Total Dust Concentration Research Articles

Wood dust exposure in the Danish furniture industry using conventional and passive monitors

A study of wood dust exposure at furniture factories in one county in Denmark was performed as a cross sectional study. Dust exposure was measured with personal passive dust monitors and calibrated against active sampling on filters. Measurements of 1685 workers were included in the exposure assessment. The passive dust monitor conversion models for equivalent concentrations of inhalable dust and total dust based on data from the present study were not significantly different from the original models. Therefore models based on all available data were used. The parameters of the distribution of equivalent concentration of inhalable dust were 0.94 mg/m3 (geometric mean) and 2.10 (geometric standard deviation). Compared with a national cross sectional study from 1988 the exposure level (geometric mean) was reduced by a factor 2.0. Inhalable dust exposure was about 50% higher than exposure measured by the Danish ‘total’ dust method.

Sensitisation to enzymes in the animal feed industry

OBJECTIVESTo assess the prevalence of enzyme sensitisation in the animal feed industry.METHODSA cross sectional study was conducted in four animal feed factories, where several enzymes had been used in powder...

Wood dust exposure in the Danish furniture industry using conventional and passive monitors

Abstract A study of wood dust exposure at furniture factories in one county in Denmark was performed as a cross sectional study. Dust exposure was measured with personal passive dust monitors and calibrated against active sampling on filters. Measurements of 1685 workers were included in the exposure assessment. The passive dust monitor conversion models for equivalent concentrations of inhalable dust and total dust based on data from the present study were not significantly different from the original models. Therefore models based on all available data were used. The parameters of the distribution of equivalent concentration of inhalable dust were 0.94 mg/m3 (geometric mean) and 2.10 (geometric standard deviation). Compared with a national cross sectional study from 1988 the exposure level (geometric mean) was reduced by a factor 2.0. Inhalable dust exposure was about 50% higher than exposure measured by the Danish ‘total’ dust method.

Ochratoxin A in airborne dust and fungal conidia.

Farm workers are often exposed to high concentrations of airborne organic dust and fungal conidia, especially when working with plant materials. The purpose of this investigation was to study the possibility of exposure to the mycotoxin ochratoxin A (OTA) through inhalation of organic dust and conidia. Dust and aerosol samples were collected from three local cowsheds. Aerosol samples for determination of total conidia and dust concentrations were collected by stationary sampling on polycarbonate filters. Total dust was analysed by gravimetry, and conidia were counted using scanning electron microscopy. A method was developed for extraction and determination of OTA in small samples of settled dust. OTA was extracted with a mixture of methanol, chloroform, HCl, and water, purified on immunoaffinity column, and analysed by ion-pair HPLC with fluorescence detection. Recovery of OTA from spiked dust samples (0.9-1.0 microg/kg) was 74% (quantitation limit 0.150 microg/kg). OTA was found in 6 out of 14 settled dust samples (0.2-70 microg/kg). The total concentration of airborne conidia ranged from < 1.1 x 10(4) to 3.9 x 15(5) per m3, and the airborne dust concentration ranged from 0.08 to 0.21 mg/m3. Conidia collected from cultures of Penicillium verrucosum and Aspergillus ochraceus contained 0.4-0.7 and 0.02-0.06 pg OTA per conidium, respectively. Testing of conidial extracts from these fungi in a Bacillus subtilis bioassay indicated the presence of toxic compounds in addition to OTA. The results show that airborne dust and fungal conidia can be sources of OTA. Peak exposures to airborne OTA may be significant, e.g., in agricultural environments.

Exposure to chemical agents in Swedish aluminum foundries and aluminum remelting plants--a comprehensive survey.

