Browsing by Subject "Lung deposited surface area"

The local sources influence the spatial distribution of air pollutants in urban settings, and these can be quite diverse. For better air quality forecasting, constant monitoring of pollutants, and a high volume of measurements are necessary at many locations. Building a dense air quality network by only using the reference instruments is expensive and not feasible. The use of complementary sensor like Vaisala AQT 420 can help achieve the goal of creating a robust air quality network. As part of the Helsinki metropolitan Air Quality Testbed (HAQT) project, AQT 420 was tested for its suitability as a complmentary component in an air quality monitoring network. AQT 420 is capable of measuring NO2, PM2.5, PM10, CO, O3, SO2, relative humidity (RH), temperature, wind speed (WS), wind direction (WD), and air pressure (AP). Proxies for condensation sink (CS), black carbon (BC), particles number concentration (N), and Pegasor AQ urban diffusion current (PAQDCLDSA, which can be parameterized to calculate lung deposited surface area (LDSA) concentrations) were developed for an urban background site in Helsinki, Finland. The intention is to use variables measured by the AQT 420 and predict additional variables by using proxies. Proxy variables will help to maximize the output of AQT 420 sensors, and giving extra data extraction capability from the sensors. PM2.5, NO2, RH and temperature yielded reliable proxies for both CS and PAQDCLDSA with the correlation coefficient r, 0.85 and 0.83, respectively. While, PM2.5, NO2, and NO2, RH were enough to produce satisfactory proxy parameters for BC (r, 0.80), and N (r, 0.76), respectively. Additionally, a campaign data for sulfuric acid (SA) from Helsinki, Finland site was used to produce a proxy for SA. SO2, global radiation, CS and RH gave the best version of that proxy (r, 0.85).