The authors declare no conflicts of interest regarding this article. The manuscript has not been published, in whole or in part, in any medical or scientific journal—whether in French or another language—nor is it currently under consideration elsewhere.
Chronic respiratory conditions are a major public health concern, affecting millions of individuals worldwide [
Wood is one of the most important renewable natural resources in the world, and in Benin in particular. It is a key raw material used in the manufacture of various types of furniture. Wood dust and its constituents enter the respiratory tract through inhalation, causing irritation of the mucous membranes and manifesting as respiratory symptoms in exposed workers [
According to the National Institute of Statistics and Demography (INStaD) in Benin, the “carpentry and construction” sector is a branch of the informal economy representing 6.5% of artisanal units, 82% of which take on apprentices [
This study aims to bridge the gap caused by the lack of empirical data in our local context. The general objective of this study was to examine the relationship between respiratory symptoms and functional measurements on the one hand, and wood dust exposure on the other, in Parakou in 2024.
This study was conducted in carpentry workshops, banks, the town hall, and the courthouse in the city of Parakou.
2.2.1. Study Type and Period
This was a comparative cross-sectional study involving prospective data collection. The study took place over a four-month period, from June to September 2024.
2.2.2. Population
The study population comprised two groups: a group exposed to wood dust and a group not exposed to wood dust. The target population consisted of all carpenters working in the city of Parakou. The source population consisted of all carpenters working in the city of Parakou who were accessible, either geographically or after three scheduled appointments.
Inclusion criteria for the exposed group:
Carpenters included in the study were those who:
were at least 18 years old;were non-smokers;had provided informed consent;were free from any psychiatric condition likely to impair their reasoning;had no contraindications for spirometry (stroke within the past 3 months, hospitalization for a cardiac condition, known arterial aneurysm, active pulmonary tuberculosis, recent surgery on the abdomen, thorax, or brain ≤ 3 weeks).
The target population consisted of all administrative staff working in banks, the town hall, and the courthouse in the city of Parakou.
The source population consisted of administrative staff working in banks, the town hall, and the courthouse in the city of Parakou who were accessible, either geographically or after three scheduled appointments.
Inclusion criteria for non-exposed individual:
Individuals included in the study were those who:
were at least 18 years of age;were non-smokers;had provided informed consent;were free from any psychiatric condition likely to impair their reasoning;had no contraindications to undergoing spirometry (see spirometry).
The matching criteria between the two groups were:
inclusion of one administrative worker (bank, town hall, or court) for each selected carpenter,
The participants were not individually matched. There was no matching between each exposed individual and their unexposed counterpart.
2.2.3. Sampling
A voluntary sampling approach was used for carpenters and administrative workers (bank, town hall, or court) due to the difficulty of obtaining their total population figures.
The sample size was calculated using OpenEpi software (
2.2.4. Study Variables
The dependent variable was “presence or absence of respiratory symptoms in the last 12 months.” Respiratory symptoms include upper respiratory tract symptoms—namely pharyngeal pain, nasal congestion, nasal obstruction, sneezing, rhinorrhea, and epistaxis—and lower respiratory tract symptoms, such as cough, expectoration, dyspnea, chest tightness, and wheezing.