Secondary aluminum melting is mainly performed in sand, die, and static die-casting foundries and remelting plants. In seven Swedish foundries and two remelting plants, the exposure and area concentrations of total dust, metals, organic gases, and vapors were determined mainly as daily, time-weighted averages (TWAs). For most combinations of jobs and agents, the exposure levels were well below the current threshold limits suggested by the American Conference of Governmental Industrial Hygienists (ACGIH). However, high exposure levels of mineral oil mist (geometric mean [GM] = 0.6 mg/m3) were observed in the die-casting process, with a maximum of 4 mg/m3. The findings were similar for total dust (GM = 5.1 mg/m3) and crystalline quartz (GM = 0.05 mg/m3) during molding operations in the sand foundries, maximum air concentrations being 31 mg/m3 and 0.22 mg/m3, respectively. Other agents which occasionally reached high exposure levels included furfuryl alcohol (up to 23 mg/m3 during furan binder use in sand foundries), aniline (up to 2.6 mg/m3 during thermal degradation of cold-box binders), and dimethylethylamine (up to 9 mg/m3) in the cold-box process used in static die-casting and sand foundries. The average aluminum exposure levels (GM = 0.043 mg/m3) were low in all foundries, individual values not exceeding 0.94 mg/m3. The exposures to metals were below 10 percent of their threshold limits. Similarly low levels were detected of polyaromatic hydrocarbons, phenol, formaldehyde, methylenebisphenyl diisocyanate, and phenylisocyanate. In the aluminum remelting plants, a few high exposure levels of total dust (GM = 1.4 mg/m3) up to 8 mg/m3 were detected in furnace workers. Aluminum and other metals were well below 10 percent of their threshold limits, with the exception of a few high concentrations of manganese, up to 0.14 mg/m3. The between-worker variability (GSDB) in the foundries for total dust, aluminum, and oil mist were on the order of 3-4. The heterogenicity of secondary aluminum melting requires assessment of a wide variety of chemical agents. For certain exposures, technical and medical monitoring programs are still needed.

Exposure to microbes, endotoxins and total dust in cigarette and cigar manufacturing: an evaluation of health hazards

The concentrations of airborne microbes, endotoxins and total dust were measured in one cigar and two cigarette factories in order to evaluate the risk of respiratory symptoms. The role of humidifiers as a source of microbes was investigated. Air samples for the analyses were collected near workers' breathing zones during different phases of production. Gram-negative bacteria, mesophilic fungi, thermotolerant fungi and thermophilic actinomycetes, but not Aspergillus glaucus fungi, were found in higher concentrations in the cigar factory than in the cigarette factories. High microbe concentrations (10 4 –10 5 cfu m −3 ) occurred throughout the production line in the cigar factory. The highest dust and endotoxin concentrations were found in the wick-making department in the cigar factory (3.3 mg dust per m 3 and 38 ng endotoxin per m 3 ) and during the weighing or handling of raw tobacco in the cigarette factories (4.5 mg dust per m 3 and 106 ng endotoxin per m 3 ). The spray humidifiers in the cigar factory were a more important source of microbes than was raw tobacco. In the cigarette factories, steam humidifiers were used; the humidified air was free of microbes. The microbe concentrations in the tobacco factories were lower than in environments known to have caused allergic alveolitis.

Exposure to Microbes, Endotoxins and Total Dust in Cigarette and Cigar Manufacturing: an Evaluation of Health Hazards

The concentrations of airborne microbes, endotoxins and total dust were measured in one cigar and two cigarette factories in order to evaluate the risk of respiratory symptoms. The role of humidifiers as a source of microbes was investigated. Air samples for the analyses were collected near workers' breathing zones during different phases of production. Gram-negative bacteria, mesophilic fungi, thermotolerant fungi and thermophilic actinomycetes, but not Aspergillus glaucus fungi, were found in higher concentrations in the cigar factory than in the cigarette factories. High microbe concentrations (10(4)-10(5)cfu m(-3)) occurred throughout the production line in the cigar factory. The highest dust and endotoxin concentrations were found in the wick-making department in the cigar factory (3.3mg dust per m(3) and 38ng endotoxin per m(3)) and during the weighing or handling of raw tobacco in the cigarette factories (4.5 mg dust per m(3) and 106ng endotoxin per m(3)). The spray humidifiers in the cigar factory were a more important source of microbes than was raw tobacco. In the cigarette factories, steam humidifiers were used; the humidified air was free of microbes. The microbe concentrations in the tobacco factories were lower than in environments known to have caused allergic alveolitis.

