Inhalable Dust Concentrations Research Articles

Determining occupational exposure to inhalable wood dust in motor manual felling and processing

ABSTRACT The occupational exposure to softwood and hardwood wood dust was determined during forestry work in timber stands. In the determination of inhalable wood dust, three tree species (Fagus sylvatica, Quercus sp. and Pinus brutia) and three chainsaw operating parameters were taken into account (in total six assessment indicators). The first operating parameter was the chainsaw operating under normal conditions (regular chain sharpening). The second and third operating parameters were improper chainsaw maintenance (irregular chain sharpening) and low throttling pressing (operating the chainsaw at low engine speeds), respectively. The determination of inhalable wood dust concentrations from the ambient air was performed using the Inhalable Organic Matter (IOM) sampler, manufactured by SKC Button Sampler (Dorset, United Kingdom). Out of a total of 108 concentration cases of inhalable wood dust, 44 (40.74%) showed concentrations greater than 3.00 mg·m−3, while in 10 (9.26%) cases, the dust concentration exceeded 5 mg·m−3. The eight-hour time-weighted average exposure to wood dust ranged from 0.99 mg·m−3 to 12.52 mg·m−3, with an average of 4.22 mg·m−3. The results indicated that the increase in wood dust concentration was dependent on improper chainsaw maintenance, while low throttling pressing reduces dust concentration levels. Additionally, an increase in wood dust concentration was observed in species with thick bark (Pinus brutia and Quercus petraea).

Assessment of exposure to fungi in archives and libraries based on analyses of filter and nasal samples: preliminary investigation

The aim of this study was to characterize the occupational exposure to inhalable dust and airborne fungi among archive and library workers based on qualitative and quantitative analyses of stationary and personal filter samples as well as nasal swabs. The study was carried out in 3 archives and 2 libraries and involved 9 workers of these institutions. Airborne fungi and inhalable dust samples were collected by stationary and personal measurements using filter samplers. Additionally, the nasal swabs from workers were taken after work-shift and microbiologically analysed. The average concentrations of inhalable dust and airborne fungi were 49 µg/m3 (SD = 91) and 299 CFU/m3 (SD = 579), respectively. Both dust and bioaerosol concentrations obtained using personal measurements were significantly higher than that measured by stationary sampling. The correlation analysis showed strong relationships between the concentrations of inhalable dust and airborne fungi (R = 0.57; p < 0.001). The fungal concentrations in swab samples from archive workers (median: 104 CFU/ml) were significantly higher than that in swabs from librarians (median: 1.4 CFU/ml). Among the airborne fungi, the widest spectrum of species was found among Penicillium and Aspergillus (including pathogenic A. fumigatus) genera. However, in samples from archives, yeast-like fungi from Sporidiobolus and Candida (including pathogenic C. albicans) genera predominated among isolated mycobiota. The results of this study revealed that airborne fungi were able to efficiently contaminate the nasal cavity of archive and library employees. The analysis of nasal swabs can be considered as an important analytical tool supporting the assessment of workers’ exposure to bioaerosols.