Upper respiratory tract symptoms in the last 12 months and their link to workNasal congestion: a binary variable referring to swelling of the nasal mucosa that creates the impression of a nasal voice. It is recorded based on the worker’s self-report during the interview. Categories: yes or no.Work-related nasal congestion: a binary variable referring to nasal congestion that worsens at the workplace and improves on days off or public holidays. It is recorded based on the worker’s self-report during the interview. Categories: yes or no.Pharyngeal pain: a binary variable referring to a sore throat exacerbated by swallowing. It is recorded based on the worker’s self-report during the interview. Categories: yes or no.Work-related pharyngeal pain: a binary variable referring to pharyngeal pain that worsens at the workplace and improves on days off or public holidays. It is recorded based on the worker’s self-report during the interview. Categories: yes or no.Nasal obstruction: a binary variable recorded for a worker who reports an obstruction to airflow entering and leaving the nose. Categories: yes or no.Work-related nasal obstruction: a binary variable referring to any nasal obstruction that worsens at the workplace and improves on days off or public holidays. It is determined based on the worker’s statements during questioning. The options are: yes or no.Sneezing: binary variable; refers to any sudden, forceful expulsion of air through the nose and mouth, triggered by irritation of the upper respiratory tract mucosa. It is recorded based on the worker’s statements during questioning. Categories: yes or no.Work-related sneezing: binary variable; refers to any bout of sneezing that worsens at the workplace, with improvement on days off or public holidays. It is recorded based on the worker’s statements during questioning. Categories: yes or no.Rhinorrhea: binary variable; recorded for a worker reporting fluid discharge from the nasal passages or sinuses. Categories: yes or no.Work-related rhinorrhea: binary variable; refers to rhinorrhea that worsens at the workplace, with improvement on days off or public holidays. It is recorded based on the worker’s statements during questioning. Categories: yes or no.Epistaxis: binary variable; recorded for a worker reporting bleeding from the nasal passages. Categories: yes or no.Work-related epistaxis: binary variable; refers to epistaxis that worsens at the workplace, with improvement on days off or public holidays. It is recorded based on the worker’s statements during questioning. Categories: yes or no.Lower respiratory tract symptoms in the last 12 months and work-relatednessCough: binary variable; recorded for a worker reporting a sudden, jerky, noisy exhalation lasting several minutes, days, or months, rather than an occasional cough. Categories: yes or no. Work-related cough: a binary variable referring to a cough that worsens at the workplace and improves on days off or public holidays. It is determined based on the worker’s statements during the interview. The response options are: yes or no.Expectoration: a binary variable referring to the presence of bronchial secretions brought up by coughing over a period of minutes, days, or months, rather than transient expectoration. It is determined based on the worker’s statements during the interview. The response options are: yes or no.Work-related expectoration: a binary variable referring to any expectoration that worsens at the workplace and improves on days off or public holidays. It is identified based on the worker’s statements during the interview. Categories: yes or no.Paroxysmal dyspnea: a binary variable identified in workers who report periodic episodes of breathing difficulty lasting several minutes or even hours, with symptom-free intervals. Categories: yes or no.Work-related paroxysmal dyspnea: a binary variable referring to paroxysmal dyspnea that occurs at the workplace and improves on days off or public holidays. It is identified based on the worker’s statements during the interview. Categories: yes or no.Chronic dyspnea: a binary variable referring to persistent breathing difficulty—without symptom-free intervals—that typically worsens with exertion and lasts for several months or even years. It is identified based on the worker’s statements during the interview. Categories: yes or no.Work-related chronic dyspnea: refers to persistent chronic dyspnea that worsens at the workplace and improves on days off or public holidays. It is identified based on the worker’s statements during the interview. Categories: yes or no.Recurrent wheezing: a binary variable referring to respiratory sounds resembling a cat’s meow or bird chirping that occur regularly. It is identified based on the worker’s statements during the interview. Categories: yes or no.Work-related recurrent wheezing: a binary variable referring to recurrent wheezing that occurs at the workplace and subsides on days off or public holidays. It is determined based on the worker’s statements during questioning. The categories are: yes or no.Chest tightness: a binary variable referring to an unpleasant sensation of heaviness, pain, or pressure in the chest. It is determined based on the worker’s statements during questioning. The categories are: yes or no.Work-related chest tightness: a binary variable referring to chest tightness that occurs at the workplace and subsides on days off or public holidays. It is determined based on the worker’s statements during questioning. The categories are: yes or no.Recurrent lower respiratory tract infections: a binary variable identified in a worker reporting a recurring pattern of cough with expectoration accompanied by fever. The categories are: yes or no.
The independent variables were sociodemographic characteristics (age, sex, ethnicity, marital status, education level) and medical history and lifestyle factors (asthma, pulmonary tuberculosis, hypertension, diabetes, passive smoking status, alcohol consumption and biomass exposure), work-related characteristics (Exposed group: daily working hours, duration of employment, room ventilation, presence of dust extraction systems, dust levels, use of personal protective equipment specific to wood dust; Non-exposed group: daily working hours, duration of employment), social security details, anthropometric characteristics (weight, height, body mass index), the relationship between respiratory symptoms and work, pleuropulmonary examination findings, and spirometry results.
