National Physical Laboratory

Polycyclic Aromatic Hydrocarbons (PAHs) Network

The UK PAH Monitoring and Analysis Network measures the concentrations of PAHs in ambient air at 31 monitoring sites across the UK (see map below). NPL took over the operation of the Network in September 2010.

Benzo[a]pyrene (B[a]P)

The Network discharges the UK Government's obligation under the EC Air Quality Fourth Daughter Directive to monitor the mass concentration of benzo[a]pyrene (B[a]P) in the PM10 fraction (particles with an equivalent aerodynamic diameter of 10 μm or less) of ambient air. The target value for B[a]P in the PM10 fraction of ambient air, averaged over a calendar year, is 1.0 ng.m-3.

Samples analysed and PAHs measured

The Network produces three types of samples:

  • PM10 particulate samples (31 sites) taken daily using a Digitel sampler fitted with a quartz filter.

  • PM10 particulate + vapour samples (2 sites) taken for 24 hours every three days with a Digitel sampler fitted with a quartz filter and polyurethane foam cartridge.

  • Deposition samples (2 sites) collected fortnightly in deposition bottles.

All samples are chemically extracted and analysed for up to 39 PAHs using GC-MS. Further details of the analysis method are available.


Acenaphthene Acenaphthylene Anthanthrene
Anthracene Benzo[a]anthracene Benzo[a]pyrene
Benzo[b]naph[2,1-d]thiophene Benzo[b+j]fluoranthene Benzo[c]phenanthrene
Benzo[e]pyrene Benzo[ghi]perylene Benzo[k]fluoranthene
Biphenyl Cholanthrene Chrysene
Coronene Cyclopenta[c,d]pyrene Dibenzo[a,e]pyrene
Dibenzo[a,h]pyrene Dibenzo[a,h+a,c]anthracene Dibenzo[a,i]pyrene
Dibenzo[a,l]pyrene Fluoranthene Fluorene
Indenopyrene 1-Methyl anthracene 1-Methyl Napthalene
1-Methyl phenanthrene 2-Methyl anthracene 2-Methyl Napthalene
2-Methyl phenanthrene 4,5-Methylene phenanthrene 5-Methyl Chrysene
9-Methyl anthracene Naphthalene Perylene
Phenanthrene Pyrene Retene


Location of PAH Network sites


Location of PAH Network sites

(Image courtesy of Defra
- click to enlarge)



Last Updated: 21 Jun 2012
Created: 30 Nov 2011


Please note that the information will not be divulged to third parties, or used without your permission