Table 1.

Description of the articles selected for review with the effects of exposure

Author, year	Design	Population: sex and age	Profession	Exposure	Period	Country	Exposure effects
Alonso-Díaz, 2014[36]	Cross-sectional	207 41 ± 8 years and 42 ± 6 years Men	Body shops and assembling	≥85 dB(A)	<10 years 10–20 years> 20 years	Spain	In one third of workers exposed audiometry were obtained compatible with hearing injuries noise
Flamme and Williams, 2013[14]	Cross-sectional	n=321 Men and women Age: ≥18 years. Predominantly between 30 and 60 years	Referees	Whistle (104–116 dB (A) from 90 to 95 s respectively)	Questionnaire: 1 day	Michigan (EEUU)	Whistle use contributes to approximately 36% of hearing lose in referees and to tinnitus appearance
Chung et al., 2012[11]	Repeated measures	N: 81 agriculture equipment factory N: 371 firemen Men	Agricultural equipment factory and firemen	Agricultural equipment factory and firemen: 82 dB (A) (66–97)Firemen: 76–79 dB(A)	Study duration: 4 years (2006–2009) Exposed: 8 h/5 days of week Not exposed: 9 h, 2 consecutive days, 15 evening hours of 2 consecutive days and 2 free days	South Korea	Agricultural equipment factory workers have higher level of hearing loss (P < 0.0001) in both ears, adjusted to age, work duration and yes/no smokers. These results are significant after 10 years of work history in stratified analysis
Kitcher et al., 2012[18]	Comparative cross-sectional	N: 140 stone crushers (42.58 ± 7.85 years) N: 150 healthy workers (42.19 ± 12 years) Men and women	Stone crusher	61.2–99.6 dB(A)	Exposure period: 0–30 years	Ghana	Suggestive noise-induced hearing lose in 21.5% of crushers
Jensen et al., 2009[19]	Case and control	42 team leaders (mean age: 47.8 years); 42 plane mechanics (45.8 years); 17 ex-team leaders Men	Mechanics	144 dB (peak) and 124 dB (L(eq)), during limited time. Highest sound pressure of 2–4 kHz levels	Mean of worked years: 19.6 years for team leaders and 24.1 years for mechanics	Denmark “intuit”	The ex-team leaders show a lower number of diseases related with hearing and a higher number of respiratory diseases (significant)
El Dib et al., 2008[20]	Cross-sectional	n: 82 sound technicians n: 95 controls Age: >19 years Men and women	Sound technicians	Noise (music sound)	Minimum 5 years of exposure Majority between 5 and 14.9 years)	Brazil	A higher number of diseases between sound technicians (26.8%) that controls (11.5%) statistically significant
Kaerlev et al., 2008[15]	Cohort	N: 5994 sailors N: 2740 fishermen 20–59 years Men and women	Sailors and fishermen	Not available	Duration results not contemplated Recruitment period: (1989–1998) Follow-up period: 1994–2003 Exposure period of <6 years to >12 years	Denmark	Workers in engine rooms of vessels had more frequent hearing problems No available data for the accumulative effects of a long period RR = 2.39 (IC 95% 1.74–3.26)
Korres et al., 2008[24]	Case and control	N exposed = 139 (86 men and 53 women) (mean age: 41.9 ± 9.0 years range: 24–54 years) N controls = 32 (18 men and 14 women) (mean age: 38.4 ± 6.9 years range: 25–53 years)	Food processing factory workers (Bakery)	92 dB(A). Steady continuous noise	Follow-up period: 2 years (2005–6) Mean exposure time: 11.8 ± 6.9 years (1–33 years)	Not available	Significant statistical correlation between pure tone threshold and exposure time to all frequencies between 250 and 20,000 Hz except in 10,000 Hz.are not sex-dependent
