Assessing the Health Risks of Sawmill Workers Associated with Particulate Matter Toxicity: A Case Study of Benin City, Nigeria
1
Department of Environmental Management and Toxicology, Faculty of Life Sciences, University of Benin, Benin City, Nigeria
Publication date: 2025-09-14
Trends in Ecological and Indoor Environmental Engineering, 2025;3(3):8-19
KEYWORDS
householdsurbanizationcircular economywaste collection optimizationwaste transportationsustainable management
ABSTRACT
Background:
Sawmills are essential to the timber industry, but they pose significant occupational health risks, primarily from airborne particulate matter (PM) pollution.
Objectives:
This study aims to assess the toxicity of PM and its link to reported respiratory problems among sawmill workers in Benin City, Nigeria.
Methods:
Quantitative measurements of PM2.5 and PM10 were conducted in 10 randomly selected sawmills using a calibrated BR-SMART-126S handheld air quality detector. The toxicity potential of the measured PM concentrations was determined. A cross-sectional study involving 200 participants utilised a modified British Medical Research Council questionnaire to assess respiratory symptoms. A binomial logistic regression model was employed to identify factors associated with these symptoms. Data were analysed using SPSS v21.0 with descriptive statistics, chi-square tests, and bivariate logistic regression; significance was set at p < 0.05. Results were presented as medians, box plots, frequencies, percentages, cORs, and 95% CIs.
Results:
The particulate matter exposure levels among sawmill workers ranged from 32 – 36 µg/m3 (PM2.5) and 40 – 44 µg/m3 (PM10). The level of PM2.5 exceeded the limit of 15 µg/m3 set by the WHO. The toxicity potential (TP) values of PM2.5 were greater than 1 at all the sampling sites. The prevalence rates of reported respiratory symptoms among workers were 31%, 26%, 29%, 26% and 23% for shortness of breath, wheezing, cough, chest pain, and sore throat, respectively. Work experience (cOR = 5.96; 95% CI: 1.243 – 28.629), daily duration of exposure (cOR = 3.51; 1.737 – 7.130), open burning of wood waste (cOR = 20.68; CI = 3.537 – 120.96) and use of diesel-powered generators (cOR = 16.44; CI = 5.660 – 47.752) in the sawmills were determining factors for reported respiratory symptoms among workers.
Conclusion:
The study found a high prevalence of respiratory health issues among workers. The key factors contributing to these problems include: longer employment, prolonged daily exposure, open burning of sawmill wastes and the use of diesel-powered generators: These generators release harmful emissions which increase the likelihood of respiratory symptoms.
Sawmills are essential to the timber industry, but they pose significant occupational health risks, primarily from airborne particulate matter (PM) pollution.
Objectives:
This study aims to assess the toxicity of PM and its link to reported respiratory problems among sawmill workers in Benin City, Nigeria.
Methods:
Quantitative measurements of PM2.5 and PM10 were conducted in 10 randomly selected sawmills using a calibrated BR-SMART-126S handheld air quality detector. The toxicity potential of the measured PM concentrations was determined. A cross-sectional study involving 200 participants utilised a modified British Medical Research Council questionnaire to assess respiratory symptoms. A binomial logistic regression model was employed to identify factors associated with these symptoms. Data were analysed using SPSS v21.0 with descriptive statistics, chi-square tests, and bivariate logistic regression; significance was set at p < 0.05. Results were presented as medians, box plots, frequencies, percentages, cORs, and 95% CIs.
Results:
The particulate matter exposure levels among sawmill workers ranged from 32 – 36 µg/m3 (PM2.5) and 40 – 44 µg/m3 (PM10). The level of PM2.5 exceeded the limit of 15 µg/m3 set by the WHO. The toxicity potential (TP) values of PM2.5 were greater than 1 at all the sampling sites. The prevalence rates of reported respiratory symptoms among workers were 31%, 26%, 29%, 26% and 23% for shortness of breath, wheezing, cough, chest pain, and sore throat, respectively. Work experience (cOR = 5.96; 95% CI: 1.243 – 28.629), daily duration of exposure (cOR = 3.51; 1.737 – 7.130), open burning of wood waste (cOR = 20.68; CI = 3.537 – 120.96) and use of diesel-powered generators (cOR = 16.44; CI = 5.660 – 47.752) in the sawmills were determining factors for reported respiratory symptoms among workers.
