Personal exposure to gaseous and particulate phase polycyclic aromatic hydrocarbons (PAHs) and nanoparticles and lung deposited surface area (LDSA) for soot among Norwegian chimney sweepers.

Exposure to polycyclic aromatic hydrocarbons (PAHs) of high molecular weight from chimney soot can cause cancer among chimney sweepers. These sweepers may also be exposed to high concentrations of nanosized particles, which can cause significant inflammatory responses due to their relatively greater surface area per mass. In this study, the authors aimed to assess the exposure profiles of airborne personal exposure to gaseous and particulate PAHs, and real-time samples of the particle number concentrations (PNCs), particle sizes, and lung-deposited surface areas (LDSAs), for chimney sweepers in Norway. Additionally, the authors aimed to assess the task-based exposure concentrations of PNCs, sizes, and LDSAs while working on different tasks. The results are based on personal samples of particulate PAHs (n = 68), gaseous PAHs (n = 28), and real-time nanoparticles (n = 8) collected from 17 chimney sweepers. Samples were collected during a "typical work week" of chimney sweeping and fire safety inspections, then during a "massive soot" week, where larger sweeping missions took place. Significantly higher PAH concentrations were measured during the "massive soot" week compared to the "typical work week," however, the time-weighted average (TWA) (8-hr) of all gaseous and particulate PAHs ranged from 0.52 to 4.47 µg/m3 and 0.49 to 2.50 µg/m3, respectively, well below the Norwegian occupational exposure limit (OEL) of 40 µg/m3. The PNCs were high during certain activities, such as emptying the vacuum cleaner. Additionally, during 2 days of sweeping in a waste sorting facility, the TWAs of the PNCs were 3.6 × 104 and 7.1 × 104 particles/cm3 on the first and second days, respectively, which were near and above the proposed nano reference limit TWA value of 4.0 × 104 particles/cm3 proposed by the International Workshop on Nano Reference Values. The corresponding TWAs of the LDSAs were 49.5 and 54.5 µm2/cm3, respectively. The chimney sweepers seemed aware of the potential health risks associated with exposure, and suitable personal protective equipment was used. However, the PNCs reported for the activities show that when the activities change or increase, the PNCs' TWAs can become unacceptably high.

Comparing PM2.5, respirable dust, and total dust fractions using real-time and gravimetric samples in an exposure chamber study.

Using an exposure chamber, we investigate the precision of the DustTrak DRX monitor by comparing its results to those obtained from taking traditional gravimetric samples of two stone minerals commonly used in asphalt and lactose powder. We also discuss the possibility of using real-time monitors such as DustTrak DRX for occupational exposure monitoring purposes. The results are based on 19 days of experiment, each day with measurements collected over 4 h. Compared to the gravimetric samples, the DustTrak DRX overestimated the PM2.5 and respirable dust concentrations, while it underestimated the total dust concentration by a factor of nearly two. However, the ratios, being done for more than one material, between the DustTrak DRX and the gravimetric sample readings varied daily and across the different exposure materials. Real-time sensors have the potential to excel at identifying exposure sources, evaluating the measured control efficiency, visualizing variations in exposure to motivate workers, and contributing to the identification of measures to be implemented to reduce exposure. For total dust, a correction factor of at least two should be used to bring its readings up to those for the corresponding gravimetric samples. Also, if the DustTrak DRX is used in the initial profiling of occupational exposure, the exposure could be considered acceptable if the readings are well below the occupational exposure limit (OELs) after correction. If the DustTrak DRX readings, after correction, is close to, or above, the accepted exposure concentrations, more thorough approaches would be required to validate the exposure.

Characterization of elements, PAHs, AhR-activity and pro-inflammatory responses of road tunnel-derived particulate matter in human hepatocyte-like and bronchial epithelial cells.

