Self-reported exposure to dust and diesel exhaust, respiratory symptoms, and use of respiratory protective equipment among Arctic miners.

Arctic miners face significant risks from diesel exhaust and dust exposure, potentially leading to adverse respiratory health. Employers must limit harmful exposures, using personal protective equipment (PPE) as a last line of defense. This study explored the association between reported respiratory exposure and symptoms, and PPE training and usage. Data from the MineHealth study (2012-2014) included a total of 453 Arctic open pit miners in Norway, Sweden, and Finland. Participants answered questions on exposure to dust and diesel exhaust, respiratory symptoms, and PPE use, in addition to age, gender, BMI, smoking, and self-rated health. Estimated exposure to dust was common, reported by 91%, 80%, and 82% and that of diesel exhaust by 84%, 43%, and 47% of workers in Sweden, Finland, and Norway, respectively. Reported dust exposure was significantly related to respiratory symptoms (OR 2.2, 95% CI 1.3-3.7), diesel exposure increased the occurrence of wheezing (OR 2.6, 95% CI 1.3-5.4). PPE use varied between the studied mines. Non-use was common and related to reduced visibility, wetness, skin irritation and fogging of the respiratory PPE. Future research should employ more precise exposure assessment, respiratory function as well as explore the reasons behind the non-compliance of PPE use.

Welding fume exposure and prevalence of chronic respiratory symptoms among welders in micro- and small-scale enterprise in Akaki Kality sub-city, Addis Ababa, Ethiopia: a comparative cross-sectional study.

BACKGROUND: Exposure to welding fumes can lead to different respiratory health disorders, including lung cancer, due to long-term exposures. In Ethiopia, large numbers of people are engaged in the welding sector. Often, these workers are exposed to welding fumes at their workplaces, however, the level of exposure and its health effects have never been studied. OBJECTIVE: To measure the level of personal welding fume exposure and assess chronic respiratory symptoms and associated factors, among micro and small-scale enterprise metal workshop workers, in Akaki Kality Sub city, Ethiopia. METHODS: A comparative cross-sectional study involving 226 welders and 217 controls. Chronic respiratory symptoms were assessed using a standardized questionnaire adopted from the American Thoracic Society (ATS). Welding fumes were collected from the welder's breathing zone using 37 mm close-faced plastic cassettes fitted with Polyvinyl Chloride (PVC) filters connected to Casella pumps at an airflow rate of 2 L/min. RESULT: The overall prevalence of chronic respiratory symptoms among welders and controls were 54 (23.9%) and 20 (9.2%) respectively. The geometric mean and geometric standard deviation (GSD) of personal welding fume exposure, among welders was 5.98 mg/m3 (± GSD = 1.54). In this study, 53.3% of the samples exceeded the Occupational Exposure Limit defined by the American Conference of Governmental Industrial Hygiene. Chronic respiratory symptoms were significantly associated with educational status (Adjusted Odds Ratio (AOR): 5.11, 95% CI: 1.35, 19.33), respiratory protective equipment use (AOR: 3.33, 95% CI: 1.52, 7.31), safety training (AOR: 2.41, 95% CI: 1.10, 5.28), smoking (AOR:3.57, 95% CI: 1.54, 8.23), welding machine maintenance (AOR: 1.87, 95% CI: 1.01, 3.59) and welding site (i.e. indoors vs. outdoor) (AOR: 6.85. 95% CI: 2.36, 19.89). CONCLUSIONS: The prevalence of chronic respiratory symptoms among welding workers was significantly higher than controls. More than half of the samples exceeded the Occupational Exposure Limit. Educational status, implementation of safety training, and welding sites were significantly associated with chronic respiratory symptoms. The results suggested a need to reduce welding fume exposure to improve the respiratory health of the workers.

Respirable dust and crystalline silica concentrations among workers at a brick kiln in Bhaktapur, Nepal.

