Table 1

 Combustion products of fossil fuels

Carbon dioxide (as C)Sulphur dioxidePM10Nitrogen oxidesCarbon monoxide
*Lower limits for hotspots in tonnes/km2/year; †children migrating >1.0 km and with one address within 1.0 km of nearest hotspot and the other address outside 1.0 km.
Hotspot criteria*126410425160
Number of hotspots6462512817397445387513371
Number of children†12462008290820722943
Outward migration8381034207415012324
Inward migration408974834571619
Ratio out/in2.0541.0622.4872.6293.754