The aims were to characterize the content of elements and polycyclic aromatic hydrocarbons (PAHs) in size-separated particulate matter (PM) sampled in a road tunnel, estimate the contribution of PAHs to the toxic potential, and measure the pro-inflammatory potential of PM samples and extracts with increasing polarity. Several elements/metals previously associated with cytokine responses were found. Based on PAHs levels and published PAHs potency, the calculated mutagenic and carcinogenic activities of size-separated samples were somewhat lower for coarse than fine and ultrafine PM. The AhR-activity of the corresponding PM extracts measured in an AhR-luciferase reporter model (human hepatocytes) were more similar. The highest AhR-activity was found in the neutral (parent and alkylated PAHs) and polar (oxy-PAHs) fractions, while the semi-polar fractions (mono-nitrated-PAHs) had only weak activity. The neutral and polar aromatic fractions from coarse and fine PM were also found to induce higher pro-inflammatory responses and CYP1A1 expression in human bronchial epithelial cells (HBEC3-KT) than the semi-polar fractions. Fine PM induced higher pro-inflammatory responses than coarse PM. AhR-inhibition reduced cytokine responses induced by parent PM and extracts of both size fractions. Contributors to the toxic potentials include PAHs and oxy-PAHs, but substantial contributions from other organic compounds and/or metals are likely.

Short-term exposure to stone minerals used in asphalt affect lung function and promote pulmonary inflammation among healthy adults.

OBJECTIVE: Stone minerals are a partially ignored environmental challenge but a significant contributor to urban air pollution. We examined if short-term exposure to two stone minerals - quartz diorite and rhomb porphyry - commonly used in asphalt pavement would affect lung function, promote pulmonary inflammation, and affect bronchial reactivity differently. METHODS: Our randomized crossover study included 24 healthy, non-smoking young adults exposed to the stone minerals quartz diorite, rhomb porphyry, and control dust (lactose). Exposure occurred in an exposure chamber, in three separate 4-hour exposure sessions. Fractional exhaled nitric oxide (FeNO) and lung function were monitored before exposure, then immediately following exposure, and 4 and 24 hours after exposure. In addition, methacholine was administered 4 hours following exposure, and exhaled breath condensate (EBC) was collected before exposure, then immediately and 4 hours after exposure. EBC was analyzed for pH, thiobarbituric acid reactive substances (TBARS), intercellular adhesion molecule 1 (ICAM-1), interleukin-6 (IL-6), IL-10, P-Selectin, surfactant protein D (SP-D), and tumor necrosis factor-α (TNF-α). RESULTS: Our results showed significantly elevated concentrations of FeNO after exposure to quartz diorite compared to rhomb porphyry, suggesting that quartz diorite is more likely to trigger pulmonary inflammation after short-term exposure. Moreover, short-term exposure to rhomb porphyry was associated with a modest but statistically significant decline in forced vital capacity (FVC) compared to quartz diorite. CONCLUSION: These results emphasize that using stone material in asphalt road construction should be reconsidered as it may affect lung inflammation and lung function in exposed subjects.

Association between exposure to different stone aggregates from asphalt and blood coagulability: A human exposure chamber study.

A large fraction of particulate matter (PM), especially PM10, concentrations are due to non-exhaust emissions, such as road abrasion and wear on tires and brake pads. Concentrating on road abrasion, we aimed to investigate blood coagulability in healthy adults after exposure to two types of stone materials commonly used in asphalt on Norwegian roads. This study followed a randomized, double-blind, cross-over study design. Using an exposure chamber, 24 healthy young volunteers were exposed to aggregates of two different types of rocks and placebo dust: quartz diorite, rhomb porphyry, and lactose (placebo dust). Each exposure session lasted for 4 hours (h), and blood samples were collected before exposure (baseline), 4 h post-exposure, and 24 h post-exposure to analyse potential changes in the von Willebrand factor (vWF) as well as of fibrinogen, d-dimer, leukocytes, and thrombocytes. The dust concentration in the exposure chamber was measured with real-time instruments and gravimetric samples of total dust, respirable dust, PM10, PM2.5, and ultrafine particles (UFP). The results were analysed using a linear mixed-effect model. Leukocyte blood counts increased post-exposure for all exposure materials; however, none of the increases were statistically significant. The concentration of fibrinogen increased after exposure to quartz diorite, while it decreased after exposures to rhomb porphyry and lactose. Type of material was a statistically significant explanatory variable for the concentration of fibrinogen, with the most significant increase occurring 24 h post-exposure to quartz diorite. After exposure to the three materials, vWF decreased. For the thrombocytes, an increase in blood count was observed 24 h post-exposure to quartz diorite and rhomb porphyry, with a modest (p = 0.09) positive association for quartz diorite. Although the results are limited, we conclude that the different effects observed post-exposure to quartz diorite support considering potential health effects when choosing materials in the production of asphalt.