Exposure to respirable dust and crystalline silica (SiO2) has been linked to chronic obstructive pulmonary disease, silicosis, cancer, heart disease, and other respiratory diseases. Relatively few studies have measured respirable dust and SiO2 concentrations among workers at brick kilns in low- and middle-income countries. The purpose of this study was to measure personal breathing zone (PBZ) respirable dust and SiO2 concentrations among workers at one brick kiln in Bhaktapur, Nepal. A cross-sectional study was conducted among 49 workers in five job categories: administration, fire master, green (unfired) brick hand molder, green brick machine molder, and top loader. PBZ air samples were collected from each worker following Methods 0600 (respirable dust) and 7500 (respirable crystalline SiO2: cristobalite, quartz, tridymite) of the U.S. National Institute for Occupational Safety and Health. Eight-hour time-weighted average (TWA) respirable dust and quartz concentrations were also calculated. SiO2 percentage was measured in one bulk sample each of wet clay, the release agent used by green brick hand molders, and top coat soil at the brick kiln. The geometric mean (GM) sample and TWA respirable dust concentrations were 0.20 (95% confidence interval [CI]: 0.16, 0.27) and 0.12 (95% CI: 0.09, 0.16) mg/m3, respectively. GM sample and TWA quartz concentrations were 15.28 (95% CI: 11.11, 21.02) and 8.60 (95% CI: 5.99, 12.34) µg/m3, respectively. Job category was significantly associated with GM sample and TWA respirable dust and quartz concentrations (all p < 0.0001). Top loaders had the highest GM sample and TWA respirable dust concentrations of 1.49 and 0.99 mg/m3, respectively. Top loaders also had the highest GM sample and TWA quartz concentrations of 173.08 and 114.39 µg/m3, respectively. Quartz percentages in bulk samples were 16%-27%. Interventions including using wet methods to reduce dust generation, administrative controls, personal protective equipment, and education and training should be implemented to reduce brick kiln worker exposures to respirable dust and SiO2.

Respirable dust exposure impact on respiratory symptoms among cleaners in a Selangor Public University, Malaysia.

INTRODUCTION: Cleaners perform a vital role in environmental health by keeping the place clean, but they are also exposed to various hazards. Yet, there is a lack of effective and accessible occupational safety standard measures, thus making this to be difficult to monitor the long-term health effects of cleaners. This study aims to determine the respirable dust exposure on respiratory symptoms among cleaners in a public university in Selangor. MATERIALS AND METHODS: A cross-sectional study was carried out among 51 cleaners. The respondents' background information and respiratory symptoms were gathered using a series of standardised questionnaires validated by the American Thoracic Society (ATS-DLD-78-A). The 8- hour respirable dust exposure to cleaners was measured using an air sampling pump (Gillian & Sensodyne Gil Air 3). RESULTS: The mean of respirable dust was lower than permissible exposure limit with 0.63±0.57mg/m3. The respiratory symptoms among the cleaners showed no significant association between cough, phlegm, and breathing difficulties with working tenure. Meanwhile, wheezing and coughing with phlegm have an almost significant association with working tenure among cleaners with (Χ2=1.00, p=0.08) and (Χ2=1.00, p=0.07) respectively. Exposure to respirable dust has exhibited 6 times the prevalence of coughing with phlegm among cleaners (PR=6.28, 95% CI: 0.44, 89.38). CONCLUSION: The findings of this study demonstrated that the cleaners were significantly affected by the respirable dust. The cleaners' working environment has caused them to be exposed to respirable dust.

[Exploration of detection methods for free silica with different crystal forms in dust].