93 Microbial Contaminants and Pro-Inflammatory Properties of Organic Dust From Different Occupational Settings

Abstract The study aimed to characterize the microbial contamination of dust samples from various occupational environments and to assess their impact on the release of pro-inflammatory cytokines from cell culture. The research was conducted in six occupational settings, including waste sorting and composting plants, a sewage treatment plant, a cement plant using alternative fuel, a power plant co-firing biomass as well as a poultry farm. In total, 76 organic dust samples were collected at 26 workplaces in the above-mentioned plants to assess the concentrations of: inhalable dust fraction, crystalline silica, aerobic and anaerobic bacteria, fungi as well as peptidoglycans, endotoxins and (1→3)-β-D-glucans. The alveolar epithelial cells (A549) were exposed to dust extracts and the levels of pro-inflammatory cytokines (IL-6 and IL-8) were determined. The highest inhalable dust concentrations were found in the power plant samples – 5.60 mg/m3 (SD=9.13). In poultry houses, the highest concentrations were noted for aerobic and anaerobic bacteria – 201129 cfu/m3 (SD=62795) and 72702 cfu/m3 (SD=13532), respectively. In turn, the waste sorting plant workplaces were the most contaminated with fungi – 36335 cfu/m3 (SD=27270), endotoxins – 23.9 ng/m3 (SD=21.5) and SiO2 – 0.024 mg/m3 (SD=0.026). The highest levels of peptidoglycans – 7930 ng/m3 (SD=6049) and (1→3)-β-D-glucans – 180.5 ng/m3 (SD=46.4) were found at workplaces in composting plant. The release of cytokines was significantly dependent (p&amp;lt;0.05) on dust concentrations for composting and cement plants; however, to a lesser extent, their production were also stimulated by aerobic bacteria, fungi, endotoxins and crystalline silica. The microbial characteristics of organic dusts may trigger the pro-inflammatory reactions in workers.

Occupational Bioaerosol Exposures Associated with Poultry Farming

ABSTRACT This study aimed to investigate occupational exposure to particulate dust, endotoxin, and (1–3)-β-D-glucan among workers involved in various poultry farming activities. A total of 298 personal samples were collected from randomly selected individuals from exposure groups based on distinct poultry farming activities comprising broiler farms, rearing, laying, hatchery, and catching activities. Aside from the inhalable particulate dust concentration that was determined, filter extracts were also analyzed for (1–3)-β-D-glucan and endotoxin using the endpoint Glucatell® and Limulus amoebocyte lysate (LAL) assays, respectively. Data were analyzed using STATA 12 and linear regression models developed. The mean (GM) dust particulate concentration was 11.04 mg/m3 (GSD = 3.87); 2298 endotoxin units (EU/m3) (GSD = 10.56) and 149 ng/m3 for (1–3)-β-D-glucan (GSD = 4.62). A modest positive correlation was observed between log-transformed endotoxin and (1–3)-β-D-glucan concentrations (Pearson r = 0.44, p < .001), whilst a moderate negative correlation was observed for inhalable dust particulate and (1–3)-β-D-glucan (Pearson r = −0.33, p < .001). However, there was a very poor correlation between inhalable dust and endotoxin (Pearson r = −0.02, p < .001). In the regression models, exposure group based on the nature of farming activity explained 50% of the variability in dust particulate and glucan levels. For dust particulate, rearing activities were significant predictors of higher dust levels compared to hatchery work, while rearing, laying, broiler and catching activities were significant predictors of higher endotoxin or glucan levels. Furthermore, working in a small broiler was a significant determinant of elevated glucan exposures. Farms using automated laying activities had significantly higher particulate levels compared to those using manual laying activities. This study revealed that workers engaged in poultry farming activities were exposed to significantly high levels of inhalable particulate dust, endotoxin, and (1–3)-β-D-glucan concentrations, posing an increased risk for adverse respiratory health effects in these farm workers.

Characteristics of thermally modified hardwood dust in determining workers’ occupational exposure

Thermal modification of wood changes its mechanical properties, generally reducing its strength, such that it is more easily chipped during processing than untreated hardwood. This study presents specific parameters used in the determination of mass concentration of thermally modified (TM) hardwood by gravimetric and photometric methods. An optical device, the Split 2, was used in the active mode, of which the holder of the inhalable dust IOM (Institute of Occupational Medicine) filter was the input part. Side-by-side determination of the respirable and inhalable mass concentration was made using the Higgins-Dewell respirable dust cyclone and an inhalable dust IOM sampler. Side-by-side determination of inhalable and total dust mass concentration was made using an IOM and open-faced (OF) filter holder to establish an IOM / OF sampling ratio. A correction factor of 1.16 was calculated for applying the photometric method as the ratio of mass concentration determined by gravimetric and photometric methods. Minimal concentrations of respirable and inhalable wood dust (geometric mean: cr = 0.058 mg/m3; cinh = 0.882 mg/m3) and a 12.76% share of respirable dust in the inhalable concentration cr / cinh, had a significant influence on the efficiency of the photometric method. The mass concentration obtained by IOM and OF samplers did not significantly differ (p = 0.36).

