Assessment of Noise Levels at Renovation Site ...

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Regional Occupational Health Centre (Eastern), Indian Council of Medical Research, Block-DP-. 1, Sector-V ... the ill effects of exposure to high level of noise.
IJEP 36 (2) : 124-130 (2016)

(Received on September 11, 2015)

Assessment of Noise Levels at Renovation Site, Eastern India Anupa Yadav, Ashit K. Mukherjee, Sanjit K. Roy and Surjit Das Regional Occupational Health Centre (Eastern), Indian Council of Medical Research, Block-DP1, Sector-V, Salt Lake, Kolkata-700 091 The study being reported here has been carried out in an office building which was under renovation work, in Kolkata city of Eastern India. Continuous equivalent sound pressure level Leq has been measured by hand held analyzer type-2250L. The study involves 76 subjects (36 workers and 30 office staff members as control group). The result reveals that noise level in certain activities, like railing polishing and marble cutting is more than the accept limits of 90dB (A) for 8 hr exposure stipulated by OSHA and IFA (1948). While noise level in other activities, like plaster removal from walls, drilling of surfaces, etc., is less than 90 dB (A).The results of personnel interview reveal the followings : (i) Speech interference by 97% and 64% of control group and workers, respectively, (ii) 44% of workers and 77% of control group are aware about adverse effects of noise exposure, (iii) noise annoyance by 64% of workers but 100% of control group, (iv) only 6% of workers using hearing protection device and (v) 14% of workers know about the benefits of using PPE. The study demonstrates the presence of high noise at renovation site and high noise annoyance by control group than workers. However, workers are at high risk of developing noise induced hearing loss (NIHL). KEYWORD Speech interference, Noise annoyance, Hearing protection device, Personal protective equipments, Noise induced hearing loss. INTRODUCTION Renovation usually requires all of the sub-trades that are needed for the construction of a new building. Construction and renovation sites are characterized by intense use of impact equipments and tools, like hammer, drill machine, saws, marble/rod cutting machine, railing polishing machine, etc. Practices, like wall faulting, floor faulting, plaster removal from walls, surface drilling, tiles cutting, concrete blocks cutting, etc., results in the production of high level of noise at work sites. Therefore, workers are exposed to high level of noise as a part of their job. In developing and third world countries, like India, there is still ignorance about the ill effects of exposure to high level of noise. Whereas noise induced hearing loss (NIHL) is a well known noticeable disease among 124

occupational workers and compensable in nature under Indian Factories Act (IFA) (1948) and Workmen Compensation Act (1923). Construction workers are at high risk of developing auditory/ non-auditory effects (Suter, 2002). The International Labour Office (ILO) encyclopedia lists the construction industries as the 4th nosiest industry sector.High noise level, not only hinders communication between workers, but depending upon the level and duration of exposure, it may also result in various auditory and non-auditory morbidity in workers (Sinhg and Dawar, 2004; Stansfeld and Matheson, 2003; Vidya and Nageshware, 2006). It is well known that excessive noise has interference with safety of workers (Sen et al., 2010). A study conducted in north India by Singh et al. (2009), in small scale industries shows 95% of the workers involved in the study suffered with speech interference and 20% with high noise annoyance. Miyakita and Ueda (1997) and Wu et al. (1998) reported that approximately 16-50% workers in const-ruction industries suffering with noise induced hearing loss and Arndt et al.

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Table 1. Demographic characteristic of study group Study

Number

group

(n)