Objective: To investigate the differences and applicability of free silica detection methods of different crystal forms in dust, and to provide a basis for the selection of various methods. Methods: From December 2021 to June 2022, dust samples from 20 enterprises in different industries in 18 cities in Henan Province were randomly selected as the investigation objects. X-ray diffraction (XRD) method was used to analyze the samples and classify the samples. Based on GBZ/T 192.4-2007 "Determination of Dust in the Air of Workplace-Part 4: Content of Free Silica in Dust", pyrophosphate method and infrared spectrophotometry were used for quantitative determination. The measured results were analyzed by paired sample t test to evaluate the advantages and disadvantages of the two methods and their applicable scope. Results: The XRD results of 20 dust samples could be divided into α, ß, γ crystal types and the mixed type of α and γ. There was no significant difference between pyrophosphate method and infrared spectrophotometry (P=0.180). The pyrophosphate method results of ß, γ and α, γ mixed crystalline free silica were significantly higher than those of infrared spectrophotometry, and the difference was statistically significant (P<0.001) . Conclusion: Pyrophosphate method and infrared spectrophotometry are suitable for α-type free silica, while pyrophosphate method is suitable for ß, γ and α, γ mixed crystalline free silica.

[Ion chromatography for the determination of n-butylamine in the workplace air].

Objective: To establish a method for the determination of n-butylamine in the air of the workplace by ion chromatography. Methods: In February 2022, on-site sampling was carried out using an atmospheric sampler. N-butylamine was adsorbed by a neutral silica gel tube and then performed for qualitative and quantitative determination by ion chromatography after ultrasonic desorption with 10 mmol/L sulfuric acid solution. Results: The linear range of the method was 0.0375-100.0 µg/ml, the linear equation of the standard curve was y=0.0713x-0.0327, the correlation coefficient was 0.9992. The detection limit of the method was 11.25 µg/L, and the lower limit of quantification was 37.50 µg/L, the lowest quantitative concentration was 0.025 mg/m(3) (in term of sampling 7.5 L). The average desorption efficiency of the method was 91.50%-95.38%, the precision was 1.10%-2.30%, the standard recovery was 83.83%-100.02%, sampling efficiency was 100.00%. Conclusion: This method is fast, sensitive and accurate, and can be used for the determination of n-butylamine in the air of workplace.

[Determination of dimethyl oxalate and diethyl oxalate in workplace air by high performance liquid chromatography].

Objective: To establish a high performance liquid chromatography method for the simultaneous determination of dimethyl oxalate (DMO) and diethyl oxalate (DEO) in workplace air. Methods: From January 2022 to January 2023, air samples were collected by silica gel tubes, desorbed by acetonitrile, separated by C18 chromatographic column, detected by photo-array detector, and retention time was used to characterize and peak area was used to quantify at 210 nm wavelength. Results: The linear relationships of DMO and DEO were good, r>0.999. The detection limits of DMO and DEO were 0.39 and 0.52 µg/ml, respectively. The quantitative limit was 1.28 µg/ml for DMO and 1.72 µg/ml for DEO. Average desorption efficiency for DMO was 82.40%-92.72%, and DEO was 94.13%-97.69%. The intra-assay precision of DMO was 1.87%-6.18%, and DEO was 2.25%-3.31%. Inter-assay precision of DMO was 3.29%-5.73%, and DEO was 1.38%-2.94%. Average sampling efficiencies were 100% for both DMO and DEO. Breakthrough capacity of DMO was 37.61 mg (200 mg solid adsorbent), DEO was >28.11 mg (200 mg solid adsorbent). Samples should be stored at 4 ℃ for at least 7 days. Conclusion: This method is easy to operate and has strong practicability. All indicators meet the requirements of the specification, and it is suitable for the simultaneous determination of DMO and DEO in the workplace air.

[Discussion on the application status and method improvement of gas chromatography in occupational health inspection standards in China].

As a rapid, accurate and efficient analytical technique, gas chromatography is widely used in the detection of volatile organic compounds and inorganic small molecule toxins, and it is the main analytical method in the national testing standards for occupational health. The existing effective national standards of gas chromatography for the detection of some substances have low column efficiency, high toxicity of reagents, poor correlation of the standard curve and low desorption efficiency and other problems, some of which can be solved through method improvement. At the same time, with the use of new materials and new processes, new types of toxic substances are emerging, and there are still many occupational disease hazards of limited value without supporting detection methods, gas chromatography can be applied to the detection of some toxic substances to better complement the vacancy of China's occupational health detection methods. This paper analyzes the current situation of the application of gas chromatography in occupational health testing standards, discusses the improvement of some of these methods, and helps to promote the application and development of gas chromatography in occupational health testing.