RESPIRATORY HEALTH EFFECTS OF COTTON INHALABLE DUST ON WORKERS IN THE GARMENT PROCESSING UNIT

&#x0D; &#x0D; &#x0D; A cross-sectional study was conducted among 150 garment factory workers selected with stratified random sampling technique to examine their lung impairment with respect to cotton dust. Vital capacity (VC), forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), forced vital capacity ratio (FEV1/FVC) and forced expiratory flow (FEF (25%-75%)) were obtained according to American Thoracic Society criteria. Exposure to cotton inhalable dust concentration was measured in accordance with National Institute of Occupational Safety and Health criteria. Mann Whitney U test was used for comparison among target groups and statistical significance of the study was set at p&lt;0.05. Cough, phlegm and dyspnea was observed in 78%, 51% and 44% patients (workers) respectively. Personal exposure of the subjects to cotton inhalable dust was measured in stitching, button hall and special effect sections of the garment processing unit at mean dust levels of .603±.436 mg/m3, .446±.257 mg/m3 and .382±.174 mg/m3 respectively. The exposed group was categorized into three groups having normal, obstructive and restrictive pattern of disease. This study provided evidence for relationship between exposure to cotton dust and other respiratory impairments without any association to smoking.&#x0D; &#x0D; &#x0D;

Assessment of exposure to dust, gaseous pollutants and endotoxins in sewage treatment plants of Ahmedabad city, India.

Sewage treatment plant workers (STPs) are exposed to gaseous pollutants (H2S) and bioaerosols and their health is at risk. The aim of the study was to evaluate exposures to dust, 1,3 Beta D Glucans, endotoxins and gaseous pollutants in different process plants and to provide suitable recommendations. Gaseous pollutants and bioaerosols (inhalable dust, 1,3 beta D-glucans and endotoxins) were evaluated in two sewage treatment plants (STPs) of Ahmedabad city, India. The concentration of H2S, CO, CH4 and Cl2 were monitored in two process areas of STPs using real-time gas detectors. The dust, 1,3 beta D-glucans and endotoxins were evaluated as per standard methods. The mean concentration of H2S exceeded the permissible exposure limit of 10 ppm, whereas the concentration of other gaseous pollutants (CO, Cl2 and CH4) were below the permissible exposure limits of Indian Factories Act, 1948. The inhalable dust concentration was also within the permissible exposure limit of 10 mg/m3 as per Indian Factories Act, 1948. Significant exposures to gaseous and bioaerosols were found in the work environment of STPs. The paired t-test result showed a significant difference between two STPs for H2S, 1,3 beta D-Glucans and endotoxins. STPs were advised to reduce the exposure to H2S and bioaerosols as per CPCB guidelines applicable to India to prevent health effects.

