Low Volume Air Sampler Research Articles

Particulate Polycyclic Aromatic Hydrocarbons and Their Nitrated Derivatives in Three Cities in Liaoning Province, China

Airborne particulates were collected in nine size fractions by using Andersen low-volume air samplers in the cities of Shenyang, Fushun, and Tieling, Liaoning Province, in northeast China, during the period from July 2001 through December 2003. Nine polycyclic aromatic hydrocarbons (PAHs) and seven nitropolycyclic aromatic hydrocarbons (NPAHs) in the airborne particulates were determined. The mean concentrations of the sums of the nine PAHs and seven NPAHs were highest in Fushun, which is an industrial city, and lowest in Shenyang, which is a commercial city, although the consumption of petroleum and coal were largest in Shenyang. The nine fractions were grouped into three groups: > 7 μ m, 2.1–7 μ m and < 2.1 μ m. In each city, more than 50% of the total PAHs and total NPAHs were found in the fine particulate fraction (< 2.1 μ m). In each city, all PAHs and all NPAHs were clearly higher in winter than in summer. The concentration ratio of 1-nitropyrene to pyrene, which is a suitable indicator to identify diesel engine and coal combustion as proposed by our previous study, showed that the major contributors of PAHs and NPAHs in the airborne particulates were coal-combustion systems both in summer and winter in Fushun and Tieling. In Shenyang, atmospheric PAHs and NPAHs also seemed to be affected by coal combustion systems in winter, whereas gasoline engine vehicles seemed to be a major contributor in summer by the larger concentration ratio of 1-nitropyrene to pyrene. Cluster analysis and other diagnostic ratios such as benz[a]anthracene to chrysene, benzo[ghi]perylene to benzo[a]pyrene supported these results.

環境大気中のダイオキシン類の濃度推移とＣｏ‐ＰＣＢｓの汚染原因

Continuous sampling of dioxins in ambient air was carried out using a low-volume air sampler at the southeast site in Tokyo during a period of FY 2000 to FY 2004. The temporal trend of toxic equivalency quantity (TEQ) was evaluated the relation with Tokyo's inventory which was estimated to be almost completely emitted from combustion sources. The annual average of TEQ was observed to have a more similar tendency to a variation in the inventory than that of regular monitoring with a short term sampling. However, the reduction rate of TEQ for 5 years was less than that of the inventory. Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) increased from late autumn to winter, whereas those of coplanar polychlorinated biphenyls (Co-PCBs) elevated in summer and the seasonal variation seemed to be dependent on temperature. As PCB products and combustion were known to be the major sources of Co-PCBs, we have attempted to estimate the source contribution rates using the method of Bayesian chemical mass balance. Though Co-PCBs derived from PCB products were extrapolated a significant contributor at total concentration base, Co-PCBs emitted from combustion seemed to constitute over 90 % based on TEQ as consequence of higher toxic equivalency factor of their isomers.

Calibration of polyurethane foam (PUF) disk passive air samplers for quantitative measurement of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs): Factors influencing sampling rates

PUF disk passive air samplers are increasingly employed for monitoring of POPs in ambient air. In order to utilize them as quantitative sampling devices, a calibration experiment was conducted. Time integrated indoor air concentrations of PCBs and PBDEs were obtained from a low volume air sampler operated over a 50 d period alongside the PUF disk samplers in the same office microenvironment. Passive sampling rates for the fully-sheltered sampler design employed in our research were determined for the 51 PCB and 7 PBDE congeners detected in all calibration samples. These values varied from 0.57 to 1.55 m3 d(-1) for individual PCBs and from 1.1 to 1.9 m3 d(-1) for PBDEs. These values are appreciably lower than those reported elsewhere for different PUF disk sampler designs (e.g. partially sheltered) employed under different conditions (e.g. in outdoor air), and derived using different calibration experiment configurations. This suggests that sampling rates derived for a specific sampler configuration deployed under specific environmental conditions, should not be extrapolated to different sampler configurations. Furthermore, our observation of variable congener-specific sampling rates (consistent with other studies), implies that more research is required in order to understand fully the factors that influence sampling rates. Analysis of wipe samples taken from the inside of the sampler housing, revealed evidence that the housing surface scavenges particle bound PBDEs.