Exposure to Ultrafine Particles in the Ferroalloy Industry Using a Logbook Method.

BACKGROUND: It is difficult to assess workers' exposure to ultrafine particles (UFP) due to the lack of personal sampling equipment available for this particle fraction. The logbook method has been proposed as a general method for exposure assessment. This method measures the time and concentration components of the time-weighted average concentration separately and could be suitable for investigation of UFP exposure. OBJECTIVES: In this study, we have assessed workers' exposure to UFP in a ferrosilicon plant. The main tasks of the furnace workers were identified, and the logbook method was used in combination with stationary measurements of UFP taken as close to the identified task areas as possible. In order to verify the results, respirable particles were collected using stationary sampling in close proximity to the UFP measuring instrument, and personal full-shift sampling of respirable particles was performed simultaneously. Thus, exposure to respirable particles determined using the logbook method could be compared to the results of standard measurement. METHODS: The particle number concentration of ultrafine particles was determined using a NanoScan SMPS. Respirable particle concentration and exposure were determined using a sampling train consisting of a pump, filter, filter cassettes, and SKC Cyclone for the respirable fraction. Attendance times for workers at each work location were registered via thorough observations made by the research team. RESULTS: The logbook method for exposure estimation based on stationary sampling equipment made it possible to calculate UFP exposure for workers operating the furnaces at a ferrosilicon plant. The mid-size furnace and the large furnace were evaluated separately. The workers operating the largest furnace were exposed to 1.47 × 104 particles/cm3, while workers operating the mid-size furnace were exposed to 2.06 × 104 particles/cm3, with a mean of 1.74 × 104 particles/cm3. Substantial contributions from the casting area, ladle transport corridor, and both tapping areas were made. Exposure to respirable particles was 2.04 mg/m3 (logbook); 2.26 mg/m3 (personal sampling) for workers operating the large-sized furnace, 3.24 mg/m3 (logbook); 2.44 mg/m3 (personal sampling) for workers operating the medium-sized furnace, and 2.57 mg/m3 (logbook); 2.53 mg/m3(personal sampling) on average of all tappers. The average ratio of these two methods' results was 1.02, which indicates that the logbook method could be used as a substitute for personal sampling when it is not possible to perform personal sampling, at least within this industry. CONCLUSIONS: The logbook method is a useful supplement for exposure assessment of UFP, able to identify the most polluted areas of the workplace and the contribution of different work tasks to the total exposure of workers, enabling companies to take action to reduce exposure.

Comparison of four nanoparticle monitoring instruments relevant for occupational hygiene applications.

BACKGROUND: The aim of this study is to make a comparison of a new small sized nanoparticle monitoring instrument, Nanoscan  SMPS, with more traditional large size instruments, known to be precise and accurate [Scanning Mobility Particle Sampler (SMPS) and Fast Mobility Particle Sizer (FMPS)], and with an older small size instrument with bulk measurements of 10-1000 nm particles (CPC3007). The comparisons are made during simulated exposure scenarios relevant to occupational hygiene studies. METHODS: Four scenarios were investigated: metal inert gas (MIG) welding, polyvinyl chloride (PVC) welding, cooking, and candle-burning. Ratios between results are compaed and Pearsson correlations analysis was performed. RESULTS: The highest correlation between the results is found between Nanoscan and SMPS, with Pearsson correlation coefficients above 0.9 for all scenarios. However, Nanoscan tended to overestimate the results from the SMPS; the ratio between the UFP concentrations vary between 1.44 and 2.01, and ratios of total concentrations between 1.18 and 2.33. CPC 3007 did not show comparable results with the remaining instruments. CONCLUSION: Based on the results of this study, the choice of measurement equipment may be crucial when evaluating measurement results against a reference value or a limit value for nanoparticle exposure. This stresses the need for method development, standardisation, and harmonisation of particle sampling protocols before reference values are introduced. Until this is established, the SMPS instruments are the most reliable for quantification of the concentrations of UFP, but in a more practical occupational hygiene context, the Nanoscan SMPS should be further tested.