Assessment of fungal hazards in archives based on nasal swab samples

BACKGROUND AND AIM Scientists are looking for exposure indicators that could accurately describe the impact of bioaerosols on workers’ health. Especially useful in this regard seems to be the swabs collected from the nose or nasopharynx, which represent easy to obtain biological samples. The aim of this study was to identify a mycobiota occurring in the upper respiratory tract of archive workers as a result of work shift exposure. METHODS Eleven workers from three archives and two libraries participated in this study. Each of them was equipped with a personal measurement set consist of CIS sampler to check the concentration of inhalable dust and, after work shift, the swab samples from nasal cavity were collected. Qualitative mycobiota analysis was performed using culture-based method and isolated pathogens were additionally diagnosed based on MALDI-TOF MS. RESULTS The average fungal concentration in swab samples was 43 CFU/ml, (SD=59). In turn, the concentrations of airborne fungi were very variable and depended on the place of measurement (mean value: 2916 CFU/m³, SD=3051). The qualitative analysis of the samples revealed the presence of 33 fungal species belonging to 17 genera. The swab samples were dominated by the yeast of Candida genus and filamentous fungi from Penicillium and Aspergillus genera. It was shown that 59% of identified fungal strains were simultaneously present in the air at workplaces and in the nasal cavities of employees. Two isolated fungal genera, i.e., Aspergillus and Microsporum, represent human pathogens classified in risk group 2, according to the Commission Directive (EU) 2019/1833. CONCLUSIONS As airborne fungi in archives and libraries can colonize the upper respiratory tract of workers, the microbiologcal analysis of nasal swabs can be a precise tool to assess the exposure to biological aerosol in this working environment. KEYWORDS archive workers, exposure assessment, fungal aerosols, nasal swabs

Occupational exposure to inhalable and respirable wood dust of pedunculate oak (Quercus robur L.) in a furniture factory

Given the well-known carcinogenicity of hardwood dust, occupational exposure to oak wood dust has been determined in a furniture factory on different wood processing machines during sanding, planing, and milling. Determination of the mass concentrations of respirable and inhalable oak wood dust from ambient air was performed using personal sampling pumps and two types of filter holders: the Higgins-Dewell respirable dust cyclone, manufactured by Casella (Bedford, UK), and the inhalable dust IOM sampler manufactured by SKC (Dorset, UK). Out of a total of 30 values of inhalable mass concentration, 7 (23%) exceeded the occupational exposure level (OEL). The highest exposure levels for inhalable and respirable wood dust from the belt sander were 1.569 to 3.710 mg/m3 and 0.243 to 1.342 mg/m3, respectively. Worker exposure may be below the level of increased risk of 2 mg/m3 if a machine such as a planer or router is connected to a suction system. The share of respirable particles in the inhalable fraction ranged between 12% and 31%, and for samples with an inhalable mass concentration exceeding 2 mg/m3, the share was lower than 16%, with a slightly decreasing tendency. Thus, the risk of lower respiratory tract diseases increases with higher exposure to inhalable particles, and the OEL is an indirect measure of protection against exposure to respirable particles.

Assessment of Indoor Air Quality for Group-Housed Macaques (Macaca spp.)

Simple SummaryIndoor air quality is strongly associated with animal health and wellbeing. Therefore, animal enclosures must be consistently and sufficiently ventilated to provide for the health and well-being of animals and caretakers. Although there are several publications concerning assessments and effects of suboptimal air quality on rodents, no publications are available on group-housed non-human primates and the exposure of caretakers to inhalable dust and endotoxins. The indoor air quality of group-housed macaques at the Biomedical Primate Research Center (Rijswijk, the Netherlands) was assessed to identify possible problems regarding air circulation and the concentrations of inhalable dust, endotoxin, ammonia, fungi, temperature and relative humidity in the indoor environment. In addition, the exposure to inhalable dust and endotoxins of caretakers was evaluated. The observed values for these air quality parameters, measured at fixed locations in the animal enclosures, did not exceed the proposed human threshold limit values (TLV). However, caretakers were exposed to higher levels than the animals likely due to nature of their tasks. This study provides practical tools that can be used to improve the indoor air quality in group-housed macaques. Moreover, the results show that the exposure of caretakers to inhalable dust and endotoxins during daily work routines should be reduced.Indoor Air Quality (IAQ) is strongly associated with animal health and wellbeing. To identify possible problems of the indoor environment of macaques (Macaca spp.), we assessed the IAQ. The temperature (°C), relative humidity (%) and concentrations of inhalable dust (mg/m3), endotoxins (EU/m3), ammonia (ppm) and fungal aerosols were measured at stationary fixed locations in indoor enclosures of group-housed rhesus (Macaca mulatta) and cynomolgus macaques (Macaca fascicularis). In addition, the personal exposure of caretakers to inhalable dust and endotoxins was measured and evaluated. Furthermore, the air circulation was assessed with non-toxic smoke, and the number of times the macaques sneezed was recorded. The indoor temperature and relative humidity for both species were within comfortable ranges. The geometric mean (GM) ammonia, dust and endotoxin concentrations were 1.84 and 0.58 ppm, 0.07 and 0.07 mg/m3, and 24.8 and 6.44 EU/m3 in the rhesus and cynomolgus macaque units, respectively. The GM dust concentrations were significantly higher during the daytime than during the nighttime. Airborne fungi ranged between 425 and 1877 CFU/m3. Personal measurements on the caretakers showed GM dust and endotoxin concentrations of 4.2 mg/m3 and 439.0 EU/m3, respectively. The number of sneezes and the IAQ parameters were not correlated. The smoke test revealed a suboptimal air flow pattern. Although the dust, endotoxins and ammonia were revealed to be within accepted human threshold limit values (TLV), caretakers were exposed to dust and endotoxin levels exceeding existing occupational reference values.

