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JOURNAL OF INFORMATION, KNOWLEDGE AND RESEARCH IN CIVIL ENGINEERING EVALUATION AND CONTROL OF NOISE HAZARDS IN TEXTILE MILLS MALU DEVADASAN M.E.-sem IV (Environmental Management), L. D. College of Engg., Ahmedabad, Gujarat. [email protected] ABSTRACT— Noise has become an integral part of our day to day life. Introduction of more and more mechanization, powerful equipment is expected to increase more noise problems thereby inducing noise doses with associated physiological and psychological problems to the exposed populations. Repeated or prolonged exposure to excessive noise levels will lead to hearing impairment. Development of modern automated machines in textile industries has considerably decreased the physical burden of work on workers but one of the most undesirable and unavoidable product of these machines are noise pollution. The main objective of this paper is to assess noise levels in a Textile plant and to recommend control measures to reduce the risk of exposure on the employees. The study being reported here has been carried out in a Textile plant located in Ahmedabad city of Gujarat state. Equivalent sound pressure level Leq has been measured in various sections of these plants with the help of a Class-II type digital sound level meter. A questionnaire has been completed on 60 workers, randomly selected who were exposed to different levels of occupational noise. The results of the study establish the fact that noise level in certain sections of the plants i.e. Loom Shed, Ring Frame, Speed Frame and TFO area was more than the acceptable limit of 90 dB(A) for 8 hour exposure stipulated by OSHA. The noise level in other sections like carding, blow room, combing etc., although was less than 90 dB(A) , but was quite higher than limits used for assessment of noise for community response. Control measures starting at the source i.e. regarding modifications in the spinning and other noise causing machinery, to path and receiver end are been discussed here. Keywords— Evaluation, Control, Noise Hazards, Textile Mills clatter of gears, high speed whine of twisting and spinning machinery and impact noise of looms have I. INTRODUCTION long been regarded as necessary evils of the trade. Sound is a useful communication or pleasant sounds Most of the machinery in use today is more or less viz. music, speech while noise is a discord or unchanged from the design of three decades ago. unpleasant sound. Noise that is defined as unwanted The only significant difference today is that these sound has been a source of discontent ever since machines now run at very high speeds. The ring people began living together. The modern life of sheds of the spinning mills and loom sheds of many types of industrial noise, high volumes of weaving are the noisiest departments. As might be musical sound, noise due to vehicles and transports anticipated, this trend towards greater speeds has and addition of constant noise in environment from resulted in higher noise levels, often exceeding 100 variety of sources have generated a Noise Pollution. dBA in some operations. Despite the fact that Noise is one of the most common occupational health spinners and weavers have been found to have hazards. In heavy industrial and manufacturing significantly greater hearing loss than a controlled environments, permanent hearing loss is the main unexposed population, little progress has been made health concern. Annoyance, stress and interference in reducing noise in textile industries. with speech communication are the main concern in A number of studies have been carried out in last few noisy environments. So far as textile industry is decades to evaluate the occupational environment in concerned, the noise pollution is not new. The textile industries. Most of the studies have been introduction of mechanization has undoubtedly carried out in developed countries, whereas a large accentuated the noise problem. Development of proportion of textile industries over the world are modern automated machines in textile industries has located in developing countries like India. considerably decreased the physical burden of work B. Effects of noise on human health on workers but one of the most undesirable and The effect of noise will depend upon how long we unavoidable product of these machines are noise are exposed to a sound, the loudness of the sound, pollution. and the ability of our body to recover after that A. Noise in Textile industries exposure. High noise levels have been traditionally taken for Temporary threshold