Browsing by Author "Nchimunya, Bbautu"

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    Efficacy of noise control measures at high noise zones from a copper mine in Zambia
    (University of the Witwatersrand, Johannesburg, 2024) Nchimunya, Bbautu; Hayumbu, Patrick; Masekameni, Masilu Daniel
    Noise exposure is a global problem, it is estimated that about 30 million workers in the United States of America (USA) are exposed to high noise levels while across Europe, 28% of the workers are exposed to high noise levels. Hazardous noise exposure is associated with a wide range of health effects that include noise induced hearing loss (NIHL), stress, poor concentration, communication difficulties and fatigue due to lack of sleep. The mining industry worldwide is struggling with hearing loss due to noise overexposure and in a copper mining set-up, the concentrator section is assumed to be among high noise zones exposing workers to noise above the occupational exposure limit (OEL) of 85 dB(A). This study aimed at evaluating the efficacy of noise control measures at various sections at Konkola Copper Mine concentrator section in Zambia. This quantitative cross-sectional study was conducted at Konkola Copper Mines (KCM) Konkola Business Unit (KBU) in Chililabombwe District in the Copperbelt Province of Zambia. A walk through survey was conducted to collect information to describe the operations, identify noise sources, understand noise release mechanisms and describe noise control measures. Quality control was achieved by triplicate noise measurement per location using an instrument with a valid annual calibration certificate. Raw data was pre-processed by cleaning to make it ideal for use. An ethical waiver W-CBP-230428-01 was granted as this study did not involve animal or human subjects but only area noise samples using CR: 172B SLM. The study identified the noise sources, described noise release mechanisms, described the noise controls and assessed the efficacy of noise controls in four sections within the concentrator of a copper mine in Zambia. Seventeen noise generating equipment were identified with about 53% of the equipment operated at the crushing section, 18% operated at the Flotation and Filtration section respectively and 11% at Milling section. A substantial portion (65%) of the identified noise sources in the concentrator are not housed, and among these, 36% are mobile in nature. It was also found that none of the noise areas were demarcated There are three types of noise controls (enclosure, silencer & HPD) that are in use at the concentrator and they fall in two categories of the hierarchy of controls (engineering & PPE). Out of the nine noise sources at the Crushing section, 56% (5 of the 9) utilized enclosure as control, 33% (3 of the 9) had HPDs as control and 11% (1 of the 9) source was installed with a silencer as a control. Enclosure is utilized to control noise from the two sources found in the Milling section while HPDs and enclosure are the noise control measures in use at both Flotation and Filtration sections of the concentrator. Enclosure is the most available control in the concentrator at 53%, followed by HPDs at 41%, and the least available is silencer at 6 %. About 76.5% (13) of the noise controls at the concentrator had efficacy strong enough to reduce noise levels to below the OEL while 23.5% (4) of the controls had weak efficacy that failed to reduce noise levels to below the OEL. This has prompted the need to strengthen efficacy in areas where controls were found to be weak. There is need to sustain controls that were found to be strong to maintain their efficacy. About 75% (3 of the 4) of the controls with lower efficacy were from the Crushing section while 25% (1 of the 4) was from Filtration section