Exposure of cleaning workers to chemical agents and physical conditions in swimming pools and spas

Swimming pools and spas require a high hygiene level, and therefore constant cleaning. In this study, cleaning workers’ exposure to volatile organic compounds (VOCs), trichloramine (TCA), and particulate matter (PM) in the swimming pools and spas were evaluated. Also, statistical methods were employed to determine what activities affect the exposure to disinfection byproducts (DBPs). The study was conducted in 32 swimming pools and spas. The measurement locations were pool areas, bathrooms, and locker rooms, both during cleaning and opening hours. During the cleaning, the total volatile organic compound (TVOC) concentrations were low, on average 96, 251, and 91 µg/m3 for locker rooms, bathrooms, and pool areas, respectively. Similarly, during the opening hours, the TVOC concentrations were on average 78, 125, and 83 µg/m3, for locker rooms, bathrooms, and pool areas, respectively. This is in line with previous studies investigating cleaning work in other environments. The most prevalent compounds during the cleaning were 2-(2-butoxyethoxy)ethanol (DEGBE), 2-(2-ethoxyethoxy)ethanol (DEGEE), 2-butyl-1-octanol, trichloromethane (chloroform), decamethylcyclopentasiloxane (D5), and carbon tetrachloride. The most prevalent compounds during the opening hours were D5, D-limonene, carbon tetrachloride (bathrooms and pool areas), and trichloromethane (bathrooms and pool areas). The TCA concentrations during the cleaning in the bathrooms and pool areas were on average 60 and 67 µg/m3, respectively, and during the opening hours, 28 and 122 µg/m3, respectively. The use of disinfectants was found to increase the TCA concentration in the bathrooms, while the other cleaning products did not. Even though the TCA concentrations were below the WHO’s guideline and the Finnish occupational exposure limit value of 500 µg/m3, the measured TCA levels were occasionally high enough to pose a risk of irritative symptoms. The PM concentrations were low, both in the real-time monitoring (aerodynamic diameter, Dae ≤ 15 µm) and inhalable dust samples (Dae ≤ 100 µm). Highest measured inhalable dust concentration was 350 µg/m3, well below the Finnish occupational limit value of 5,000 µg/m3 for organic inhalable dust.

APPLICATION OF PHOTOMETRY IN DETERMINING THE DUST MASS CONCENTRATION OF HARDWOODS

Given the carcinogenicity of hardwood dust, the aim of this study was to determine the effectiveness of the photometric method for different types of woodworking machines and its application in determining the mass concentration of inhalable dust for raw and dry hardwoods. In addition to the optical part of the device, the input part of the measuring device contains the Institute of Occupational Medicine (IOM) inhalable dust filter holder. This correlation of gravimetric and photometric methods in determining the dust mass concentration showed that photometry underestimates the mass concentration measured gravimetrically. The results of this study recommend the application of a correction factor 2 for a timber band saw and a correction factor 3 for circular saws in determining the mass concentration of hardwood dust by the photometric method. It was showed that photometry can be used if the correction factor of the optical device has been previously tested for specific wood processing place.