shift granted in Textile Industries. The noise because of ISSN: 0975 – 6744| NOV 10 TO OCT 11 | Volume 1, Issue 2 Page 47 JOURNAL OF INFORMATION, KNOWLEDGE AND RESEARCH IN CIVIL ENGINEERING Temporary threshold shift (TTS) is a temporary loss The danger limit value shall be 90-dB (A) of hearing. If we are exposed to a very noisy job, by above which the danger of hearing impairment and the end of the shift we may have noticed a loss of deafness may result from an unprotected ear. hearing sensitivity. The greatest portion of temporary A worker should not be allowed to enter, hearing loss occurs within the first two hours of without appropriate ear protection, an area in which exposure. the noise level is 115-dB (A) or more. Permanent threshold shift Personal protective equipment shall be worn, Permanent threshold shift is a permanent hearing loss if there are single isolated outbursts of noise, which that is very similar to the pattern of temporary can go above 130-dB (A) "Impulse", or 120-dB (A) hearing loss, except that we do not recover. "Fast". ¨ No worker shall be allowed to enter an area Tinnitus where noise level exceeds 140-dB (A). Tinnitus is a ringing in the ears, similar to highTABLE 1 pitched background squealing with TVs and THRESHOLD LIMIT VALUES (TLV) FOR NOISE Computers. It may accompany temporary and (OSHA) permanent hearing loss. Sound Pressure Level Duration of Exposure Presbycusis (dBA) (Hrs) Presbycusis is a hearing loss as a result of aging. Its 85 8 onset and the amount of damage vary among people. 90 4 It usually begins around age 50. It can be accelerated 95 2 by noise exposure. 100 1 Non-Auditory Effects 105 0.5 Noise can affect more than just our hearing such as: 110 0.25 Cardiovascular and physiological problems. Sleep disorders and headache II. FIELD STUDY AND DATA Mental fatigue & stress COLLECTION Annoyance, speech interference and reduced The study reported here has been carried out at the alertness, compared to those working in a relatively Textile plant located in the Ahmedabad city of quiet room (60-75 dBA) Gujarat state. The plant involved in this study employ Increased blood pressure, deep body approximately 2500 workers. Estimates of noise temperature and pulse rate. levels were determined in all the work areas of both Speed of performance was impaired the plants using a Lutron SL-4013, Type-II digital significantly by noise sound level meter. A cross- sectional study has been Loss of working efficiency. conducted involving 60 workers, randomly selected C. Directive for noise control and working in various locations of both the plants. In order to limit high level occupational noise, Workers were interviewed personally to study the maximum permissible occupational noise exposure presence of subjective noise annoyance, and other limit in the range of 85–90 dB(A) Leq for 8 h/d (40 factors i.e. awareness about effects of noise, use of h/wk) has been allowed by the International hearing protection devices etc. Standards Organisation (ISO), EEC and other A. Evaluation of Sound Level and Daily developed countries. United Kingdom, Belgium, Exposure Italy, Canada, France and Denmark allow 90 dB(A) Measurement of sound level at all the sites has been Leq Japan Sweden, Germany, Norway allow 85 done by using Lutron SL-4013, digital sound level dB(A) Leq. These limits are allowed for halving rates meter of Class-II accuracy. The SLM was calibrated of 3 dB(A) and working schedules of 8 h/d. OSHA before start of study. The measurement of sound (USA) allows 90 dB(A) for 8 h/d with halving rate of pressure has been done to determine A-weighted 5 dB(A). The TLV of noise given by OSHA are sound pressure level. shown in Table 1. Results of the noise measurement show that overall In India, model rules under Indian Factories Act— noise levels and exposure to noise in the textile plant 1948 stipulate a limit of 90 dB(A) for 8 h exposure. included in this study ranged between 80-102 dB(A) But due consideration shall be given to the fact that Leq. The details of the Leq values of noise to which most of the plants in India operate 6 d in a week and workers were exposed in various work areas is shown total noise exposure per week is therefore 48 h. in Table 2 Figure 1 shows mean noise levels i.e. Leq, Schedule 3 u/r 102 of the Gujarat Factories Rules Minimum and Maximum SPL at different machines. defines high noise as 90 dBA or more. The daily noise exposure of workers in areas like DGMS Circular No.18 (Tech), 1975 A warning limit loom shed, ring frame, speed frame, TFO (Two for of 85-dB (A) may be set as the level below which