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The total deposition of environmental tobacco smoke (ETS), diesel and petrol smoke in the respiratory tract of 14 non-smokers between the ages of 20 and 30 was determined experimentally. A scanning mobility particle sizer (SMPS) measuring a size range of 0.016-0.626 mu m was used to characterise the inhaled and exhaled aerosol during relaxed nasal breathing over a period of 10 min. The ETS, diesel, and petrol particles had average count median diameter (and geometric standard deviation) of 0.183 mu m (1.7), 0.125 mu m (1.7), and 0.069 mu m (1.7), respectively. The average total number deposition of ETS was 36% (standard deviation 10%), of diesel smoke 30% (standard deviation 9%), and of petrol smoke 41% (standard deviation 8%). The analysis of the deposition patterns as a function of particle size for the three aerosols in each individual showed that there is a significant difference between each aerosol for a majority of individuals (12 out of 14). This is an important result as it indicates that differences persist regardless of inter-subject variability. (C) 2005 Elsevier Ltd. All rights reserved.

As part of a large study investigating indoor air in residential houses in Brisbane, Australia, the purpose of this work was to quantify emission characteristics of indoor particle sources in 15 houses. Submicrometer particle number and approximation of PM2.5 concentrations were measured simultaneously for more than 48 h in the kitchen of all the houses by using a condensation particle counter (CPC) and a photometer (DustTrak), respectively. In addition, characterizations of particles resulting from cooking conducted in an identical way in all the houses were measured by using a scanning mobility particle sizer (SMPS), an aerodynamic particle sizer (APS) and a DustTrak. All the events of elevated particle concentrations were linked to indoor activities using house occupants diary entries, and catalogued into 21 different types of indoor activities. This enabled quantification of the effect of indoor sources on indoor particle concentrations as well as quantification of emission rates from the sources. For example, the study found that frying, grilling, stove use, toasting, cooking pizza, cooking, candle vaporizing eucalyptus oil and fan heater use, could elevate the indoor submicrometer particle number concentration levels by more than five times, while PM2.5 concentrations could be up to 3, 30 and 90 times higher than the background levels during smoking, frying and grilling, respectively.

Diurnal variation of indoor submicrometer (0.007–0.808 mm) particle number andparticle mass (approximation of PM2.5) concentrations was investigated in 15 houses in a residential suburb of Brisbane during winter in 1999. Continuous monitoring for more than 48 h was conducted using a condensation particle counter (CPC) and a photometer (DustTrak) in the kitchen of each house, and the residents kept diaries of the activities conducted. In addition, data from a central monitoring station was used to investigate indoor/outdoor relationships. The results show that there were clear diurnal variations in both particle number and approximation of PM2.5 concentrations, for all the investigatedhouses. The pattern of diurnal variations variedfrom house to house, however, there was always a close relationship between the concentration andhuman indoor activities. The average number and mass concentrations during indoor activities were (18.273.9)103 particles cm3 and(15.5 77.9) mgm3, respectively, andund er nonactivity conditions, (12.472.7)103 particles cm3 (11.172.6)7mgm3, respectively. In general, there was a poor correlation between mass andnumber concentrations and the correlation coefficients were highly variable from day to day and from house to house. This implies that conclusions cannot be drawn about either one of the number or mass concentration characteristics of indoor particles, based on measurement of the other. The study also showed that it is unlikely that particle concentrations indoors could be represented by measurements conducted at a fixed monitoring station due to the large impact of indoor and local sources.

In this paper, the CALINE4 software package, designed for calculation of concentrations of carbon monoxide near a busy road, is adapted for the analysis of aerosols of fine and ultra-fine particles, generated by vehicles on the road. A scaling procedure of the CALINE4 package is developed and justified. A new efficient method of determination of the average emission factor for fine particle emission from the average fleet (one average vehicle) on a given road is also developed. This method is based on measurements of the average particle number concentration at just one point near the road. An example of a specific road in the Brisbane area, Australia, is considered. The average emission factor for vehicles on this road is calculated to be ∼4.5×1014 particle/vehicle/mile. The obtained scaling coefficient is shown to be correct, and the procedure is directly applicable for the analysis of an arbitrary road with different types of vehicles and their average speed. Good agreement between the experimental results and the predicted theoretical dependencies of concentration on distance from the road clearly confirms the applicability of the CALINE4 package for the analysis of propagation of fine particle aerosols from a busy road. Statistical analysis of the experimental and theoretical results demonstrates that the concentration of fine and ultra-fine particles approximately reduces as a power law in distance from the road.