Controlling flour dust exposure by an intervention focused on working methods in Finnish bakeries: a case study in two bakeries

Objectives. The purpose of this study was to examine the effectiveness of intervention strategies to control mass concentrations and peak exposures of flour dust in two Finnish bakeries. The effect of the intervention on the proportion of various particle size fractions of the total particulate matter was also investigated. Methods. Mass concentrations of flour dust were measured during three working days in a pre-intervention and post-intervention study in both an industrial and a traditional bakery. Gravimetric sampling and real-time measurements were performed. Relevant intervention strategies focused on working methods were planned in collaboration with the managers of the bakeries. Results. The average mass concentration of inhalable flour dust reduced in most of the stationary locations post intervention. The reductions in exposure levels were between 39 and 45%. However, the exposure levels increased 28–55% in the breathing zone. Real-time measurements showed reductions in the peak mass concentrations in the traditional bakery post intervention. In both bakeries, the total particulate matter size fraction consisted predominantly of particles with an aerodynamic diameter lower than 1 µm and greater than 10 µm. Conclusion. Further studies are needed to plan more effective intervention measures supplemented by technical control methods in both bakeries.

Inflammatory and coagulatory markers and exposure to different size fractions of particle mass, number and surface area air concentrations in the Swedish hard metal industry, in particular to cobalt

Purpose To study the relationship between inhalation of airborne particles and cobalt in the Swedish hard metal industry and markers of inflammation and coagulation in blood. Methods Personal sampling of inhalable cobalt and dust were performed for subjects in two Swedish hard metal plants. Stationary measurements were used to study concentrations of inhalable, respirable, and total dust and cobalt, PM10 and PM2.5, the particle surface area and the particle number concentrations. The inflammatory markers CC16, TNF, IL-6, IL-8, IL-10, SAA and CRP, and the coagulatory markers FVIII, vWF, fibrinogen, PAI-1 and D-dimer were measured. A complete sampling was performed on the second or third day of a working week following a work-free weekend, and additional sampling was taken on the fourth or fifth day. The mixed model analysis was used, including covariates. Results The average air concentrations of inhalable dust and cobalt were 0.11 mg/m3 and 0.003 mg/m3, respectively. For some mass-based exposure measures of cobalt and total dust, statistically significant increased levels of FVIII, vWF and CC16 were found. Conclusions The observed relationships between particle exposure and coagulatory biomarkers may indicate an increased risk of cardiovascular disease.

Occupational exposure to anaerobic bacteria in a waste sorting plant

ABSTRACT The study focused on exposure assessment to bacterial aerosols and organic dust in waste sorting plant. Samples were collected at different workplaces of waste sorting cycle i.e.: waste press, reloading area, loading of conveyor belt, sorting cabin, sorting hall, and control room. A quantitative analysis of aerobic and anaerobic bacteria was supplemented by qualitative analysis of anaerobic biota with the use of culture-based methods and biochemical tests. In addition, inhalable dust concentrations were also evaluated. To confirm the presence of Clostridium genus, the PCR reaction with specific primers (Chis150f and ClostIr) was performed. The average concentration of total bacteria in waste sorting plant was 4347 CFU m−3 (SD = 2439), of which 66% were anaerobic strains (2852 CFU m−3; SD = 2127). It was found that about 24% of anaerobic bacteria belonged to Clostridium genus (682 CFU m−3; SD = 633). The highest contamination with anaerobic bacteria was observed near the waste reloading plant (3740 CFU m−3), and the lowest in the control room (850 CFU m−3). The average concentration of inhalable dust in the waste sorting plant was 0.81 mg m−3 (SD = 0.59). The correlation analysis showed that the presence of anaerobic bacteria, including clostridia was significantly determined by the microclimate parameters. Qualitative analysis showed the presence of 16 anaerobic species belonging to 9 genera, of which Actinomyces, Clostridium, and Gemella were present at all workplaces. The molecular analysis confirmed the presence of Clostridium genus in both bioaerosol and settled dust samples. Implications: The study showed that anaerobic bacteria should be taken into account as an important component of this microbiota when assessing the exposure of waste sorting workers to biological agents. However, future studies should investigate more precisely how the composition of sorted waste as well as the season can affect the diversity of anaerobic bacteria in this working environment. More attention should be paid to regular cleaning of equipment surfaces in the plant, as deposited organic dust is an important reservoir of anaerobic bacteria, including those of a potentially pathogenic nature.