Real-Time Measurements and Characterization of Airborne Particulate Matter from a Primary Silicon Carbide Production Plant.

Airborne particulate matter in the silicon carbide (SiC) industry is a known health hazard. The aims of this study were to elucidate whether the particulate matter generated inside the Acheson furnace during active operation is representative of the overall particulate matter in the furnace hall, and whether the Acheson furnaces are the main sources of ultrafine particles (UFP) in primary SiC production. The number concentration of ultrafine particles was evaluated using an Electrical Low Pressure Impactor (ELPITM, Dekati Ltd., Tampere, Finland), a Fast Mobility Particle Sizer (FMPSTM, TSI, Shoreview, MN, USA) and a Condensation Particle Counter (CPC, TSI, Shoreview, MN, USA). The results are discussed in terms of particle number concentration, particle size distribution and are also characterized by means of electron microscopy (TEM/SEM). Two locations were investigated; the industrial Acheson process furnace hall and a pilot furnace hall; both of which represent an active operating furnace. The geometric mean of the particle number concentration in the Acheson process furnace hall was 7.7 × 104 particles/cm³ for the UFP fraction and 1.0 × 105 particles/cm³ for the submicrometre fraction. Particulate matter collected at the two sites was analysed by electron microscopy. The PM from the Acheson process furnace hall is dominated by carbonaceous particles while the samples collected near the pilot furnace are primarily rich in silicon.

Nano-sized emission from commercially available paints used for indoor surfaces during drying.

Consumers worry about the presence of nano-particles in paints and the risk of exposure. As a result, the paint industry now omits marketing paints as containing nanoparticles. The industry claims that no nanoparticles are released into the indoor environment; this, however, has yet to be documented. In this study, the emission of nano-sized emission from four indoor paints was investigated. The emission was studied for both base and full-pigmented versions of the paints, which consisted of three water-borne acrylic paints and one solvent-borne alkyd paint. All experiments were performed twice in a 6.783 m3 stainless-steel test chamber under standardized conditions (22.98 °C, 50.08% RH, air exchange rate 0.48 h-1). Emissions during the paint-drying period were measured using a TSI Fast Mobility Particle Sizer (FMPS) measuring the number concentration of nano-particles and the size distribution in the range 5.6-560 nm. The results from the solvent-borne paint showed the highest concentration, with a mean concentration of 3.2·105 particles/cm3 and a maximum of 1.4·106 particles/cm3. This paint also had the smallest particle size distribution, with 9.31 nm particles as the most dominant particle size. The results from this study showed that the exposure to nanoparticles for the residents evaluated over a 7 or 28 day period was low and that interior paints are probably not very important when it comes to identifying products that release nano-particles into indoor environments.

Comparison of Three Real-Time Measurement Methods for Airborne Ultrafine Particles in the Silicon Alloy Industry.

The aim of this study was to compare the applicability and the correlation between three commercially available instruments capable of detection, quantification, and characterization of ultrafine airborne particulate matter in the industrial setting of a tapping area in a silicon alloy production plant. The number concentration of ultrafine particles was evaluated using an Electric Low Pressure Impactor (ELPI(TM)), a Fast Mobility Particle Sizer (FMPS(TM)), and a Condensation Particle Counter (CPC). The results are discussed in terms of particle size distribution and temporal variations linked to process operations. The instruments show excellent temporal covariation and the correlation between the FMPS and ELPI is good. The advantage of the FMPS is the excellent time- and size resolution of the results. The main advantage of the ELPI is the possibility to collect size-fractionated samples of the dust for subsequent analysis by, for example, electron microscopy. The CPC does not provide information about the particle size distribution and its correlation to the other two instruments is somewhat poor. Nonetheless, the CPC gives basic, real-time information about the ultrafine particle concentration and can therefore be used for source identification.

