Showing papers by "Lidia Morawska published in 1998"

Submicrometer and Supermicrometer Particles from Diesel Vehicle Emissions

Abstract: There is growing evidence that fine airborne particulates could play the most important role in determining health effects. The aim of this work was to investigate the number concentration and size...

Submicrometer and Supermicrometer Particulate Emission from Spark Ignition Vehicles

Abstract: Particulate emissions from 11 gasoline powered and 2 liquefied petroleum (LPG) powered passenger vehicles were characterised during the Accelerated Simulation Mode driving cycles on a chassis dynamometer. The test fleet consisted of 10 catalyst-equipped vehicles operated with unleaded gasoline (5 Ford Falcons and 5 Holden Commodores), 2 LPG powered vehicles (both Ford Falcons), and 1 older type noncatalyst vehicle operated with leaded gasoline. Particulate characterisation included determination of total particulate number concentration and size distribution using the Scanning Mobility Particle Sizer (SMPS) and the Aerodynamic Particle Sizer (APS). The average particle number concentrations in the SMPS range for all modes was lower for Ford Falcons and somewhat higher for Commodores, with values of 1.5x104 and 4.1x104 cm-3, respectively. This difference is significant and was observed for all modes. The number concentration levels were higher for the LPG fuelled cars (8.4x104 cm-3) and for the leaded gasoline powered vehicle (7.9x105 cm-3). There was not a significant variation in particle count median diameter in the SMPS and the APS ranges, either for different operating conditions of the vehicles investigated, or between different vehicle groups. The observed size distributions were bimodal with average values of CMD ranged from 39.1 to 60.2nm in the SMPS range and from 0.9 to 1.4µm in the APS range. The results obtained from this study can be used as a first order estimation towards emission inventories for vehicle groups included in the investigations.

Particulate Matter in the Hospital Environment

Abstract: Investigations of particle concentration levels and size distribution were conducted in the complex hospital system of the Royal Children's and the Royal Brisbane Hospitals in Queensland, Australia. The aim of the measurements was to provide an indication of particulate sources in the hospital environment and relate particle characteristics to the operating parameters of the hospitals. The measurements were performed using the most advanced instrumentation for size classification in the submicrometer and supermicrometer levels. The conclusions from the investigation were: (i) that indoor concentration levels of particle numbers are closely related to outdoor concentration levels, indicating that outdoor particulates were the main contributor to the indoor particulates in the hospitals under investigations; and (ii) that the performance of filtration/ventilation systems is the most critical parameter in reducing general particulate concentration levels in those hospital units where medical procedures can result in generation of potentially hazardous organic aerosols.

Science and Practice of Indoor Environment: Where Are They Going?

Abstract: The reasons as to why indoor air environment cannot be treated as a scientific discipline in its own right are discussed. The two directions with which the issue of the future of the indoor environment can be considered are highlighted.