Vangelova and Deyanov, 2007[7]	Case and control	N: 545 n: 271 intense noise (age 44.7 ± 10.2 years) n: 159 heat (age 40.3 ± 10.6 years) n control: 115 (41.5 ± 9.2 years)Age: <32 years; 33–45 years; >46 years Men	Industry workers	Intense noise (86–92 dB(A)) and environmental heat (35.4°C (28.4–41.7)	<9 years 10–19 years> 20 years	Not available	AP: 140/90 mmHg is significantly higher in individuals of mean age exposed to noise (of mean age) in both groups (P < 0.05).Dyslipidemia levels were significantly higher in mean age individuals exposed to heat and in both exposed age groups (P < 0.05)
Shupak et al., 2007[23]	Controlled prospective cohort	N exposed = 42 N not exposed = 4 Men 18–20 years	Engine rooms workers	Exposed: 87–117 dB(A) (use ear protectors) Not exposed: <80 dB(A)	Follow-up period: 2 years	Israel	Significant elevation was shown in groups exposed to thresholdPTaud to 4000 Hz in both ears and to 6000 Hz in the left ear
Dias et al., 2006[21]	Cross-sectional	N: 284 20–72 years (media: 42.51 years) Men and women	Several professions	Not available	Recruitment: April–October 2003	Brazil	Increase of tinnitus with a progression of hearing damage, controlled by age and wave noise exposure
Dement et al., 2005[22]	Case and control	n = 3510 Audiometric test participants: Age: 56.6 years and mean work time: 12.2 years Men and women	Construction and shop workers (trade workers)	Co: <80 dB(A)	Recruitment: 1996–2003	EEUU	The risk of disability in construction workers was higher. Smokers and exposed to high noises OR 95% = 2.7 (2.0–3.6)
Rios and da Silva, 2005[37]	Case and control	4033–50 years Men	Unknown	≥85 dB(A)	40 h/week more than 8 years	Brazil	Mild and moderate noise-induced hearing loss (P < 0.01)
Gitanjali and Dhamodharan, 2004[35]	Retrospective cohort	8 participants in each group 24 controls (20–45 years) Men and women	Conductors of “autorickshaws”	Occupational noise >75 dB during 1 or 2 years. Occupational noise >75 dB during 5–10 years Occupational noise a >75 dB during >15 years	Study period: 2000–2001	India	Could be concluded that workers exposed to high levels of occupational noise increase the risk of low sleep quality But the adaptation to this effect probably takes some years
Leme, 2001[26]	Case and control	Ca: 61 employees of San Francisco Oliveira Public Health Service State Hospital Mean: 44.67 ± 9.45 years (29–62 years)Co: 30 Sex not available	Ca: San Francisco Oliveira Public Health Service State Hospital	Carpentry: mean 94.65 dBSawmill: mean 94.65 dBMechanics: mean 97.6 dBLaboratory: mean 85.5 dBFrequencies used: 250, 500, 1000, 2000, 3000, 4000, 6000 and 8000 Hz	Study from 1996 to 1997 Test was performed after 14 h of sound response	Not available	Significant differences in all the frequencies even for right (P < 0.005) or left ear (P < 0.02)
Tomei et al., 2000[25]	Case and control	N = 52 bedframe N = 65 light metal N = 64 office workers Men Mean age: 48.2 ± 7.2 years	Bedframe factory workers	>90 dB(A) (exposed)	Mean exposure period: 21.2 ± 6.7 years	Not available	Mean systolic and diastolic of bedframe workers is significantly higher that control groups Bedframe workers exposed to >90 dB present higher means of systolic and diastolic that those exposed to <90 dB
Lee, 1999[27]	Cross-sectional	43 exposed employees (mean age: 23.9 years) 37 controls Sex not available	Nightclub workers	>85 dB	Mean exposure time: 5.1 h (3.6–6.9 h)	Singapore	The exposed group had a higher significant prevalence of (41.9%) sensorineural hearing lose respecting to their control group (13.5%), also suffer more tinnitus (21% versus to 2.7%)
