ABSTRACT
ABSTRACT
The purpose of this study was to quantify noise exposure of professional physical education instructors in Portugal, understand how they perceive risk and the effects associated with this exposure as well as examine the existence of health complaints potentially related to the exposure to noise. Quantification of sound level exposure comprised 200 measurements of different sport activities in state schools and private health clubs. Characterization of risk perception as well as symptomatology was performed by a three-part survey that provided to a sample of 48 physical education professionals and a comparison group of 52 non-professionals. Results showed the existence of high noise levels that may endanger physical education teachers’ health. These levels are significantly higher in health clubs. Health complaints were significantly higher in the group of professionals, especially concerning hearing difficulties, muffled hearing, intolerance to loud sounds, constant headaches, and irritability. The majority of the physical education instructors are exposed to high levels of sound pressure on a daily basis, which depending on their working hours may compromise their health. This study also reveals the importance of training as well as organizational and structural measures to reduce exposure to harmful noise levels during the performance of sports activities.
INTRODUCTION
The subject of occupational noise has been studied in a wide range of fields (Smith and Broadbent 1992; Irwin 1997; Melamed et al. 1999; Rabinowitz et al. 2011). The modern industrialized world is characterized by a permanent contact with technology that makes difficult the avoidance of the omnipresence of noise.
Long periods of exposure to noise may lead to noise-induced hearing loss (NIHL), which is characterized by a sensorineural, irreversible, and progressive change in hearing thresholds (Guida 2007). Other auditory symptoms that may be observed include tinnitus and noise sensitivity (Widen and Erlandsson 2004). Regarding the extra-auditory effects of noise, some studies have identified irritability, fatigue, sleep disorders, cardiovascular, and gastrointestinal disorders as consequences of noise exposure (Floru and Cnockaert 1994; Melamed and Bruhis 1996; Crandell et al. 1997; Toppila et al. 2000). Noise can also act as a non-specific physiologic stress (Anticaglia and Cohen 1970).
Directive 2003/10/EC states the minimum health and safety requirements regarding the exposure of workers to noise, stipulating lower and upper exposure action values of LEX,8h 80 and 85 dB(A) and Ppeak 135 and 137 dB(C), respectively, which when exceeded will imply the adoption of preventive measures to reduce the risk to the health and safety of the worker. It also defines the personal exposure limit values, LEX,8h = 87 dB(A) and Ppeak = 140 dB(C), which must never be exceeded.
Physical education instructors often work in closed spaces (gyms and/or classrooms), with reverberation characteristics where sound propagates in all directions. The sports activities in gyms are very noisy (bouncing balls, shouting, etc.). Moreover, nowadays many activities in health clubs (body pump/attack/combat, step, hydrogymnastics, targeted fitness, etc.) are often accompanied by music with high sound levels in order to set the rhythm of the exercise being performed. This fact results in the exposure of physical education instructors and those practicing the activity in question to high levels of noise.
Music, which is used in many fitness activities, has some benefits; for instance, it appears to significantly increase students’ endurance and effort during exercise (Karageorghis and Priest 2008). However, it may contribute to an increase in the noise levels in a room where sport is practiced. The perception of the risk associated with noise, in these conditions, is influenced by subjective criteria, to the extent that it may seem pleasant, which means that the physical education instructor or those practicing the activity may not always be aware of the risk to which they are subject. Studies have shown that a noise classified as pleasurable may cause less damage than a noise considered unpleasant that has the same sound pressure level (Reid and Holland 2008).
Some studies carried out in school environments show the existence of unacceptably high sound levels (Jiang 1997; Pękala and Leśna 2005; Maffei et al. 2009). However, studies that characterize the exposure to noise of physical education instructors in health clubs are still scarce. Examples of studies on this subject include those by Mirbod et al. (1994) and Maffei et al. (2009). As a consequence, the need to examine the exposure of physical education instructors to noise, not only in a school environment but also in other sports facilities, and to understand how they perceive that exposure and its potential health effects provides a research opportunity.
This study aimed to achieve the following objectives:
| • | Describe the activity of physical education instructors; | ||||
| • | Evaluate the sound levels in physical education classes in schools and in various activities in health clubs; | ||||
| • | Identify the existence of auditory and extra-auditory symptoms, which are potentially related to the exposure to noise; | ||||
| • | Characterize the perception of risk and its effects by this group of physical education professionals and compare it to a similar group that is not exposed to comparable noise (the comparison group). | ||||
METHODS AND MATERIALS
Several health clubs and schools in Portugal were contacted with the purpose of establishing protocols for collaborating in the study. Sound levels were evaluated in eight separate sports facilities in the Greater Porto area—one typical state school and seven health clubs. The architecture of school buildings in Portugal is quite similar, especially for sports pavilions, therefore the selected state school was considered typical of such schools. The study covered more than 200 classes in various types of activities: physical education classes in the 2nd and 3rd cycle in state school and fitness classes (step, targeted fitness, jump, combat, pump, indoor cycle, etc.) and water activities (swimming, hydrogymnastics, hydrobike, etc.) in health clubs.
