Genome-wide somatic mutation analysis of sinonasal adenocarcinoma with and without wood dust exposure.

BACKGROUND: Sinonasal adenocarcinoma is a rare cancer, encompassing two different entities, the intestinal-type sinonasal adenocarcinoma (ITAC) and the non-intestinal-type sinonasal adenocarcinoma (non-ITAC). Occurrence of ITAC is strongly associated with exposure to hardwood dusts. In countries with predominant exposure to softwood dust the occurrence of sinonasal adenocarcinomas is lower and the relative amount of non-ITACs to ITACs is higher. The molecular mechanisms behind the tumorigenic effects of wood dust remain largely unknown. METHODS: We carried out whole-genome sequencing of formalin-fixed paraffin-embedded (FFPE) samples of sinonasal adenocarcinomas from ten wood dust-exposed and six non-exposed individuals, with partial tobacco exposure data. Sequences were analyzed for the presence of mutational signatures matching COSMIC database signatures. Driver mutations and CN variant regions were characterized. RESULTS: Mutation burden was higher in samples of wood dust-exposed patients (p = 0.016). Reactive oxygen species (ROS) damage-related mutational signatures were almost exclusively identified in ITAC subtype samples (p = 0.00055). Tobacco smoke mutational signatures were observed in samples of patients with tobacco exposure or missing information, but not in samples from non-exposed patients. A tetraploidy copy number (CN) signature was enriched in ITAC subtype (p = 0.042). CN variation included recurrent gains in COSMIC Cancer Gene Census genes TERT, SDHA, RAC1, ETV1, PCM1, and MYC. Pathogenic variants were observed most frequently in TP53, NF1, CHD2, BRAF, APC, and LRP1B. Driver mutations and copy number gains did not segregate by subtype. CONCLUSIONS: Our analysis identified distinct mutational characteristics in ITAC and non-ITAC. Mutational signature analysis may eventually become useful for documentation of occupation-related cancer, while the exact mechanisms behind wood dust-driven carcinogenesis remain elusive. The presence of homologous recombination deficiency signatures implies a novel opportunity for treatment, but further studies are needed.

Prevalence of chronic respiratory symptoms and associated factors among woodwork workers in Bahir Dar City, Ethiopia; a comparative cross-sectional study.

BACKGROUND: Exposure to wood dust can cause respiratory symptoms, like cough, phlegm, breathlessness, and chest pain, reduce lung function. OBJECTIVE: The objective of the study was to assess the prevalence of respiratory symptoms and associated factors among woodwork workers in Bahir-Dar city, Ethiopia. METHODS: A comparative cross-sectional study was employed among 229 exposed and 228 unexposed groups. Participants for the study were selected using simple random sampling technique. The chronic respiratory symptoms were assessed using a questionnaire adopted from the American Thoracic Society. The data was entered using Epi-Data version 4.6 and export to SPSS version 22 for analysis. Poisson regression, Multivariate linear regression and multivariable logistic regression analysis were used to identify factors associated with woodworkers, general population and in pooled analysis. RESULT: The prevalence of having at least one chronic respiratory symptom was higher among exposed group (59.4%) than unexposed group (18.0%) with PR = 3.03(95%CI: 2.45, 4.45). In woodworker; Not taking health and safety training(5.15,95%(CI:1.93-13.76),primary educational(3.85,95%,CI:(1.1,13.47), not using Mask(6.38, 95%CI:(2.69-15.76) & number of families(3.05,95%,CI:1.04-9.028), In general population; Number of family members(2.75, 95%CI:1.1-7.19)& lower monthly income (3.3, 95%CI: (1.49-7.4), and In pooled analysis; wood dust exposure status 14.36 95%, CI:(7.6-27.00),primary education(2.93,95%CI:1.24-6.92), number of families(3.46,95%CI:1.8-6.64), lower monthly income(2.13,95%CI:1.19-3.81), & smoking (6.65, 95%CI:1.19-36.9) were associated with respiratory symptom. CONCLUSION: Prevalence of respiratory symptoms was higher among exposed group than unexposed group. Reduced wood dust exposure status, Provision of occupational safety and health training, use of respiratory protective devices is recommended to reduce respiratory symptoms among woodwork workers.

Health and Safety Executive research on wood dust exposure controls in British manufacturing.