one twister), winding etc. exceeds the maximum very little risk to an unprotected ear of hearing exposure limit of 90 db(A), specified by OSHA. The impairment exists for an eight-hour exposure. noise exposure in other work areas like blow room, combing etc. was recorded less than 90 dB(A), but ISSN: 0975 – 6744| NOV 10 TO OCT 11 | Volume 1, Issue 2 Page 48 JOURNAL OF INFORMATION, KNOWLEDGE AND RESEARCH IN CIVIL ENGINEERING was quite higher than limits used for assessment of noise for community response. The direct application of OSHA regulations in Indian plants is also not valid; as most of the plants operate 8h/day and 6d/week i.e. exposure time is 48h/wk, which is 20% higher than the exposure time per week in USA or European countries. TABLE 2 EQUIVALENT SPL AT VARIOUS LOCATIONS OF TEXTILE MILL Department Work area Machine Shirting division Spinning Blow room 3 line Carding 21 83.6 Comber 15 88.7 14 84.9 12 94.1 33 97.4 19 101.1 3 95.2 10 93.3 3 91.9 2 92.4 TFO Assembl e winding Random winding Singenin g Rewindi ng Knitting division Leq dBA 8 Draw frame Speed frame Ring frame Weaving Work ers Winding 21 Looms 158 Knitting machine 77 Winding 9 Looms 110 270 357 83.5 95.3 102.1 309 90.1 89.8 Bottom weight Weaving 141 100.1 Fig 1: Mean noise levels at different machines B. Subjective response to noise The questionnaire given in Table 3 has been applied to 60 workers randomly selected working in different workplaces of the Textile mill. Noise has been reported as a major factor causing speech interference by 71% of workers. The awareness amongst the workers, regarding the effects of exposure to high noise levels was minimal i.e.28%. This factor is very closely related to use of hearing protection devices or personal protective equipments (PPE), which were being used by only 27% workers. The noise was considered an annoyance by 45% of the workers. The 20% of workers also complained of headache. The overall satisfaction with the working environment, speech interference, annoyance and headache during working hours reported by workers was directly related to noise levels in the work area given in figure 2. TABLE 3 QUESTIONNAIRE FOR PERSONAL INTERVIEW 1. Do you use hearing Protection Devices (PPE)? A: Yes B: No 2. Does speech causes speech Interference? A: Yes B: No 3. Are you aware about effects of excessive noise exposure? A: Yes B: No 4. Are you annoyed by noise in the working environment? A: Yes B: No 5. Do you frequently have headache during working hours? A: Yes B: No ISSN: 0975 – 6744| NOV 10 TO OCT 11 | Volume 1, Issue 2 Page 49 JOURNAL OF INFORMATION, KNOWLEDGE AND RESEARCH IN CIVIL ENGINEERING pyramidal or rectangular in shape. They use fiberglass as packing material. For controlling noise of spinning machine one of the efficient ways, due to the theoretical predictions of barriers, is to place a partial noise barrier as nearest to the source as possible as shown in figure 3. Thus the barrier should be closely faced to the operation point of the machine [11]. Fig 2: Results of interview questions III. NOISE CONTROL MEASURES Noise-induced hearing loss is, at present, incurable and irreversible, however, it is definitely preventable; therefore the implementation of adequate preventive programs is essential. Control methods should be aimed at: Fig 3: Placement of barrier in front of sources plus its Controlling noise at sources dimensions Precluding the propagation, amplification and reverberation of noise (path) C. Control at the receiver end[1] Isolating the workers(receivers) Hearing protection is not an acceptable alternative to A. Control at the source noise control – but there are circumstances where this Noise in spinning section can be reduced by is likely to be the only option. This is the last resort to providing elastomeric spindle mounts, elastomeric protect the ear, if other methods of control are not ring holders, proper maintenance and lubrication of possible or feasible or economical. Ear plugs and ear gears etc. The highest noise levels have been found in muffs can be used as Personal Protective Equipment loom shed. Replacement of parts with resilient (PPE). If a limited number of workers or people are materials instead of metal can provide reduction in involved this may be sometime be an attractive and impulse noise of looms. Attempts shall be made to economic approach (to protect one worker working produce complete acoustic enclosures around the with large noisy machine). looms. Sound reducing housings should be provided IV. CONCLUSION in twisters, spinning frames or the like having a The study has clearly demonstrated