Respirable Dust Levels Research Articles

Altered immune responses in broiler chicken husbandry workers and their association with endotoxin exposure.

Exposure to bioaerosols in indoor animal farms associates with respiratory illnesses, but little is known about the immune modulation to chicken farmers. This study aimed to compare the general immunity of chicken farmers with those of control subjects with non-agricultural jobs. Blood taken from the farmers and controls was subjected to plasma IgE and IgG subclass measurements. Isolated peripheral blood mononuclear cells (PBMC) were stimulated and cytokine production was measured. Indoor total and respirable dust levels and their endotoxin (LPS) and aflatoxin (AF) levels in the farms were measured. In total, 29 chicken farmers on 19 farms and 14 age- and sex-matched office workers participated. Hematological differences were not observed. The farmers tended to have higher serum IgE and IgG subclass levels with significance for IgG1. The cytokines released by PBMC from farmers indicated skewing toward Type-2 helper T-cell responses: interferon (IFN)-γ:interleukin (IL)-4 and IFNγ:IL-13 ratios were significantly lower than for control PBMC. The farms had 707.1 EU/m3 LPS in total dust, and 15.8 EU/m3 LPS in respirable dust. Farmers exhibited immune skewing towards allergic immune responses that correlated with the LPS levels on their farms. Chicken farmers may be at risk of respiratory allergies due to occupational endotoxin exposure.

Respirable dust measured downwind during rock dust application.

The Pittsburgh Mining Research Division of the U.S. National Institute for Occupational Safety and Health (NIOSH) conducted underground evaluations in an attempt to quantify respirable rock dust generation when using untreated rock dust and rock dust treated with an anticaking additive. Using personal dust monitors, these evaluations measured respirable rock dust levels arising from a flinger-type application of rock dust on rib and roof surfaces. Rock dust with a majority of the respirable component removed was also applied in NIOSH's Bruceton Experimental Mine using a bantam duster. The respirable dust measurements obtained downwind from both of these tests are presented and discussed. This testing did not measure miners' exposure to respirable coal mine dust under acceptable mining practices, but indicates the need for effective continuous administrative controls to be exercised when rock dusting to minimize the measured amount of rock dust in the sampling device.

Coal mine dust lung disease in the modern era.

Coal workers' pneumoconiosis (CWP), as part of the spectrum of coal mine dust lung disease (CMDLD), is a preventable but incurable lung disease that can be complicated by respiratory failure and death. Recent increases in coal production from the financial incentive of economic growth lead to higher respirable coal and quartz dust levels, often associated with mechanization of longwall coal mining. In Australia, the observed increase in the number of new CWP diagnoses since the year 2000 has necessitated a review of recommended respirable dust exposure limits, where exposure limits and monitoring protocols should ideally be standardized. Evidence that considers the regulation of engineering dust controls in the mines is lacking even in high-income countries, despite this being the primary preventative measure. Also, it is a global public health priority for at-risk miners to be systemically screened to detect early changes of CWP and to include confirmed patients within a central registry; a task limited by financial constraints in less developed countries. Characteristic X-ray changes are usually categorized using the International Labour Office classification, although future evaluation by low-dose HRCT) chest scanning may allow for CWP detection and thus avoidance of further exposure, at an earlier stage. Preclinical animal and human organoid-based models are required to explore potential re-purposing of anti-fibrotic and related agents with potential efficacy. Epidemiological patterns and the assessment of molecular and genetic biomarkers may further enhance our capacity to identify susceptible individuals to the inhalation of coal dust in the modern era.

15 years of monitoring occupational exposure to respirable dust and quartz within the European industrial minerals sector.