Biomonitoring of polycyclic aromatic hydrocarbons exposure and short-time health effects in wildland firefighters during real-life fire events.

Human biomonitoring data retrieved from real-life wildland firefighting in Europe and, also, worldwide are scarce. Thus, in this study, 176 Portuguese firefighters were biomonitored pre- and post- unsimulated wildfire combating (average:12-13 h; maximum: 55 h) to evaluate the impact on the levels of urinary polycyclic aromatic hydrocarbons hydroxylated metabolites (OHPAH; quantified by high-performance liquid chromatography with fluorescence detection) and the associated short-term health effects (symptoms, and total and differentiated white blood cells). Correlations between these variables and data retrieved from the self-reported questionnaires were also investigated. Firefighters were organized into four groups according to their exposure to wildfire emissions and their smoking habits: non-smoking non-exposed (NSNExp), non-smoking exposed (NSExp), smoking non-exposed (SNExp), and smoking and exposed (SExp). The most abundant metabolites were 1-hydroxynaphthalene and 1-hydroxyacenaphthene (1OHNaph + 1OHAce) (98-99 %), followed by 2-hydroxyfluorene (2OHFlu) (0.2-1.1 %), 1-hydroxyphenanthrene (1OHPhen) (0.2-0.4 %), and 1-hydroxypyrene (1OHPy) (0.1-0.2 %); urinary 3-hydroxybenzo(a)pyrene was not detected. The exposure to wildfire emissions significantly elevated the median concentrations of each individual and total OHPAH compounds in all groups, but this effect was more pronounced in non-smoking (1.7-4.2 times; p ≤ 0.006) than in smoking firefighters (1.3-1.6 times; p ≤ 0.03). The greatest discriminant of exposure to wildfire emissions was 1OHNaph + 1OHAce (increase of 4.2 times), while for tobacco smoke it was 2OHFlu (increase of 10 times). Post-exposure, white blood cells count significantly increased ranging from 1.4 (smokers, p = 0.025) to 3.7-fold (non-smokers, p < 0.001), which was accompanied by stronger significant correlations (0.480 < r < 0.882; p < 0.04) between individual and total OHPAH and total white blood cells (and lymphocytes > monocytes > neutrophils in non-smokers), evidencing the impact of PAH released from wildfire on immune cells. This study identifies Portuguese firefighters with high levels of biomarkers of exposure to PAH and points out the importance of adopting biomonitoring schemes, that include multiple biomarkers of exposure and biomarkers of effect, and implementing mitigations strategies.

Preliminary analyses of accumulation of carcinogenic contaminants on retired firefighter ensembles.

Personal protective equipment (PPE) is designed to protect firefighters from hazards encountered on the fire scene, including heat and products of combustion. Decontamination practices for firefighter turnout gear have been developed to remove combustion products and other contaminants from the fabric of structural firefighting ensembles (i.e., turnout or bunker gear). Chronic exposures to residual polycyclic aromatic hydrocarbons (PAH) are a contributing cause of firefighter cancers. To identify and quantify residual contamination of PAH, samples were taken from two individual decommissioned structural firefighting ensembles and analyzed by layer (outer canvas shell, moisture barrier, and the thermal protective liner) for (1) textile integrity via field emission scanning electron microscopy and (2) quantity of PAH contamination by high-pressure liquid chromatography with ultraviolet/fluorescence detection. The results of these analyses show the presence of the PAH compounds pyrene (35% of the total mass of PAH), phenanthrene (21%), benzo(a)pyrene (14%), and benzo(a)anthracene (14%) which present a risk for dermal absorption. The data also revealed that PAH penetration through the layers of the firefighting ensemble was strongly inhibited by the moisture barrier layer.

