Exploratory measurements of ambient air quality in a residential area applying a diffusion charge based UFP monitor/Orientierende Messungen der Luftqualität in einem Wohngebiet mit einem auf Diffusionsaufladung basierten UFP-Monitor

Abstract

In the context of the revision of the EU Ambient Air Qualitiy Directive (2008/50/EC), measurement of ultrafine particles (UFP) in ambient air is proposed and discussed. To investigate the local ambient UFP concentration (immis- sion), exploratory measurements of air pollution with UFPs were performed over several months in a residential area. The measurement device is based on charge detection of the measurement aerosol (AQ Guard Smart 2000 of the manufacturer Palas®). The background particle concentrations are within the typical background level for rural residential areas (3,000 to 5,000 cm-3). Increased UFP concentration levels were predominantly measured during the evening and the night. On 53 days of the total measurement duration of 101 days increased par- ticle concentrations above the background level (at least 6,000 cm-3) regarding the 15-minute average values were measured for at least one hour during the evening and night (16:00 to 0:00). The main source of the increased particle concentra- tion is the operation of woodstoves in the neighbourhood of the measuring location. This air pollution in the evening hours is not reflected in the context of daily or monthly averages. Other pollution sources (barbecue, new-years fireworks, traffic – different measurement location) were also identified and differences of the mean particle diameter of the ambient aerosol with regards to the background level (80 nm) could be determined. The device is suitable for UFP measurements and offers a lower detectable size-range compared to conventional scattered-light based optical particle counters.