Characterisation of Exposure to Ultrafine Particles from Surgical Smoke by Use of a Fast Mobility Particle Sizer.

INTRODUCTION: Electrosurgery is a method based on a high frequency current used to cut tissue and coagulate small blood vessels during surgery. Surgical smoke is generated due to the heat created by electrosurgery. The carcinogenic potential of this smoke was assumed already in the 1980's and there has been a growing interest in the potential adverse health effects of exposure to the particles in surgical smoke. Surgical smoke is known to contain ultrafine particles (UFPs) but the knowledge about the exposure to UFPs produced by electrosurgery is however sparse. The aims of the study were therefore to characterise the exposure to UFPs in surgical smoke during different types of surgical procedures and on different job groups in the operating room, and to characterise the particle size distribution. METHODS: Personal exposure measurements were performed on main surgeon, assistant surgeon, surgical nurse, and anaesthetic nurse during five different surgical procedures [nephrectomy, breast reduction surgery, abdominoplasty, hip replacement surgery, and transurethral resection of the prostate (TURP)]. The measurements were performed with a Fast Mobility Particle Sizer (FMPS) to assess the exposure to UPFs and to characterize the particle size distribution. Possible predictors of exposure were investigated using Linear Mixed Effect Models. RESULTS: The exposure to UFPs was highest during abdominoplasty arithmetic mean (AM) 3900 particles cm(-3) and lowest during hip replacement surgeries AM 400 particles cm(-3). The different job groups had similar exposure during the same types of surgical procedures. The use of electrosurgery resulted in short term high peak exposure (highest maximum peak value 272 000 particles cm(-3)) to mainly UFPs. The size distribution of particles varied between the different types of surgical procedures, where nephrectomy, hip replacement surgery, and TURP produced UFPs with a dominating mode of 9nm while breast reduction surgery and abdominoplasty produced UFPs with a dominating mode of 70 and 81nm, respectively. Type of surgery was the strongest predictor of exposure. When only including breast reduction surgery in the analysis, the use of one or two ES pencils during surgery was a significant predictor of exposure. When only including hip replacement surgery, the operating room was a significant predictor of exposure. CONCLUSION: The use of electrosurgery resulted in short-term high peak exposures to mainly UFPs in surgical smoke. Type of surgery was the strongest predictor of exposure and the different types of surgical procedures produced different sized particles. The job groups had similar exposure. Compared to other occupational exposures to UFPs involving hot processes, the personal exposure levels for UFPs were low during the use of electrosurgery.

Personal exposure to ultrafine particles from PVC welding and concrete work during tunnel rehabilitation.

OBJECTIVES: To investigate the exposure to number concentration of ultrafine particles and the size distribution in the breathing zone of workers during rehabilitation of a subsea tunnel. METHODS: Personal exposure was measured using a TSI 3091 Fast Mobility Particle Sizer (FMPS), measuring the number concentration of submicrometre particles (including ultrafine particles) and the particle size distribution in the size range 5.6-560 nm. The measurements were performed in the breathing zone of the operators by the use of a conductive silicone tubing. Working tasks studied were operation of the slipforming machine, operations related to finishing the verge, and welding the PVC membrane. In addition, background levels were measured. RESULTS: Arithmetic mean values of ultrafine particles were in the range 6.26×10(5)-3.34×10(6). Vertical PVC welding gave the highest exposure. Horizontal welding was the work task with the highest maximum peak exposure, 8.1×10(7) particles/cm(3). Background concentrations of 4.0×10(4)-3.1×10(5) were found in the tunnel. The mobility diameter at peak particle concentration varied between 10.8 nm during horizontal PVC welding and during breaks and 60.4 nm while finishing the verge. CONCLUSIONS: PVC welding in a vertical position resulted in very high exposure of the worker to ultrafine particles compared to other types of work tasks. In evaluations of worker exposure to ultrafine particles, it seems important to distinguish between personal samples taken in the breathing zone of the worker and more stationary work area measurements. There is a need for a portable particle-sizing instrument for measurements of ultrafine particles in working environments.