In 2000, a prospective Dust Monitoring Program (DMP) was started in which measurements of worker's exposure to respirable dust and quartz are collected in member companies from the European Industrial Minerals Association (IMA-Europe). After 15 years, the resulting IMA-DMP database allows a detailed overview of exposure levels of respirable dust and quartz over time within this industrial sector. Our aim is to describe the IMA-DMP and the current state of the corresponding database which due to continuation of the IMA-DMP is still growing. The future use of the database will also be highlighted including its utility for the industrial minerals producing sector. Exposure data are being obtained following a common protocol including a standardized sampling strategy, standardized sampling and analytical methods and a data management system. Following strict quality control procedures, exposure data are consequently added to a central database. The data comprises personal exposure measurements including auxiliary information on work and other conditions during sampling. Currently, the IMA-DMP database consists of almost 28,000 personal measurements which have been performed from 2000 until 2015 representing 29 half-yearly sampling campaigns. The exposure data have been collected from 160 different worksites owned by 35 industrial mineral companies and comes from 23 European countries and approximately 5000 workers. The IMA-DMP database provides the European minerals sector with reliable data regarding worker personal exposures to respirable dust and quartz. The database can be used as a powerful tool to address outstanding scientific issues on long-term exposure trends and exposure variability, and importantly, as a surveillance tool to evaluate exposure control measures. The database will be valuable for future epidemiological studies on respiratory health effects and will allow for estimation of quantitative exposure response relationships.

Air Quality in Norwegian Horse Stables at Low Outdoor Temperatures

Many horse stables have mechanical-fan ventilation systems but still try to regulate ventilation manually by closing doors and windows on a cold winter night. The aim of this study was to investigate the variation in air quality in Norwegian horse stables with different ventilation systems on days with low outdoor air temperatures. A total of 19 insulated, mechanically ventilated stables with horses kept inside during the night were included in the study. Almost all fans were operated during the night (n = 18), but inlets for fresh air were highly variable in design and management leading to potential for ineffectiveness of ventilation functions. In four of the stables, there were no specific air inlet systems, and in five stables, the exit door was used as the only air inlet. The air exchange rate was sufficient in all the stables with an automated temperature thermostat for ventilation control. Mean level of carbon dioxide (CO2) was 1,800 ppm and in one stable CO2 exceeded 3,000 ppm. Mean inside ammonia (NH3) was 1.3 ppm, and only in one stable the level of NH3 exceeded 5 ppm. The total dust concentration was 0.69 ± 0.19 mg/m3, and in two stables, the dust concentration exceeded 1.0 mg/m3. Total and respirable dust levels were higher in stables with ventilation rate below recommended level. Half of the stables visited had a lower calculated air exchanges rate than recommended, and the majority of the stables regulated the ventilation manually by closing doors and inlets during night. This indicates a general lack of knowledge among the stable managers of climatic demand in horses and how to operate mechanical ventilation. Still, the majority of the stables maintained acceptable air quality, with NH3 and dust levels within recommended levels, although most stables had elevated humidity.

Indoor and outdoor PM10 levels at schools located near mine dumps in Gauteng and North West Provinces, South Africa

BackgroundFew studies in South Africa have investigated the exposure of asthmatic learners to indoor and outdoor air pollution at schools. This study compared outdoor PM10 and SO2 exposure levels in exposed (1–2 km from gold mine dumps) and unexposed schools (5 km or more from gold mine dumps). It also examined exposure of asthmatic children to indoor respirable dust at exposed and unexposed schools.MethodsThe study was conducted between 1 and 31 October 2012 in five schools from exposed and five from unexposed communities. Outdoor PM10 and SO2 levels were measured for 8-h at each school. Ten asthmatic learners were randomly selected from each school for 8-h personal respirable dust sampling during school hours.ResultsThe level of outdoor PM10 for exposed was 16.42 vs. 11.47 mg.m−3 for the unexposed communities (p < 0.001). The outdoor SO2 for exposed was 0.02 ppb vs. 0.01 ppb for unexposed communities (p < 0.001). Indoor respirable dust in the classroom differed significantly between exposed (0.17 mg.m−3) vs. unexposed (0.01 mg.m−3) children with asthma at each school (p < 0.001).ConclusionThe significant differences between exposed and unexposed schools could reveal a serious potential health hazard for school children, although they were within the South African Air Quality Standards’ set by the Department of Environmental Affairs. The indoor respirable dust levels in exposed schools could have an impact on children with asthma, as they were significantly higher than the unexposed schools, although there are no published standards for environmental exposure for children with asthma.