2.2.5. Data Collection
The data collection equipment consisted of:
A survey questionnaire: this was pre-tested on a sample of ten workers and subsequently revised.An electronic scale (STRIDES brand) with a 180 kg capacity and 100 g precision for weighing: the device is first turned on (displaying 0) and placed on a flat surface. The patient then steps onto the scale, and the weight is displayed.A stadiometer for measuring participant height: height was measured with participants standing, barefoot with feet flat on the floor and heels together, using a tape measure placed vertically against a wall, extending from the heels to the top of the head.A stethoscope for lung auscultation.A Contec SP10 spirometer.Spirometer mouthpieces (spirettes) compatible with the device.An air quality measuring device: indoor air monitor for PM2.5, PM1.0, and PM10. The measurement was individual.
The data collection team was led by a seventh-year general medicine student as part of her thesis, with two pulmonologists and an occupational physician serving as supervisors—specifically, the thesis director and co-directors.
The study was proposed to workers at their workplaces. An anonymous individual interview was conducted to gather information on sociodemographic and clinical data, medical history and lifestyle, occupational characteristics, the presence of respiratory symptoms, and the results of pleuropulmonary and ENT examinations. Spirometry was performed after ruling out contraindications (stroke within the previous 3 months, hospitalization for cardiac disease, known arterial aneurysm, active pulmonary tuberculosis, or abdominal, thoracic, or cranial surgery within the previous 3 weeks). A regularly calibrated portable SP10 spirometer was used. Spirometry data were anonymized and interpreted by a pulmonologist. Reference values were determined using the Global Lung Initiative 2012 equations. Dust levels were measured using an outdoor air quality monitor. Measurements were taken during peak dust episodes over a 15-minute period, during which both the operator and the subject wore FFP2-type masks. Based on these measurements, the short-term occupational exposure limit (STEL) was determined. This STEL represents the maximum concentration of a chemical substance in the air, measured or calculated over a maximum period of 15 minutes.
2.2.6. Data Processing and Analysis
Data collected on the survey forms were double-entered into EpiData software (version 2.0.7.7.22) and subsequently analyzed using R software (version 4.4.1). Quantitative variables were described using means (standard deviation) or medians (with interquartile range), depending on whether their distribution was normal or non-normal. Qualitative data were described using frequencies and percentages. Comparisons were made between the two groups regarding the presence of respiratory symptoms and the spirometric measurements obtained. Factors associated with the presence of respiratory symptoms in the past 12 months—including wood dust exposure—were investigated using simple logistic regression. Crude odds ratios (cOR), their 95% confidence intervals, and p-values were determined. Factors that were statistically significant or had a p-value < 0.2 were included in a multiple logistic regression model to determine adjusted odds ratios (aOR), their 95% confidence intervals, and p-values. Subsequently, factors associated with an increased risk of respiratory symptoms specifically among carpenters—based on demographic characteristics, comorbidities, and occupational characteristics—were investigated using the same statistical analysis approach. Pearson’s chi-squared and Fisher’s exact tests (where applicable) were used. The significance threshold was set at <5%.
A total of 216 workers participated in this study, comprising 108 carpenters (representing the group exposed to wood dust) and 108 administrative staff members (from city hall, the courts, and banks) representing the group not exposed to wood dust.
The mean age of the carpenters was 39.66 years ± 11.13 years, ranging from 23 to 68 years. The mean age of the administrative staff was 37.73 years ± 9 years, ranging from 23 to 67 years. There was no significant difference between the mean age of the carpenters and that of the administrative staff (p = 0.163). All participants were male. University-level education was found in 89.81% of the administrative staff and 7.41% of the carpenters. Forty-six (42.59%) carpenters had a secondary education. There was a significant difference between the educational level of the carpenters and that of the administrative staff (p < 0.001).
