The Scottish Environment Statistics - 1998

4. ATMOSPHERE

Table 4.21 The UK National Strategy- air quality objectives Pollutant Standard Objective Concentration measured as to be achived by 2005 Benzene 5 ppb running annual mean 5 ppb 1,3 -Butadiene 1 ppb running annual mean 1 ppb Carbon monoxide 10 ppm running 8-hour mean 10 ppm Lead 0.5mg/m3 annual mean 0.5mg/m3 Nitrogen dioxide 150 ppb 1 hour mean 150 ppb, hourly mean 21 ppb annual mean 21 ppb, annual mean Ozone 50ppb running 8-hour mean 50 ppb, measured as the 97th percentile Fine particles(PM10) 50mg/m3 daily maximum running 24-hour mean 50mg/m3 measured as the 99th percentile Sulphur dioxide 100 ppb 15 minute mean 100 ppb measured as the 99.9th percentile Source: The National Strategy ppm = parts per million ppb = parts per billion mg/m3= micrograms per cubic metre