To generate new intelligence on occupational exposure to wood dust in woodworking manufacturing activities in Britain, the Health and Safety Executive (HSE) performed 22 occupational hygiene site visits to assess exposure and exposure controls between 2014 and 2017. The work aimed to characterise good practice and therefore sites with a poor health and safety record, as identified from HSE inspection records, were not invited to participate. Sites selected covered furniture production, joinery, saw milling, and boat building and repair. Twenty-three follow-up telephone interviews were also carried out across 15 of the companies with supervisors and managers to explore how they tried to promote good practice among the workforce, and if there are any potential challenges encountered. The aim of the interviews was to gain a better understanding of how to enable organisations to improve the management of wood dust exposure. This study found that 6.0% of all wood dust exposure measurements (15 out of 252) were above 5 mg/m³, and 17.6% of exposures to hardwood dust or mixtures of hardwood and softwood dust (38 out of 216) were above 3 mg/m³ (the then current and future workplace exposure limits). Sanding, cleaning, and maintenance activities were of particular concern. Improvements to exposure controls are required, in particular, improvements to local exhaust ventilation controls for hand-held power tools and hand sanding. The management, selection, and use of respiratory protective equipment were poor. All the managers and supervisors recognised that exposure to wood dust can pose serious health risks, and that controls were crucial to protecting workers' health. The findings from the telephone interviews suggest that supervision and provision of information about the health effects of exposure to wood dust were common approaches that organisations used to raise awareness and promote good practice, in relation to managing wood dust exposure. Worker attitudes towards controls, such as perceptions that they hinder task completion and habitual ways of working, were identified as factors influencing the use of controls. Risk communication approaches that focus on increasing workers' awareness of their susceptibility to ill-health using credible sources, such as peers, can help enhance the uptake of messages on the use of controls. Financial constraints were identified as a challenge to improving the control of wood dust, particularly for small companies.

Abatement of environmental pollution by research on electrical resistivity and conductivity mechanism of poplar dust.

Under conventional processing conditions, the resistivity of wood dust is in the range of insulating materials, which can induce a dust cloud explosion when there are static sparks. This paper took the fast-growing poplar wood commonly used in Chinese wood processing and studied the effects of moisture content, temperature, and particle size on the electrical resistivity value of sanded wood dust. Orthogonal analysis was conducted on the influencing factors. The results showed that the influence of moisture content on electrical resistivity was the most significant factor, followed by temperature and particle size. Further experiments have shown that when the moisture content increased from 6% to 32%, the resistivity decreased from 109 Ω cm to 105 Ω cm, which reached the suitable resistivity range of static discharge method. The ion concentration of wood dust extracted in cold water and hot water and the resistivity of poplar dust residue after extraction were determined. Nine metal ions (a total of 105.02 mol/g) were detected in cold-water extract, and the concentrations of K+, Na+, Mg2+ and Ca2+ accounted for 99.8%. The original poplar dust and the extracted poplar dust were measured and analyzed. The changes in water-soluble ion content, functional groups, crystallinity, and complexes of the wood dust before and after ion dissolution, jointly led to changes in the electrical resistivity of the wood dust (a difference of 2-4 orders of magnitude). It was verified that the way wood dust conducts electricity is through ion conduction. There were more abundant capillary system structures between poplar dust particles, allowing water-soluble ions to move more freely with water channels. The larger specific surface area and higher temperature also promoted the dissolution of water-soluble ions, which affected the electrical resistivity.

Dynamics of pre-shift and post-shift lung function parameters among wood workers in Ghana.

Background: Diseases affecting the lungs and airways contribute significantly to the global burden of disease. The problem in low- and middle-income countries appears to be exacerbated by a shift in global manufacturing base to these countries and inadequate enforcement of environmental and safety standards. In Ghana, the potential adverse effects on respiratory function associated with occupational wood dust exposure have not been thoroughly investigated. Methods: Sixty-four male sawmill workers and 64 non-woodworkers participated in this study. The concentration of wood dust exposure, prevalence and likelihood of association of respiratory symptoms with wood dust exposure and changes in pulmonary function test (PFT) parameters in association with wood dust exposure were determined from dust concentration measurements, symptoms questionnaire and lung function test parameters. Results: Sawmill workers were exposed to inhalable dust concentration of 3.09 ± 0.04 mg/m3 but did not use respirators and engaged in personal grooming habits that are known to increase dust inhalation. The sawmill operators also showed higher prevalence and likelihoods of association with respiratory symptoms, a significant cross-shift decline in some PFT parameters and a shift towards a restrictive pattern of lung dysfunction by end of daily shift. The before-shift PFT parameters of woodworkers were comparable to those of non-woodworkers, indicating a lack of chronic effects of wood dust exposure. Conclusions: Wood dust exposure at the study site was associated with acute respiratory symptoms and acute changes in some PFT parameters. This calls for institution and enforcement of workplace and environmental safety policies to minimise exposure at sawmill operating sites, and ultimately, decrease the burden of respiratory diseases.

