Estimates of sources of benzo(a)pyrene (BaP) emissions have been made in two inventories carried out for New Zealand (Figure 8.1). Both indicate domestic home heating is the primary contributor for these areas. This is also consistent with monitoring data for Christchurch, which shows a strong correlation between concentrations of PM10 and concentrations of BaP during the winter months (Gunathlika, 2002). Emission inventory studies for Christchurch show domestic heating is the dominant source of PM10 emissions (NIWA, 1998, Wilton, 2001c). It is therefore also most likely to be the main source of BaP.