Estimating Factors to Convert Chinese ‘Total Dust’ Measurements to ACGIH Respirable Concentrations in Metal Mines and Pottery Industries

Historical data on the dust exposures of Chinese workers in metal mines (iron/copper, tin, tungsten) and pottery industries are being used in an ongoing joint Chinese/United States epidemiological study to investigate the exposure–response relationship for the development of silicosis, lung cancer, and other diseases. The historical data include ‘total dust’ concentrations determined by a Chinese method. Information about particle size distribution and the chemical and mineralogical content of airborne particles is generally not available. In addition, the historical Chinese sampling strategy is different from a typical American eight-hour time-weighted average (TWA) sampling strategy, because the Chinese samples were collected for approximately 15 minutes during production so the sample could be compared to their maximum allowable concentration (MAC) standard. Therefore, in order to assess American respirable dust exposure standards in light of the Chinese experience, factors are needed to convert historical Chinese total dust concentrations to respirable dust concentrations. As a part of the joint study to estimate the conversion factors, airborne dust samples were collected in 20 metal mines and 9 pottery factories in China during 1988 and 1989 using three different samplers: 10mm nylon cyclones, multi-stage ‘cassette’ impactors, and the traditional Chinese total dust samplers. More than 100 samples were collected and analysed for each of the three samplers. The study yielded two different estimates of the conversion factor from the Chinese total dust concentrations (measured during production processes) to respirable dust concentrations. The multivariate analysis of variance (MANOVA) reveals that, with a fixed sampling/analysis method, conversion factors were not statistically different among the different job titles within each industry. It also indicates that conversion factors among the industries were not statistically different. However, the two estimates consistently showed that conversion factors were the lowest in the pottery industry. Average conversion factors were then calculated for each of the estimates across the industries studied. A pooled mean conversion factor, 0.25±0.04, was then derived for all the job titles and industries. Respirable dust levels were estimated from the historical ‘total dust’ concentrations collected between 1952 and 1992 by adopting the American standard.

Estimating Factors to Convert Chinese ‘Total Dust’ Measurements to ACGIH Respirable Concentrations in Metal Mines and Pottery Industries

Historical data on the dust exposures of Chinese workers in metal mines (iron/copper, tin, tungsten) and pottery industries are being used in an ongoing joint Chinese/United States epidemiological study to investigate the exposure–response relationship for the development of silicosis, lung cancer, and other diseases. The historical data include ‘total dust’ concentrations determined by a Chinese method. Information about particle size distribution and the chemical and mineralogical content of airborne particles is generally not available. In addition, the historical Chinese sampling strategy is different from a typical American eight-hour time-weighted average (TWA) sampling strategy, because the Chinese samples were collected for approximately 15 minutes during production so the sample could be compared to their maximum allowable concentration (MAC) standard. Therefore, in order to assess American respirable dust exposure standards in light of the Chinese experience, factors are needed to convert historical Chinese total dust concentrations to respirable dust concentrations. As a part of the joint study to estimate the conversion factors, airborne dust samples were collected in 20 metal mines and 9 pottery factories in China during 1988 and 1989 using three different samplers: 10mm nylon cyclones, multi-stage ‘cassette’ impactors, and the traditional Chinese total dust samplers. More than 100 samples were collected and analysed for each of the three samplers. The study yielded two different estimates of the conversion factor from the Chinese total dust concentrations (measured during production processes) to respirable dust concentrations. The multivariate analysis of variance (MANOVA) reveals that, with a fixed sampling/analysis method, conversion factors were not statistically different among the different job titles within each industry. It also indicates that conversion factors among the industries were not statistically different. However, the two estimates consistently showed that conversion factors were the lowest in the pottery industry. Average conversion factors were then calculated for each of the estimates across the industries studied. A pooled mean conversion factor, 0.25±0.04, was then derived for all the job titles and industries. Respirable dust levels were estimated from the historical ‘total dust’ concentrations collected between 1952 and 1992 by adopting the American standard.