Occupational exposure of firefighters to hazardous pollutants during prescribed fires in Portugal.

Firefighters perform high-risk activities and during the course of their functions are highly exposed to a wide range of occupational hazards, including air pollution. Thus, this study aimed to assess the exposure of firefighters in prescribed wildland fires and their occupational exposure, as well as to identify and chemically characterise the particles collected during wildland firefighting and inside fire stations. Exposure to wildfire smoke was evaluated in 7 prescribed fires in Portugal, 2 in the north and 5 in the south of Viseu district. The concentrations of PM2.5, NO2, SO2, CO and VOCs were monitored and exceedances to occupational exposure limit values were identified. Moreover, the chemical composition of PM2.5 was analysed. The results showed that firefighters were exposed to high concentrations of these pollutants during prescribed fires and that, in some cases, exceeded occupational exposure limits, both for time-weighted average concentrations for an 8-h working day (a time-weighted average, TWA) of PM2.5, and for short-term exposure values (STEL) of NO2 and SO2. Despite being exposed to very high concentrations of CO, no exceedances to the occupational exposure values were observed. FT-IR and SEM-EDS allowed to chemically characterise the composition of the particles collected inside the fire stations and also during wildland fires, identifying mainly quartz, aluminium and magnesium silicates, characteristic of earth's crust constituents. and also, fibres that have undergone combustion. Concluding, firefighters' exposure to high concentrations of harmful pollutants, can lead to the degradation of their respiratory health. It is therefore extremely important to increase existing knowledge and conduct further studies, especially longitudinal ones, that can assess their lung function. This will allow an understanding of the impacts of smoke on firefighters' health and develop effective strategies to protect them during wildland firefighting operations.

Development of handling energy factors for use of dustiness data in exposure assessment modelling.

Several exposure assessment models use dustiness as an input parameter for scaling or estimating exposure during powder handling. Use of different dustiness methods will result in considerable differences in the dustiness values as they are based on different emission generation principles. EN17199:2019 offers 4 different dustiness test methods considering different dust release scenarios (e.g. powder pouring, mixing and gentle agitation, and vibration). Conceptually, the dustiness value by a given method can be multiplied with a scenario-specific modifier, called a handling energy factor (Hi), that allows conversion of a dustiness value to a release constant. Therefore, a Hi, scaling the effective mechanical energy in the process to the energy supplied in the specific dustiness test, needs to be applied. To improve the accuracy in predictive exposure modelling, we derived experimental Hi to be used in exposure algorithms considering both the mass- and number-based dust release fraction determined by the EN17199-3 continuous drop (CD) and the EN17199-4 small rotating drum (SRD) test methods. Three materials were used to evaluate the relationship between dustiness and dust levels during pouring powder from different heights in a controlled environment. The results showed increasing scatter and difference between the Hi derived for the 2 test methods with increasing pouring height. Nearly all the Hi values obtained for both SRD and CD were <1 indicating that the dustiness tests involved more energy input than the simulated pouring activity and consequently de-agglomeration and dust generation were higher. This effect was most pronounced in CD method showing that SRD mechanistically resembles more closely the powder pouring.

Assessment of PAH exposure and health risks among South Korean firefighters based on urinary PAH metabolites.