The mean duration of professional practice was 17.67 years ± 11.9 years (range: 2 - 40 years) for carpenters. For administrative staff, it was 8.49 years ± 6.38 years (range: 2 - 34 years). There was a significant difference in the duration of professional practice between the two groups (p < 0.001). The work environment was well-ventilated for all administrative staff and for 73.15% of carpenters. A significant difference existed between the work environments of carpenters and administrative staff (p < 0.001). The daily working time was 8 hours or more for 98.15% of workers in both groups surveyed (
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| <15 | 47 | (43.52) | 85 | (78.70) |
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| ≥15 | 61 | (56.48) | 23 | (21.30) |
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| Airy | 79 | (73.15) | 108 | (100) |
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| Confined | 29 | (26.85) | 0 | (0.00) |
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| <8 | 2 | (1.85) | 2 | (1.85) | >0.999 |
| ≥8 | 106 | (98.15) | 106 | (98.15) | >0.999 |
3.3.1. Types of Wood Used and Dust Levels
The types of wood used were African teak (65.64%), afzelia (63.85%), Senegal mahogany (8.33%), and gmelina (3.70%). The mean dust level was 1.40 mg/m3 ± 0.61 mg/m3, ranging from 0.10 to 2.91 mg/m3 for PM10 particles. For PM2.5 particles, the mean dust level was 1.22 mg/m3 ± 0.56 mg/m3, ranging from 0.98 to 2.74 mg/m3. The mean dust level for PM1.0 particles was 1.15 mg/m3 ± 0.58 mg/m3, ranging from 0.16 to 2.34 mg/m3. Dust levels exceeded 1 mg/m3 for 73.27% of carpenters regarding PM10 particles. For PM2.5 particles, levels exceeded 1 mg/m3 for 70.30% of carpenters, and for PM1.0 particles, this figure was 56.44%. Sixty-six carpenters (61.11%) used machinery. Workshop cleaning methods consisted of dry sweeping in 61.11% of cases and the use of a compressor in 4.63% of cases.
3.3.2. Data on Workplace Protection Measures for Carpenters
One hundred carpenters (92.59%) worked in workshops lacking wood dust collection systems. Homemade masks were used as personal protective equipment (PPE) by 107 carpenters (99.07%). Fifty-two carpenters (48.15%) reported using PPE “sometimes.”
The prevalence of respiratory symptoms over the past 12 months was 93.52% among carpenters and 55.56% among administrative staff. There was a significant difference in respiratory symptoms between carpenters and administrative staff (p < 0.001). Carpenters were 1.68 times more likely to experience respiratory symptoms than administrative staff.
3.4.1. Prevalence of Upper Respiratory Tract Symptoms
All symptoms related to upper respiratory tract involvement—namely sneezing (p < 0.001), nasal obstruction (p < 0.001), rhinorrhea (p < 0.001), nasal congestion (p < 0.001), pharyngeal pain (p < 0.001), and epistaxis (p = 0.006)—were significantly more frequent among carpenters compared to administrative staff. Sneezing, nasal obstruction, and rhinorrhea were observed in carpenters in 76.85%, 65.74%, and 59.26% of cases, respectively. Twelve carpenters (11.11%) reported epistaxis.
3.4.2. Prevalence of Lower Respiratory Tract Symptoms
Symptoms related to lower respiratory tract involvement—such as cough (p < 0.001), expectoration (p < 0.001), chest tightness (p < 0.001), paroxysmal dyspnea (p = 0.009), and wheezing (p = 0.006)—were significantly more frequent among carpenters compared to administrative staff. Cough, expectoration, chest tightness, and chronic dyspnea were reported by carpenters in 63.69%, 59.26%, 29.63% of cases, and 3.78% of cases, respectively. No administrative staff member reported chronic dyspnea (
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| Cough | 69 | (63.69) | 15 | (13.89) |
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| Sputum production | 64 | (59.26) | 3 | (2.78) |
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| Chest tightness | 32 | (29.63) | 3 | (2.78) |
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| Paroxysmal dyspnea | 19 | (17.59) | 6 | (5.56) |
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| Wheezing | 12 | (11.11) | 2 | (1.85) |
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| Recurrent lower respiratory tract infections | 5 | (4.63) | 1 | (0.93) | 0.125 |
| Chronic dyspnea | 3 | (3.78) | 0 | (0.00) | 0.125 |
3.4.3. Prevalence of Work-Related Respiratory Symptoms
Of the 108 carpenters presenting with respiratory symptoms, 99 (91.67%) reported that they were work-related. Among the 108 administrative staff members who reported respiratory symptoms, 21 (19.44%) stated that these symptoms were work-related. There was a significant difference regarding work-related respiratory symptoms between carpenters and administrative staff (p < 0.001). Carpenters were 4.71 times more likely to experience work-related respiratory symptoms than administrative staff.