Lead and cadmium in indoor air and the urban environment

The present study was conducted to find potential terrestrial biomonitors for heavy metals in indoor air in an urban environment. TSP, PM 10, and PM 2.5 were collected in three retirement facilities in the urban area of Vienna. In addition, particulate matter and soil, vegetation, and isopods ( Porcellio scaber L.) were collected in the adjacent garden areas. Aerosols were sampled with a low-volume air sampler. The sampled materials were wet ashed and total lead and cadmium contents were determined. Water-soluble heavy metal concentrations were measured in aqueous extracts from air exposed filters, soil, and vegetation. Lead and cadmium were analyzed by graphite furnace AAS. Lead contents in the vegetation were inferred from water-soluble lead in soils. Lead in isopods generally reflected the contents in vegetation. Cadmium in plants probably derived from soil solutions as well as from atmospheric input. Isopods reflected the total cadmium contents in soils. Particulate matter was dominated by PM 2.5, both with respect to mass concentrations and to heavy metal contents. The indoor aerosol was found to be influenced by human activity, indoor sources, and outdoor particles. Relationships between indoor airborne heavy metals and the contents in vegetation (lead and cadmium: positive) and isopods (lead: negative) were identified to have the potential for biomonitoring indoor air quality.

Determination of Formic and Acetic Acid in the Interior Atmosphere of Display Cases and Cabinets in Athens Museums by Reverse Phase High Performance Liquid Chromatography

Formic and acetic acid levels were determined in 15 display cases and 5 cabinets of the National Archaeological Museum and the Numismatic Museum of Athens after both active and passive sampling. Low volume air samplers with solid sorbent silica gel tubes and activated charcoal personal passive samplers were used. The organic acids were analysed by Reverse Phase High Performance Liquid Chromatography with phosphate buffer (pH = 2.5) as the mobile phase and UV detection at 210nm. Formic acid concentrations in display cases and cabinets ranged from 0.03 to 0.18mg·m−3, and acetic acid concentrations ranged from 0.06 to 2.42mg·m−3.

作業環境測定基準に基づく吸入性粉じんとロウボリウムサンプラ用多段分粒装置の性能評価

The relationship between dust size and penetration for a static horizontal elutriator (Sibata C-30) was measured in calm air. The elutriator as a low-volume air sampler is widely used as a dust size classifier in work environment measurements. The actual penetrations were compared with the theoretical models of the sampler and with sampling convention for respirable dust in work environment measurement. The sampling convention was recently introduced into the Japanese standard for work environment measurement and is based on the ISO 7708 respirable dust convention. The bias of sampled masses from the respirable dust was calculated for two flow rates of the sampler, i.e., 50% cut sizes of 4 microm and 5 microm, from measured penetration curves. The bias of the sampler was overestimated in the 5 microm, 50% cut condition and underestimated in the 4 microm, 50% cut condition for most workplace sampling situations.

Concentrations, enrichment and predominant sources of Sb and other trace elements in size classified airborne particulate matter collected in Tokyo from 1995 to 2004

APM was collected and trace elements existing in the particles were monitored since May 1995 in this study. APM sample was collected separately by size (d < 2 microm, 2-11 microm and >11 microm) on the roof of the university building (45 m above ground) in the campus of Faculty of Science and Engineering, Chuo University, Tokyo, Japan, using an Anderson low volume air sampler. The collected sample was digested by HNO3, H2O2 and HF using a microwave oven, and major elements (Na, Mg, Al, K, Ca and Fe) were measured by ICP-AES, and trace elements (Li, Be, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sb, Ba and Pb) were measured by ICP-MS. It was observed that the APM concentration was higher between the winter and the spring, compared to during the summer. The enrichment factor was calculated for each element in each set of APM (d < 2 microm, 2-11 microm and >11 microm). Seasonal trends of enrichment factors were examined, and the elements were classified into 3 groups according to the common seasonal behavior. It is likely that the elements in the same group have common origins. Toxic pollutant elements (Sb, Se, Cd, Pb and As) were found in small particles with d of <2 microm in concentrated levels. Antimony (Sb) had the highest enrichment factor, and the results suggested that Sb level in APM was extremely high. The origins of Sb were sought, and wastes from plastic incineration and brake pad wears of automobiles were suspected. Each set of APM (d < 2 microm, 2-11 microm and >11 microm) was classified by the shape, and the shape-dependent constituents of a single APM particle were quantitatively measured by SEM-EDX. High concentration of Sb was found in APM <2 microm and square particles. Particles less than 2 microm and square shaped particles were major particles produced by actual car braking experiments. From these experimental results it was concluded that the source of Sb in squared APM <2 microm is considered to be from brake pad wear.