Respiratory and auditory disorders in a ceramic manufacturing factory (Queisna City, Menoufia Governorate)

Objectives The aim of this study was to evaluate respiratory and auditory disorders among workers in a ceramic manufacturing factory and their relationship with workplace environment in the same factory. Background The ceramic industry is one of the most hazardous industries to the respiratory system. In addition, disorders due to occupational exposure to noise are possible. Participants and methods A cross-sectional, comparative study was carried out on 138 workers in a ceramic manufacturing factory and 138 nonoccupationally exposed participants (control group). An environmental study for total, respirable, and differential dusts and noise was carried out. Spirometric measurements, audiometric assessment, and plain chest radiography were applied. Results The mean value of respirable dust level, free crystalline silica concentration, and noise levels were higher than international permissible levels. Ceramic manufacturing factory workers had a higher significant prevalence of respiratory and auditory manifestations as well as deteriorated spirometric measurements, abnormal audiometric assessment, and abnormal radiological findings. Conclusion Exposure to free crystalline silica concentrations more than permissible levels results in abnormal spirometric measurements and abnormal radiological findings. Continuous exposure to noise levels more than 90 dBA leads to abnormalities in audiogram in the form of threshold shifting and V-dip depression. Regular use of good-quality personal protective equipment, especially masks and ear muffs, and periodic medical examination are highly recommended.

The Effect of Management Regime on Airborne Respirable Dust Concentrations in Two Different Types of Horse Stable Design

Airborne respirable dust (ARD) (<5 μm) in the stable environment is strongly implicated in equine asthma. Bedding, forage, ventilation rate, and stable management activities all contribute to ARD. This study investigated the relationship between ARD in the breathing zone (BZ) and the stable zone (SZ) in eight American barns (ABs) and eight stable complexes with individual stables under four different management regimes. Airborne respirable dust was measured in eight replicate stables per regime in ABs (n = 32) and eight per regime in single stables (n = 32). Regimes were as follows: (1) steamed hay and shavings; (2) dry hay and shavings; (3) haylage and straw; and (4) dry hay and straw. Samples were taken in quite periods between 3 PM and 4 PM hours. Airborne respirable dust levels were analyzed using Split-Plot analysis of variance and Wilcoxon matched-pairs test (Genstat 15) with P < .05 as significant. The lowest ARD (<360 RP/L air) was found for shavings and steamed hay in AB and single stables in both BZ and SZ. Straw and dry hay in ABs produced ARD of 6,250 (SZ), 5,079 RP/L air (BZ) which was greater (P < .05) than the 2,901 (SZ) and 942 (BZ) RP/L air in single stables. Straw and haylage produced more ARD across both zones in single stables compared with ABs. Shavings and dry hay = more dust in the BZ than in the SZ, whereas straw and haylage = higher ARD in the SZ versus the BZ across both stable designs. Using dry hay and/or straw cannot be recommended as a suitable management regime for stabled horses.

Workplace Respirable Dust Monitoring And Risk Factor Assessment In Foundry Process

A study was carried out among iron foundry workers to assess occupational exposure to ambient respiratory dust in their work environment and rates of risk factors in each process by using Bayesian decision analysis (BDA) and AIHA (American Industrial Hygiene Association) exposure categorization guidelines. A total of 93 respirable dust samples were collected in various processes, including the molding, melting, shakeout, heat treatment, felting and finishing units of the foundries. The mean concentrations of respirable dust were 1.40±0.86 mg/m 3 in the molding process, 1.42±0.63 mg/m 3 in melting, 0.56±0.59 mg/m 3 in shakeouts, 1.63±0.85mg/m 3 in heat treatment, 2.17±0.61 mg/m 3 in felting, and 3.30±3.47 mg/m 3 in the finishing sections, respectively. The mean levels of respirable dust in the finishing process exceed the ACGIH standard (TLV 3 mg/m 3 ). The results of BDA show that the respirable dust exposures were in AIHA Category 4 for shakeouts (96.7% probability), felting (98.1% probability), and finishing (100% probability), respectively. The exposures belonged to category 3 for molding (52.8% probability), melting (79.4% probability) and heat treatment (40.3% probability), respectively. Therefore, it is required to have immediate control and safety adaptation by personal protective equipment of proper respiratory musk, engineer control, chemical analysis of respirable dust, exposure surveillance in order to prevent from being exposed to respirable dust among the foundry workers.