Polysaccharide Composite Films Utilising Wood Waste.

This study aimed to investigate the effect of raw waste pine wood dust (Pinus sylvestris) from furniture production on polysaccharide biopolymer film properties. The obtained biocomposite films produced via the casting method were prepared with 20% glycerol and 0%, 5%, 10%, 15%, 20%, and 25% of added wood dust in relation to the dry starch matter. Wood dust composition and particle size distribution analysis were performed. In order to evaluate the material surface properties, tests were carried out using an atomic force microscope (AFM) and a contact angle goniometer. Utilising uniaxial tensile test methodology, the values for both tensile strength and Young's modulus were determined. In addition, the barrier properties, water solubility index, and colour were also investigated. The research showed that wood dust affected the functional parameters of the obtained biocomposites. A wood dust content increase causes the Young's modulus value to rise with a progressive decrease in the max. strain. The filler did not change the films' wetting properties, and each had a hydrophilic surface regardless of the additive amount. The bio-sourced composites obtained were non-toxic and environmentally neutral materials, suitable to be applied in the packaging industry as well as the agriculture sector.

Perturbations in indices of oxidative stress, oxidative DNA damage and lung function in chronic exposure to wood dust in Southern Nigeria.

OBJECTIVES: Oxidative stress (OS) and oxidative DNA damage accruing from chronic exposure to wood dust have been implicated in the development of chronic lung conditions among woodworkers. Indices of OS, inflammation, oxidative DNA damage and lung function in relation to duration of exposure to wood dust were assessed in woodworkers to determine their possible utility as risk evaluation indices for chronic lung conditions. METHODS: Ninety participants comprising 30 active woodworkers, 30 passive woodworkers, and 30 controls were enrolled into this cross-sectional study. The total plasma peroxides, total antioxidant capacity (TAC), oxidative stress index (OSI), malondialdehyde (MDA), reduced glutathione, nitric oxide, high sensitivity C-reactive protein (hs-CRP), 8-hydroxy-2'-deoxyguanosine (8-OHdG) and peak expiratory flow rate (PEFR) were determined in all participants. RESULTS: Woodworkers had lower PEFR, TAC, and higher malondialdehyde, OSI, hs-CRP, and 8-OHdG compared to controls (p < 0.05). Active woodworkers had higher malondialdehyde, 8-OHdG, and hs-CRP compared to passive woodworkers (p < 0.05). Increasing duration of exposure to wood dust is associated with higher malondialdehyde, hs-CRP, and 8-OHdG in active woodworkers (p < 0.05) and higher 8-OHdG and hs-CRP in passive woodworkers (p < 0.05). Negative correlation was observed between hs-CRP and TAC (r=-0.367, p = 0.048) in active workers. CONCLUSION: The association of exposure to wood dust with elevated indices of inflammation, OS, lipid peroxidation, oxidative DNA damage, and reduction in antioxidants and peak expiratory flow rate; and the concomitant increase in oxidative DNA damage and inflammation with increasing duration of exposure suggest that these indices may be useful in predicting woodworkers at risk of development of chronic lung conditions.

Hearing loss and respiratory health symptoms among large-scale sawmill workers of the timber processing factories within the Gert Sibande District Municipality: a comparative cross-sectional study.