Understanding the distribution of outdoor pollutants around a building envelope, generated by sources located in its vicinity, is important for choosing the location of building ventilation system intakes, as well as for quantifying the exposure of people living or working in the building. A systematic experimental characterisation of the number concentration of submicrometre particles was undertaken around the envelope of six buildings (both low- and high-rise) at different distances from a road, (the main pollution source). The concentrations were measured using two TSI Scanning Mobility Particle Sizers. PM2.5 concentrations were also monitored around the low-rise buildings using two TSI DustTraks. For the three high rise buildings the concentration of fine and ultra-fine particles decreased in most cases to about 50 - 60% from the approximate ground level readings (between heights of 0 to 6 m), to full building height (from 24 to 33 m above the ground). Measurements of submicrometre particle number concentrations as well as PM2.5 fraction in the envelope around low-rise isolated buildings did not show any significant trends from the front to the rear of the building. The sensitivity of PM2.5 measurements to a small number of larger particles, possibly from sources other than vehicle emissions, was observed.

The relationship between indoor and outdoor airborne particles was investigated for 16 residential houses located in a suburban area of Brisbane, Australia. The submicrometer particle numbers were measured using the Scanning Mobility Particle Sizer, the larger particle numbers using the Aerodynamic Particle Sizer and an approximation of PM2.5 was also measured using a DustTrak. The measurements were conducted for normal and minimum ventilation conditions using simultaneous and non-simultaneous measurement methods designed for the purpose of the study. Comparison of the ratios of indoor to outdoor particle concentrations revealed that while temporary values of the ratio vary in a broad range from 0.2 to 2.5 for both lower and higher ventilation conditions, average values of the ratios were very close to one regardless of ventilation conditions and of particle size range. The ratios were in the range from 0.78 to 1.07 for submicrometer particles, from 0.95 to 1.0 for supermicrometer particles and from 1.01 to 1.08 for PM2.5 fraction. Comparison of the time series of indoor to outdoor particle concentrations shows a clear positive relationship existing for many houses under normal ventilation conditions (estimated to be about and above 2 h−1), but not under minimum ventilation conditions (estimated to be about and below 1 h−1). These results suggest that for normal ventilation conditions, outdoor particle concentrations could be used to predict instantaneous indoor particle concentrations but not for minimum ventilation, unless air exchange rate is known, thus allowing for estimation of the “delay constant”.

This paper presents the results of measurements conducted to determine particle and gas emissions from two large compressed natural gas (CNG) spark ignition (SI) engines. Particle size distributions in the range from 0.01–30 μm, and gas composition were measured for five power settings of the engines: 35, 50, 65, 80 and 100% of full power. Particle emissions in the size range between 0.5 and 30 μm, measured by the aerodynamic particle sizer (APS), were very low at a level below two particles cm−3. These concentrations were comparable with average ambient concentration, and were not considered in the succeeding analysis. Both engines produce significant amounts of particles in the size range between 0.015 and 0.7 μm, measured by the scanning mobility particle sizer (SMPS). Maximum number of concentrations of about 1×107 particles cm−3 were very similar for both engines. The CMDs were in the range between 0.020 and 0.060 μm. The observed levels of particulate emission are in terms of number of the same order as emissions from heavy duty diesel engines (Morawska et al., Environ. Sci. Tech. 32, 2033–2042). On the other hand, emissions of CO and NOx of 5.53 and 3.33 g kW h−1, respectively, for one of the tested engines, were considerably lower than set by the standards. According to the specifications for the gas emissions, provided by the US EPA (US EPA, 1997), this engine can be considered as a “low-emission” engine, although emissions of submicrometer particles are of the same order as heavy-duty diesel vehicles.

As part of a program of study to assess the exposure risks related to particulate matter in the outdoor environment, number concentrations of particles from vehicle emissions were measured at increasing distances from a major road. Particles in the size range from 0.015 to 0.697 μm were measured with the scanning mobility particle sizer (SMPS) and in the size range from 0.5 to 20 μm, with the aerodynamic particle sizer (APS). In addition to number concentration measurements, an approximation of PM 2.5 fraction was obtained using a DustTrak (simple photometer). The measurements conducted at distances from the road ranging from 15 to 375 m showed, that for conditions where the wind is blowing directly from the road, the concentration of fine and ultrafine particles decays to around half of the maximum (measured at the closest point to the road) at a distance of approximately 100–150 m from the road. For the wind blowing parallel to the road, the reduction to half of the concentration occurs at 50–100 m. There is no effect on total particle number concentration at a distance greater than 15 m from the road when the wind is blowing towards the road and away from the sampling points. Total number concentrations of larger particles measured were not significantly higher than the average values for the urban environment, and decrease with distance from the road, reaching about 60% at 150 m from the road for wind from the road. PM 2.5 levels also decrease with distance to around 75% for wind from the road and to 65% for wind parallel to the road, at a distance of 375 m.