The risk of pulmonary tuberculosis in underground copper miners in Zambia exposed to respirable silica: a cross-sectional study.

BackgroundPulmonary tuberculosis (PTB) among underground miners exposed to silica remains a global problem. Although well described in gold and coal mining, risk in other mining entities are not as well documented. This study aims to determine dust-related dose response risk for PTB among underground miners exposed to silica dust in Zambia's copper mines.MethodsA cross sectional study of in-service miners (n = 357) was conducted at Occupational Health and Safety Institute (OHSI), Zambia. A systematic review of medical data over a 5-year period from assessments conducted by doctors at OHSI and statutory silica exposure data (n = 16678) from the Mine Safety Department (MSD) were analysed. Lifetime cumulative exposure metrics were calculated. Multivariate logistic regression analysis was used to determine the association between PTB and lifetime exposure to silica, while adjusting for various confounders.ResultsThe median respirable silica dust level was 0.3 mg/m3 (range 0.1–1.3). The overall prevalence of PTB was 9.5 % (n = 34). High cumulative respirable silica dust category showed a statistically significant association with PTB (OR = 6.4 (95 % CI 1. 8–23)) and a significant trend of increasing disease prevalence with increasing cumulative respirable silica dust categories was observed (ptrend < 0.01). Smoking showed a statistically significant association with PTB with OR = 4.3 (95 % CI 1.9–9.9).ConclusionsOur results demonstrate the association of increased risk for certified active TB with cumulative respirable dust in a dose related manner among this sample of copper miners. There is need to intensify dust control measures and incorporate anti-smoking interventions into TB prevention and control programmes in the mines.

Respiratory health effects of occupational exposure to charcoal dust in Namibia.

Charcoal processing activities can increase the risk of adverse respiratory outcomes. To determine dose-response relationships between occupational exposure to charcoal dust, respiratory symptoms and lung function among charcoal-processing workers in Namibia. A cross-sectional study was conducted with 307 workers from charcoal factories in Namibia. All respondents completed interviewer-administered questionnaires. Spirometry was performed, ambient and respirable dust levels were assessed in different work sections. Multiple logistic regression analysis estimated the overall effect of charcoal dust exposure on respiratory outcomes, while linear regression estimated the exposure-related effect on lung function. Workers were stratified according to cumulative dust exposure category. Exposure to respirable charcoal dust levels was above occupational exposure limits in most sectors, with packing and weighing having the highest dust exposure levels (median 27.7mg/m3, range: 0.2-33.0 for the 8-h time-weighted average). The high cumulative dust exposure category was significantly associated with usual cough (OR: 2.1; 95% CI: 1.1-4.0), usual phlegm (OR: 2.1; 95% CI: 1.1-4.1), episodes of phlegm and cough (OR: 2.8; 95% CI: 1.1-6.1), and shortness of breath. A non-statistically significant lower adjusted mean-predicted % FEV1 was observed (98.1% for male and 95.5% for female) among workers with greater exposure. Charcoal dust levels exceeded the US OSHA recommended limit of 3.5mg/m3 for carbon-black-containing material and study participants presented with exposure-related adverse respiratory outcomes in a dose-response manner. Our findings suggest that the Namibian Ministry of Labour introduce stronger enforcement strategies of existing national health and safety regulations within the industry.