Workers Control Male Female

36 28 02

Gender

Age,

Work,

Education

Working,

year

year

College+

HS or less

hr/day

Male

18-60

1-20

0

36

8**

Male Female

26-61 28-53

2-38 2-35

30

0

8

** Many times working hr/day may vary as per work load (1996) observed, it was as a common morbidity in construction industries workers. A longitudinal study (10 years period) on construction workers, revealed noise-induced auditory morbidity even at noise level of 85 dB (A) (Seixas et al., 2012). Noise control directives For prevention of high occupational noise exposure, maximum permissible occupational noise level limit range 85-90dB (A) Leq for 8 hr/ day (40 hr/week), has been allowed by the International Standards Organization (ISO), European Commission (EEC) and other developed countries. Occupational Safety and Health Administration (USA) allows 90 dB (A) L eq for 8 hr/day (40 hr/week). ISO suggested that the range of ontologically normal young adult should be 27 dB(A) at 250 Hz, 11.5 dB(A) in midrange 3 KHz, 16 dB(A) at 6 KHz and 15.5 dB(A) at 8 KHz (w.r.t. level of 20 µpa). In India, rules under Indian Factory Act (1948) (IFA) stipulate a limit of 90 dB (A) for 8 hr exposure. But due consideration shall be given to the fact that most of the industries in India operate 6 days in a week, so total noise exposure per week is 48 hr. Most of the workers employed in industries are skilled or semi skilled, illiterate or semi illiterate, having no information about the noise regulations and adverse effects of noise on their health. The present study also reveals the same and other factors, like speech interference/annoyance, etc. SUBJECT AND METHOD The present study has been carried out in an office building which was under renovation work, in Kolkata city of eastern India. The building was

renovated for infrastructural improvement. It was not vacant and office work was also going side by side alongwith renovation work. This renovation work involved many processes, like removal of plaster from walls, wall faulting, floor faulting, drilling, railing installation/polishing, marble cutting, etc. Total 76 subjects (36 workers and 30 office staff as control group) were involved in this study. The control subjects were from the same building in which renovation work was going. The demographic characteristic of the study subjects are presented in table 1. A comprehensive questionnaire (Table 5) was formulated to assess the subjective information regarding the noisy environment. The information from both the study groups was collected by personal interview through questionnaire method. Since the workers were mostly illiterate or less educated, therefore, statements of the questionnaire were translated in local language Bengali and National language Hindi. Noise measurement The noise level measurement for various activities during renovation work was done by using Hand–Held analyzer type 2250L with microphone type-4950, Bruel and Kjaer, Denmark. The sound level meter was calibrated periodically with sound calibrator type-4231. The measurements of equivalent continuous Aweighted sound pressure level were done. The measurements were recorded through data logging facility of the sound level meter and then transferred to computer for further analysis. The inbuilt software enhanced by Bruel and Kjaer was used for calculation and analysis. Measurement of equivalent sound pressure level

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Table 2. Noise level at renovation site Renovation activities

Leq(A) dB

LMin(A) dB

LMax(A) dB

TWA dB

Plaster removal from wall Wall faulting Floor faulting Drilling Railing installation Railing polishing Marble cutting

85 .8 83 .8 82 .3 86 .5 88 .0 92 .3 95 .4

60 .9 54 .9 56 .5 53 .1 61 .0 59 .9 53 .0

106.6 100.3 102.7 106.3 107.1 101.7 105.6

81 .5 80 .8 79 .6 82 .5 84 .4 86 .9 91 .0

(Leq) in each activity is presented in table 2. As per prevailing practice the workers were given lunch break of 1 hr and two tea breaks (10 min each) including the work time of 8 hr but many times they were doing 2-3 hr overtime depending on work load. Mostly work was done inside the building rooms and on stairs inside the building premises. The noise measurement was recorded for 1 hr each time for each process and same was recorded atleast 7-8 times for every work. Sound level meter was placed at the centre of rooms at appropriate height each time for every activity noise measurement. In each working location 4-5 workers were engaged. All the subjects involved in the study were asked various questions, like noise annoyance, speech interference, headache, awareness about hazardous impacts of noise, etc. Authors endeavored to find the level of difference among workers and control group for response towards some common questions by their personal interview.

While the noise exposure in other process, like railing polishing and marble cutting exceeds the exposure limit of 90 dB(A). Renovations usually involve all of the sub-trades that are used for the construction of a new building and in this work area application of OSHA norms is very difficult because many times working hour of construction labour is more than 8 hr/day or 6 days/week, that is exposure duration is 48 hr/ week. When study subjects were interviewed personally then it was reported that they opt for 2-3 hr/day or 12-18 hr/week overtime (Table 1). Therefore, total exposure time of workers in a week was 22-25% higher than the exposure time in USA and European countries (Bedi, 2006; Singh et al., 2009). Personnel response to noise

Noise level

Personnel reactions for noisy environment were collected from exposed workers (n=36), categorywise; 5 mistries, 2 electricians, 22 construction labours, 4 marble/tiles cutting workers and 3 railing workers and control group (n=30). The demographic characters of both the study groups are shown in table 1.