Exposure assessment to inhalable and respirable dust in the post - earthquake construction sites in the city of l'Aquila.

ObjectivesFollowing an earthquake that occurred in middle Italy in 2009, the involved territory hosted in 10 years thousands of construction sites. The aim of this study is to assess inhalable, respirable, and respirable crystalline silica exposure of the construction workers involved in the rebuilding activities.MethodsSix construction companies joined the study and hosted the air sampling activities. We identified four work tasks: bricklayer and similar; scaffolder and carpenter; manual demolition; other tasks. We reported 8‐h time‐weighted concentrations.ResultsThe “All tasks” geometric mean concentration of inhalable dust was 4.73 mg/m3 and the higher, TLV exceeding exposure was observed for “Manual demolition workers” (13.92 mg/m3, GM). The “All tasks” geometric mean concentration of respirable dust was 0.25 mg/m3 and no TLV‐exceeding exposure (geometric mean values) was observed among the work‐related groups. About the respirable crystalline silica dust exposure, the “All tasks” average concentration was 0.004 mg/m3. No TLV‐exceeding exposure was observed among the whole data sample.ConclusionsThe comparison of the results shows that manual demolition workers are exposed to high levels of inhalable dust, exceeding the TLV‐TWA (Threshold Limit Values‐Time Weighted Average) limit of 10 mg/m3. About the respirable dust concentration, none of the analyzed work task dust concentrations exceeded the TLV‐TWA limit of 3 mg/m3 (geometric mean values). Measurements of respirable crystalline silica dust have shown levels below the threshold limit value of 0.025 mg/m3. Our findings overall match with the available scientific data.

Reliability of the measurement method in determining the mass concentration of hardwood dust

The reliability of the measurement method in determining the mass concentration of wood dust relates to the sampling time for the detection of wood particles in the ambient air of woodworking places. The aim of this study was to calculate the mass limit of detection (LOD), limit of quantification (LOQ), and the minimal sampling time (tLOD and tLOQ) for determination and quantification of samples, based on the hardwood dust mass concentration at various woodworking places in the sawmills, floor production factories, and carpentries. Determination of the mass concentration of respirable, inhalable, and total hardwood dust from ambient air was performed using personal sampling pumps and three types of filter holders: respirable dust cyclone, Institute of Occupational Medicine IOM inhalable dust sampler, and total dust open-faced filter holder. The average limit of detection amounts to 0.052, 0.083, and 0.167 mg for respirable, inhalable, and total hardwood dust, respectively. The minimal detection sampling time for collecting all observed types of dust fractions ranged between 1.12 h and 1.72 h. The minimal quantification time for all collected hardwood dust samples ranged from 3.75 h to 5.51 h. Pearson’s correlation test showed that the reliability of the measurements was affected more by the dustiness of the workspace than the real sampling time.