Risk of enzyme allergy in the detergent industry

OBJECTIVESTo assess the prevalence of enzyme sensitisation in the detergent industry.METHODSA cross sectional study was conducted in a detergent factory. Sensitisation to enzymes was examined by skin prick and radioallergosorbent...

Evaluation of workers' exposure to dust, ammonia and endotoxin in poultry industries at the province of Isfahan, Iran.

This study was conducted to assess various environmental exposure measurements (total dust, ammonia and endotoxin) of poultry workers at the province of Isfahan, Iran. The results show that the workers who worked in enclosed systems of parent stock barns have the highest exposure to total and respirable dust: 21.3 +/- 3.2 and 4.6 +/- 0.9 mg/m3, respectively. In comparison with different ages of chicken, the highest concentration of total and respirable dust were 5.4 +/- 0.7 and 3.3 +/- 0.7 mg/m3 in the 45th day. In the above mentioned situation, the results of endotoxin concentrations were 20.6 +/- 1.1, 23.6 +/- 2.2, 21.3 +/- 1.2 and 26.8 +/- 1.8 ng/m3, respectively. Ammonia concentrations had the highest rate in enclosed systems of laying hens in winter and the 45th day of chicken age, measuring 33.2 +/- 5.2 and 20.2 +/- 3.0 mg/m3, respectively.

The Effect of InternaI Parameter on the Dust Concentration in Broiler Houses

The results of this study indicate that light has a significant effect on total dust concentration. The total dust concentration in the light period was two times more than in the dark period. The results show that the Ievel of total dust concentration varies significantly for difef rent days of measurement. It should be noted that, although the Ievels of dust concentration vary, there is no direct correlation between dust concentration and days.

Ventilatory function and personal breathing zone dust concentrations in Lancashire textile weavers.

BACKGROUND: To report findings on ventilatory function and estimations of concentrations of personal breathing zone dust in Lancashire textile weavers. Weaving room dust is considered to be less harmful than...

Environmental measurements of total dust and fiber concentration in manufacturer and user of man-made mineral fibers.

Man-made mineral fibers (MMMF), most of which are referred to as man-made vitreous fibers (MMVF), are mostly amorphous silicates manufactured from glass, rock, or other minerals. Analysis for MMMF have been restricted largely to the measurement of total airborne mass concentrations, but more recently to the determination of airborne fiber levels by phase contrast optical microscopy. In Korea, many small factories are related with manufacturing and using MMMF without any special evaluation of environmental measurements. Though MMMF are known as the substitute of asbestos and their toxicity are regarded as very low, MMMF do not totally excluded from the respiratory and/or skin diseases now. Therefore, we evaluated the environments of many workplaces with total dust and fiber concentration. Most dust and fiber concentrations were below threshold limit value (TLV) at various industries and working processes. However, these data showed a slight relationship between total dust and fiber concentration.

Dust concentration around the sites of demolition work after the Great Hanshin-Awaji Earthquake

The total dust concentration and the particle size distribution were determined around die sites of demolition associated with the Great Hanshin-Awaji Earthquake, which occurred on January 17, 1995. The total dust concentrations ranged from 0.20 to 0.23 mg/m(3), being about 1.2 to 2.2 times that in die non-demolition area, and intermediate particles (2.1-11.0μm) made up a large proportion of the dust. The dust concentrations were not influenced by the weather on the day preceding measurement around the sites of demolition of concrete buildings, whereas the values decreased to about half around die sites of demolition of wooden buildings, nearly the same concentration in the control areas, when it had rained on the previous day. The dust concentrations increased compared with that in an average year but to The degree of die upper limit of die environmental standard (1 hr-value<0.20 mg/m(3)) . The dust due to the smoke of Mt. Sakurajima in the surrounding areas accounted for a higher proportion of large particles (<11.0>m) than in the earthquake-devastated area. The concentration of respirable dust (<;7.07>m) in a worker engaged in demolition was 4.0 mg/m(3), being twice the recommended concentration (2 mg/m(3)) of the Japan Society for Occupational Health. It was thus considered that workers should use a respiratory protective device.

