Wood Dust Concentrations Research Articles

Effect of Teak Wood Dust as Filler Material on Mechanical Properties of Abaca-Pineapple-Epoxy Hybrid Composite

ABSTRACT Composite manufacturers and consumers are increasingly turning to natural-based composites for their biocompatibility, cost-effectiveness, and widespread availability. This study investigates the potential of using teak wood dust as an economical filler material, combined with natural fibers, within an epoxy matrix to create a composite. Specifically, it examines how varying concentrations of teak wood dust—3 wt%, 6 wt%, and 9 wt%—affect the mechanical properties such as tensile strength, flexural strength, impact resistance, inter-laminar shear strength (ILSS), and hardness of an abaca-pineapple-epoxy hybrid composite. The composites were fabricated using the hand layup method followed by hot pressing. Among the different configurations, the composite with 6 wt% teak wood dust (SD-6) demonstrated superior performance, with improvements in tensile, flexural, ILSS, and impact strengths ranging from 3% to 35% compared to other variants. Scanning Electron Microscope (SEM) analysis of the fractured surfaces indicated that the inclusion of 6 wt% teak wood dust enhanced fiber-matrix adhesion, leading to improved mechanical properties of the composite.

Respiratory Effects and Pulmonary Functions Related to Wood Dust Exposure among Workers in a Rubber Wood Factory

This study aimed to determine the effects of wood dust exposure on respiratory symptoms and pulmonary functions in wood dust factory workers and the association between wood dust exposure and pulmonary functions. This cross-sectional study comprised of one hundred workers who answered a self-reported questionnaire. Two factory areas, the production department and the back office, were explored using stationary air sampling. The wood dust concentration was collected using NIOSH Method 0600. Pulmonary function parameters were evaluated through spirometry. A descriptive statistics analysis was done for personal information. Binary logistic regression determined the association between wood dust exposure and respiratory symptoms. The prevalence of respiratory symptoms related to wood dust exposure at work was 49.00 percent. Three major symptoms in the exposed group includes chest pain, shortness of breath, and asthma. The average amount of PM10 in the saw mill area was significantly higher than in the back office (7.23 vs. 1.60 mg/m3). There was a significant difference in forced expiratory capacity between the reference and exposure groups (mean difference = -4.03, p-value = 0.011). The adjusted odd ratio showed that the high wood dust-exposed group had a lower runny nose and dry cough than the reference group. All workers need to consider using personal protective equipment with appropriate specifications in the sawmill area and also the other areas where wood dust levels are high. To control the concentration of respirable particles, resource and pathway control must be applied to reduce the concentration of respirable particles in the workplace.

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

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

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.

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

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

Influence of Saw Chain Type and Wood Species on the Mass Concentration of Airborne Wood Dust during Cross-Cutting

Chainsaw operation is associated with several hazards, including exposure to wood dust, a risk factor which requires serious attention due to health impacts such as respiratory disease. This study aims to investigate the effect of saw chain type and wood species on the mass concentration of airborne wood dust during chainsaw cross-cutting operations. Real-time inhalable and respirable dust measurements in the breathing zone of the chainsaw operator were carried out using a desktop aerosol monitor. Three types of cutter shape (semi chisel, full chisel, and chamfer chisel) and four types of wood species (oak, beech, spruce, and fir) were used in the experiments. The split-plot ANOVA results showed that both respirable and inhalable mass concentrations of wood dust were affected exclusively by wood species. No statistically significant differences were found among particular levels of cutter shape. The highest average mass concentrations of airborne dust were generated by the combination of oak wood and a full chisel cutter.

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

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

Organic Wood Dust Exposure as a Risk Factor for Lung Function Disorders in Workers : Systematic Review

Wood dust is wood particles that result from wood processing and handling. The level of fine dust in the work environment can expose to workers breathing and cause lung function disorders. Obstructive lung function disorders, namely blockages that make it difficult for air to escape from the lungs, resulting in a decrease in airflow velocity. The purpose of this systematic review was to determine wood dust exposure and risk factors for impaired lung function for workers. Article searches carried out through the Portal Garuda Indonesia, PubMed, Scopus, ProQuest, and Google Scholar. There are 9 articles reviewed. Exposure to wood dust was assessed as a significant risk factor for impaired lung function in workers as seen from the statistical analysis results in each study showing that the p-value < 0.05. The risk factors that were stated to have a significant relationship were the concentration of wood dust, gender, work location, use of personal protective equipment (mask), length of work, and smoking habits. Exposure to wood dust increases the risk of impaired lung function in workers, with dust levels ranging from 1.15 mg/m3– 24 mg/m3.