Conclusion:
The study found a high prevalence of respiratory health issues among workers. The key factors contributing to these problems include: longer employment, prolonged daily exposure, open burning of sawmill wastes and the use of diesel-powered generators: These generators release harmful emissions which increase the likelihood of respiratory symptoms.
REFERENCES (60)
1.
Abulude, F. O., Fagbayide, S. D., Akinnusotu, A., Makinde, O. E., & Elisha, J. J. (2019). Assessment of the indoor air quality of Akure South - West Nigeria. Quality of Life, 10, 15–27.
2.
Adekunle, V. A. J., Olagoke, A. O., & Ogundare, L. F. (2013). Timber exploitation rate in tropical rainforest ecosystem of southwest Nigeria and its implications on sustainable forest management. Applied Ecology and Environmental Research, 11(1), 123–136. http://dx.doi.org/10.15666/aee....
3.
Adeoye, O. A., Adeomi, A. A., Olugbenga-Bello, A. I., Bamidele, J. O., Abodunrin, O. L., & Sabageh, O. A. (2014). Respiratory symptoms and peak expiratory flow among sawmill workers in south western Nigeria. Journal of Environmental and Occupational Science, 3(3), 141–146. https://doi.org/10.5455/jeos.2....
4.
Agbana, B. E., Joshua, A. O., Daikwo, M. A., & Metiboba, L. O. (2016). Knowledge of occupational hazards among sawmill workers in Kwara state, Nigeria. Nigerian Postgraduate Medical Journal, 23(1), 25. https://doi.org/10.4103/1117-1....
5.
Amaechi, C. F., & Okoduwa, A. K. (2023). Risk Perception Assessment for Sawmill Workers in Benin Metropolis, Edo State, Southern Nigeria. Jordan Journal of Earth and Environmental Sciences, 14(4), 268–279.
6.
Amoabeng Nti, A. A., Arko-Mensah, J., Botwe, P. K., Dwomoh, D., Kwarteng, L., Takyi, S. A., Acquah, A. A., Tettey, P., Basu, N., Batterman, S., Robins, T. G., & Fobil, J. N. (2020). Effect of Particulate Matter Exposure on Respiratory Health of e-Waste Workers at Agbogbloshie, Accra, Ghana. International Journal of Environmental Research and Public Health, 17(9), 3042. https://doi.org/10.3390/ijerph....
7.
Asfaw, S., Enquselassie, F., Tefera, Y., Gizaw, M., Wakuma, S., & Woldemariam, M. (2018). Determinants of Chronic Respiratory Symptoms among Pharmaceutical Factory Workers. Journal of Tropical Medicine, 2018, 3815689. https://doi.org/10.1155/2018/3....
8.
Awoke, T. Y., Takele, A. K., Mekonnen, W. T., Abaya, S. W., Zele, Y. T., Alemseged, E. A., & Abay, B. G. (2021). Assessment of dust exposure and chronic respiratory symptoms among workers in medium scale woodwork factories in Ethiopia; a cross-sectional study. BMC Public Health, 21(1), 309. https://doi.org/10.1186/s12889....
9.
Ayodele, C. O., Fakinle, B. S., Jimoda, L. A., & Sonibare, J. A. (2016). Investigation on the ambient air quality in a hospital environment. Cogent Environmental Science, 2(1), 1215281. https://doi.org/10.1080/233118....
10.
Bello, S. R., & Mijinyawa, Y. (2010). Assessment of Injuries in Small Scale Sawmill Industry of South Western Nigeria. CIGR Journal of Scientific Research and Development, 12, 1–11. http://www.cigrjournal.org/.
11.
Chaiear, N., Ngoencharee, J., & Saejiw, N. (2018). Respiratory Symptoms and Pulmonary Function among Workers in a Rubber Wood Sawmill Factory in Thailand. American Journal of Public Health Research, 6(2), 65–71. https://doi.org/10.12691/ajphr....
12.
Chamseddine, A., Alameddine, I., Hatzopoulou, M., & El-Fadel, M. (2019). Seasonal variation of air quality in hospitals with indoor–outdoor correlations. Building and Environment, 148, 689–700. https://doi.org/10.1016/j.buil....