Simulated restaurant cook exposure to emissions of PAHs, mutagenic aldehydes, and particles from frying bacon.

This study investigated the exposure of cooks to polycyclic aromatic hydrocarbons (PAHs), higher mutagenic aldehydes, total particles, and ultrafine particles during cooking. Experiments were performed by pan frying fresh and smoked bacon on both electric and gas stoves, and with the gas alone. Detailed analyses of PAHs were performed, with analyses of the levels of 32 different PAHs. A TSI-3939 scanning mobility particle sizer system was used to measure the ultrafine particles. The results showed that total PAHs were in the range of 270-300 ng/m(3) air. However, the smoked bacon experiment showed a somewhat different PAH pattern, whereby retene constituted about 10% of the total PAHs, which is a level similar to that of the abundant gas phase constituent phenanthrene. The reason for the elevated retene emissions is unknown. The total cancer risk, expressed as toxic equivalency factors, showed a somewhat higher risk on the electric stove (p < 0.05) compared with the gas stove. Levels of trans, trans-2,4-decadienal were between 34 and 54 µg/m(3) air. The level of total particles was between 2.2 and 4.2 mg/m(3). Frying on a gas stove caused a statistically significant higher amount of ultrafine particles compared with frying on an electric stove. Large variations in the mobility diameter at peak particle concentration were found (74.4 nm-153.5 nm). The highest mobility diameter was found for frying on an electric stove. The gas flame itself showed a maximum production of 19.5-nm-sized particles and could not be the explanation for the difference between frying on the gas stove and frying on the electric stove. No single indicator for the exposure to cooking fume could be selected. Each compound should be measured independently to provide a comprehensive characterization of the cooking exposure.

Exposure to polycyclic aromatic hydrocarbons (PAHs), mutagenic aldehydes and particulate matter during pan frying of beefsteak.

OBJECTIVES: Cooking with gas or electric stoves produces fumes, especially during frying, that contain a range of harmful and potentially mutagenic compounds as well as high levels of fine and ultrafine particles. The aim of this study was to see if polycyclic aromatic hydrocarbons (PAHs) and higher mutagenic aldehydes which were collected in the breathing zone of the cook, could be detected in fumes from the frying of beefsteak. METHODS: The frying was performed in a model kitchen in conditions similar to those in a Western European restaurant kitchen. The levels of PAHs (16 EPA standard) and higher aldehydes (trans,trans-2,4-decadienal, 2,4-decadienal, trans-trans-2,4-nonadienal, trans-2-decenal, cis-2-decenal, trans-2-undecenal, 2-undecenal) were measured during frying on an electric or gas stove with margarine or soya bean oil as the frying fat. The number concentration of particles <100 nm in size (ultrafine) was also measured, as well as the mass concentration of total particulate matter. RESULTS: Levels of naphthalene were in the range of 0.15-0.27 microg/m(3) air. Measured levels of mutagenic aldehydes were between non-detectable and 61.80 microg/m(3) air. The exposure level of total aerosol was between 1.6 and 7.2 mg/m(3) air. Peak number concentrations of ultrafine particles were in the range of 6.0x10(4)-89.6x10(4) particles/cm(3) air. CONCLUSION: Naphthalene and mutagenic aldehydes were detected in most of the samples. The levels were variable, and seemed to be dependent on many factors involved in the frying process. However, according to the present results, frying on a gas stove instead of an electric stove causes increased occupational exposure to some of the components in cooking fumes which may cause adverse health effects.