Edinburgh from the initiation of these measurements in the 1990s. All data obtained from the UK air quality data archive (http://uk-air.defra.gov.uk/data)