Working conditions and health in hairdressing salons.

The purpose of the study was to assess the working conditions in hairdressing salons and the influence of work factors on the workers' health. Twenty randomly sampled hairdressing salons in the Helsinki, Finland, metropolitan area were selected for the study. The study was performed during winter 1994-1995; it included a survey of the hairdressing chemicals in use, the measurement of physical and chemical working conditions, and a self-administered questionnaire of the work environment and health of the workers. The air temperature varied between 16-25 degrees C, air velocity 0.02-0.3 m/s, and relative humidity, 18-42 percent. The total dust concentration varied between 66-133 micrograms/m3. The concentration of volatile organic compounds was 84-465 micrograms/m3 and the peaks rose to 25-45 mg/m3. The highest concentration of ammonia detected was 3.5 mg/m3. The long-term concentrations of thioglycolates and persulfates were at their lowest below the detection limit, and at their highest 1.8 micrograms/m3 for thioglycolates and 4.7 micrograms/m3 for persulfates, respectively, and the peaks of persulfates, 30 micrograms/m3. Hairdressing chemicals, awkward work postures, and repetitive movements were the most frequent causes of discomfort and for some had caused a work-related disease. Good general ventilation decreased the health complaints caused by hairdressing chemicals, but caused discomfort as a result of drafts. On average, the physical and chemical working conditions in the hairdressing salons were satisfactory compared with the Finnish criterion for indoor climate. However, the frequent high peak concentrations of chemicals during dyeing, bleaching, permanenting, and aerosol spraying still pose a significant health problem. Although effective general ventilation alleviated the effects of the air pollutants, it could not completely solve the problem. Therefore, local exhaust ventilation is recommended at the mixing places for hairdressing chemicals and wherever they are applied to the hair. According to our results, already increasing the air exchange rate up to 5 to 7 times per hour during the high exposure jobs would improve the situation.

Respiratory function and immunological status in paper-recycling workers.

The respiratory function and immunological status of workers employed in the paper recycling industry were studied. The mean age of the 101 studied workers was 41 years, and the mean duration of their exposure was 17 years. A group of 87 unexposed workers of similar age, duration of employment, and smoking history was studied for the prevalence of chronic respiratory symptoms. Lung function in the paper workers was measured by recording maximum expiratory flow volume (MEFV) curves and recording forced vital capacity (FVC), 1-second forced expiratory volume (FEV1), and maximum expiratory flow rates at 50% and the last 25% of the FVC (FEF50, FEF25). Immunological studies were performed in all 101 paper workers and in 37 control workers (volunteers). These included skin-prick tests with paper-dust extracts and other nonoccupational allergens, as well as the measurement of total serum immunoglobulin E. Significantly higher prevalences of all chronic respiratory symptoms were found in paper compared with control workers (P < 0.01). The highest prevalences were found for chronic cough (36.6%), chronic phlegm (34.7%), chronic bronchitis (33.7%), sinusitis (31.7%), and dyspnea (18.8%). Occupational asthma was diagnosed in four (4.0%) of the paper workers. A logistic regression analysis performed on chronic respiratory symptoms of paper workers indicated significant effects of smoking and exposure, with the smoking effect being the most important. Multivariate analysis of lung-function parameters indicate significant effects of exposure. For paper workers, the measured FEF50 and FEF25 were significantly decreased, compared with predicted values, suggesting obstructive changes located primarily in smaller airways. Among 101 tested paper workers, 16 (15.8%) had positive skin-prick tests to at least one of the paper extracts; none of the control workers reacted to these extracts. Increased serum IgE levels were found in 21% of the paper workers and in 5% of control workers (P < 0.05). Paper workers with positive skin-prick tests to any of the paper and/or other tested extracts had higher prevalences of chronic respiratory symptoms and lower measured lung-function tests compared with predicted than did those with negative skin-prick tests, but the differences were not statistically significant. The measured concentrations of total and respirable dust in this industry were higher than those recommended by Croatian standards. Our study suggests that work in the paper-recycling industry is associated with respiratory impairment and that sensitive workers employed in this industry may be at particular risk of developing chronic respiratory abnormalities.