Sound levels were measured using a Bruel and Kjaer class 1 integrating sound level meter, model 2260, equipped with a 1/2 inch diameter condenser microphone. The device was calibrated by an accredited laboratory according to standard IEC method 61672-1:2002, and has a standard uncertainty of 0.7 dB, which is specified for class 1 sound levels (ISO 9612:2009).
The sound level fluctuates or varies randomly over time T, and we can define an average level, LAeq,T, expressed in dB(A), that produces the same noise energy as the true sound during the same time period, which is given by: 
The maximum exposure time to a given sound level, without causing hearing damage, varies from one organism to another. However, Directive 2003/10/EC of the European Parliament and of the Council of 6 February defines, for a normal workload of 8 h per day 5 days a week, a sound level Exposure Limit Value, ELV, per day that should never be exceeded, and an Upper Action Value, UAV, which when exceeded implies the adoption of preventive measures for reducing the risk to the health and safety of workers. These values are 87 dB(A) and 85 dB(A) for the ELV and UAV, respectively.
Using the expression: 
Rearranging Eq. (2), we obtain: 
Table 1 L A,eq,Te and Te corresponding to the exposure to ELV and UAV.
Sound level measurements were performed for both groups (comparison and professional group) and comprising the duration of the class (50/60 minutes). For the professional group the measurements were held by activity and the number of them varied between 3 and 28. Equivalent continuous sound level, LAeq , and the C-weighted peak sound pressure level, LCpico , were recorded.
A survey was provided to a sample of physical education teachers and a non-professional group that works in the field of education in order to evaluate the daily routine of all surveyed, the existence of auditory and extra-auditory symptoms, and the perception of risk and its related effects by all the elements surveyed.
The first part of the survey obtained information about sociodemographic data of the subjects such as gender, age, and professional and non-professional activities that involve noise exposure. The second part of the survey gathered information about the existence of hearing diseases or lesions, as well as auditory and extra-auditory symptoms related to noise exposure. The symptoms considered and listed in the survey were adopted from studies by Fernandes and Morata (2002) and Sabaté (2007).
The third and last part of the survey evaluated the perception of risk of the subjects as well as the perception of the effects of noise exposure on subjects’ health. The questions related to the perception of risk and its effects were formulated based on a model used by Arezes (2002), and were subsequently adapted to the needs of this study. This individual perception of risk was evaluated based on a collection of questions with a Likert-type optional response scale, based on two sub-groups: the first from 1, “High risk,” to 5, “No risk,” and the second from 1, “Completely agree,” to 5, “Completely disagree.” The survey was provided to all professionals whose classes were subject to a noise measurement.
The proportions of positive responses related to the auditory and extra-auditory symptoms reported by the group of physical education professionals and the comparison group were determined. The P-value method was then used to compare these proportions. For the study of the risk perception and its effects, medians were calculated and the Mann-Whitney test (U-test) was used to test whether the two samples were drawn from populations with the same medians. The tables and statistics were derived using the software programme PAWS Statistics for Windows, version 18.0.
Samples
The study comprised two samples. A sample of 48 physical education teachers, 28 men (58.3%) and 20 women (41,7%), aged between 24 and 55 years, with an average age of 32.9 years (SD = 7.4). For the data analysis only cases involving more than 1 year's work experience and more than 10 contact hours per week were considered. The average work experience of individuals in the sample was 10.3 years of work (SD = 7.5), with an average of 29 contact hours per week (SD = 15.7), out of which an average of 13 hours (SD = 7.5) were taught with musical accompaniment. Regarding the professional profile, only 9% of the sample taught classes only in schools and 40% taught only in health clubs, while the remainder taught in both systems.
The sample used for the comparison group comprised individuals from the same region, who worked in the field of education (teachers of other subjects), which are mainly exposed to the noise of a regular classroom, 50 to 70 dB(A) (Crandell and Smaldino 2000). There were 52 individuals in the comparison group, 31 men (59.6%) and 21 women (40.4%), aged between 19 and 49 years, with an average age of 31.3 years (SD = 8.1).