Field Calibration of Rapidly Equilibrating Thin-Film Passive Air Samplers and Their Potential Application for Low-Volume Air Sampling Studies

This paper reports on a field calibration and ambient deployment study with rapidly equilibrating thin-film passive air samplers. POlymer-coated Glass (POG) samplers have a coating of ethylene vinyl acetate (EVA) less than 1 microm thick coated on to glass, which can be dissolved off after exposure and prepared for quantification of persistent organic pollutants (POPs) that have partitioned into the film during field exposure. In this study, POGs were exposed for up to 18 d, in a study to assess compound uptake rates and their time to approach equilibrium. Results confirmed theoretical predictions, with time to equilibrium varying between a few hours to ca. 20 d for PCB-18 and PCB-138, respectively. Performance reference compounds and contaminated POGs were used to investigate depuration kinetics, confirming that lighter congeners behave extremely dynamically with substantial losses from the films over periods of a few hours. Repeated deployments of the samplers for different3-d periods yielded detectable levels of a range of PCB congeners, which had partitioned from as little as approximately 2 to 10 m3 air. This highlights the potential utility of POGs for extremely sensitive and dynamic passive air sampling in the future to help improve understanding of sources, environmental fate, and behavior of POPs. Recommendations are made for future improvements/refinements in POG sampling and handling procedures.

First assessment of the PM10 and PM2.5 particulate level in the ambient air of Belgrade city.

As the strong negative health effect of exposure to the inhalable particulate matter PM10 in the urban environment has been confirmed, the study of the mass concentrations, physico-chemical characteristics, sources, as well as spatial and temporal variation of atmospheric aerosol particles becomes very important. This work is a pilot study to assess the concentration level of ambient suspended particulate matter, with an aerodynamic diameter of less than 10 microm, in the Belgrade central urban area. Average daily concentrations of PM10 and PM2.5 have been measured at three representative points in the city between June 2002 and December 2002. The influence of meteorological parameters on PM10 and PM2.5 concentrations was analyzed, and possible pollution sources were identified. Suspended particles were collected on Pure Teflon filters by using a Mini-Vol low-volume air sampler (Airmetrics Co., Inc.; 5 l min(-1) flow rate). Particle mass was determined gravimetrically after 48 h of conditioning in a desiccator, in a Class 100 clean room at the temperature T = 20 degrees C and at about 50% constant relative humidity (RH). Analysis of the PM10 data indicated a marked difference between season without heating--(summer; mean value 56 microg m(-3)) and heating season--(winter; mean value 96 microg m3); 62% of samples exceeded the level of 50 microg m(-3). The impact of meteorological factors on PM concentrations was not immediately apparent, but there was a significant negative correlation with the wind speed. The PM10 and PM2.5 mass concentrations in the Belgrade urban area had high average values (77 microg m(-3) and 61 microg m(-3)) in comparison with other European cities. The main sources of particulate matter were traffic emission, road dust resuspension, and individual heating emissions. When the air masses are coming from the SW direction, the contribution from the Obrenovac power plants is evident. During days of exceptionally severe pollution, in both summer and winter periods, high production of secondary aerosols occurred, as can be seen from an increase in PM2.5 in respect to PM10 mass concentration. The results obtained gave us the first impression of the concentration level of particulate matter, with an aerodynamic diameter of less than 10 microm, in the Belgrade ambient air. Due to measured high PM mass concentrations, it is obvious that it would be very difficult to meet the EU standards (EEC 1999) by 2010. It is necessary to continue with PM10 and PM2.5 sampling; and after comprehensive analysis which includes the results of chemical and physical characterization of particles, we will be able to recommend effective control measures in order to improve air quality in Belgrade.