Assessment of explosion risk for wood dust in a ventilation-dust separation installation, by determining the concentration of total dust in suspension inside of the installation

Most of combustible dusts present both fire and explosion hazard. Explosion may occur at certain concentrations of dust mixed with air and in the presence of an ignition source. The threat posed by this real danger was confirmed by the events that took place in economic units such as: feed factories, wood products, textile industry, steel, etc. Among the parameters of explosiveness of combustible dust, which can cause an explosion, we mention: maximum explosion pressure, lower explosion limit, explosive index, minimum ignition energy, electrical resistivity of dust, minimum ignition temperature of dust layer and cloud, particle size and concentration of dust in suspension. The current paper presents the results of determinations of combustible wood dust concentrations, performed at an important economic unit, manufacturing veneer and wood panels, at a dusting ventilation installation composed of fan, cyclone and textile filter. These determinations were made in the pipe connecting the fan and the bag filter, to assess possible danger of explosion in the pipe, by relating the measured concentration to the lower explosion limit (concentration of wood dust).

RESPIRATORY HEALTH DISORDERS AMONG WORKERS IN JOINERY WORKSHOPS

Introduction: Occupational exposure to wood dust may result in different toxic and alor molds affecting respiratory system and skin. Aim of work: To study the respiratoryhealth disorders among workers in some joinery workshops and to assess their workplaceenvironment. Materials and Methods: A cross sectional study was conductedduring the period from the February 1st, 2019 to August 31th, 2020, on 100 woodworkerschosen from 11 joinery (wood made furniture) workshops, Menouf city, Menoufia governorate.Similar numbers of subjects were chosen randomly from workers’ relativeswho were never exposed to similar hazards. All participants were interviewed using apredesigned questionnaire. Physical examination and spirometric measurements wereperformed for them. Environmental study of the workplace was done. Results: Themean concentration of respirable wood dust was 3.61±2.00 mg/m3, which is higherthan the international permissible levels. Workers exposed to wood dust had significantlyhigher prevalence of respiratory manifestations e.g. rhinitis, cough, expectoration,wheezes, shortness of breathing, chest pain and asthma (59%, 64%, 51%, 34%,70%, 4% and 24%; respectively) as well as decreased spirometric measurements comparedto the controls. The higher prevalence of respiratory manifestations as well asdecreased spirometric measurements were positively correlated with time intensity factor.Conclusion and recommendations: Exposure to wood dust in a concentrationmore than permissible level has been adversely affecting the respiratory system andcausing decrease in spirometric measurements. Regular use of good quality personal protective equipment, proper ventilation and periodic medical examination are highlyrecommended. Also, regular monitoring of the work environment and keeping dustlevel below permissible levels are mandatory.

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

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

Wood dust exposure and risks of nasopharyngeal carcinoma: a meta-analysis.

Wood dust has been confirmed as one kind of human carcinogen. However, there are inconsistent study results of exploring the relationship of exposure to wood dust and occurrence of nasopharyngeal cancer (NPC). For a greater clarification, the authors systemically reviewed the relevant published articles on the relationship of exposure to wood dust and occurrence of NPC. And meta-analysis was conducted. The databases of PubMed, U.S. National Library of Medicine (MEDLINE), Embase and Science Direct were searched for the relevant publications. And Newcastle-Ottawa scale was employed for judging the quality of articles. Random-effect model was utilized for meta-analysis. Among a total of 583 retrieved items, 10 case-control studies and 1 cohort study were selected. The ratio of maximal/minimal exposure concentration of wood dust yielded a pooled odd ratio (OR) of 2.18 (95% CI = 1.62-2.93, P = 0.063) with a moderate heterogeneity (I2: 43.0%; P = 0.001). And subgroup analysis was performed for such factors as exposure status, exposure population and geographic region. No publishing bias was noted. Exposing to a high concentration of wood dust was positively proportional to occurring risk of NPC. It hints at the contributing effect of wood dust upon NPC. For eliminating the effects of other confounding factors, larger prospective cohort studies are required for further elucidating the relationship of exposure to wood dust and occurrence of NPC.

Adverse health outcomes among workers of wood pellet production facilities.