Assessing chainsaw operators’ exposure to wood dust during timber harvesting

Exposure to wood dust during logging operations is generally associated with a variety of adverse health effects. The aim of the present study is to determine the exposure of forestry workers to wood dust during timber harvesting tasks in a cutover. The concentrations of inhalable hardwood dust produced from Fagus sylvatica and Quercus petraea as well as softwood dust from Pinus brutia stands were examined. In total, 24 samples were collected with the use of a Personal SKC Button Sampler. Dust collection was performed every working day. The study also took into account the duration of each work phase in which the chainsaw was used (running time) as well as the delays, during which the chainsaw was either at idle or not running at all (downtime). Measurements were carried out throughout the daily work of the logger, which lasted from June to September. Mean concentration of inhalable dust for an 8 h exposure was found to be approximately 4.84 mg m−3. Fifty per cent of the samples showed dust concentrations lower than 3.00 mg m−3, while in approximately 20.8% of the samples, dust levels were higher than 5 mg m−3. Results also revealed that the concentration of inhalable dust is in inverse proportion to the increase in breast height diameter, implying that larger trees generated lower dust amounts. Furthermore, timbering activities in Quercus petraea stand were found to result in higher dust concentrations.

Selection of operational parameters for a smart spraying system to control airborne PM10 and PM2.5 dusts in underground coal mines

Airborne dust in underground hard coal mines is an ongoing explosion and respiratory health hazard. The latest design solution for controlling dusts, the smart spraying system, is described. From the results of stand tests, the main factors determining the efficiency of the new device are: 1) the integrated real-time acquisition of dust particle size and concentration data, determined using a new optical dust meter; 2) the fractional distribution of water droplets; and 3) the selection of droplet size to capture PM10 and PM2.5. The latter two factors are automatically controlled, based on dust measurements, by varying the pressure of water and compressed air supplied to the sprayer nozzles. The effects of varying these parameters and the results of stand tests are presented. The spraying device was tested for the effectiveness of PM2.5 dust and PM10 dust reduction in underground conditions in the KWK Pniówek mine. The tests were based on the following Polish Standards: PN-91/Z-04030/05 and PN91/Z-04030/06, which define the methodology for measurements of inhalable and respirable dust at workplaces using the filtration-weighing method to determine the concentration of inhalable and respirable dust with the spraying system on and off. The results showed that the assumed objective, i.e. development of a dust control device that would reduce PM2.5 dust (by min. 25 %) and PM10 dust (by min. 20 %) more effectively than the currently used solutions, was achieved in the project. At the same time, the device, due to application of dust sensor, continuously adjusts the parameters of spraying streams to the dust concentration level, optimizing the consumption of water and compressed air. Similar results in reduction of PM10 and PM2.5 dust, with an average effectiveness of over 60 % is the undoubted advantage of the device.

Relationships between inhalable and total hexavalent chromium exposures in steel passivation, welding and electroplating operations of Ontario.

The main aim of the study was to assess the relationship between inhalable hexavalent chromium and "total" hexavalent chromium. Air sampling was conducted at steel passivation operation of a steel manufacturer at a stainless steel welding operation and at two hard chrome electroplaters. Air samples were taken side-by-side for "total" dust using closed-face 37-mm diameter cassette samplers and for inhalable dust using Institute of Occupational Medicine inhalable samplers. A total of 40 pairs of total and inhalable dust samples were collected and later analyzed. The range of "total" dust and inhalable dust concentrations in μg/m3 measured were 30-410 and 0.02 to 740 respectively for steel passivation; 260 to 1520 and 477 to 6970 for welding; and 0.01 to 1500 and 204 to 2130 for electroplaters. The range of "total" dust hexavalent chromium and inhalable dust hexavalent chromium concentrations in μg/m3 were 0.02-89 and 0.02 to 150 respectively for steel making; 4.1 to 4.9 and 2.2 to 6.9 for welding and 0.01 to 9.3 and 0.01 to 21 for electroplaters. A linear relationship between inhalable hexavalent chromium and "total" hexavalent chromium was found with a slope of 1.4 (CI:1.3, 1.5) and 0 offset. A ratio of 1.4 can thus be used as a conversion factor to convert previous data of hexavalent chromium taken on "total" dust basis to inhalable hexavalent chromium concentrations.