Characterization of soluble and insoluble components in PM 2.5 and PM 10 fractions of airborne particulate matter in Kofu city, Japan

A systematic method combining water and diluted-acid extractions has been developed for the manifold evaluation of soluble and insoluble fractions in ambient aerosol. The pre-washed regenerated cellulose membrane filter was used as a collection medium of a low-volume air sampler. The collection time of 7–14 days was required to obtain the sample amounts enough for the systematic analysis. Simple and efficient extraction procedures using the filtration of water and 0.1 M hydrochloric acid were recommended in order to obtain the information about the dissolution behaviors of various elements in the aerosol. Soluble components in both the extracts were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) and ion chromatography (IC). These extraction procedures were also preferred to prepare thin-layer specimens suitable to the succeeding X-ray fluorescence spectrometry (XRF) for insoluble components. Elemental compositions of the extraction residues were conveniently determined by the XRF calibrated with thin-layer standard specimens prepared with activated carbon. The determination of the 17 representative elements (Na, Mg, Al, Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Cu, Zn, Br, Pb) in these three fractions from an aerosol sample was performed rapidly within 4 h. The proposed systematic method was applied to PM 2.5 and PM 10 aerosol samples collected in Kofu City, Central Japan, and the enrichment behaviors of various elements and their source apportionment such as soil, anthropogenic substances and vehicle exhaust particulates could be demonstrated by the present method.

Successful experiences with a handy equipment to measure dust concentrations in various workplaces.

Performance of a direct-reading handy equipment for dust counting in workroom air, PDR (MIE, USA), was field-tested in comparison with the results of low-volume air sampling-gravimetry. Application in 64 workplaces of various type dust work with dust concentrations of up to 1.6 mg/m3 showed that the agreement was generally good with a correlation coefficient (r) >0.64. The calculated regression line had a slope close to one, and the intercept on the axis was next to nil, suggesting that the measurement with PDR is essentially the same with that by low-volume air sampling. Further analysis by types of dust work disclosed that the correlation was best when examined in 12 foundries with r as large as 0.95. In contrast, r was small (0.52) in 11 welding workplaces, possibly due to smaller particle size of dust generated during welding.

Real-Time and Integrated Measurement of Potential Human Exposure to Particle-Bound Polycyclic Aromatic Hydrocarbons (PAHs) from Aircraft Exhaust

We used real-time monitors and low-volume air samplers to measure the potential human exposure to airborne polycyclic aromatic hydrocarbon (PAH) concentrations during various flight-related and ground-support activities of C-130H aircraft at an Air National Guard base. We used three types of photoelectric aerosol sensors (PASs) to measure real-time concentrations of particle-bound PAHs in a break room, downwind from a C-130H aircraft during a four-engine run-up test, in a maintenance hangar, in a C-130H aircraft cargo bay during cargo-drop training, downwind from aerospace ground equipment (AGE), and in a C-130H aircraft cargo bay during engine running on/off (ERO) loading and backup exercises. Two low-volume air samplers were collocated with the real-time monitors for all monitoring events except those in the break room and during in-flight activities. Total PAH concentrations in the integrated-air samples followed a general trend: downwind from two AGE units > ERO-loading exercise > four-engine run-up test > maintenance hangar during taxi and takeoff > background measurements in maintenance hangar. Each PAH profile was dominated by naphthalene, the alkyl-substituted naphthalenes, and other PAHs expected to be in the vapor phase. We also found particle-bound PAHs, such as fluoranthene, pyrene, and benzo[a]pyrene in some of the sample extracts. During flight-related exercises, total PAH concentrations in the integrated-air samples were 10-25 times higher than those commonly found in ambient air. Real-time monitor mean responses generally followed the integrated-air sample trends. These monitors provided a semiquantitative temporal profile of ambient PAH concentrations and showed that PAH concentrations can fluctuate rapidly from a baseline level < 20 to > 4,000 ng/m(3) during flight-related activities. Small handheld models of the PAS monitors exhibited potential for assessing incidental personal exposure to particle-bound PAHs in engine exhaust and for serving as a real-time dosimeter to indicate when respiratory protection is advisable.

Real-time and integrated measurement of potential human exposure to particle-bound polycyclic aromatic hydrocarbons (PAHs) from aircraft exhaust.