Workers of pellet production facilities (WPPF) are exposed to high concentrations of wood dust and microbial pollutants. Such stimulation may lead to numerous allergic and toxic reactions, infections, and other non-specific syndromes. To check the influence of individual traits of workers and characteristic features / factors of their living and working environments on the probability of adverse outcomes' appearance. The questionnaire study assessing adverse health effects resulting from individual exposure was conducted among 28 workers of 10 Polish WPPF. The logistic regression (for dichotomous variables) was used to determine the appearance probability (given as odds ratio) of adverse symptoms or diseases. WPPF workers may have an increased risk of developing work-related adverse health outcomes. Both the individual traits and environmental exposure factors significantly influence the probability of their occurrence.

Nasal lavage as analytical tool in assessment of exposure to particulate and microbial aerosols in wood pellet production facilities

Occupational exposure to wood dust and bioaerosols may lead to numerous respiratory tract diseases. We aimed to assess a degree of workplace contamination with dust, bacteria, fungi, endotoxins, and (1 → 3)-β-D-glucans released into the air during wood processing in pellet production facilities and to check against this background the usefulness of nasal lavage (NAL) as analytical tool for assessment of combined workers' exposure to airborne dust and microbiological contaminants. In 10 pellet plants, the particulate (wood dust) aerosol concentrations were determined by using Grimm aerosol spectrometer and CIS filter sampler. The collected CIS samples were subsequently used to evaluate endotoxin and (1 → 3)-β-D-glucan concentrations. Simultaneously with particulate aerosol, bioaerosol samples were collected by using 6-stage Andersen and single-stage MAS impactors. Bacterial and fungal aerosol concentrations were calculated and all isolated microorganisms were taxonomically identified. NAL fluid samples were collected from workers exposed to studied aerosols and the concentrations of proinflammatory mediators (IL-1β, IL-6, IL-8, and TNFα) and cytological image of nasal mucosa (expressed as cell counts) were established. The dynamics of production activities resulted in wide range of observed wood dust, microorganism, endotoxin and (1 → 3)-β-D-glucan concentrations reaching periodically extremely high values up to 65 mg m−3, 19,320 CFU m−3, 215 ng m−3 and 1525 ng m−3, respectively. Environmental stress caused by exposure to particulate and microbial aerosols stimulated immune response among workers of pellet production facilities. Correlation analysis revealed that interleukin levels and the number of cells in NAL were significantly affected by both wood dust and bioaerosol concentrations. As nasal mucosa serves as the primary barrier against inhaled pollutants, NAL seems a reliable analytical material to assess work-related adverse respiratory health outcomes derived from such exposure.

Thermal treatment’s effect on dust emission during sanding of meranti wood

The aim of this research was to investigate the effects of various temperatures of thermal treatment of red meranti (Shorea accuminata) wood on mass concentration and size distribution of wood dust produced by a hand-held belt sander. The experiment was conducted during the sanding of the meranti wood in the natural state and using specimens that were heat-treated via the ThermoWood® technology at the temperatures of 160 °C, 180 °C, 200 °C, and 220 °C. An analysis of variance was used to measure the significance of the effects. Average values of the inhalable and respirable fractions of wood dust mass concentration determined via the optical and gravimetric method was highest at the treatment temperature of 160 °C. The results showed that mass concentration was not significantly influenced by thermal treatment.

Development of Quantitative Estimates of Wood Dust Exposure in a Canadian General Population Job-Exposure Matrix Based on Past Expert Assessments.

The CANJEM general population job-exposure matrix summarizes expert evaluations of 31 673 jobs from four population-based case-control studies of cancer conducted in Montreal, Canada. Intensity in each CANJEM cell is represented as relative distributions of the ordinal (low, medium, high) ratings of jobs assigned by the experts. We aimed to apply quantitative concentrations to CANJEM cells using Canadian historical measurements from the Canadian Workplace Exposure Database (CWED), taking exposure to wood dust as an example. We selected 5170 personal and area wood dust measurements from 31 occupations (2011 Canadian National Occupational Classification) with a non-zero exposure probability in CANJEM between 1930 and 2005. The measurements were taken between 1981 and 2003 (median 1989). A Bayesian hierarchical model was applied to the wood dust concentrations with occupations as random effects, and sampling duration, year, sample type (area or personal), province, and the relative proportion of jobs exposed at medium and high intensity in CANJEM cells as fixed effects. The estimated geometric mean (GM) concentrations for a CANJEM cell with all jobs exposed at medium or high intensity were respectively 1.3 and 2.4 times higher relative to a cell with all jobs at low intensity. An overall trend of -3%/year in exposure was observed. Applying the model estimates to all 198 cells in CANJEM with some exposure assigned by the experts, the predicted 8-hour, personal wood dust GM concentrations by occupation for 1989 ranged from 0.48 to 1.96 mg m-3. The model provided estimates of wood dust concentrations for any CANJEM cell with exposure, applicable for quantitative risk assessment at the population level. This framework can be implemented for other agents represented in both CANJEM and CWED.