13.
Chandra, K. N., & Rosdiana, E. (2022). Preliminary study: health risk analysis of PM2.5 and PM10 mass concentrations in Bandung Metropolitan. IOP Conference Series: Environmental Earth Sciences, 824(1), 012049. https://doi.org/10.1088/1755-1....
14.
Chirdan, O. O., & Akosu, J. (2004). Respiratory symptoms in workers at Katako wood market, Jos, Plateau state Nigeria. Journal of Community Medicine and Primary Health Care, 16, 30–33. https://doi.org/10.4314/jcmphc....
15.
Eghomwanre, A. F., Oguntoke, O., & Taiwo, A. M. (2022). Levels of indoor particulate matter and association with asthma in children in Benin City, Nigeria. Environmental Monitoring and Assessment, 194(7), 467. https://doi.org/10.1007/s10661....
16.
Eghomwanre, A. F., & Oguntoke, O. (2022a). Concentrations of Indoor Gaseous Air Pollutants and Risk Factors Associated with Childhood Asthma in Benin City, Nigeria. Environmental Monitoring and Assessment, 194(5), 391. https://doi.org/10.1007/s10661....
17.
Eghomwanre, A.F., & Oguntoke, O. (2022b). Levels of Fungi Aerosols in Residential Houses within Benin City, Southern Nigeria. Dutse Journal of Pure and Applied Sciences, 8(2a), 69–79. https://doi.org/10.4314/dujopa....
18.
Elechi, C. E., & Warmate, D. (2019). The occupational health hazards associated with Sawmill Workers in Port Harcourt Metropolis in River State, Nigeria. International Journal of Innovative Healthcare Research, 7(1), 1–7. https://doi.org/10.1007/s42797....
19.
Elijah, F. B., & Elegbede, I. (2018). Environmental Sustainability Impact of the Okobaba Sawmill Industry on Some Biogeochemistry Characteristics of the Lagos Lagoon. Poultry, Fisheries and Wildlife Sciences, 3, 131. https://doi.org/10.4172/2375-4....
20.
FAO. (2001). Global Forest resource assessment 2000. United Nations Food and Agriculture Organization. https://www.fao.org/forest-res....
21.
Fentie, D., Gmariam, T., Mulat, E., & Reta, W. (2019). Assessment of Respiratory Symptoms among Woodworkers in Jimma Town, Southwest Ethiopia, A Comparative Cross-Sectional Study. Biomedical Journal of Scientific and Technical Research, 18(2), 1–6. https://doi.org/10.26717/BJSTR....
22.
FIM. (2017). Update on global timber demand. FIM Service Limited. https://greshamhouse.com/wpcon....
23.
Garcia, C. A., & Hora, G. (2017). State-of-the-art of waste wood supply chain in Germany and selected European countries. Waste Management, 70, 189–197. https://doi.org/10.1016/j.wasm....
24.
Johnson, O. E., & Umoren, Q. M. (2018). Occupational hazards and health problems reported by workers in a Sawmill in Uyo, Nigeria. Journal of Environmental and Occupational Health, 7(2), 17–24.
25.
Lelieveld, J., Evans, J. S., Fnais, M., Giannadaki, D., & Pozzer, A. (2015). The contribution of outdoor air pollution sources to premature mortality on a global scale. Nature, 525(7569), 367–371.
26.
Mahmood, N. M. A., Karadaky, K., Hussain, S. A., Ali, A. K., Mohammad, G. M., & Mahmood, O. M. (2015). Respiratory function among sawmill workers in different areas of Sulaimani City. International Journal of Medical Science and Public Health, 5, 351–355. http://dx.doi.org/10.5455/ijms....
27.
Medical Research Council. (1960). Committee on the aetiology of Chronic Bronchitis. Standard questionnaire on respiratory symptoms. British Medical Journal, 2, 1665–1668. https://doi.org/10.1016/s0140-....
28.
Mensa-Yawson, S., Baidoo, K. K., Jangu, A. A., Kitcher, E. D., & Abaidoo, B. (2023). Noise-induced hearing loss among sawmill workers in a Sub-Saharan African country. Preprint. https://doi.org/10.21203/rs.3.....
29.