Assessment of mine ventilation systems and air pollution impacts on artisanal tanzanite miners at Merelani, Tanzania

This article assesses mine ventilation systems and air pollution impacts on 4000 artisanal tanzanite miners at Merelani. Concentration of carbon monoxide (CO) in five selected mines averaged 66.2 ppm (with maximum of 102 ppm) which is 2.5 times higher than the maximum concentration specified by Ontario Ministry of Labour (2015). The average level of respirable dust was 8 mg dust/m3 air, which is 4 times higher than the allowable American guidelines for mines. Suffocation accidents consists of 29% of the total accidents in Merelani which claimed lives of 44 miners from 2005 to 2014. About 82% of the suffocation accidents were caused by unauthorized entry in temporary stopped or abandoned mines. Many miners suffer from silicosis and other lung diseases and 6.6% of miners have tuberculosis (TB). Based on the results of field studies it was found that small compressors being used for both drilling and ventilation are capable of providing 11.4 m3 of air/min in average. Usually 100 to 120 miners per shift are working in the mining fronts and this air quantity is not adequate to provide enough fresh air and comfort to workers and to dilute contaminants to a safe concentration. Interviews with managers of 50 mining fronts revealed that dry drilling is used by 92% and only 10% of miners wear masks. The study highlights the need of forced fans, dust control strategies, use of dust mask, pre and post medical checks, gas monitoring, training and abiding to safe mining practices as the measures to improve health and safety of the miners at the area.

Optical Estimation on Pollution Level of Respirable Dust Based on Infrared Transmitting Behavior in Coalmine Fully Mechanized Working Face

Respirable coal particle generated during underground mining is the main cause for gas-dust explosions and coal workers’ pneumoconiosis (CWP) which needs accurate monitoring especially on its concentration. Focusing on the coal dust pollution in the fully mechanized working face of Huangbaici coalmine, coal particle was sampled for further industrial analysis and FT-IR test to obtain its chemical composition and optical constant. Combined with the simulated spatial distribution of airborne dust, the spectral transmission characteristics of coal dust within wavelengths of 2.5 to 25 μm under different operating conditions were obtained. The simulation results show that the transmittance and aerosol optical depth (AOD) of coal dust are closely linked and obviously influenced by the variation of dust generation source (intensity of dust release, position of coal cutting, and the wetting of the coal seam) and airflow field (wind speed and direction of ventilation). Furthermore, an optical channel of 1260–1280 cm−1(7.937–7.813 μm) which is almost only sensitive to the variation of dust concentration but dull to the diameter change of coal dust was selected to establish the correlation of dust concentration and infrared transmittance. The fitting curve was then applied to retrieve the equivalent dust concentration based on optical information, and the comparison results demonstrate that the estimated pollution level is consistent with field measurement data in engineering practice.

The Effect of Steaming and Soaking on the Respirable Particle, Bacteria, Mould, and Nutrient Content in Hay for Horses

Forage is crucial for stabled horses, promoting gut health, supplying valuable nutrients, and maintaining normal feeding behaviors. Forage can contain high levels of respirable dust predisposing horses to respiratory disorders. This study examined the effect of different treatments on the airborne respirable particles (ARPs), microbial and nutrient content of hay for horses in three experiments. Experiment 1a eight bales of meadow hay were subjected to five treatments n = 40: dry (D), 10-minute soak in water (W), steamed in a wheelie bin (TWB), steamed in a Haygain (HG) 600, and steamed with a kettle of boiling water (K) on ARP content. Experiment 1b microbial contamination was measured in five bales of meadow hay after treatments D, TWB, and HG in cold conditions (0–7°C) (n = 15). Experiment 2 measured the nutrient content of 30 different hays after D and HG treatments, n = 60. Data in experiments 1a and 1b were analyzed using analysis of variance and least significant difference test: hay and treatment as factors. Experiment 2 was analyzed using paired t-test with significance levels accepted P < .05. Results showed steaming in the HG reduced ARP and microbial contamination by 99%. TWB or K reduced ARP in hay by 88%. W, TWB, or K did not reduce microbial contamination. HG treatment preserved mineral and protein contents but reduced water-soluble carbohydrate by 18.3%. Steaming using an HG steamer is a feasible long-term strategy for reducing ARP and microbial contamination, while conserving mineral and protein content in hay and is thus suitable for providing hygienically clean forage to stabled horses.