BACKGROUND: Occupational exposure to wood dust may cause respiratory illnesses, while prolonged exposure to loud noise may cause noise-induced hearing loss. OBJECTIVE: The objective of the study was to assess the prevalence of hearing loss and respiratory symptoms among large-scale sawmill workers within the Gert Sibande Municipality in Mpumalanga Province, South Africa. METHODS: A comparative cross-sectional study consisting of 137 exposed and 20 unexposed randomly selected workers was undertaken from January to March 2021. The respondents completed a semi-structured questionnaire on hearing loss and respiratory health symptoms. DATA ANALYSE: The data was analysed using Statistical Package for Social Sciences (SPSS) version 21 (Chicago II, USA). The statistical analysis of the difference between the two proportions was done using an independent student t-test. The level of significance was set at p < 0.05. RESULTS: There was a statistically significant difference between the exposed and unexposed workers on the prevalence of respiratory symptoms like phlegm (51.8 vs. 0.0%) and shortness of breath (chest pain) (48.2 vs. 50%). There was also a statistically significant difference between the exposed and unexposed workers on the signs and symptoms of hearing loss like tinnitus (ringing in the ears) (50 vs. 33.3%), ear infections (21.4 vs. 66.7%), ruptured ear drums (16.7 vs. 0.0%), and ear injuries (11.9 vs. 0.0%). The exposed workers reported always wearing personal protective equipment (PPE) (86.9%) compared to the unexposed workers (75%). The reason for not wearing PPE consistently by the exposed workers was due to not being available (48.5%), compared to the unexposed workers who reported other reasons (100%). CONCLUSION: The prevalence of respiratory symptoms among the exposed workers was higher than that of the unexposed workers, except for chest pains (shortness of breath). The prevalence of symptoms of hearing loss among the exposed workers was higher than the unexposed workers, except for ear infections. The results suggest that measures should be implemented at the sawmill to help protect workers' health.

[Research progress of occupational hazards in plywood manufacturing].

Occupational disease hazards in plywood manufacturing mainly include wood dust, formaldehyde, phenol, ammonia, noise, terpene, microorganisms, etc. The exposure is complex with multiple factors accompanied or coexisted. In the production process, these factors are exceeded, and mass occupational disease hazard events occurred among workers. Exposure to wood dust, formaldehyde, terpene, etc., put workers at increased risk of cancer. This article provides a review of this issue in order to provide a scientific basis for the prevention and control of occupational disease hazards in plywood manufacturing.

Development of a quantitative North and Central European job exposure matrix for wood dust.

Wood dust is an established carcinogen also linked to several non malignant respiratory disorders. A major limitation in research on wood dust and its health effects is the lack of (historical) quantitative estimates of occupational exposure for use in general population-based case-control or cohort studies. The present study aimed to develop a multinational quantitative Job Exposure Matrix (JEM) for wood dust exposure using exposure data from several Northern and Central European countries. For this, an occupational exposure database containing 12653 personal wood dust measurements collected between 1978 and 2007 in Denmark, Finland, France, The Netherlands, Norway, and the United Kingdom (UK) was established. Measurement data were adjusted for differences in inhalable dust sampling efficiency resulting from the use of different dust samplers and analysed using linear mixed effect regression with job codes (ISCO-88) and country treated as random effects. Fixed effects were the year of measurement, the expert assessment of exposure intensity (no, low, and high exposure) for every ISCO-88 job code from an existing wood dust JEM and sampling duration. The results of the models suggest that wood dust exposure has declined annually by approximately 8%. Substantial differences in exposure levels between countries were observed with the highest levels in the United Kingdom and the lowest in Denmark and Norway, albeit with similar job rankings across countries. The jobs with the highest predicted exposure are floor layers and tile setters, wood-products machine operators, and building construction labourers with geometric mean levels for the year 1997 between 1.7 and 1.9 mg/m3. The predicted exposure estimates by the model are compared with the results of wood dust measurement data reported in the literature. The model predicted estimates for full-shift exposures were used to develop a time-dependent quantitative JEM for exposure to wood dust that can be used to estimate exposure for participants of general population studies in Northern European countries on the health effects from occupational exposure to wood dust.

Wood dust in France. Trends in the population of exposed workers between 1982 and 2017 based on a job-exposure matrix assessment.