Individuals who reported some form of hearing impairment or who used hearing aids were excluded from the study, as well as individuals who reported frequently using fire arms, practicing motor sports, going to concerts and nightclubs, listening to music with headphones, and playing musical instruments with amplifiers as part of their non-professional activities.
RESULTS
Sound Levels
Presented in Table 2 are the results of the evaluation of the sound levels recorded in school gyms and in health clubs, with the minimum, maximum, and average sound level by activity, related uncertainty, and the sample size. In the health club activities, the number of samples varies quite a lot, and the activities with the largest number of samples are those that were available in virtually all of the clubs surveyed. Some activities were only available in one or two of the health clubs, and therefore have such a small number of samples. The sources of uncertainty considered to determine uncertainty (U) were reproducibility, the measuring device, and the location of the microphone. The value of the coverage factor used was k = 1.65, which corresponds to a unilateral confidence interval of 95% (ISO 9612:2009).
Table 2 Sound pressure levels by activity. U is uncertainty and n is the sample size.
The highest sound measurements were recorded for the activities cycle, jump and combat, with an average value of 92 ± 2.3; 92 ± 3.1, and 92 ± 2.4 dB(A), respectively. Cardio fitness and weight training and swimming had the lowest average values, 79 ± 2.5 and 81 ± 2.5 dB(A), respectively.
Auditory and Extra-Auditory Symptoms
Auditory and extra-auditory symptoms associated with exposure to noise mentioned by the individuals in both samples are presented in Tables 3 and 4. The P-value method of hypothesis testing for the two population proportions was used, with a significance level α = 0.05, assuming that the null hypothesis as symptom proportion of the physical education group equals to the symptom proportion of the comparison group. The P-values found are also presented in Tables 3 and 4. We found statistically significant differences in proportions (p < 0.05) of the symptoms: hearing difficulties, muffled hearing, intolerance to loud sounds, constant headaches, and irritability; when comparing the groups of sports professionals with the comparison group. For the other symptoms there were no statistically significant differences (p > 0.05).
Table 3 Distribution of the auditory symptoms felt by those surveyed and the P-value of test statistic for proportions. The proportion, p, was defined by the proportion ± the margin of error (95% confidence interval).
Table 4 Distribution of the extra-auditory symptoms felt by those surveyed and the P-value of test statistic for proportions. The proportion, p, was defined by the proportion ± the margin of error (95% confidence interval).
Perception of the Risk of Exposure to Noise and its Effects
Regarding the perception of risk, four questions were posed for the individuals surveyed to evaluate the level of risk associated with different situations. The answers collected for both groups are presented as percentages in Table 5. We found that a relatively high percentage of instructors have a perception of the risk they are exposed to when in situations with high sound levels. Among the instructors surveyed, 89.6% felt there was a high/some risk when exposed to sources of sound nearby such as speakers; 89.6% when exposed to “very loud music”; 54.2% when exposed to the noise caused by work, and 72.9% when exposed to music with headphones. The comparison group revealed lower percentages in all. When comparing the median level of risk of professional and comparison groups, the results showed that instructors and members of the comparison group have the same perception of the risk. Using the Mann-Whitney test, we found no statistically significant differences (p > .05) in the medians of the answers reported by the groups (Table 6), with the exception of Question Q3 “Exposure to the noise caused by work,” where there was a statistically significant difference (p < .05).
Table 5 Evaluation of the level of risk, by the professional and comparison groups, when exposed to different situations (percentages obtained by comparison group are highlighted in grey).
Table 6 Medians and P-value obtained when comparing the results of risk level of both groups through the use of Mann-Whitney test.
Instructors’ perception is corroborated by a second subset of questions, where they were asked to state whether they agreed or not with the statements presented in Table 7. The medians of the answers collected for the professional and comparison groups are presented in the graph shown in Table 8.
Table 7 Percentage of professional and comparison groups answers when they were asked to agree or not with a set of statements (percentages obtained by comparison group are highlighted in grey).
Table 8 Medians and P-value obtained when comparing the results of risk perception of both groups through the use of Mann-Whitney test.
Based on the Mann-Whitney test, statistically significant differences (p < .01) were found in the medians of the populations from which these samples were drawn (Table 8), for the statements S3—”During my work noise is loud”; S4—”I suffer from hearing problems due to exposure to noise”; S6—”I cannot talk to students easily (without raising my voice)”; and S10—“At the end of day I have trouble hearing but my full hearing is restored.”
DISCUSSION
A wide range of evaluated activities showed a significantly high sound level, with maximum values around 96–97 dB(A) recorded in activities in health clubs and around 86 dB(A) in school gyms. Studies by Deus and Brittes (2000), Barreira and Carvalho (2005), and Conceição (2009) recorded values similar to those presented in this study in some activities. Nehring et al. (2012) in a study performed in a dance academy involving 22 teachers recorded similar noise levels values, which varied from 65 to 95 dB, for all forms of dance and that 45.5% of the teachers accompanied their classes with music which noise levels were higher than 85 dB.