Casson et al., 1998[28]	Cross-sectional	Fishermen: 139 (45.39 ± 9.57 years) Control: 136 (40.75 ± 8.37 years) Men	Deep-sea fishermen	Not available	Not available	Italy	Deep-sea fishing RR = 3.64 (1.07–12.4), years working as fisher (RR = 1.60 (1.16–2.20) and the age (RR = 2.04 (1.47–2.83) have influence on the noise-induced hearing lose in a significant way. Also, the exposure to noise produce an increase in systolic pressure (RR = 190 (1.03–3.51)
Szczepanński and Otto, 1995[29]	Case and control	Not available	Vessels crew and engine room workers	93–102 dB(A)3000–4000 Hz	Study workers: 1975–1988	Poland	The higher increase of hearing threshold in the range of 5.0–5.8 dB was shown in engine rooms workers in different types of vessels
Hirai et al., 1991[30]	Cross-sectional	N: 2124 industry workers (age: 20–59 years) Exposed to 85–115 dB: 615 Exposed to <85 dB: 1141 Silent office: 368 men	Industry	Exposed to 85–115 dBExposed to <85 dB Silent office	10 years	Japan	The prevalence of hearing lose in exposed group to levels of 85–115 dB is of 16.5% higher that moderate group (7.5%) and than the silent one (2.8%) Significant
Tarter and Robins, 1990[31]	Cross-sectional	N: 150 White workers N: 119 Black workers of 35–65 years Men	Car factory	>85 dB(A), 8 h/day	≥5 exposure years	Not available	Hearing lose to 4000 Hz and worked years in jobs with high level of noise are significantly associated with the mean of arterial pressure and for hypertension between black workers but not for white ones
Thiery and Meyer-Bisch, 1988[32]	Cross-sectional	N: 234 Not exposed: exposed to 80 dB(A)Exposed: >95 dB(A) (3 groups divided by age) Sex not available	Sheet metal workshop in a car factory	95 dB(A)	<20 years	Not available	Significant hearing lose after 9 years of exposure in comparison with a quasi-steady exposure to the same extent Hearing lose higher at 6 kHz than a 4 kHz
Mäntysalo and Vuori, 1984[12]	Case and control	N:99 Group 1 exposed 3 and 4 years to impulse noise (age: 24.6 ± 2.83 years): 10 Group 2 exposed 5 and 6 years to impulse noise (28.3 ± 2.83 years): 10 Group 3 exposed 7–10 years (30.1 ± 2.23 years): 10 Exposed to continuous steady-state noise (28.3 ± 4.87 years): 12 Group control (23.8 ± 3.36 years): 10 Men Born in 1940 or later	Exposed to boost: Noise: electroplating workers and welder Exposed to continuous steady-state noise: Workers of cable factory	Environmental noise: 80–85 dBPeaks from 130 to 140 dB and inclusive 150 dB from 300 to 800 ms	Exposed to impulse noise: 3–10 years Exposed to continuous steady-state noise: 5–42 years	Finland	Most of the exposed to impulse noise used hearing protectors, practically none used it in steadyThose exposed to impulse noise (using or not ear protectors) had higher hearing lose than those exposed to steady Higher sensibility was shown with frequencies between 4000 and 6000 Hz
Sataloff et al., 1983[33]	Cross-sectional	N: 295 Sex and age not available	Different type of factories: wood, paper, “pulp” water company, steel, gas company, “smelting company,” foundry, electrical	99–118 dB(A)	1 to >20 years	Not available	An intermittent exposure to intense noise frequencies results in a very sever lose but is relatively lower or not the hearing lose at lower frequencies even after many years of exposure
Sulkowski et al., 1981[34]	Retrospective cross-sectional	14,81129–60 years Men and women	Majority miners and textile industry employees	≥90 dB(A)	Follow-up period: 1971–9	Poland	It was shown a noise-induced hearing lose (INHL) in all the professions Incidence: 16/100,000 employees The highest rates were for industry transporters, miners and textile industry