3.4.4. Prevalence of Work-Related Upper Respiratory Tract Symptoms
All symptoms associated with upper respiratory tract involvement—namely sneezing (p < 0.001), rhinorrhea (p < 0.001), nasal obstruction (p < 0.001), nasal congestion (p < 0.001), pharyngeal pain (p < 0.001), and epistaxis (p = 0.016)—were significantly more frequent among carpenters compared to administrative staff. Sneezing, nasal obstruction, rhinorrhea, and epistaxis were reported by carpenters as being work-related in 75.93%, 61.11%, 54.63%, and 5.56% of cases, respectively (
3.4.5. Prevalence of Work-Related Lower Respiratory Tract Symptoms
Work-related lower respiratory tract symptoms—such as cough (p < 0.001), sputum production (p < 0.001), chest tightness (p < 0.001), paroxysmal dyspnea (p = 0.009), and wheezing (p = 0.002)—were significantly more frequent among carpenters compared to administrative staff. Cough and sputum production occurring at the workplace were reported by 63 carpenters (58.33%). Among administrative staff, only cough was reported as work-related, representing a proportion of 1.85% (
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| Sneezing | 82 | (75.93) | 17 | (15.74) |
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| Nasal obstruction | 66 | (61.11) | 10 | (9.26) |
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| Rhinorrhea | 59 | (54.63) | 8 | (7.41) |
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| Nasal congestion | 46 | (42.59) | 4 | (3.70) |
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| Pharyngeal pain | 37 | (34.26) | 1 | (0.93) |
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| Epistaxis | 6 | (5.56) | 0 | (0.00) |
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| Cough | 63 | (58.33) | 2 | (1.85) |
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| Sputum production | 63 | (58.33) | 0 | (0.00) |
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| Chest tightness | 31 | (28.70) | 0 | (0.00) |
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| Paroxysmal dyspnea | 18 | (16.67) | 0 | (0.00) |
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| Wheezing | 10 | (9.26) | 0 | (0.00) |
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| Chronic dyspnea | 3 | (2.78) | 0 | (0.00) | 0.123 |
Spirometry was performed on all 216 participants.
Restrictive ventilatory defects were significantly more common among carpenters compared to administrative staff (p < 0.001). Fifty-two (48.15%) carpenters presented with a restrictive ventilatory defect. One carpenter (0.93%) presented with an obstructive ventilatory defect (
3.6.1. Bivariate Analysis Using Simple Logistic Regression among Carpenters and Administrative Staff
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| Normal spirometry | 55 | (50.93) | 86 | (79.63) |
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| Restrictive ventilatory defect | 52 | (48.15) | 22 | (20.37) |
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| Obstructive ventilatory defect | 1 | (0.93) | 0 | (0.00) | 0.500 |
In the bivariate analysis, the occupation of carpenter (ORb = 11.54; p < 0.001) was associated with the occurrence of respiratory symptoms
In the bivariate analysis, reported medical history was not associated with the occurrence of respiratory symptoms.