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.

Indoor air contains a complex mixture of bioaerosols such as fungi, bacteria and allergens, as well as non-biological particles including products from various combustion processes. To date little work has been done to investigate the interactions and associations between particles of biological and non-biological origin, however, any occurring interactions could affect pollutant behaviour in the air and ultimately the effect they have on health. The aim of this work was to examine associations between the concentration levels of airborne particles and fungi measured in 14 residential suburban houses in Brisbane. The most frequently isolated fungal genus was Cladosporium, Curvularia, Alternaria, Fusarium and Penicillium. The average outdoor and indoor (living room) concentrations of fungal colony forming units were 1133+/-759 and 810+/-389, respectively. Average outdoor and indoor (normal ventilation) concentrations of submicrometre and supermicrometre particles were 23.8 x 10(3) and 21.7 x 10(3) (particles/cm(3)), 1.78 and 1.74 (particles/cm(3)), respectively. The study showed that no statistically significant associations between the fungal spore and submicrometre particle concentrations or PM(2.5) were present, while a weak but statistically significant relationship was found between fungal and supermicrometre particle concentrations (for the outdoors R(2)=0.4, P=0.03 and for a living room R(2)=0.3, P=0.04). A similarity in behaviour between the submicrometre particle and fungal spore concentrations was that the fungal spore concentrations were related directly to the distance from the source (a nearby park), in a very similar way in which the submicrometre particles originating from vehicle emissions from a road, were dependent on the distance to the road. In the immediate proximity to the park, fungal concentrations rose up to approximately 3100 CFU/m(3), whereas for houses more than 150 m away from the park the concentrations of fungi were below 1000 CFU/m(3). Recommendations have been provided as the future study designs to gain a deeper insight into the relationships between biological and non-biological particles.

Measurements of 15 nonsmokers and 3 smokers breathing environmental tobacco smoke (ETS), were conducted to study particle deposition within the human respiratory tract. The subjects inhaled ETS of count median diameter (CMD) of about 0.2 micron and geometric standard deviation (GSD) of 1.7 The particle size distribution in the submicrometer range in the inhaled and exhaled air from the subjects was measured using a scanning mobility particle sizer (SMPS). A deposition of 56.0 +/- 15.9% was observed for nonsmokers while breathing ETS through the nose and 48.7 +/- 11.6% while breathing ETS through the mouth. One individual tested four times gave an average deposition of 57.4 +/- 11.5%, providing an indication of intraindividual variation. Such a variation is expected since the breathing rate was not controlled in order that an indication of the deposition experienced on a day-to-day basis could be obtained. For nonsmokers the deposition while breathing through the mouth was lower than through the nose and the variability within the measurements was also lower for mouth breathing. The latter could be due to the variation in individual size and shape of the nasal passage. Smokers had, on average, a higher rate of deposition but also a higher interindividual variability making it difficult to draw conclusions with respect to the affect of smoking on ETS particle deposition. The average deposition of the three smokers was 65.3 +/- 24.1% for nasal breathing and 66.1 +/- 17.6% for mouth breathing.

In petrol engines, solid particle phases are formed as a result of incomplete combustion. In emissions from combustion processes such as petrol, natural gas or diesel, concentration of particles smaller than 1 µm could be several orders of magnitude higher than those which are larger than 1 µm. Due to their physical properties, submicrometer particles have a high probability of deposition in the deeper parts of the respiratory tract. It is known that petrol particles are mutagenic and carriers of hydrocarbons (and other compounds) adsorbed on the particulate and as a result represent a serious health hazard if inhaled. The present paper reports on some measurements of particle size distribution and composition of the bulk aerosol, as well as on morphological and elemental information from individual particles. The study was performed on non-diluted petrol exhaust obtained under different engine operation conditions. The bulk aerosol chemistry study has been performed. The concentrations of the following trace elements were measured: Boron, Calcium, Titanium, Chromium, Manganese, Iron, Cobalt, Nickel, Copper, Zinc, Cadmium, Barium, and Lead. The petrol particles have been found to be spherical. The most abandon elements were Fe, Ca, and Zn that have their origin from the additives in lubricating oil. It is interesting to note that although particle concentrations increased for 3 orders of magnitude from 40 to 120 km/h, emissions of metals did not significantly increase. This would indicate that most of the particle emission at higher loads comes from the unburned fuel and consists mainly of carbon either in elemental or organic form.