Laboratory Investigations Applied to Wood Dust Emmited by Electrical Hand-Held Belt Sander

Abstract Aim of this paper was to investigate the effects of grit size and wood species on mass concentration and size distribution of wood dust produced by hand-held belt sander. Experimental study was designed as 2x2 full factorial experiments. Experimental parameters and their levels were abrasive grain size (P80, P120) and wood species (European beech (Fagus sylvatica L.), Norway spruce (Picea abies)).The mass concentration of emitted wood dust was measured using aerosol monitor (TSI Inc., DustTrak DRX 8533). Sampler head was sited in place representing breathing zone of operator of sander. The results was analysed employing the analysis of variance (ANOVA) with 5% of significance level. Real-time measurements demonstrated that spruce wood generated higher dust concentrations than beech wood due to difference in abrasion durability. Compared to sanding belt with P80 grit size, approximately 16%-32% higher dust concentration was generated when the sanding belt with P120 grit size was used.

Wood dust – aspiration fraction Documentation of proposed values of occupational exposure limits (OELs)

Wood dust – aspiration fraction Documentation of proposed values of occupational exposure limits (OELs)

Early detection of lung cancer potential among Egyptian wood workers.

Wood dust is known to be a human carcinogen, with a considerable risk of lung cancer. The increased cancer risk is likely induced through its genotoxic effects resulting from oxidative DNA damage. This study aimed at assessing the genotoxicity of wood dust and demonstrating the role of sputum PCR as a screening tool for early prediction of lung cancer among wood workers. The study was carried out in the carpentry section of a modernized factory involved with the manufacture of wooden furniture in Greater Cairo, Egypt. Environmental assessment of respirable wood dust concentrations was done. Frequency of chromosomal aberrations (CA%) and sister chromatid exchanges (SCE%) in peripheral blood lymphocytes (PBL) was assessed and comet assays were performed in samples from among the study population (n=86). Levels of superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzymes were measured. The polymerase chain reaction (PCR) was used to study hypermethylation of p16 and ̸or O6-methylguanine-DNA methyltransferase (MGMT) gene promoters in sputum DNA. The concentrations of respirable wood dust exceeded the Egyptian and international permissible limits with highest levels generated by sawing operations. Laboratory investigations revealed statistically significantly higher frequencies of CA and SCE as well as increased comet tail length associated with significant decrement in the levels of SOD and GPx among exposed group. A statistically significant elevation in the extent of hypermethylation was detected for the p16 and MGMT gene promoters in the sputum DNA of studied wood workers. The study results support the conclusion that prolonged unprotected occupational exposure to wood dust is associated with possible genotoxicity and oxidative stress that might raise the risk for carcinogenesis including lung cancer.

Analysis of dust exposure during chainsaw forest operations

In 1999, the European Union proclaimed hardwood dust carcinogenic based on the classification of the International Agency for Research on Cancer (IARC) issued in 1995. The operational exposure limit (OEL) for inhalable wood dust has been set to 5 mg m-3 by EU directives, though in different countries the OEL ranges from 1 to 5 mg m-3. The objective of this study was to determine the exposure to wood dust of forest workers in chainsaw cutting and processing and suggest possible countermeasures. The study took into consideration different silvicultural treatments (coppice clear cut, conifer thinning, conifer pruning, and sanitary cut) and chainsaw fuel (normal two-stroke gasoline mix and two alkylate fuels). All the forest operations were carried out in forests located in Central Italy, on the Apennine mountain range. During the tests, 100 samples were collected by means of personal SKC Button Sampler (one sample per worker per day). The results showed that exposure to wood dust varied widely with forest operation type, while no significant difference were found for different type of chainsaw fuel. The average wood dust concentration was about 1.5 mg m-3 for all operations except coppicing, which showed a mean level of about 2.1 mg m-3. About 93% of the samples showed a concentration lower than 3 mg m-3, and in only two samples (one in conifer pruning and one in clear cut in coppice), the concentration was slightly higher than 5 mg m-3.