Respiratory Symptoms and Blood Eosinophil Level in Workers Exposed to Quarry Dust in South-Eastern Nigeria

Objectives: We investigated the respiratory symptoms and eosinophil levels of workers exposed to quarry pollutants in Ebonyi State, Nigeria. Methods: 400 workers exposed to quarry dust and 400 age, sex, BMI-matched unexposed controls participated in the study. Incidences of respiratory and allergic symptoms were investigated. The level of respiratory dust and gas emissions in quarry sites were measured. Results: The incidence of respiratory symptoms and mean eosinophil levels were significantly greater in workers exposed to quarry dust compared to controls. Mean levels of respirable dust and certain poisonous gases from quarry sites were significantly higher compared to those of control environments. The hazard index of respiratory irritants was greater than 1. Conclusion: The higher incidence of respiratory infections and aggravated inflammatory responses observed in quarry workers may be attributable to the presence of higher level of respiratory system irritants in the quarry sites.

Pneumoconiosis and quartz content of respirable dusts in the coal mines in Zonguldak, Turkey

Coal Worker's Pneumoconiosis (CWP) is one of the most important occupational health problems in Turkish coal mining. Despite the decrease in employment and production at Turkish Hardcoal Enterprise (TTK) in the Zonguldak Basin, the occurrence of pneumoconiosis is still very high, particularly among the face workers. This study aims to evaluate the dust concentrations and quartz contents of respirable dusts in coal faces and pneumoconiosis risks related to face workers in TTK collieries. The mean respirable dust exposure experienced by the face workers was evaluated and compared with the occupational exposure limits. The data on the dust samples exhibit great variations. The quartz contents of respirable dusts were determined by a FTIR spectrophotometer. The mean respirable dust concentration in the coal faces varies from 1.6 to 14.5mg/m3 while the quartz content varies from 0.7 to 10.4%. The mean respirable dust concentrations in the coal faces in Karadon, Amasra, Armutcuk and Kozlu collieries are above the TLV (5mg/m3) of Turkey and the percentage of the measurements exceeding the TLV in the coal faces range from 25% to 100. An analysis of variance was performed to investigate the effects of workplace and seam characteristics on respirable dust levels. According to the results of variance analysis (ANOVA), it was seen that there are significant differences between seams and collieries in terms of dust concentration and quartz contents of respirable dust.CWP is still the most important problem in the collieries of TTK. The occurrence of CWP is higher among underground face workers. There have been 200 CWP cases in the last decade with a prevalence rate of 6.3%. CWP rates in the coal faces of the collieries increase as the respirable dust levels and quartz contents increase in general. This finding indicates that the TLV (5mg/m3) of Turkey should be re-evaluated and additional safety precautions should be taken in the workplaces where high quartz contents of respirable dust exist.

Pulmonary function, respiratory symptoms, and dust exposures among workers engaged in early manufacturing processes of tea: a cohort study