3.6.2. Factors Associated with Respiratory Symptoms among Carpenters and Administrative Staff via Multivariate Analysis Using Multiple Logistic Regression
Being a carpenter increases the risk of experiencing respiratory symptoms (ORa = 6.55; p < 0.001) after adjusting for work environment, biomass exposure, and duration of employment in the profession (
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| Administrative staff | 1 | ||
| Carpenters | 6.55 | 2.72 - 17.7 |
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| Well-ventilated | 1 | ||
| Confined | 0.67 | 0.19 - 2.76 | 0.6 |
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| No | 1 | ||
| Yes | 2.72 | 0.92 - 10 | 0.09 |
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1 | 0.96 - 1.04 | >0.9 |
3.7.1. Bivariate Analysis Using Simple Logistic Regression among Carpenters
Association with age, weight status, and lifestyle:
In the bivariate analysis, age, weight status, and passive smoking were not associated with the occurrence of respiratory symptoms among carpenters (
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0.98 | 0.93 - 1.04 | 0.5 |
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| Normal | 69/73 | (94.52) | 1 | ||
| Undernutrition | 2/4 | (50) | 0.058 | 0.02 - 0.64 | 0.3 |
| Overweight | 23/24 | (95.83) | 1.33 | 0.48 - 54 | 0.3 |
| Obesity | 6/7 | (85.71) | 0.74 | 0.11 - 14.9 | 0.8 |
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86/92 | (93.48) | 1 | ||
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15/16 | (93.75) | 2.04 | 0.35 - 38.6 | 0.5 |
ORc: Crude odds ratio; 95% CI: 95% confidence interval.
3.7.2. Association between the Occurrence of Respiratory Symptoms, Duration of Employment, and Work Environment
In the bivariate analysis, duration of employment and work environment were not associated with the occurrence of respiratory symptoms among carpenters (
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- | - | 0.98 | 0.92 - 1.03 | 0.4 |
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| Well-ventilated | 74/79 | (93.67) | 1 | ||
| Confined | 26/29 | (89.66) | 0.59 | 0.20 - 2.82 | 0.6 |
ORc: Crude odds ratio; 95% CI: 95% confidence interval.
The majority of our study population consisted of adults, with a mean age of 39.66 years ± 11.13 years for carpenters and 37.73 years ± 9 years for administrative staff; there was no significant difference between the two groups. These results are similar to those reported by Ennin
Education levels were significantly higher among administrative staff than among carpenters. Generally, employment in public or private administration requires at least a secondary education, whereas this is not the case for the carpentry profession.
Exposure to biomass smoke and secondhand smoke was more common among carpenters than among administrative staff (p < 0.001). This exposure is likely attributable in part to the less favorable socioeconomic conditions of most carpenters, who often still rely on wood or charcoal fires for cooking. Furthermore, challenging working conditions may encourage tobacco use among some individuals—or those around them—as a means of boosting physical stamina to increase productivity.
The mean duration of professional practice was 17.67 years ± 11.9 years for carpenters and 8.49 years ± 6.38 years for administrative staff, a significant difference. Assessments of the duration of practice in trades such as carpentry often include the apprenticeship period, whereas in administration, it is calculated from the date of taking office. This could explain the longer mean duration observed among carpenters. In 2009, Beladed
Administrative staff reported working in well-ventilated environments more frequently than carpenters (p < 0.001). This result reflects the stark contrast between working conditions in administration—a formal sector—and carpentry, which remains part of the informal economy in Benin. Much remains to be done to properly structure this sector and ensure an adequate working environment for woodworkers.
In this study, carpenters were exposed to wood dust from various species, notably afzelia, African teak, Senegal mahogany, and gmelina. Mean dust concentration levels were 1.397 mg/m3 ± 0.61 mg/m3 for PM10 particles, 1.221 mg/m3 ± 0.56 mg/m3 for PM2.5 particles, and 1.153 mg/m3 ± 0.58 mg/m3 for PM1.0 particles. Most carpenters were exposed to dust levels exceeding 1 mg/m3—the wood dust exposure limit established in the Labor Code under Decree No. 2003-1254 of December 23, 2003, as defined by the National Research and Safety Institute (INRS) [
The presence of at least one respiratory symptom over the past 12 months was reported significantly more often by almost all carpenters compared to nearly half of the administrative staff (p < 0.001). Several authors have obtained results similar to ours. Indeed, in a 2016 study in Nigeria involving 227 woodworkers and 227 workers from a water bottling plant, Tobin
The high prevalence of respiratory symptoms among carpenters is likely linked to wood dust generated during sawing and sanding operations; this dust is inhaled and deposited throughout the respiratory tract (nose, bronchi, and lungs). In most of the workshops where the study was conducted, more than three-quarters of the carpenters used machines that produce ultrafine dust capable of remaining airborne for several hours, thereby exposing them to excessive dust levels. Additionally, some carpenters worked in confined environments (26.85%). All these factors could be responsible for the irritative and allergic symptoms affecting the respiratory tract.