Results reveal that overall noise level and exposure to noise in various activities during renovation work ranged from 82.3-95.4 dB(A) Leq. The details of Leq, Lmin, Lmax and TWA values are presented in table 2. The noise exposure of workers in renovation activities, like plaster removal from walls, drilling of surfaces, walls faulting, floor faulting and railing installation is less than the maximum exposure limit of 90 dB(A) recommended by OSHA and IFA (1948), but is quite higher than limits used for assessment of noise for community responses.

Workers response : The response ratio of workers to various questions on noise environment are summarized in figure 1. The result of personal interview by questionnaire method reveals that 6% of the workers’ felt high annoyance, 3% felt annoyance, 53% felt moderate but 39% felt no annoyance by work noise. The same could be attributed to the workers acceptance of noise as a part of their job and they are adapted with this high noise exposure. Noise annoyance felt by workers also varies with age and exposure duration, noise

RESULT AND DISCUSSION

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Figure 1. Response ratio of the control group for various questions on noise environment

Figure 2. Response ratio of the workers for various questions on noise environment annoyance was more in age range 31-40 years and exposure groups of 1-5 years as compared to other groups (Table 3), findings are consistent with results of Singh et al. (2009). Comparitive response ratio for noise annoyance between workers and controls is shown in figure 3 and this reflects adaptability of the workers towards high noise work exposure. Workplace noise has been also reported to cause speech interference

Figure 3. Noise annoyance felt by control and exposed group by 64% workers. Most of the workers were illiterate or less educated so awareness about the effects of excessive noise exposure is less, only 44% workers are aware about adverse effects of noise exposure. Unfortunately this may be the reason that 14% of them know about benefits of using personal protective equipments and only 6% of them using hearing protection device. Hearing disability is more in age range 40-49 years (Table 4) that may since everyone develop some degree of presbycusis but exposed workers develop it sooner due to regular heavy noise exposure. Exposed group of 5-10 years also shows more hearing disability than the other groups (Table 4), possible reason is that continuous or intermittent noise exposure increases hearing loss most rapidly during the first 10-15 years of exposure and it was evident that previously noise-exposed ears are not more sensitive to future noise exposure (Kirchner et al., 2012). Control group response : Questionnaire responses are summarized in figure 2. Noise produced during renovation work has been reported the major factor causing speech

Table 3. Workers noise annoyance distribution w.r.t. age and exposure duration Age range, year

20

Total

9 (43%)

4 (19%) 4 (19%) 2 (10%) 2 (10%) 2 1

11-15

41-50

16-20

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Table 4. Hearing disability in exposed workers w.r.t. age and exposure duration Age range, year

20-29

30-39

40-49

Total

Noise annoyance number of worker

2 (20%)

5 (10%)

3 (30%)

10

Exposure, year

5-10

11-15

16-20

Total

Noise annoyance number of worker

6 (60%)

2 (20%)

2 (20%)

10

Table 5. Questionnaire for personal interview 1.

Dose noise causes any speech interference? (i) Yes (ii) No 2 . Are you aware about effects of excessive noise exposure? (i) Yes (ii) No 3 . (A) Are you annoyed by noise in the working environment? (i) Yes (ii) No If yes: (B) Rate the annoyance due to noise : (i) Very annoying (ii) Annoying (iii) Moderate (iv) None 4 . Rate the overall satisfaction with working environment: (i) Very high (ii) High iii) Moderate iv) Low 5 . Do you frequently have headache: (i) Yes (ii) No 6 . Do you use any hearing protecting devices? (i) Yes (ii) No 7 . Do you know about benefit of PPE? (i) Yes (ii) No 8 . Do you have hearing disability due to work? (i) Yes (ii) No 9 . When exposed to excessive noise and noise get stopped suddenly then you feel some effect on hearing / ear : (i) Yes (ii) No 1 0 . Have any time you told to worker to stop the work and do it after office hours due to noise annoyance? (i) Yes (ii) No 1 1 . Have you felt anytime that when this noisy work gets finish so that we work peacefully? (i) Yes (ii) No Note : Questions 1-5 common for both the study group, Q. 6-8 only for worker and Q. 9-11 only for control interference by 97% and annoyance by 100% office staff (control group). Headache, effect on ears and heavy noise irritation are felt by 47%, 63% and 60% of control group, respectively. All 128

the office staff members were well educated (Table 1). They are not habituated for daily exposure to such heavy noise. They worked in calm and quite office environment, therefore,