We used real-time monitors and low-volume air samplers to measure the potential human exposure to airborne polycyclic aromatic hydrocarbon (PAH) concentrations during various flight-related and ground-support activities of C-130H aircraft at an Air National Guard base. We used three types of photoelectric aerosol sensors (PASs) to measure real-time concentrations of particle-bound PAHs in a break room, downwind from a C-130H aircraft during a four-engine run-up test, in a maintenance hangar, in a C-130H aircraft cargo bay during cargo-drop training, downwind from aerospace ground equipment (AGE), and in a C-130H aircraft cargo bay during engine running on/off (ERO) loading and backup exercises. Two low-volume air samplers were collocated with the real-time monitors for all monitoring events except those in the break room and during in-flight activities. Total PAH concentrations in the integrated-air samples followed a general trend: downwind from two AGE units > ERO-loading exercise > four-engine run-up test > maintenance hangar during taxi and takeoff > background measurements in maintenance hangar. Each PAH profile was dominated by naphthalene, the alkyl-substituted naphthalenes, and other PAHs expected to be in the vapor phase. We also found particle-bound PAHs, such as fluoranthene, pyrene, and benzo[a]pyrene in some of the sample extracts. During flight-related exercises, total PAH concentrations in the integrated-air samples were 10-25 times higher than those commonly found in ambient air. Real-time monitor mean responses generally followed the integrated-air sample trends. These monitors provided a semiquantitative temporal profile of ambient PAH concentrations and showed that PAH concentrations can fluctuate rapidly from a baseline level < 20 to > 4,000 ng/m(3) during flight-related activities. Small handheld models of the PAS monitors exhibited potential for assessing incidental personal exposure to particle-bound PAHs in engine exhaust and for serving as a real-time dosimeter to indicate when respiratory protection is advisable.

The concentration, trend and seasonal variation of metals in the atmosphere in 16 Japanese cities shown by the results of National Air Surveillance Network (NASN) from 1974 to 1996

In this study, the data from National Air Surveillance Network (NASN) for selected crustal elements (Al, Ca, Fe, Mn, Sc and Ti), anthropogenic elements (As, Cu, Cr, Ni, Pb, V and Zn) and a marine element (Na) in atmospheric particulate matter have been evaluated over Japan from 1974 to 1996. The NASN had 16 sampling stations, Nopporo, Sapporo, Nonotake, Sendai, Niigata, Tokyo, Kawasaki, Nagoya, Kyoto-Hachiman, Osaka, Amagasaki, Kurashiki, Matsue, Ube, Chikugo-Ogori and Ohmuta in Japan, at which aerosols were regularly collected every month and samples collected by low volume air sampler were analyzed by neutron activation analysis (NAA) and X-ray fluorescence (XRF). Results of trend analysis showed that the annual average concentrations of crustal and anthropogenic elements decreased significantly between 1974 and 1996. Furthermore, the concentrations of selected crustal and anthropogenic elements were higher between 1974 and 1979 than between 1980 and 1989. Crustal elements displayed high concentrations in the “Kosa” period (the dust season from March to May) and in winter (November and December) and low concentrations in summer (July and August). The ratios of elemental average concentrations in the Kosa period to those of summer were 2–5 times higher and those of winter relative to those of summer were 1.5–3 times higher for crustally derived elements. Particularly, concentration of Sc in Matsue was 8 times higher during the Kosa period than during summer time. Some of anthropogenic elements also showed high concentrations in the Kosa Season and low concentrations in summer. The ratios of elemental concentration in the Kosa period to those of summer and those of winter relative to summer were 2–4 times higher for some anthropogenically derived elements. Especially, the concentration of Zn in Chikugo-Ogori was 5.7 times higher during wintertime than during summertime.

381 SALVENT, a prototype for continuous low volume air sampling through HEPA filter

381 SALVENT, a prototype for continuous low volume air sampling through HEPA filter

Study on air pollution monitoring in Korea using low volume air sampler by instrumental neutron activation analysis

The aim of this research was to enhance the use of nuclear analytical techniques for air pollution studies and to study the feasibility of the use of instrumental neutron activation analysis (INAA) as a routine monitoring tool to reveal environmental pollution sources. For the collection of air particulate samples, the Gent stacked filter unit, low volume sampler with Nucleopore membrane filters were used. Trace elements in samples collected at two suburban residential sites, Taejon and Wonju city in the Republic of Korea, were analyzed by INAA. Variations of the elemental concentrations were measured monthly and the enrichment factors were calculated for the fine (<2 μm EAD) and coarse size (2–10 μm EAD) fractions. The analytical data were treated statistically to estimate the relationship between the two variables, the concentrations of elements and the total suspended particulate matter. The results were used to describe the emission source and their correlation.

