LEVELS, TRENDS AND EXPOSURE DOSES OF NOISE EMITTED BY SMALL SCALE ENTERPRISES IN ABEOKUTA, SOUTH-WESTERN NIGERIA
Monitoring of noise levels and their impact are common in large scale and corporate industrial establishments while the small scale industries have not received sufficient attention. Consequently, the present study examined the levels and pattern of noise emission from small-scale enterprises that are generally ignored from compliance monitoring of the relevant agencies. The study utilises the results of noise emission quantification, determination of safe distance to the selected small-scale enterprises and impact on human as input for noise policy formulation. Three types of small-scale enterprises sampled from seventy-five (75) sites in Abeokuta were selected for noise measurement using a portable noise meter. Questionnaire and field observation were employed to assess the impact of noise on machine operators and their apprentices. Mean noise emission from the aluminum slitting machines ranged from 103.9 – 118.4 d(BA), iron welding machines; 97.0 – 108.8 d(BA) and food grinding machines; 91.6 to 108.2 d(BA). Daily Noise Dose (DND) from these three types of machine workshops were 800 – 19230% (aluminum slitter), 200 – 2400% (iron welder), and 100 – 3305% (food grinder). Time Weighted Average (TWA) for 8 hours noise exposure values were 94.0 – 107.8, 88.0 – 98.8 and 85.0 – 100.2 respectively. The spatial dimension of noise emission from the studied machines showed that acceptable levels were obtained at 20 meters from the machines sites. As predictors of variations in noise emission, the age of the machines explained 8.3 – 13.6%, 17.2 – 17.8% and 29.1 – 55.4% of noise emitted by food grinders, aluminum slitters and iron welders. The capacities of the studied machines predicted 7.9 – 13.5%, 18.4 – 30.5 and 43.9 – 56.3% of the noise emitted by iron welders, aluminum slitter and food grinders respectively. While the noise levels at the sites of the machines were significantly higher than the permissible limit, 25% of the workers were exposed for upwards of 10 hours daily and 30% for more than five years. The array of health problems; stress, dizziness, tinnitus, sleep disturbance and speech interference, experienced by the machines operators may not be unconnected to their non-use of Personal Protective Equipment (PPE) to minimize noise hazard. Policy formulation for public protection from noise pollution should prescribe limit for small scale enterprises, enforce noise level compliance, monitor wearing of appropriate PPE by machine operators and maintained a minimum of 20 meters between the sites of these machines and other human activities.
Akinrinola O.O. 2011. Informal economy, economic growth and poverty in Nigeria: a macro-economic analysis. Accessed from http://www.hsbremen.de/internet/studium/stg/isvw /conferenc/impactonafrica on July 19 2011.
CCOHS – Canadian Centre for Occupational Health and Safety 2016. Noise – Occupational Exposure Limits in Canada. Accessed from https://www.ccohs.ca/oshanswers/phys_agents/ exposure_can.html on July 28 2016.
Egunjobi, L. 1983. Perception of environ-mental Problems, Pilot Study centred on the City of Ibadan, Research Report, NISER, Ibadan.
Evans, G.W., Lepore, S.J. 1993. Non-auditory effects of noise on children; a critical review. Children’s Environments, 10:31-51.
Evans, G.W., Lercher P., Meis M., Ising H., Kofler W.W. 2001. Community noise exposure and stress in children. Journal of Acoustic Society of America, 109 (3):1023-1027.
Evans, G.W., Maxwell L. 1997. Chronic noise exposure and reading deficits: The mediating effects of language acquisition. Environment and Behaviour, 29: 638-656
Fields, J.M. 1998. Reactions to environmental noise in an ambient noise context in residential areas. Journal of the Acoustical Society of America, 104: 2245-2260.
Gibson, T., van der Vaart H. J. 2008. Defining SMEs: A Less Imperfect Way of Defining Small and Medium Enterprises in Developing Countries. Publication of Brooking Global Economy and Development. Accessed from http://www.brookings.edu/~/media/research/files/papers/2008/9/development%20gibson.pdf on November 27 2015.
Hear-it.org 2012. The global burden of noise induced hearing loss. Accessed from http://www.press.hear-it.org on July 30 2012.