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they felt comparati-vely more annoyance, speech interference and headache, etc. It was also felt by 97% of the control group that they get relief from the noisy environment when the building renovation gets finished. CONCLUSION The study clearly demonstrates that high noise exposure causes more annoyance and speech interference among the control group then exposed workers, may be construction workers get adapted towards this noise but office staff has habituated to work in clam working environment. Simultaneously the construction workers are at high risk of developing noise induced hearing loss and other associated nonauditory effects due to excessive occupational noise exposure. There is need to develop and apply well defined, comprehensive and enforceable noise regulations. The limits of 90 dB(A) for 8 hr/day stipulated by OSHA and IFA (1948) shall be followed strictly, as in India construction workers work for 6 days/week alongwith 2-3 hr/day overtime, that is 22-25% higher than the exposure time per week in USA and European countries. There is immediate need to provide hearing protection device to the occupationally exposed workers and encourage them to use the same by organizing awareness programmes. For long lasting of workers’ health, it is need to organize hearing conser-vation programmes on yearly basis, the components of which shall include noise assessment, increasing awareness about adverse auditory/ non-auditory effects of noise on workers’ health, use of hearing protection devices, etc. Although less practical, but if possible apply equal energy principle, that is the exposure time must be reduced with the increase of Leq. Construction workers often move from one work site to another to carry out serial construction projects. Therefore, construction contractors, unions, health and safety associations and Ministry of Labour in India need to consider improved methods for prevention of occupational noise induced hearing loss in construction workers. REFERENCE Arndt, V., et al. 1996. Older workers in the construction industry : Results of a routine health examination and a five year follow up. Occup.

Env. Med., 686–691. Bedi R. 2006. Evaluation of occupational environment in two textile plants in northern India with specific reference to noise. Ind. Health. 44 : 112–116. Kirchner, B., et al. 2012. Occupational noiseInduced hearing loss. J Occup. Env. Med., 54 : 106-108. Miyakita, T. and A. Ueda. 1997. Estimates of workers with noise-induced hearing loss and population at risk. J Sound Vib., 205 : 441– 449. Seixas, N.S., et al. 2012. 10 year prospective study of noise exposure and hearing damage among construction workers. Occup. Env. Med., 69 : 643-650. Sen, T., et al. 2010. Study and comparison of the noise dose on workers in a small scale industry in West Bengal. Int. J. Env. Sci. Develop., 1. Singh, L.P., et al. 2009. Occupational noise exposure in small scale hand tools manufacturing (forging) industry (SSI) in northern India. Ind. Health. 47 : 423–430. Sinhg, N. and S.C. Dawar. 2004. Noise pollution-Sources, effects and control. J. Hum. Ecol., 16 : 181-187 Stansfeld, S.A. and M.P. Matheson. 2003. Noise pollution : Non-auditory effects on health. British Medical Bulletin. 68 : 243-257, Suter, A.H. 2002. Construction noise : Exposure, effects and the potential for remediation : A review and analysis. Am. Ind. Hyg. Assoc. J., 63 : 768–789. Vidya, S.T. and R.G. Nageshware. 2006. Noise pollution levels in Visakhapatnam city. J. Env. Sci. and Eng., 48 : 139-142. Wu, T.N., et. al. 1998. Surveillance of noiseinduced hearing loss in Taiwan, ROC : A report of the PRESS NIHL results. Prev. Med., 27 : 65–69. AUTHOR 1*. Ms. Anupa Yadav, Technical Assistant, Regional Occupational Health Centre (Eastern), Indian Council of Medical Research, Block-DP1, Sector-V, Salt Lake City, Kolkata-700 091. 2. Dr. Ashit Kumar Mukherjee, Scientist ‘F’, Regional Occupational Health Centre (Eastern),

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Indian Council of Medical Research, Block-DP1, Sector-V, Salt Lake City, Kolkata-700 091. 3. Mr. Sanjit Kumar Roy, Technician, Regional Occupational Health Centre (Eastern), Indian Council of Medical Research, Block-DP-1, Sector-V, Salt Lake City, Kolkata-700 091. 4. Mr. Surjit Das, Technical, Regional Occupational Health Centre (Eastern), Indian Council of Medical Research, Block-DP-1, Sector-V, Salt Lake City, Kolkata-700 091.

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