Appendix 2

AEAT-3133

The Rural Maps
Maps of rural concentrations of air pollutants underpin the maps presented in this report. The derivation of these maps is given in Table A2.

Table A2. The derivation of the maps of rural concentrations

Pollutant
NO2	Interpolated from monthly measurements of NO2 by diffusion tubes at Acid Deposition Secondary Network sites.
NOx	Derived from the rural NO2 map by multiplying by 1.2 (the measured ratio at Lullington Heath, which is very similar to that found at other rural automatic monitoring sites).
SO2	Interpolated from measurements at Rural SO2 Monitoring Network sites (daily and weekly bubbler measurements) and automatic measurements at Rural Monitoring Network sites and sites within the Joint Environment Programme.
benzene	Derived from the rural NO2 map by multiplying by 0.031 (the measured ratio at Harwell).
1,3-butadiene	Derived from the rural NO2 map by multiplying by 0.00538 (the measured ratio at Harwell).
CO	A constant value of 0.150 ppm was chosen in the absence of rural monitoring data.
PM10	Secondary particle concentration estimated from measurements of particulate sulphate concentrations at eight Acid Deposition Monitoring sites (118, 120-126). The concentration of particles derived from stationary combustion and non-combustion sources was taken to be 6 mgm-3 in the west of Northern Ireland and 12 mgm-3 in Eastern England. These values were inferred from an examination of the concentrations of PM10 measured at rural monitoring sites.
Lead	Derived from the rural NO2 map by multiplying by 1.344 (the ratio between estimated NO2 and measured Pb concentrations at rural and urban background PB monitoring sites).
O3 summer	Summer mean ozone concentration. Interpolated from measurements at Rural Monitoring Network sites and adjusted for the effects of altitude.
O3 days	The number of days with maximum running 8-hour ozone concentration >= 50 ppb, Interpolated from measurements at Rural Monitoring Network sites.

INDEX