Mohagheghzadeh, A., Faridi, P., Shams, A., & Ghasemi, Y. (2006). Medicinal smokes. Journal of Ethnopharmacology, 108, 161–184. https://doi.org/10.1016/j.jep.....
30.
Mong’are, R. O., Mburu, C., & Kiiyukia, C. (2017). Assessment of occupational safety and health status of sawmilling industries in Nakuru County, Kenya. International Journal of Health Sciences, 5(4), 75–102. https://doi.org/10.15640/ijhs.....
31.
Neghab, M., Jabari, Z., & Kargar, S. F. (2018). Functional disorders of the lung and symptoms of respiratory disease associated with occupational inhalation exposure to wood dust in Iran. Epidemiology and Health, 40, e2018031. https://doi.org/10.4178/epih. e2018031.
32.
Nnaji, A. O., & Chiedozie, C. C. (2014). Effects of Diesel-Powered Generator Fumes on Ambient Air Quality over Lagos Island, Nigeria. Research Journal of Agriculture and Environmental Management, 3(7), 320–325. http://www.apexjournal.org.
33.
Gu, J., Kirsch, I., Schripp, T., Froning-Ponndorf, F., Berthold, D., & Salthammer, T. (2018). Human exposure to airborne particles during wood processing. Atmospheric Environment, 193, 101–108. https://doi.org/10.1016/j.atmo....
34.
Oghenovo, I., Benso, A. A., & Fred-Ahmadu, O. (2019). Assessment of particulate matter (PM2.5) in residential staff quarters of Covenant University, Nigeria. IOP Conf. Series: Journal of Physics: Conf. Series, 1299, 012101. https://doi.org/10.1088/1742-6....
35.
Oguntoke, O., Emoruwa, F. O., & Taiwo, M. A. (2019). Assessment of air pollution and health hazard associated with sawmill and municipal waste burning in Abeokuta Metropolis, Nigeria. Environmental Science and Pollution Research International, 26(32), 32708–32722. https://doi.org/10.1007/s11356....
36.
Oguntoke, O., Otusanya, O. K., & Annegarn, H. J. (2013). Emission of pollutants from wood waste incineration at sawmills in Abeokuta metropolis, Nigeria. International Journal of Environmental Sciences, 70(6), 964–975. http://dx.doi.org/10.1080/0020....
37.
Okedere, O. B., Fakinle, B. S., Sonibare, J. A., Eliminate, F. B., & Adesina, O. A. (2017). Particulate matter pollution from open burning of sawdust in Southwestern Nigeria. Cogent Environmental Science, 3(1). https://doi.org/10.1080/233118....
38.
Okwari, O. O., Antai, A. B., Owu, D. U., Peters, E. J., & Osim, E. E. (2005). Lung function status of workers exposed to wood dust in timber markets in Calabar, Nigeria. African Journal of Medicine and Medical Sciences, 34(2), 141–145.
39.
Olalekan, R. M., Timothy, A. A., Enabulele, C. E., & Olalekan, A. S. (2018). Assessment of Air Quality Indices and its Health Impacts in Ilorin Metropolis, Kwara State, Nigeria. Scientific Research and Impact, 4(4), 060–074.
40.
Olawuni, P. O., & Okunola, O. H. (2014). Socioeconomic Impacts of Sawmill Industry on Residents. A Case Study of Ile-Ife. Journal of Economics and Development Studies, 2(3), 167–176. https://doi.org/10.15640/jeds. v2n3a12.
41.
Olorunnisola, A. O. (2023). The Past, Present and Future Outlook of the Wood Industry in Nigeria. In Intech Open (pp. 1–14). https://doi.org/10.5772/intech....
42.
Olujimi, O., Nofiu, M., Oguntoke, O., & Soaga, J. (2023). Occupational exposure to wood dust and prevalence of respiratory health issues among sawmill workers in Abeokuta metropolis, Ogun state, Nigeria. Journal of Natural Sciences Engineering and Technology, 22(1), 11–27.
43.
Onowhakpor, A. O., Abusu, G. O., Adebayo, B., Esene, H. A., & Okojie, O. H. (2017). Determinants of occupational health and safety: knowledge, attitude, and safety practices toward occupational hazards of sawmill workers in Egor Local Government Area, Edo State. African Journal of Medical and Health Sciences, 16, 58–64. https://doi.org/10.4103/2384-5....
