Recommendation for an Air Quality Standard for Polycyclic Aromatic Hydrocarbons

42. Taking benzo[a]pyrene as a marker for the total mixture of polycyclic aromatic hydrocarbons in the United Kingdom the Panel recommend an Air Quality Standard of 0.25ng/m³ B[a]P as an annual average. This recommendation is intended to reduce any risk to the population of the United Kingdom from exposure to polycyclic aromatic hydrocarbons to one which the Panel believes would be so small as to be undetectable.

43. The Panel note the uncertainties surrounding the use of B[a]P as a marker for carcinogenic PAHs in the ambient air. The Panel, therefore, strongly recommend that the number of PAH monitoring sites in the United Kingdom should be increased, in particular to include areas influenced by industrial emissions. Emphasis should be placed on at least the seven PAHs classified as probably or possibly carcinogenic to humans upon which this report has focused. This increased monitoring should provide data to check that the use of B[a]P as a marker remains appropriate. It is recommended that techniques for monitoring the Standard should be consistent with those used by the Department of the Environment, Transport and the Regions. The Panel attaches considerable importance to this expanded monitoring programme and the results will be regularly reviewed as they accrue.

Figure 1 The molecular structure and chemical formula of benzo[a]pyrene.

Figure 1: The molecular structure and chemical formula of benzo[a]pyrene

Alternative names by which benzo[a]pyrene has been known:

benz[a]pyrene
benzo[a]pyrene
benz[a]pyrene
1,2-benzopyrene
PAH EPA no. 73