that the plurality of spindle assemblies. It reduces undesirable workforce in the textile plant included in this study sound produced in the m/c and is characterized by are at high risk of developing noise induced hearing providing access to spindle assemblies for services loss (NIHS) and other associated ailments due to while also reducing noise during such servicing. excessive occupational exposure to noise in the spinning and weaving departments especially those B. Control at the path[1] who work near looms, TFO, speed and ring frames. High frequency sounds can be absorbed by applying There is a need to develop and apply a well defined, sound absorbents to ceilings and walls in the form of comprehensive and enforceable noise regulation. acoustical tiles, plasters and blankets of porous materials such as glass wool. Acoustic baffles can be The efforts shall also be made towards hung from the ceilings. A variety of absorbent reducing the noise generated at the source by materials are available for an acoustic engineer in the modifications in existing technologies. form of vegetable or asbestos fibers, glass or mineral There is a need to establish a hearing wool and hard but porous plaster having less conversation program in the plants, the components susceptibility to physical damage, fire resistance, of which shall include noise assessment, increasing light reflection, aesthetic qualities etc. Application of awareness among the workers about the adverse acoustical material on ceiling and side walls can effects of noise, use of hearing protection devices and reduce 3 to 8 dB noise level and bring down the audiometry. general reverberate noise level to make the noise Although less practical, wherever possible conditions less confusing. by application of equal energy principle, the exposure Functional Sound Absorbers may be clustered as near time must be decreased with increase in the Leq. the machines as possible. These units may be suspended and distributed in any pattern to obtain lower noise levels within the machine shop. They are ISSN: 0975 – 6744| NOV 10 TO OCT 11 | Volume 1, Issue 2 Page 50 JOURNAL OF INFORMATION, KNOWLEDGE AND RESEARCH IN CIVIL ENGINEERING ACKNOWLEDGMENT I would offer my sincere thanks to Prof. N. S. Varandani (HOD) and Assit. Prof. Minarva Pandya who helped and guided me in the making and presenting of the report. I am also thankful to general manager (HRD) of textile plant for giving me permission to conduct noise survey and all extended sorts of help. REFERENCES [1] Dr. K. U. Mistry, Fundamentals of Industrial Safety and Health, 2008. [2] S C Bhatia, Textbook of Noise Pollution and its control, 2006 [3] Lawrence K. Wang, Norman C. Pereira and Yung-Tse Hung, Advanced Air and Noise Pollution Control,2005 [4] R. K. Jain and Sunil S. Rao , Industrial Safety, Health and Environmental Management Systems,2009 [5] Istvan L. Ver and Leo L. Beranek, Noise and Vibration Control Engineering: Principles and Applications,2006 [6] Canandanian Center for Occupational Health and Safety, www.ccohs.ca/oshanswers.html [7] Raman Bedi, “Evaluation of occupational environment in two textile plants in Northern India with specific reference to noise”, Industrial Health 2006, Vol-44, No.1, Pg. 112-116. [8] Aitbar Ali Abbasi, Hussain Bux Marri and Murlidhar Nebhwani, “Industrial noise pollution and its impacts on workers in the Textile based cottage industries: An empirical study”, Mehran University Research Journal of Engineering & Technology, January 2011, Vol. 30, Pg. 35-44 [9] Md. Yusuf Haider, Ahmmad Taous, Manjur Rahim, A. H. M. Zahurul Huq, M Abdullah, “Noise induced hearing loss among the textile industry workers”, Bangladesh Journal of Otorhinolaryngology 2008, Vol-14(2), Pg. 39-45 [10] M. Mohammadi Roozbahani, P. Nassiri, P. Jafari Shalkouhi, “Risk assessment of workers exposed to noise pollution in a textile plant”, International Journal of Environmental Science & Technology-Autumn 2009, Vol-6 (4), Pg. 591-596. [11] M. R. Monazzam and A. Nezafat, “On the application of partial barriers for spinning machine noise control: A theoretical and experimental approach”, Iran Journal of Environmental Health and Science Engineering, 2007, Vol. 4, No. 2, Pg.113120 [12] Farouk M. Shakhatreh, Khader J. Abdul-Baqi, Moh’d M. Turk, “Hearing loss in a textile factory”, Saudi Medical Journal 2000, Vol-21(1), Pg. 58-60 [13] Central Pollution Control Board, www.cpcb.nic.in [14] IS: 4758-(1968) Indian Standard, Methods of measurement of noise emitted by machines. BIS, India ISSN: 0975 – 6744| NOV 10 TO OCT 11 | Volume 1, Issue 2 Page 51