Polycyclic aromatic hydrocarbons (PAHs) comprise a group of compounds resulting from the incomplete combustion of organic matter. Firefighters engaged in fire suppression are highly exposed to PAHs. This study centered on evaluating the exposure levels and health risks of PAHs in South Korean firefighters involved in firefighting activities. The concentrations of 10 PAH metabolites in the urine of firefighters were measured immediately after, and two weeks post their engagement in extinguishing a large tire factory fire. The levels of OH-PAHs in urine samples immediately after fire suppression were elevated by a factor of 1.01-1.84 compared to urine samples from non-exposed period. The median concentration of total PAH metabolites (OH-PAHs) was higher in urine samples immediately after fire suppression (5910 ng/g creatinine) than in urine samples from non-exposed periods (5020 ng/g creatinine). However, the ∑OH-PAH levels in firefighters' urine were related to personal habits such as smoking. The concentrations of all individual OH-PAHs in the urine samples of nonsmokers exhibited a substantial increase, ranging from 1.37 to 2.3 times, clearly demonstrating that firefighting activities were a substantial source of PAH exposure. The calculated values associated with the health risks stemming from exposure to PAHs, including carcinogenic risk, total estimated daily intake (TEDI), and hazard quotients/index (HQs/HI), all fell within acceptable limits, indicating negligible risk. However, the HQ/HI values and TEDI for individual and total PAH exposures, except those for naphthalene, were 1.36-2.00 times higher in firefighters' samples taken after firefighting operations compared to those during regular duty. This underscores the need for more comprehensive investigations to comprehend the singular impact of firefighting activities due to the diverse sources of PAH emissions in the environment.

Diesel exhaust and respiratory dust exposure in miners and chronic obstructive pulmonary disease (COPD) mortality in DEMS II.

BACKGROUND: Diesel exhaust and respirable dust exposures in the mining industry have not been studied in depth with respect to non-malignant respiratory disease including chronic obstructive pulmonary disease (COPD), with most available evidence coming from other settings. OBJECTIVES: To assess the relationship between occupational diesel exhaust and respirable dust exposures and COPD mortality, while addressing issues of survivor bias in exposed miners. METHODS: The study population consisted of 11,817 male workers from the Diesel Exhaust in Miners Study II, followed from 1947 to 2015, with 279 observed COPD deaths. We fit Cox proportional hazards models for the relationship between respirable elemental carbon (REC) and respirable dust (RD) exposure and COPD mortality. To address healthy worker survivor bias, we leveraged the parametric g-formula to assess effects of hypothetical interventions on both exposures. RESULTS: Cox models yielded elevated estimates for the associations between average intensity of REC and RD and COPD mortality, with hazard ratios (HR) corresponding to an interquartile range width increase in exposure of 1.46 (95 % confidence interval (CI): 1.12, 1.91) and 1.20 (95 % CI: 0.96, 1.49), respectively for each exposure. HRs for cumulative exposures were negative for both REC and RD. Based on results from the parametric g-formula, the risk ratio (RR) for COPD mortality comparing risk under an intervention eliminating REC to the observed risk was 0.85 (95 % CI: 0.55, 1.06), equivalent to an attributable risk of 15 %. The corresponding RR comparing risk under an intervention eliminating RD to the observed risk was 0.93 (95 % CI: 0.56, 1.31). CONCLUSIONS: Our findings, based on data from a cohort of nonmetal miners, are suggestive of an increased risk of COPD mortality associated with REC and RD, as well as evidence of survivor bias in this population leading to negative associations between cumulative exposures and COPD mortality in traditional regression analysis.

[Comparison and analysis research on occupational exposure limits of coal dust between China and foreign countries].

Objective: To study and compare the occupational exposure limits (OELs) of coal dust between China and foreign countries, understand the OEL of coal dust in China, and provide data and basis for revising the OEL of coal dust in China. Methods: In August 2023, by searching the official websites of limits setting institutions in relevant countries and regions at home and abroad, collecting and sorting out the OELs of coal dust issued by 10 limit setting institutions in 6 countries and the background information of the formulation, and conducting specific analysis on the classification, limit level and formulation principles of coal dust OEL in each country/institution. Results: In China and Japan, the total dust and respirable dust of coal dust OEL were established respectively, while in other countries, only the time-weighted average concentration (TWA) of respirable coal dust exposure was established. The TWA prescribed by China's Notional Health Commission, the United States Occupational Safety and Health Administration (OSHA) , the United States Mining Safety and Health Administration (MSHA) and the Australian Safety Work Bureau when the SiO(2) content was less than 5% were 5, 2.4, 2 and 3 mg/m(3) respectively. China GBZ 2.1-2019 sets the limit of 2.5 mg/m(3) for respirable coal dust with SiO(2) content less than 10%. The TWA set by the American Conference of Government Industrial Hygienists (ACGIH) and the South African Department of Mines and Energy (DME) for anthracite coal were 0.4 and 0.8 mg/m(3), respectively, and bituminous coal or lignite were 0.9 and 1.8 mg/m(3), respectively. The respirable coal dust TWA set by the National Institute for Occupational Safety and Health (NIOSH) in the United States was 1 mg/m(3), and the TWA set by the New Zealand Work Safety Authority was 3 mg/m(3). Conclusion: At present, the OEL of coal dust in China is at a relatively loose level, and it is suggested to further explore the possibility of revising coal dust OEL.