BackgroundTo evaluate pulmonary function and respiratory symptoms in workers engaged in the early manufacturing processes of tea and to identify the associated factors, we conducted a study in a tea production area in Taiwan.MethodsWe recruited tea workers who engaged in the early manufacturing process in the Mountain Ali area in Taiwan and a comparison group of local office workers who were matched for age, gender, and smoking habits. We performed questionnaire interviews, pulmonary function tests, skin prick tests, and measurement of specific IgE for tea on the participants and assessed tea dust exposures in the tea factories.ResultsThe 91 participating tea workers had higher prevalence of respiratory symptoms than the comparison group (32 participants). Among tea workers, ball-rolling workers had the highest prevalence of symptoms and the highest exposures of inhalable dusts. At baseline, tea workers had similar pulmonary functions as the comparison group, but compared to the other tea workers ball-rolling workers had a lower ratio of the 1-second forced expiratory volume to forced vital capacity (FEV1/FVC) and a lower maximal mid-expiratory flow rate expressed as% of the predicted value--MMF (%pred). A total of 58 tea workers participated in the on-site investigation and the cross-shift lung function measurements. We found ball-rolling yielded the highest inhalable dust level, panning yielded the highest respirable dust level, and withering yielded the lowest levels of both dusts. Ball-rolling also yielded the highest coarse fraction (defined as inhalable dusts minus respirable dusts), which represented exposures from nose to tracheobronchial tract. During the shift, we observed significant declines in pulmonary function, especially in ball-rolling workers. Multiple regressions showed that age, height, work tasks, coarse fraction, and number of months working in tea manufacturing each year were independent predictors of certain pulmonary function parameters in tea workers.ConclusionsTea workers engaged in early manufacturing processes of tea have higher prevalence of respiratory symptoms and pulmonary function impairment, which might be related to tea dust exposures, especially the coarse fraction.

Aspergillus hazardous problem in ceramic workers

Ceramic workers are at a high risk of developing respiratory problems as they are exposed to high levels of respirable dust containing silica and high microbial counts, including high Aspergillus counts. The aim of the study was to study the percentage of ceramic workers with positive Aspergillus (A.) through polymerase chain reaction (PCR) and specific IgE (sIgE) for the different Aspergillus species. PCR and specific IgE (sIgE) for the different Aspergillus species (A. flavus, A. fumigatus and A. niger) were estimated in 40 ceramic workers and 56 control subjects. Results revealed that 32.5% of the workers' sputum was PCR positive for Aspergillus. About 69.2% of them were A. flavus positive, 15.4% A. niger positive, 7.7% A. fumigatus positive and 7.7% A. flavus and A. fumigatus positive. The percentage change in sIgE for A. fumigatus between the workers and their controls was over 100%, while less than 50% for the other two species. The sIgE levels for the three Aspergillus species were not significantly correlated with the duration of exposure. Fungal exposure could be considered potential hazardous problem in ceramic industry. There were no significant correlations between the duration of exposure and the sIgE for the different Aspergillus species.

Exposure to Respirable Flour Dust and Gliadin in Wheat Flour Mills

The aim of this study was to determine the concentrations of respirable flour dusts and gliadin as well as gliadin-specific serum antibodies in exposed workers of Hamadan wheat flour mill factories. Blood samples from 95 exposed workers and 80 air samples from flour packing, husk packing, flour production and wheat unloading areas were collected. Respirable flour dust density was measured by a gravimetric method, and dust gliadin concentration as well as serum antibodies were determined by enzyme-linked immunosorbent assays. The Time-weighted average (TWA) flour dust density was higher in all factories (1.56-4.68 mg/m(3)) compared with the threshold limit value (0.5 mg/m(3)) of ACGIH and showed a positive correlation with the gliadin concentration (p<0.05). Additionally, the respirable dust and gliadin concentrations were significantly higher at flour packing workstations compare with the other work areas. Moreover, the mean serum gliadin-specific IgA and IgG and total IgE antibodies were remarkably higher in exposed mill workers compared with the controls (p<0.05). We clearly demonstrated that workers in Hamadan flour mills are in exposed to a hazardous level of respirable flour dust, receiving the highest level of dust and gliadin in flour packing areas. Furthermore, dust-exposed workers showed upper levels of serum antibodies indicating exposure to higher amounts of allergens than controls.

A cross-shift study of lung function, exhaled nitric oxide and inflammatory markers in blood in Norwegian cement production workers

ObjectivesTo study possible effects of aerosol exposure on lung function, fractional exhaled nitric oxide (FeNO) and inflammatory markers in blood from Norwegian cement production workers across one work shift (0...