4.5.1. Analysis of the Prevalence of Work-Related Upper Respiratory Tract Symptoms
All symptoms associated with upper respiratory tract involvement—namely sneezing, rhinorrhea, nasal obstruction, nasal congestion, pharyngeal pain, and epistaxis—were significantly more frequent among carpenters than administrative staff. The most common symptoms were sneezing (75.95% vs. 15.74%; p < 0.001), nasal obstruction (61.11% vs. 9.26%; p < 0.001), and rhinorrhea (54.63% vs. 7.41%; p < 0.001). These results corroborate findings from other authors in the literature. For instance, in a 2024 study conducted in Ghana involving 104 woodworkers and a control group, Ennin
Although the prevalence of epistaxis was relatively low, its occurrence also indicates irritation and inflammation of the nasal mucosa; recurrent episodes should prompt an investigation for sinonasal cancer.
4.5.2. Analysis of the Prevalence of Work-Related Lower Respiratory Tract Symptoms
The frequency of cough was significantly higher among carpenters than among administrative staff (p < 0.001). Other work-related lower respiratory tract symptoms were reported only by carpenters and were dominated by expectoration (58.33%), chest tightness (28.70%), and wheezing (9.26%). These results are consistent with data from the literature [
Spirometry results differed significantly between carpenters and administrative staff (p < 0.001). Spirometric abnormalities were predominantly characterized by restrictive ventilatory impairment, affecting nearly half of the carpenters (48.15%) and less than a quarter of the administrative staff. In a 2001 study conducted in Morocco involving 242 carpenters and 121 subjects unexposed to wood dust, Laraqui
Following bivariate and subsequent multivariate analysis, the occupation of carpenter was significantly associated with the occurrence of respiratory symptoms (aOR = 6.55; p < 0.001) after adjusting for other factors. A 2024 study by Abateneth
Workers exhibiting ventilatory disorders were referred to specialized pulmonology and occupational health consultations. This study indicated that workplace air pollution is the primary cause of increased respiratory symptoms and reduced lung function among carpenters. Wood dust is the main pathogenic factor. Consequently, measures must be implemented to minimize the adverse effects of wood dust on carpenters and improve workplace safety. In addition to wood dust exposure, carpenters are heavily exposed to a variety of chemicals, fungi, and bacteria present on fresh wood. Consequently, the decline in lung function reported in this study could also be—at least in part—attributable to these factors. It is important to further investigate the interplay of all the mechanisms contributing to this decline in lung function among these professionals.
This study demonstrated that exposure to wood dust significantly increases the risk of developing most respiratory symptoms—affecting both the upper and lower respiratory tracts—thereby highlighting the pathogenic effects of inhaling it. It constitutes a risk factor for the development of these symptoms, even after adjusting for other variables such as workplace ventilation, exposure to biomass, and duration of employment in the trade. Respiratory functional abnormalities—predominantly restrictive defects—are significantly more prevalent among carpenters than among administrative staff. Harmful dust levels exceeding 1 mg/m3 were identified. The working conditions of these carpenters are characterized by poorly ventilated environments, the use of toxic substances, and a lack of collective and individual protective measures.
The study was conducted with the approval of the Local Ethics Committee for Biomedical Research at the University of Parakou. Informed consent was obtained from participants beforehand. Data confidentiality was maintained.
We extend our thanks to the officials of the Parakou City Hall, all the carpenters in the city of Parakou, and the Parakou Artisans’ Association for their collaboration and/or participation in this study.