[The method of determination for 2, 3-Butanedione in the air of workplace by high performance liquid chromatography with derivatization].

Objective: To establish a method for the determination of 2, 3-Butanedione (BUT) in the air of workplace, which including the process of collection by absorption in phosphoric acid aqueous solution and the process of analysis and detection by high performance liquid chromatography with derivatization. Methods: In October 2022, a porous glass plate absorption tube containing 10 ml of 0.01% phosphoric acid solution was used to collect BUT in the air of the workplace at a flow rate of 0.2 L/min. The absorption solution was derived by 2, 4-dinitrophenylhydrazine for 75 min and separated on a SB-C18 column (250 mm×4.6 mm, 5 µm) . At the column temperature of 30 ℃, the mixture of acetonitrile-water (V∶V, 1∶1) was eluted at the flow rate of 1.0 ml/min. It was detected by UV detector (λ=365 nm) , qualitatived by retention time and quantitatived by external standard. Results: It showed that BUT in phosphoric acid aqueous solution could be stored for at least 7 d at 4 ℃. There was a linear relationship within the determination range of 0.05-6.00 µg/ml, the linear regression equation was y=89.610x+0.133, r=0.9999. The sampling absorption efficiencies were 98.33%-100.00%, the detection limit of the method was 0.005 µg/ml, the minimum detection concentration was 0.016 mg/m(3) (based on V(0)=3.0 L) . The recovery rates were 95.96%-102.44%, the intra batch precision were 4.36%-7.78%, and the inter batch precision were 4.96%-6.06%. Conclusion: The method has the advantages of simple operation, high sensitivity and good accuracy. It can prevent the loss and degradation of BUT. It can be used for the determination of BUT in the air of workplace.

Stone mining work and dust pollution in Birbhum district, West Bengal, India.

Dust pollution is common in Indian roads and several industrial settings (including mines) that affects human health. Identification and characterization of the dust particles in the mining area is essential for knowing the properties of the dust that effectively causes ailments to humans, particularly among workers those who are working in unorganized industrial settings. The present study aimed to determine the level of dust pollution and to know the size and characterize the dust particles in the Pachami-Hatgacha stone mine areas of Birbhum district, West Bengal, India. Dust samples were collected and analysed for Dynamic Light Scattering (DLS) to determine the size and shape of the particles, Fourier Transform Infrared Spectroscopy (FT-IR) to determine the free silica content, and X-ray Florence (XRF) analysis for quantitative estimation of components in the sample. All the analyses were done following standard instrumentation and techniques. The size of the dust particles was much less (ranges 101-298 nm) than the size of respirable particles (2500 nm). Those were mostly generated as well as precipitated during peak working hours of the day. Presence of considerable amounts of silica was confirmed by the FT-IR (strong and broad band at 1000 cm-1) and XRF analysis (76.85% SiO2). Exposure to these dust particles may cause severe health impairments. Therefore, interventions like wet drilling and blasting, sprinkling of water during peak working hours, and awareness of use of personal protective devices among workers are required to reduce the risk and hazards associated with dust pollution to the health of miners and inhabitants around the mines.

Occupational Dust Exposure as a Risk Factor for Developing Lung Function Impairment.