Kabir, G., Madugu, A.I. 2010. Assessment of environmental impact on air quality by cement industry and mitigating measures: a case study. Environmental Monitoring and Assessment, 160(1–4): 91–99.
Kiernan, V. 1997. Noise pollution robs kids of languages skills. New Scientist, 10 (5): 120–126.
Mbuligwe, S. 2004. Levels and Influencing Factors of Noise Pollution from Small-Scale Industries (SSIs) in a Developing Country. Environmental Management, 33 (6): 830–839.
National Environmental Standards and Regulations Enforcement Agency (Establishment) Act, 2007.
Nelson, D.I., Nelson R.Y., Concha-Barrientos M. Fingerhut M. 2005. The Global Burden of Occupational Noise Induced Hearing Loss. American Journal of Industrial Medicine, 48(6): 400–408.
NIOSH, 1996. National occupational research agenda. National Institute of Occupational Safety and Health, (NIOSH) Pub. No. 96-115. Cincinnati, OH.
Oguntoke, O., Awanu, E.A., Annegarn J.H. 2012b. Impact of Cement factory operations on air quality and human health in Ewekoro Local Government Area, South-western Nigeria. International Journal of Environmental Studies, 69 (6): 934–945.
Oguntoke, O., Odeshi T., Annegarn, H. 2012a. Assessment of Noise Emitted by Vibrator-Block Factories and the Impact on Human Health and Urban Environment in Nigeria. International Journal of Applied Environmental Sciences, 7(1): 57–68.
Onuu, M.U. 2000. Road traffic noise in Nigeria: measurements, analysis and evaluation of nuisance. Journal of Sound and Vibration 233(3): 391–405.
Onyebueke, V. U. 2013. Policy implications of the spatial and structural relationships of the informal and formal business sectors in urban Nigeria: the case of Enugu (1990-2010). A PhD Thesis submitted to Stellenbosch University. Accessed from http://scholar.sun.ac.za/handle /10019.1/79889 on November 25 2015).
Scheider, F. 2002. Size and measurement of the informal economy in 110 Countries around the World. A paper presented at a workshop of the Australian National Tax Centre ANU Canberra, Australia. Accessed from http://www.economics.uni-linz.ac.at on May 17 2011.
Sexton, K., Gong, H., Bailar, J.C., Ford, J.G., Gold, D.R., Lambert, W.E., Utell, M.J. 1993. Air pollution health risks: Do class and race matter? Toxicology and Industrial Health, 9(5): 843–878.
Smith, RJH, Bale JFJ, White KR 2005. Sensorineural hearing loss in children. Lancet 365, 879–90.
Sonibare, J.A., Akeredolu, F.A., Latinwo I., Solomon B.O. 2004. Impact of tanneries on ambient noise levels in Kano, Nigeria. African Journal of Environmental Assessment and Management 8: 1–18.
Stansfeld, S.A., Matheson, M.P. 2003. Noise pollution: non-auditory effects on health. British Medical Bulletin, 68: 243–257.
Tajudeen, Y., Okpuzor, J. 2011. Variation in exposure to cement dust in relation to distance from Cement Company. Research Journal of Environmental Toxicology, 5(3): 203–212.
Tsepav, M.T., Oladipupo M.D., Ndanusa B. 2011. Assessment of the level of noise produced by sound generating machines in Lapai, Northern Nigeria. Advances in Applied Science Research, 2 (6): 520–531.
U.S. Department of Health and Human Services (US-DHHS) 1998 Criteria for a recommended standard, occupational noise exposure Revised Criteria 1998, Cincinnati, Ohio. 99p.
WHO (2001) WHO guideline on Community Noise (Ed.) Dietrich Schwela. TRB Session 391, WHO Geneva, Switzerland.
World Health Organization (2012a). Deafness and Hearing Impairment. Fact Sheet no 300, February 2012. Accessed from http://www.who.int/mediacentre/factsheets/fs300/en/index. html on July 30 2012)
WHO, 2012b. Occupational Health: A Manual for Primary Health Care Workers. Accessed from http://www.who.int/occupational_health/regions/en/oehemhealthcareworkers.pdf on November 19 2012).