Examination of dust generated from a workplace where steel wire coil are unwound

Analyses of constituents, measurement of concentrations, research of size distributions and scanning electron microscopic examinations were carried out to determine the type and amount of dust generated in a working environment where steel wire coils are unwound. In about a 700 m2 work area unit, stationary samplings, including A-sampling (24 points) and B-sampling (1 point), which are defined by the law, were carried out. The dust concentration was measured by a digital dust indicator. A low volume air sampler was used to determine the conversion factor of the values obtained by the digital dust indicator. Because the result of the dust level by A-sampling and B-sampling were 0.64 mg/m3 and 0.82 mg/m3 respectively, they can both be classified as Control Class 1. A proportion of less than 7 microns of the airborne dust made up about 15 to 20% (volume %) of the total dust in the working environments. Metallic dust and white dust were identified in the accumulated dust. By measuring with a X-ray diffractometry, it was determined that the metal dust constituent was Zn and the white dust constituent was Zn4CO3(OH)6.H2O. By a scanning electron microscopic examination, the scope of the particles was proven to be non-fibrous.

Method of Determining the Inhalation Deposition of Mutagenic Components in Environmental Tobacco Smoke Aerosol.

Total inhalation deposition of direct-acting mutagenicity associated with environmental tobacco smoke (ETS) aerosol was measured in a human volunteer. The exposures were conducted in a normal office containing well circulated ETS. The ETS aerosol was collected by filtration in the exhaled air using the Hans Rudolph mask connected to a filter holder and respirometer. The inhaled indoor air was collected by low volume air sampler. The direct-acting mutagenicity of the aerosol was determined using the ultramicrosuspension forward mutation assay in Salmonella typhimurium strain TM677. The deposition ratio was estimated as ca. 55% from the difference of the mutagenicity between exhaled and inhaled air.

Direct Determination of Lead in Suspended Particulate Matter in Air by Tungsten Furnace-Atomic Absorption Spectrometry with a Punching Technique

A simple and rapid method for the determination of trace lead in suspended particulate matter in air has been investigated. The sample is collected on a cellulose nitrate filter (diameter: 44 mm, pore size: 0. 65 μm) with a low-volume air sampler (flow rate: 15 1/min). For direct determination, a small disc (diameter: 2. 0 mm) is cut from the filter with a paper punch, and it is introduced into a tungsten furnace. Then, 1. 0 μg of palladium (palladium chloride solution) as a matrix modifier which accomplishes available atomization of lead is added to the disc. The optimal thermal programs are as follows: drying at 300°C for 30 s, ashing at 1000°C for 30 s, and atomization at 2000°C for 2 s in a mixed gas atmosphere (flow rate: hydrogen 1. 01/min, argon 4. 01/min). The 283. 3 nm line was used for lead on the peak-area method under deuterium lamp-background correction. The relative standard deviation was 14. 3% for 7 times determination on 0. 035 μg/m3 lead in a suspended particulate matter.

Measurement of airborne fumes in welding factories

Concentrations and size distributions of airborne welding fumes in work environments were measured. Samples were collected from 20 workplaces in 13 companies. In all workplaces, the stationary samplings including A-sampling and B-sampling and the personal sampling were carried out simultaneously. The fume concentration in the stationary sampling was measured with a digital dust monitor. A low volume air sampler and an Anderson cascade impactor was also used to determine the conversion factor of the values obtained by the digital dust monitor and the size distributions of the fumes. The personal exposure levels were measured with a TR sampler and a personal cascade impactor. The concentrations by the personal sampling (average: 11.3mg/m3) were much higher than those by the A-sampling (average: 0.4mg/m3 and range: 0.15-0.64mg/m3) but lower than those by the B-sampling (average: 46.8mg/m3, range: 0.66-152.8mg/m3). The mass median aerodynamic diameter (MMAD) of the stationary and the personal samplings were 2.41 microns and 0.80 microns, respectively. Fumes were observed under a scanning electron microscope. Most of the fume particles were sphere in shape but smaller fumes were aggregated and formed larger secondary particles.