OBJECTIVE: Many occupations and industries use wood as a raw material and wood dust is a well-known carcinogen. This study presents trends in occupational exposure to wood dust for all workers (employees and self-employed workers) in France between 1982 and 2017 and focuses on the exposed workers in 2017. METHODS: Exposures to this carcinogen were assessed using the Matgéné job-exposure matrix. Trends in the prevalence and proportion of exposure over the study period were estimated by linking the matrix with population data from the 1982, 1990, 1999, 2007, and 2017 censuses and are described for selected industry groups. RESULTS: The number of exposed workers to wood dust has decreased significantly over the last 40 years, from 466,900 potentially exposed workers in 1982 to 305,000 workers in 2017. The proportion of exposed workers has also decreased over time, although not uniformly across industries. Increases in the proportion of exposed workers are observed in certain industries, such as "Sawmilling and logging" (from 61.2% to 73.6% over the period for men) and "Finishing of sale premises" (from 3.3% to 6.2% for women). CONCLUSION: This article is the first to describe occupational exposure to wood dust in France for all workers and to follow its evolution over the last 40 years. Occupations and industries still at risk in 2017 are also described with the aim of helping to improve prevention policies.

Wood dust exposure and small cell lung cancer: a systematic review and meta-analysis.

INTRODUCTION: Occupational exposure role on small cell lung cancer (SCLC) onset has been little studied. Wood dust has been recognized as a human carcinogen, and many occupations have high wood-dust exposure. The aim of this study was therefore to perform a systematic review and meta-analysis of the scientific literature to summarize and analyse the risks of wood dust-related occupations on development of SCLC, taking tobacco use into account. METHODS: We conducted a literature search of PubMed, EMBASE, Web of Science and Cochrane using a predefined strategy and including case-control and cohort studies assessing occupational exposure to wood dust or wood dust-related occupations. To perform the meta-analysis, the odds ratio (OR) and 95% confidence interval (CI) of each of the studies were extracted. A random-effects model was fitted using the DerSimonian Laird method. Sensitivity and subgroup analyses were performed. Quality was assessed using the Office and Health Assessment and Translation (OHAT) for human and animal studies instrument. RESULTS: Eleven studies with a total of 2,368 SCLC cases and 357,179 controls were included. Overall, exposure to wood dust significantly increases risk of SCLC (RR = 1.41, 95% CI 1.11-1.80), with low heterogeneity between studies (I2 = 40%). The association was maintained in studies conducted on males (RR = 1.41, 95% CI 1.12-1.78) but not in those conducted on females/both sexes (RR = 1.37, 95% CI 0.35-3.44). Sensitivity analysis showed that none of the studies significantly modified the results. CONCLUSIONS: Our results support that exposure to wood-dust can increase the risk of SCLC. Although the level of evidence is low, there are strong arguments to recommend the implementation of effective control measures to reduce exposure in occupational settings, as a means of preventing SCLC. IMPACT STATEMENT: The results of this study support that exposure to wood-dust can increase the risk of developing small cell lung cancer. Determining the impact of occupational exposure on workers is essential to improve their individual protection and prevention. There is a strong case for recommending the implementation of control measures to reduce occupational exposure to wood dust, specifically for highly exposed occupations such as carpenters and sawmills, in order to prevent small cell lung cancer.

Effect of Wood Dust Fibre Treatments Reinforcement on the Properties of Recycled Polypropylene Composite (r-WoPPC) Filament for Fused Deposition Modelling (FDM).

The efficacy of wood dust fibre treatment on the property of wood dust reinforced recycled polypropylene composite (r-WoPPC) filament was investigated. The wood dust fibre was treated using alkali, silane, and NaOH-silane. The treated wood fibre was incorporated with r-PP using a twin-screw extruder to produce filament. The silane treatment on wood dust fibre enhances interfacial bonding between wood fibre and recycled PP; hence, a filament has the highest wire pull strength, which is 35.2% higher compared to untreated and alkaline-treated wood dust filament. It is because silanol in silane forms a siloxane bond that acts as a coupling agent that improves interfacial bonding between wood dust fibre and recycled PP. The SEM micrograph of the fracture structure reveals that treated silane has strong interfacial bonding between wood dust fibre and recycled PP, having minimal void, gap, and good fibre adhesion. The water absorption test results indicate that filament with treated wood dust absorbs less water than filament with untreated wood because the treatment minimizes the gap between wood fibres and recycled PP. The FTIR analysis identified the presence of silane on the wood dust surface for silane-treated wood dust. The DSC studies suggest that the temperature range 167-170 °C be used in the extrusion machine to produce r-WoPPC filament. As a result, r-WoPPc filaments containing silane-treated wood dust have better mechanical properties and have a greater potential for usage in FDM applications.

Exposure Characterization of Wood Dust Particulate, Endotoxins, and (1-3)-ß-d-Glucans, and Their Determinants in Mozambiquan Wood Processing Workers.