Organic matter content of rural dusts in Australia

Loss on ignition (LOI) techniques have been refined to measure dust samples down to 0.0012 g. Using this method Australian rural dusts are shown to have a high organic matter content (mean 31% suspended dusts and 34% for deposited dusts). This contrasts with the low organic matter levels in soils (commonly <1%), from which the organic matter largely derives by wind erosion and possibly local mechanical disturbance. Pollen is probably the next most important source of dust organic matter. Background suspended dusts range from 2 to 90% organic matter, depending upon: the winnowing by winds, monitoring site location, and temporal variations in local vegetation and other conditions. Dusts collected during entrainment events (dust storms) are lower in organic matter (8–67%), exhibit less variability than background dusts and decrease with total dust concentration, because of the reduced winnowing capacity of strong dust storm winds and the very low soil organic matter levels in dust storm source areas. When mixed with background dusts, entrainment event dusts dilute organic matter levels, contributing to the large temporal variability of organic matter levels in dusts. Deposited dusts show similar spatial and temporal trends to suspended dusts (3–91%). These results have significance in several contexts, including: soil erosion, dust deposition in terrestrial and marine ecosystems and environmental health.

Energy Use and Dust Levels in a Segregated Early-Weaning Swine Nursery

Environmental conditions and energy use were evaluated in a new segregated early weaning (SEW) swine nursery for 9 months. Energy use and air quality were generally acceptable and followed expected trends. Mean electricity use ranged from 27 to 32 kWh·day^–1. Mean fuel gas use ranged from 30 to 40 m³ natural gas·day^–1. Ranges for total, respirable, and inhalable dust concentrations were 0.50–3.13, 0.03–0.40, and 0.18–2.98 mg·m^–3, respectively. Carbon dioxide concentrations ranged from 1,144 to 2,614 ppm. Ammonia concentration was negligible (<1 ppm) throughout the study.

Farmers’ exposure to dusts and gases in modern Finnish cubicle cow houses

The occurrence of airborne dust, gases, microbes, endotoxin and bovine epithelial antigens (BEA, BDA20) was studied in 26 modern, mainly cubicle, cow houses. Air samples of total dust, total spores, endotoxin and bovine epithelial allergens were collected on membrane filters with portable or piston pumps and analyzed with appropriate methods. Concentrations of gases (ammonia, carbon dioxide, hydrogen sulfide) were measured with diffusion tubes. Airborne viable spores were collected with a cascade impactor on five selective culture media for the identification of xerophilic, mesophilic and thermotolerant fungi and thermophilic actinomycetes. The geometric mean concentrations of total dust, BEA and BDA20 were 0.2-1.9 mg/m3, 5.2-9.7 μg/m3 and 50-260 ng/m3, respectively. The mean concentrations of ammonia and carbon dioxide were between 2.8-15 ppm and 2200-3200 ppm, respectively. The geometric mean of endotoxins was 19 ng/m3 and the concentrations of fungi were at the 101-103 cfu/m3 level. In general, the variation in concentrations of total dust, viable fungi and endotoxin was large. The concentrations of total dust and fungi were lower than in earlier studies. Thus new cubicle houses provide a better working environment with regard to airborne hazards than the traditional cow houses.