Articles | Volume 16, issue 7
Research article
05 Apr 2016
Research article |  | 05 Apr 2016

Can biomonitors effectively detect airborne benzo[a]pyrene? An evaluation approach using modelling

Nuno Ratola and Pedro Jiménez-Guerrero

Abstract. Biomonitoring data available on levels of atmospheric polycyclic aromatic hydrocarbons (PAHs) in pine needles from the Iberian Peninsula were used to estimate air concentrations of benzo[a]pyrene (BaP) and, at the same time, fuelled the comparison with chemistry transport model representations. Simulations with the modelling system WRF+EMEP+CHIMERE were validated against data from the European Monitoring and Evaluation Programme (EMEP) air sampling network. Modelled atmospheric concentrations were used as a consistent reference in order to compare the performance of vegetation-to-air estimating methods. A spatial and temporal resolution of 9 km and 1 h was implemented. The field-based database relied on a pine needles sampling scheme comprising 33 sites in Portugal and 37 sites in Spain complemented with the BaP measurements available from the EMEP sites. The ability of pine needles to act as biomonitoring markers for the atmospheric concentrations of BaP was estimated by converting the levels obtained in pine needles into air concentrations by six different approaches, one of them presenting realistic concentrations when compared to the modelled atmospheric values. The justification for this study is that the gaps still exist in the knowledge of the life cycles of semi-volatile organic compounds (SVOCs), particularly the partition processes between air and vegetation. The strategy followed in this work allows for the effective estimation by the model of concentrations in air and vegetation and of the best approaches to estimate atmospheric levels from values found in vegetation.

Short summary
This original interpretation and application of environmental databases combines biomonitoring and atmospheric field data and state-of-the-art chemistry transport models to study one of the most carcinogenic atmospheric pollutants, benzo[a]pyrene (BaP). A comparison of ways to estimate air concentrations of BaP from its levels in vegetation is also a strong asset of this study. The whole methodology proposed here is versatile and can easily be applied to other regions and chemicals of interest.
Final-revised paper