12,000

We have over 12,000 students, from over 100 countries, within one of the safest campuses in the UK

93%

93% of Lancaster students go into work or further study within six months of graduating

Home > Research > Publications & Outputs > Evaluation and application of biomagnetic monit...
View graph of relations

« Back

Evaluation and application of biomagnetic monitoring of traffic-derived particulate pollution.

Research output: Contribution to journalJournal article

Published

Journal publication date04/2009
JournalAtmospheric Environment
Journal number13
Volume43
Number of pages9
Pages2095-2103
Original languageEnglish

Abstract

Inhalation of particulate pollutants below 10 μm in size (PM10) is associated with adverse health effects. Here we use magnetic remanence measurements of roadside tree leaves to examine levels of vehicle-derived PM around Lancaster, UK. Leaf saturation remanence (SIRM) values exhibit strong correlation with both the SIRM and particulate mass of co-located, pumped-air samples, indicating that these leaf magnetic values are an effective proxy for ambient PM10 concentrations. Biomagnetic monitoring using tree leaves can thus provide high spatial resolution data sets for assessment of particulate pollution levels at pedestrian-relevant heights. Leaf SIRM values not only increase with proximity to roads with higher traffic volumes, but are also ~ 100 % higher at 0.3 m than at ~ 1.5 – 2 m height. Magnetic and SEM data indicate that the particle populations are dominated by spherical, iron-rich particles ~ 0.1 – 1 μm in diameter, with fewer larger, more angular, silica-rich particles. Comparison of the roadside leaf-calculated PM10 concentrations with PM10 concentrations predicted by a widely-used atmospheric dispersion model (ADMS-urban, CERC Ltd. Cambridge, UK; CERC, 2009), indicates some agreement between them. However, the model under-predicts PM10 concentrations at ‘urban hotspots’ such as major-minor road junctions and traffic lights. Conversely, the model over-predicts PM10 concentrations with distance from the road wherever one tree is screened by another, indicating the filtering/protective effect of roadside trees in leaf.