OBJECTIVES: Dust generated from wood processing comprises a heterogeneous mixture of inorganic and organic particles, including wood fragments, microorganisms, endotoxins, (1-3)-ß-d-glucans, and allergens. This study characterized exposure to wood dust and its determinants in the Mozambiquan wood processing industry. METHODS: A total of 124 personal inhalable samples, collected from a stratified random sample of 30 workers, were analysed for dust particulate, endotoxins, and (1-3)-ß-d-glucans. Mixed-effects models were developed to investigate significant exposure determinants. RESULTS: The geometric mean (GM) inhalable dust particulate concentrations were 3.29 mg m-3, 98 endotoxin units (EU) m-3, and 123 ng m-3 for (1-3)-ß-d-glucans. Significant predictors for higher particulate levels included machinery (GMR = 1.93), sawing (GMR = 2.80), carpentry (GMR = 2.77), or painting (GMR = 3.03) tasks. Lebombo-ironwood species was associated with higher dust particulate levels (GMR = 1.97). Determinants of endotoxin concentrations included working with dry wood and damp cleaning methods, which were associated with lower levels. Working in closed buildings (GMR = 3.10) and dry sweeping methods were associated with higher (1-3)-ß-d-glucan concentrations (GMR = 1.99). CONCLUSIONS: Work tasks in certain exposure groups (machinery, sawing, carpentry, painting), processing certain wood species (Lebombo-ironwood) and working in closed buildings were associated with higher exposures, whilst using dry wood and damp cleaning practices reduced exposure levels.

Research progress of occupational hazards in plywood manufacturing / 中华劳动卫生职业病杂志

Occupational disease hazards in plywood manufacturing mainly include wood dust, formaldehyde, phenol, ammonia, noise, terpene, microorganisms, etc. The exposure is complex with multiple factors accompanied or coexisted. In the production process, these factors are exceeded, and mass occupational disease hazard events occurred among workers. Exposure to wood dust, formaldehyde, terpene, etc., put workers at increased risk of cancer. This article provides a review of this issue in order to provide a scientific basis for the prevention and control of occupational disease hazards in plywood manufacturing.

Multicenter study to assess surgical treatments of 452 sinonasal intestinal-type adenocarcinomas: A REFCOR study.

PURPOSE: The objective was to assess the local oncological outcomes of endoscopic versus external surgical treatment of sinonasal intestinal-type adenocarcinomas (ITAC) and the factors of recurrence. METHODS: a retrospective non-randomized case-control multicenter study was carried out, including 452 untreated sinonasal ITACs recruited from 10 tertiary referral centers. The tumors were re-classified according to the UICC 2017 (pT). Survival curves were obtained using the Kaplan-Meier method. Univariate analysis was done with the log-rank test. Multivariate analysis was performed with a Cox model adjusted for age, T stage, and radiotherapy. A binary logistic regression compared surgical complications and performed two supplementary analyses on positive margins. RESULTS: We compared 195 and 257 patients operated by the external and endoscopic approach, respectively. The mean follow-up was 59.2 ± 48.7 months. Post-operative margins were invaded in 30.6 versus 18.9% of patients, respectively (p = 0.007). The overall recurrence rate was 33.8 versus 24.6%, respectively (p = 0.034). There was a significant difference in favor of the endoscopic approach regarding local recurrence-free survival thanks to better surgical margins in univariate and multivariate analysis (Odd Ratio = 2.01 (1.2-3.36) p = 0.0087). The complication rate (Odds Ratio = 3.4 (1.79-6.32) p < 0.001) was significantly lower in the endoscopic group. The histological positivity of signet-ring cells shows a statistically significant difference in recurrence-free survival (p = 0.0028). CONCLUSION: the oncological control of ITAC is better through the endoscopic approach, with negative margins and the absence of signet-ring-cells, two independent factors of recurrence.

Combustible wood dust explosions and impacts on environments and health - A review.