44.
Onuorah, C. U., Leton, T. G., & Momoh, Y. O. L. (2019). Influence of meteorological parameters on particle pollution (PM2.5 and PM10) in the tropical climate of Port Harcourt, Nigeria. Archives of Current Research International, 19(1), 1–12. http://dx.doi.org/10.9734/acri....
45.
Osagbemi, G. K., La-Kadri, R. T., & Aderibigbe, S. A. (2010). Awareness of occupational hazards, health problems and safety measures among sawmill workers in North Central Nigeria. TAF Preventive Medicine Bulletin, 9, 325–328.
46.
Ramasamy, G., Ratnasingam, J., Bakar, E. S., Halis, R., & Muttiah, N. (2015). Assessment of environmental emissions from sawmilling activity in Malaysia. BioResources, 10, 6643–6662. http://ojs.cnr.ncsu.edu/index...._.
48.
Rathipe, M., & Raphela, S. F. (2023). 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. BMC Public Health, 23, 1196. https://doi.org/10.1186/s12889....
49.
Saejiw, N., Chaiear, N., & Sadhra, S. (2009). Exposure to wood dust and its particle size distribution in a rubberwood sawmill in Thailand. Journal of Occupational and Environmental Hygiene, 6(8), 483–490. https://doi.org/10.1080/154596....
50.
Sommerhuber, P. F., Welling, J., & Krause, A. (2015). Substitution potentials of recycled HDPE and wood particles from post-consumer packaging waste in wood-plastic composites. Waste Management, 46, 76–85. https://doi.org/10.1016/j.wasm....
51.
Soongkhang, I., & Laohasiriwong, W. (2015). Respiratory tract problems among wood furniture manufacturing factory workers in the Northeast of Thailand. Kathmandu University Medical Journal, 13(50), 125–129. https://doi.org/10.3126/kumj.v....
52.
Sütçü, A., & Semerci, N. T. (2019). Occupational Health Problems of Sawmill Workers Processing Red Pine in Turkey. Applied Ecology and Environmental Research, 17(4), 7625–7639. http://dx.doi.org/10.15666/aee....
53.
Thangavel, P., Park, D., & Lee, Y. C. (2022). Recent insights into particulate matter (PM2.5)-mediated toxicity in humans: an overview. International Journal of Environmental Research and Public Health, 19(12), 7511. https://doi.org/10.3390/ijerph....
54.
Tobin, E. A., Ediagbonya, T. F., Okojie, O. H., & Asogun, D. A. (2016). Occupational Exposure to Wood Dust and Respiratory Health Status of Sawmill Workers in South‒South Nigeria. Journal of Pollution Effects and Control, 4, 154. https://doi.org/10.4172/2375-4....
55.
Tungu, A., Bråtveit, M., Mamuya, S., & Moen, B. (2015). Reduction in respiratory symptoms among cement workers: a follow-up study. Occupational Medicine, 65(1), 57–60. https://doi.org/10.1093/occmed....
56.
Ugheoke, J., Wahab, Z. K., & Erhabor, G. (2009). Prevalence of respiratory symptoms among sawmills workers in Benin City. International Journal of Tropical Medicine, 4, 1–3.
57.
Uraz, A., Aran, M. A., Hüsamoğlu, M., Okkalı., & Capar, S. (2010). Recent Trends in Female Labor Force Participation in Turkey. State Planning Organization of the Republic of Turkey and World Bank. http://dx.doi.org/10.2139/ssrn....
58.
WHO. (2018). Ambient air quality and health. World Health Organization. https://www.who.int/news-room/....
59.
WHO. (2021). WHO global air quality guidelines: particulate matter (PM2.5 and PM10), ozone, nitrogen dioxide, sulphur dioxide and carbon monoxide. World Health Organization. https://www.who.int/publicatio....
60.
Zaman, S. U., Yesmin, M., Pavel, M. R. S., Jeba, F., & Salam, A. (2021). Indoor air quality indicators and toxicity potential at the hospitals' environment in Dhaka, Bangladesh. Environmental Science and Pollution Research International, 28(28), 37727–37740. https://doi.org/10.1007/s11356....
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