According to the sound levels to which physical education instructors are exposed, in particular, those teaching activities such as cycle, jump fitness and combat, and given the average number of teaching hours per day for these activities, it can be concluded that these instructors are exposed to noise levels that exceed the upper action value (UAV) and are very close to the exposure limit value (ELV).
Most of the symptoms reported by both groups are rather similar. The percentages for some symptoms are quite high, and this fact can be explained by other factors that play a significant role, such as age or other social activities outside of work. However, there are five cases where the group of physical education professionals has a (statistically significant) larger number of complaints than the comparison group, and these should be highlighted. These are: hearing difficulties, muffled hearing, intolerance to loud sounds, constant headaches, and irritability. Given the sound levels and the contact hours reported by these professionals, it is very likely that these results may be largely attributed to noise exposure.
Symptoms like nausea, headaches, and changes in mood anxiety were reported by Crook and Langdon (1974) and Melamed et al (1988). Finke et al (1974) and Jones et al. (1981) who found high percentages of people reporting headaches, “restless nights,” and “being tense and edgy” in high noise areas through the use of community surveys. According to Stansfeld and Matheson (2003) the most widespread and well-documented subjective response to noise is annoyance and high frequency noise has been found to be more annoying than low frequency noise (Bjork 1986).
In what concerns the perception of the risks associated with noise exposure, the results pointed out that the individuals surveyed in both groups felt that there is a considerable risk to health when there is exposure to loud noise, since the majority stated that “loud noise is dangerous” and “can cause permanent hearing impairments.” When the questions focus on the type of sources of noise, respondents believe the main risk may derive from exposure to “sources of sound (for example speakers) nearby,” “very loud music,” and “music with headphones.” However, when this exposure is directly related to “the noise caused by the work,” the median of the answers reported by both groups are different (and this difference is statistically significant). This fact may be explained by differences in the activities developed in the classes by both groups, since sports activities involve a greater level of dialogue and interaction between the students, and by the fact that in classes accompanied by music there is a tendency to speak louder, in order to be heard over the music. Moreover, sports pavilions are characterized by the existence of reverberating elements, where there are several classes running at the same time, which increases the noise produced by the students.
The statistically significant differences found in the median of the answers concerning the level of agreement with statements S1 to S10 clearly show that the professionals have a higher perception of the consequences of noise exposure than the comparison group. In fact, the professionals are more likely to agree with the statement that “during (their) work noise is loud.” This group also reported having “hearing problems due to the exposure to noise” and not be able to “talk easily with/among students (without raising their voice).” Curiously, comparison group registered a higher median than the professional group in the statement S5 “Loud noise leaves me in a bad mood and feeling irritable.” This can be explained by the fact that the professional group is more acquainted with higher levels of noise and, as consequence, developed a higher tolerance to noise exposure.
CONCLUSION
Currently, deafness caused by noise exposure is one of the work-related diseases with higher incidence in Portugal (ACT 2010). Based on the results we can infer that physical education instructors, in particular those who devote part of their work to teaching with music accompaniment, are exposed to high levels of sound pressure on a daily basis, which depending on their contact hours may be seriously compromising their hearing health.
Although we found that these professionals are aware of the risk associated with noise, in practice this knowledge does not appear to be an asset since the main source of high sound levels are speakers and the volume chosen is the responsibility of the actual instructor. From this study we can conclude that there is a pressing need for these professionals to receive training on noise and its auditory and extra-auditory effects, in the short and long run, in order to raise awareness of these issues.
The measures described here should be combined with organisational and structural measures, which will help reduce the level of noise to which these professionals are exposed to, namely by:
| • | Managing the sports venues in order to avoid having several sports activities taking place at the same time; | ||||
| • | Installing sound insulation panels on the walls or ceiling of sports venues; | ||||
| • | Restricting the sound power of the sound systems used in the classes. | ||||
Apart from this training, studies that quantify, through regular audiometric exams, the state of hearing of these professionals through time may be recommended.