Wood dust is the major wastes from timber and wood-based panel processing, including wood sawing, sanding, chipping, flaking, etc., which easily causes fire and explosions. The fine wood dust had risks of inhaling the dust air, causing problems to the respiratory system of workers, as well as the explosive risk of the wood dust-air mixture. Wood dust explosions occur worldwide, which have caused massive damages to equipment, buildings, and environments, killed people, and threatened human health. This study was aimed at exploring the causes, affecting factors, mechanisms, models of wood dust explosions, and their environmental/health impacts through reviewing and analyzing the collected data in order to minimize wood dust explosion risks by improving of safety procedures in the wood processing industry. To better understood and prevent wood dust explosion cases in the future, this review collected the explosion reports and analyzed the accident information through the following aspects: 1) Summarization of published review articles regarding wood dust explosions in Introduction, 2) Scrutinization of wood dust explosion cases and design of testing device, 3) Exploration of effects of wood dust properties and surrounding conditions on explosion and their mechanisms, 4) Investigation of methods for reducing wood dust explosion risks, 5) Modeling and simulation of wood dust explosions, 6) Examination of environmental and health impacts of wood dust explosions. Finally, the findings in this review were summarized in Conclusions. By collecting dust explosion reports, reviewing literature, and analyzing the collected data, wood dust explosions can be better understood. The results of this study can be useful for the design of equipment and dust absorption systems, as well as further suggestion of safety improvement procedures to minimize or eliminate risks of wood dust-related fire and explosion in the wood processing industry and mitigate its impacts on environments and health.

Impact of filtering face pieces (FFP3) respiratory protective mask usage on the respiratory functions of informal sector carpenters in Douala: a five-month before-after study.

Introduction: informal sector carpenters in Douala, Cameroon, face potential risks to their respiratory health due to daily exposure to fine particles and wood dust. The study aims to demonstrate the importance of preventing respiratory problems in this population through regular use of filtering face pieces (FFP3) respiratory masks. Methods: the before-after study involved 37 carpenters who wore FFP3 masks during their professional activities for five months. Spirometry measurements were taken before and after the intervention to assess changes in respiratory function. Results: significant improvements were observed in forced vital capacity (FVC) 89.6 % to 95.0 % (p<0.000), forced expiratory volume in one second (FEV1) 88.1 % to 95.0 % (p<0.000), Tiffeneau index 82.4 to 84.9 (p<0.000), and peak expiratory flow (PEF) 6.7 l/s to 7.9 l/s (p<0.000) after mask usage, indicating enhanced lung function. Conclusion: the regular use of FFP3 masks had a positive impact on the respiratory health of informal sector carpenters in Douala, enhancing lung function and reducing airway obstruction. The study highlights the importance of preventive measures to safeguard the respiratory well-being of workers exposed to occupational hazards. Spell out Greek characters (i.e: alpha, beta).

Effect of Hardwood Dust and Ammonia Gas on the Respiratory Integrity of Broiler Chickens.

Dust and ammonia gas (NH3) are two of the most abundant pollutants suspended in the air of poultry houses. Chronic inhalation of poultry dust and NH3 causes damage to the airways and reduces performance in broilers. Poultry dust is a mixture of organic and inorganic matter from feed, bedding material, manure, feathers, skin debris, and microorganisms. Thus, the composition and concentration of poultry dust vary among farms. This study proposes a model to assess the individual effect of a defined fraction of poultry dust derived from bedding material (wood dust) and its effects, alone or combined with NH3, on the performance and respiratory integrity of broilers. Ninety-six, 1-day-old broilers were randomly divided into groups of 24 and placed into four controlled environment chambers to continuously receive one of four treatments: 1) negative control; 2) exposure to airborne red oak wood dust at a concentration of 7.5 × 106 particles/m3 (particulate matter5.0); 3) exposure to 50 parts per million (ppm) of NH3; and 4) exposure to airborne red oak wood dust and 50 ppm of NH3. On day 43, all birds were weighed and euthanized. Performance data were recorded. Tissue samples were collected from six birds per treatment. Histologic evaluations of the nasal turbinates, trachea, and lungs were conducted. Histologic lesion scores (0 to 3) were assigned, and tracheal mucosal thickness was measured. No significant differences among treatments were found in body weight (P = 0.066), tracheal mucosal thickness (P = 0.593), or tracheal lesion score (P = 0.07). The average nasal turbinate lesion scores were higher in the wood and wood + ammonia treatments compared with the control (P = 0.015). The lung lesion scores were higher (P = 0.004) in all treatment groups compared with the control. In conclusion, chronic exposure to red oak wood dust, alone or in combination with NH3, induced important inflammatory damage to portions of the respiratory system of broilers; however, no significant effects on performance were observed.

