Technical Guidance Sheet (TGS) on normal levels of contaminants in English soils : supplementary information : Benzo(a)pryene (BaP)

There is a paucity of BaP data for English soils as this is not routinely measured by the large systematic national surveys which have focussed on inorganic elements. Therefore, all available BaP has to be considered for domain attribution and the criteria used to define data sets suitable for use in this work (see Ander et al. 2011) are less rigidly applied. This has meant that it is necessary to combine data from several studies with inherently different sampling and analytical protocols – these are summarised in Table 1. It should also be noted that these data have been collected over a period of time, during which considerable advances in sampling, sample preservation and analytical methodologies have also been achieved. No additional English studies in which sampling locations and information other than central tendency (mean, median) or range are identified (Ander et al. 2011), and so the low sample numbers for England has meant data from Scotland and Wales has been included, particularly to generate a NBC for urban areas in England (see Figure 2 of the BaP TGS).