| L EX,8h = ELV = 87 dB(A) | L EX,8h = UAV = 85 dB(A) | ||
|---|---|---|---|
| L A,eq,Te , dB(A) | Te , hours | L A,eq,Te , dB(A) | Te , hours |
| 94 | 2.0 | 94 | 1.0 |
| 92 | 2.5 | 92 | 1.6 |
| 90 | 4.0 | 90 | 2.5 |
| 89 | 5.0 | 89 | 3.2 |
| 88 | 6.4 | 88 | 4.0 |
| LAeq minimum | LAeq average | LAeq maximum | U | ||
|---|---|---|---|---|---|
| Activity | dB(A) | dB(A) | dB(A) | dB(A) | n |
| Schools: | |||||
| 2nd Cycle | 81 | 84 | 86 | 2.4 | 10 |
| 3rd Cycle | 83 | 85 | 86 | 2.4 | 15 |
| Health Clubs: | |||||
| Cycle | 84 | 92 | 97 | 2.3 | 28 |
| Step | 87 | 91 | 95 | 2.2 | 17 |
| Jump fitness | 80 | 92 | 96 | 3.1 | 9 |
| Pump | 82 | 87 | 91 | 3.6 | 6 |
| Step local | 80 | 84 | 85 | 2.8 | 4 |
| Local | 73 | 84 | 89 | 2.4 | 24 |
| Combat | 86 | 92 | 93 | 2.4 | 8 |
| Dance and rhythms | 75 | 90 | 96 | 2.6 | 19 |
| aerobics | 83 | 87 | 89 | 2.6 | 5 |
| Cardio fitness and weight training | 70 | 79 | 83 | 2.5 | 18 |
| Body vive | 82 | 83 | 84 | 2.0 | 3 |
| Hydrobike | 73 | 87 | 91 | 3.6 | 11 |
| Hydrogymnastics | 78 | 86 | 93 | 2.5 | 18 |
| Swimming | 71 | 81 | 85 | 2.5 | 22 |
| Proportion professional | Proportion comparison | ||
|---|---|---|---|
| Auditory symptoms | (p ± E) | (p ± E) | P-value |
| Hearing difficulties | 0.19 ± 0.11 | 0 | 0.000 |
| Earaches | 0.04 ± 0.06 | 0.02 ± 0.04 | 0.489 |
| Buzzing in the ears | 0.13 ± 0.10 | 0.04 ± 0.05 | 0.112 |
| Itching in the ears | 0.10 ± 0.02 | 0.02 ± 0.04 | 0.073 |
| Liquid discharges from the ear | 0 | 0.02 ± 0.04 | 0.339 |
| Frequent ear infections | 0 | 0 | — |
| Muffled hearing | 0.13 ± 0.09 | 0.02 ± 0.04 | 0.038 |
| Intolerance to loud sounds | 0.10 ± 0.10 | 0 | 0.017 |
| Extra-auditory | Proportion professional | Proportion comparison | |
|---|---|---|---|
| symptoms | (p ± E) | (p ± E) | P-value |
| Constant headaches | 0.17 ± 0.11 | 0.04 ± 0.05 | 0.032 |
| Irritability | 0.21 ± 0.12 | 0.02 ± 0.04 | 0.002 |
| Insomnia | 0.08 ± 0.08 | 0.06 ± 0.10 | 0.617 |
| Difficulty concentrating | 0.08 ± 0.08 | 0.04 ± 0.05 | 0.347 |
| Vertigo | 0.08 ± 0.08 | 0.02 ± 0.04 | 0.149 |
| Frequent or severe dizziness | 0.04 ± 0.06 | 0 | 0.136 |
| Hypertension | 0 | 0.04 ± 0.05 | 0.171 |
| Gastrointestinal disorders | 0.02 ± 0.05 | 0.02 ± 0.04 | 0.952 |
 |
| Questions | Professional group median | Comparison group median | P-value |
|---|---|---|---|
| Q1 | 4 | 4 | 0.359 |
| Q2 | 4 | 4 | 0.620 |
| Q3 | 4 | 2 | 0.036 |
| Q4 | 4 | 4 | 0.878 |
 |
| Professional | Comparison | ||
|---|---|---|---|
| Statement | group median | group median | P-value |
| S1 | 5 | 5 | 0.166 |
| S2 | 5 | 4.5 | 0.707 |
| S3 | 4 | 2 | 0.000 |
| S4 | 3 | 1 | 0.000 |
| S5 | 3 | 4 | 0.222 |
| S6 | 4 | 3 | 0.000 |
| S7 | 2 | 2 | 0.085 |
| S8 | 2 | 2 | 0.280 |
| S9 | 2 | 1.5 | 0.055 |
| S10 | 2 | 1 | 0.005 |
ACKNOWLEDGMENTS
The authors are grateful for the funding provided by the Maiêutica, Cooperativa de Ensino Superior and the CATST, Technical Support Center for Occupational Health and Safety, Maia, Portugal. We also express our appreciation to the persons who participated in this study.
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