Measurement of Noise Pollution in Indoor Pools with Emphasis on the Health of Users (Case study: Mashhad City)

Although sound waves are considered as an essential factor in human life, but in some cases and in special circumstances, hearing these sound waves is not very pleasant and exposure to annoying sounds too much will cause hearing loss in humans. (1). Noise pollution is defined as the emission of any kind of noise and excessive vibration in open spaces and is one of the examples of damage to the environment (2); So that it will have very clear effects on human health and ecosystems (3). In addition to the negative impact on the auditory system, noise as a stressful source will also affect the human heart and arteries and stimulate the nervous system, cause anxiety and increase mental health problems (7). Environmental conditions have a significant impact on how sound is emitted. However, after a period of exposure to noise, man becomes accustomed to those conditions; But again, noise pollution is a cause of fatigue and reduces the capacity of human work, both in mental jobs and in simple physical jobs. On the other hand, noise pollution affects the mental state of people and causes problems in adapting to their work environment and even the community and family; the result will be a reduction in productivity and productivity (10). Gyms and swimming pools are poorly sounded environments due to the lack of sound-absorbing materials, noisy sports activities, the simultaneous presence of many users, and the heavy use of whistles for communication. As a result, physical education educators not only suffer from prolonged stress and strain, but are also exposed to noise-induced hearing loss. Therefore, it is necessary to carefully analyze all the factors that can affect the noise in these environments, in order to provide guidelines for officials and planners for stress management and hearing protection programs (11). The present research is an applied research that has been done by networking method. The purpose of this study was to measure noise pollution in indoor pools with emphasis on the health of staff and users of indoor pools in Mashhad.

The sound level was measured as an equivalent level by the portable device and software Decibel X version 2020 and was compared with the sound standard (OSHA-90 dBA). Measurements Calculated the parameters of sound pressure level (SPL), average sound level (LP) ̅), continuous sound equivalent level (Leq) and individual daily dose of LAEp, d in 3 shifts.

The lowest sound pressure level in the first turn was 76.5 dB and the highest pressure level in the second turn was 97.7 dB. The average sound pressure level increases with the change of time from morning (11 am) tonight (8 pm). The average sound level in indoor pools is equal to 78.4 dB and the level is equal to 85.42 and the individual daily dose of LEp, d personnel and users is 92.45 and 87.15 dB, respectively. The permissible noise exposure time was estimated at 1 hour and 30 minutes for users and 5 hours for personnel, indicating that users were 30 minutes and personnel 3 hours more exposed to noise pollution than allowed.

In the indoor pools of Mashhad, staff and users are exposed to high noise pollution and the possibility of physical and psychological injuries is high. Existing sound levels are higher than international and national standards and indicate that the use of engineering management principles is necessary to reduce the sound level in indoor pools. Swimming is one of the most popular sports activities. Diving in water, the whistling of coaches and saviors, moving equipment, the sound of music playing, athletes talking, emotional screams, etc. all provide the ground for raising the sound level. Accordingly, the prolonged or frequent presence of an athlete in an environment with high noise levels, can increase the risk of injuries due to noise pollution and may even reduce his efficiency. The results of the present study showed that the sound level in the shifts in which men were present was not much different from the shifts of women. Also, in the morning sports times (11/15/11), the sound level was significantly lower than in the evening (17-17-17), which is probably due to the smaller number of athletes in the morning compared to the evening.  In general, the absence of the above conditions has caused an increase in the sound level in the selected indoor pools. Of course, there was no significant difference in terms of sound level in different areas of Mashhad and in this regard, there can be no difference in terms of sound level published in indoor pools based on zoning in Mashhad. This research is methodologically consistent with the research conducted by Taheri et al. (1398) (32). But; their results cannot be generalized and compared with each other, because the environment studied in this study was closed space. However, the results are to a large extent consistent with the results of studies of Bahmanpour et al. (2011), Mafi et al. (2009) (28, 11). Comparison of the average sound level in the indoor pools studied with international standards shows that most of the measured pools (except pools 9 and 10) have a lower average sound level than the NIOSH, OSHA and ACGIH standards. However, all the pools studied have a sound level higher than the standard of the Environmental Protection Agency, as well as the standard of leisure centers and parks in the United Kingdom (which is equal to 55 decibels). They also differ from the United Nations Development Program (UNDP) standard of 55-65 decibels. On the other hand, the allowable exposure to the sound level in the studied pools for athletes is 1 hour and 30 minutes, which is basically 30 minutes less than the current time. In other words, at present, athletes are exposed to sound levels for about 30 minutes longer than allowed. Also, for employees (management and employees) the allowable limit of 5 hours was set, which is basically 3 hours less than the current situation. Therefore, due to the sound level in swimming pools, personnel should be present in the pool environment for 3 hours less so as not to be exposed to high sound levels.