Efecto del polvo de madera dura y el gas amoníaco en la integridad respiratoria de pollos de engorde. El polvo y el gas amoníaco (NH3) son dos de los contaminantes más abundantes suspendidos en el aire de las casetas avícolas. La inhalación crónica de polvo en casetas avícolas y de NH3 provoca daños en las vías respiratorias y reduce el rendimiento de los pollos de engorde. El polvo de aves de corral es una mezcla de materia orgánica e inorgánica procedente del alimento, material de cama, estiércol, plumas, restos de piel y microorganismos. Por lo tanto, la composición y concentración del polvo de las aves de corral varía entre granjas. Este estudio propone un modelo para evaluar el efecto individual de una fracción definida de polvo avícola derivado del material de cama (polvo de madera) y sus efectos, solos o combinados con NH3, sobre el rendimiento y la integridad respiratoria de los pollos de engorde. Noventa y seis pollos de engorde de un día de edad se distribuyeron aleatoriamente en grupos de 24 y se colocaron en cuatro cámaras de ambiente controlado para recibir continuamente uno de los cuatro tratamientos: 1) control negativo; 2) exposición a polvo de madera de roble rojo en el aire a una concentración de 7.5 × 106 partículas/m3 (material particulado5.0); 3) exposición a 50 partes por millón (ppm) de NH3; y 4) exposición a polvo de madera de roble rojo en el aire y 50 ppm de NH3. Durante el día 43, todas las aves fueron pesadas y se les practicó la eutanasia. Se registraron los datos de rendimiento. Se recogieron muestras de tejido de seis aves por tratamiento. Se realizaron evaluaciones histológicas de los cornetes nasales, la tráquea y los pulmones. Se asignaron puntuaciones de lesiones histológicas (0 a 3) y se midió el espesor de la mucosa traqueal. No se encontraron diferencias significativas entre los tratamientos en el peso corporal (P = 0.066), el grosor de la mucosa traqueal (P = 0.593) o la puntuación de la lesión traqueal (P = 0.07). Las puntuaciones medias de las lesiones de los cornetes nasales fueron más altas en los tratamientos con madera y madera + amoníaco en comparación con el control (P = 0.015). Las puntuaciones de lesiones pulmonares fueron más altas (P = 0.004) en todos los grupos de tratamiento en comparación con el control. En conclusión, la exposición crónica al polvo de madera de roble rojo, solo o en combinación con NH3, indujo un daño inflamatorio importante en partes del sistema respiratorio de los pollos de engorde; sin embargo, no se observaron efectos significativos en el rendimiento.

Evaluation of occupational exposure to wood dust among sawmill workers within the Gert Sibande District Municipality, South Africa.

INTRODUCTION AND OBJECTIVE: Wood dust is regarded as one of the human carcinogen based on an increased risk of nasal and sinonasal cancer. This study was conducted in two sawmills to measure and determine the time-weighted average (TWA) exposure level to wood dust, and compare the results with the South African occupational exposure limit (OEL). MATERIAL AND METHODS: Personal and area respirable and total inhalable wood dust samples were collected using calibrated Giliair-3 personal air sampling pump (Sensidyne, USA). Data was analysed using Microsoft Office Excel 2019 Analysis Tool Pak for a summary of descriptive statistics. Both the geometric means and standard deviation as well as the minimum and maximum values were calculated. RESULTS: The geometric mean = GM (geometric standard deviation = GSD) for personal respirable wood dust exposure at sawmill A was 0.9(4.8) mg/m3 while at sawmill B - 0.57(0.75) mg/m3. The GM(GSD) for personal total inhalable wood dust exposure at sawmill A was 0.37(0.94) mg/m3 while at sawmill B - 1.19(16.91) mg/m3. Besides that, the GM(GSD) for area respirable wood dust at sawmill A was 0.13(0.09) mg/m 3 , while at sawmill B - 0.8(0.6) mg/m3. Likewise, the GM(GSD) for area total inhalable wood dust at sawmill A was 0.13(0.16) mg/m3 while at sawmill B - 0.54(0.55) mg/m3 . CONCLUSIONS: Results for the majority of samples were below the OEL. Workers smoking tobacco or cigarettes should be encouraged to stop smoking since smoking, especially when associated with exposure to wood dust, may increase the risk of respiratory health symptoms.