Effects of environmental parameters biomonitoring polycyclic aromatic hydrocarbons in the air by Salix matsudana leaves.

Persistent organic pollutants (POPs) encompass many organic contaminant classes that show high persistence, susceptibility for long-range transport (LRT), and potential for biomagnification in food chains (1,2). Air is an efficient medium for the global dissemination of persistent organic pollutants (POPs). Epidemiological studies investigating the health risks related to air pollution suggest that ambient air pollution (including polycyclic aromatic hydrocarbons, PAHs) may be responsible for increased rates of diseases like lung cancer (3, 4). Air pollution is an important environmental problem that can result from both human and natural actions. To reduce pollution levels and minimize harmful effects on human health, it is necessary to improve air monitoring and provide useful information to the communities. Recently, biomonitoring methods using passive plant samplers may offer a practicable low cost alternative, especially in terms of high spatial resolution and time-averaged data series (5, 6). In this study, seasonal distribution characteristics of PAHs in Salix matsudana leaves covering its annual life cycle were carried out in order to evaluate plant leaf response sensitivity on air pollution. Salix matsudana leaves were collected throughout different development phases of plant leaf inclusive of bud break to fallen leaves, covering from spring (May) to autumn (November). Simultaneously, particle and gas samples were collected using a high volume air sampler. Seven different PAHs were determined from three types of samples. The leaf area and lipid content changed from season to season: both parameters increased rapidly during the spring season, maintained a stable state in summer season, while lipid content dramatically decreased in autumn season. Except spring season, total PAHs showed similar seasonal trends between plant leaves and air samples, with correlation coefficients equal to 0.74 and 0.56 in summer and autumn season, respectively. In this work, it has been demonstrated that climate changes, such as rainfall and air mass movement, influence the daily concentrations of PAHs in leaf. Furthermore, PAH composition profile in leaves and air phase have been correlated by principal component analysis.