OBJECTIVE: Dust exposure is high in several industries. We investigated associations of exposure in paper mills, wood pellet plants, and iron foundries with lung function impairment. METHODS: Respirable silica, inhalable paper dust, or inhalable wood dust were collected as personal samples and spirometry was performed. Multiple linear regression analyzed associations with FEV 1 %pred and FVC%pred. RESULTS: Wood pellet workers with high exposure to inhalable dust had lower FEV 1 %pred (95% CI) (-9.4 [-16 to -2.6]) and FVC%pred (-9.8 [-15 to -4.0]) compared with lowest exposure level. Workers at paper mills and foundries had no dose-dependent association but lower FEV 1 %pred and FVC%pred than in workers at wood pellets plants. CONCLUSIONS: Increased exposure to inhalable wood dust is associated with decreased lung function. Foundry and paper mill workers have generally lower lung function than wood pellet workers. Spirometry should be considered in workers in industries with airborne particulate matter pollution.

Personal respirable dust and respirable crystalline silica exposure in two shafts and a concentrator of a Zambian copper mine.

OBJECTIVES: Since the 1920s, Zambia's mining sector has experienced growth, which has increased the number of mine workers employed in the industry. Consequently, the potential for occupational exposure and prevalence of occupational diseases have also increased. Unfortunately, Zambia does not currently have legislative guidelines for workplace air monitoring and compliance. This study's objectives were to evaluate copper miners' personal exposure to respirable dust and respirable crystalline silica (RCS) and to assess workplace compliance using the European Standard for workplace air monitoring and measurement (EN689:2018). METHODS: This cross-sectional study collected 100 personal respirable dust exposure samples at a Zambian copper mine in 2023. These samples were weighed using NIOSH method 0600 and analyzed for crystalline silica using Fourier transform infrared spectroscopy (KBr pellet) (NIOSH method 7602). Additionally, 253 respirable dust exposure measurements collected at the mine between 2017 and 2022 were included for comparison. RESULTS: The median respirable dust exposure for the 2023 exposure measurements was 0.200 mg/m3 (95th percentile 2.871 mg/m3) compared to 0.400 mg/m3 (95th percentile 3.050 mg/m3) for the historic data. The median RCS exposure was 0.012 mg/m3 (95th percentile 0.163 mg/m3). Using EN689:2018, it was found that from 15 work areas, only six work areas complied with the standard for respirable dust exposure and only seven work areas complied with the standard for RCS exposure. CONCLUSIONS: At the mining site, several work areas had substantial exposure to respirable dust and RCS. Therefore, management needs to prioritize these areas when implementing control measures to reduce dust exposure. For the Zambia mining industry to manage exposure to respirable dust and RCS, it is necessary to implement standardized monitoring strategies. This study has demonstrated that EN689:2018 can be used successfully to determine compliance among Zambian mining work areas.

Influence of environmental parameters on workers' dust inhalation in underground mines.

Much dust is generated in underground coal mining processes, posing threats to workers' health and safety production. Dust enters the human body mainly through inhalation, primarily determined by the dust concentration around workers. In this study, the airflow field and dust distribution in the tunnel are simulated with FLUENT software. The breathing zone for a worker was defined to clarify the extent of external dust distribution influencing dust inhalation. The effects of human respiration, dust production rates, air supply velocities, and workers' positions on dust concentration in the breathing zone were investigated. The results show that there is upward airflow around the worker standing in the center of the air circulation. Human breath barely influences the airflow distribution and respirable dust concentrations in the breathing zone. Reducing the dust production rate in the tunnel can decrease the respirable dust concentration in the breathing zone by almost the same proportion. While increasing the air supply velocity by 50% would reduce only 20% of dust in the breathing zone. The dust concentrations vary along the roadway, in which the low concentration zone is located in the middle, more than 1.0 m away from the dust-producing surface and the wind surface. The research contributes to reducing workers' dust exposure with suggestions regarding ventilation optimization and working position selection.