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Street dust resuspension is one of the main sources of particulate matter with impacts on air quality, health, and climate. This research was aimed to determine the concentration, source, and health risk of polycyclic aromatic hydrocarbons (PAHs) in street dust of Mashhad city. To this end, USEPA-regulated 16 PAHs were measured in 84 dust samples using gas chromatography coupled to mass spectrometry (GC-MS). The source of Σ16PAHs was identified using diagnostic ratios (DRs), positive matrix factorization (PMF), and principal component analysis (PCA). The measured Σ16PAHs demonstrated different spatial concentrations (from 1,005 to 9,138.96 μg kg-1) and showed higher levels in summer (1,206.21-9,138.96 μg kg-1), although 4-ring PAHs exhibited maximum levels in both summer and winter. The findings revealed that the dust-deposited PAHs are predominantly emitted through combustion of fossil fuels (such as diesel and gasoline) and natural gas. The total incremental lifetime cancer risk (ILCR) was assessed by considering three possible exposure routes separately for children and adults and calculated carcinogenic risk values of 2.24E-06 and 2.14E-06, respectively. ILCR is above the baseline value (1.0E-06) for children and adults in both seasons.

The use of natural flood management (NFM) measures to address severe flooding received considerable public attention during December 2015–January 2016 storms. Within the Warwickshire-Avon Catchment, UK, high arable and improved grassland land cover with small, isolated communities at risk, lead to the exploration of novel techniques that use farmland high up in flood-prone catchments to hold water and reduce outflow discharge. This paper will discuss the methodology used to identify areas in the Warwickshire-Avon, which could be used to install NFM measures to attenuate the storm peak and provide wider ecosystem services, principally addressing total phosphate and sediment entering the receiving watercourse. This involved constructing a GIS database of catchment geomorphological characteristics whilst simultaneously engaging with those significant stakeholders of farmers and landowners to capture local input and produce a model for applied NFM for future projects looking to explore the role of working with natural processes (WwNP) for flood risk reduction within the agricultural environment. The advantages, disadvantages and key lessons learnt are also presented in this paper, to recognise the benefits and limitations of communities and catchments exploring such methods for flood risk management (FRM).