Skip to content

Advertisement

You're viewing the new version of our site. Please leave us feedback.

Learn more

BMC Public Health

Open Access
Open Peer Review

This article has Open Peer Review reports available.

How does Open Peer Review work?

Noise exposure in occupational setting associated with elevated blood pressure in China

Contributed equally
BMC Public HealthBMC series – open, inclusive and trusted201717:107

https://doi.org/10.1186/s12889-017-4050-0

Received: 5 August 2016

Accepted: 17 January 2017

Published: 23 January 2017

Abstract

Background

Hypertension is the primary out-auditory adverse outcome caused due to occupational noise exposure. This study investigated the associations of noise exposure in an occupational setting with blood pressure and risk of hypertension.

Methods

A total of 1,390 occupational noise-exposed workers and 1399 frequency matched non-noise-exposed subjects were recruited from a cross-sectional survey of occupational noise-exposed and the general population, respectively. Blood pressure was measured using a mercury sphygmomanometer following a standard protocol. Multiple logistic regression was used to calculate the odds ratio (OR) and 95% confidence interval (CI) of noise exposure adjusted by potential confounders.

Results

Noise-exposed subjects had significantly higher levels of systolic blood pressure(SBP) (125.1 ± 13.9 mm Hg) and diastolic blood pressure (DBP) (77.6 ± 10.7 mm Hg) than control subjects (SBP: 117.2 ± 15.7 mm Hg, DBP: 70.0 ± 10.5 mm Hg) (P < 0.001). Significant correlations were found between noise exposure and blood pressure (SBP and DBP) (P < 0.001). However, the linear regression coefficients with DBP appeared larger than those with SBP.

The prevalence of hypertension was 17.8% in subjects with noise exposure and 9.0% in control group (P < 0.001). Compared with the control group, the subjects with noise exposure had the risk of hypertension with an OR of 1.941 (95% CI = 1.471– 2.561) after adjusting for age, sex, smoking, and drinking status. Dose–response relationships were found between noise intensity, years of noise exposure, cumulative noise exposure and the risk of hypertension (all P values < 0.05). No significant difference was found between subjects wearing an earplug and those not wearing an earplug, and between steady and unsteady noise categories (P > 0.05).

Conclusions

Occupational noise exposure was associated with higher levels of SBP, DBP, and the risk of hypertension. These findings indicate that effective and feasible measures should be implemented to reduce the risk of hypertension caused by occupational noise exposure.

Keywords

Occupational noise exposureHypertensionSystolic blood pressure (SBP)Diastolic blood pressure (DBP)Odds ratio (OR)

Background

Noise is the most common occupational risk factor and millions of workers are exposed to harmful levels of noise in the workplace [1, 2]. Hearing loss is a well-documented primary biological adverse effect caused by occupational noise exposure [3, 4]. In addition, noise exposure activates the sympathetic and endocrine systems, thereby affecting the humoral and metabolic states of human beings [58]. Therefore, noise exposure increases the risk of out-auditory adverse outcomes such as hypertension and cardiovascular diseases, digestive and behavioral disorders, and sleep disturbances [7, 9, 10].

Although the associations between noise exposure and blood pressure and/or hypertension have been extensively studied [1116], however, the findings are not always consistent. Previous studies have primarily focused on community noise exposure [14, 1719]. There were large variations in the characteristics of noise exposure between community and occupational exposure in terms of intensity, duration, and category of noise exposure. Previous findings in occupational settings were not always consistent. Significant positive associations were found in cohort study [12, 20, 21] and cross-sectional studies [22, 23]. However, negative associations were also found in other studies [24, 25]. These inconsistent findings might be attributed to the study design, population, exposure evaluation, and modification of potential confounding factors. Different types of noise exposure and measurements of protection would affect the biological functions and cause blood pressure and cardiovascular diseases.

The objective of this study was to evaluate the associations of occupational noise exposure with blood pressure and hypertension in the Chinese population.

Methods

Subjects

The subjects in this study included 1390 occupational noise exposed workers (exposed group) and 1399 non- noise-exposed subjects (control group). The exposed subjects were randomly recruited from a cross-sectional survey of occupational noise exposure in Hangzhou, Zhejiang Province, China, which has been previously described in detail [26]. In that cross-sectional survey, the subjects were the workers who were employed in the noise-exposed factories of mechanical equipment and household appliance manufacturing, steel construction, and cigarette production/packaging in Hangzhou city, Zhejiang province, China. Subjects had occupational noise exposure for more than one year and the intensity of noise exposure was >80 dB (A) (LEX,8h). The workers were excluded if they had hypertension and other chronic diseases such as coronary heart disease, cancer, and kidney diseases. Before noise exposure. Epidemiological data were collected by face to face interview using a structured questionnaire and administered by trained professional physicians. The information in the questionnaire included demographic characteristics, smoking/drinking status, history of medical conditions and drug use, history of exposure to noise, vibration, and toxic chemicals in the workplace, health habits, and use of ear protection for noise. Intensity of noise in the workplace was determined by a noise statistical analyzer (AWA6218; Westernization Instrument Technology Co., Ltd., Beijing, China). Noise exposure was evaluated with equivalent continuous dB(A)- weighted sound pressure levels (LEX,8 h) according to the Occupational Health Standard of the People’s Republic of China: Measurement of Noise in the Workplace (GBZ/T 189.8–2007) (China, 2007). Because the majority of subjects in the cross-sectional study were males (about 91.7%), the subjects in the present study were restricted to males.

Control subjects were recruited from a cross-sectional survey of general population on metabolic syndrome in the same area with occupational noise survey. In this survey, blood pressure were measured and epidemiological data were collected using the same methods as for the exposed group. Control subjects had no specific noise exposure in workplace and resident area, which met the hygienic standard for noise in industrial enterprises and social living environmental noise (GB 3096–2008 and GB 22337–2008). The control subjects were frequency-matched with the exposed groups in the distribution of age, sex, and resident area. The study protocol was approved by the Research Ethics Committees of Hangzhou Center for Disease Prevention and Control, Zhejiang, China.

Blood pressure measurement and hypertension definition

Following gap of more than 12 h after noise exposure, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured by trained physicians following a standard protocol. Blood pressure was measured using a mercury sphygmomanometer with subjects in the sitting position after more than 15-min rest. SBP and DBP were reported as the average of three repeat measurements with 30-s intervals.

Hypertension was defined as SBP ≥ 140 mmHg and/or a DBP ≥ 90 mmHg. Any subject reporting the use of antihypertensive medications were also classified as hypertensive, regardless of the measured levels of blood pressure.

Statistical analysis

Cumulative noise exposure (CNE) was calculated as CNE = 10 × log(10SPL/10 × years of noise exposure), where SPL is the sound pressure level [dB (A)] of noise exposure. Continuous variables for normal distribution were expressed as mean ± standard deviation (SD) and as median (P25, P75) for skewed distribution. Categorical variables were expressed as frequencies (%).

χ 2 test was used to examine the statistical significance of categorical variables., One-way ANOVA was used for continuous variables followed by multiple comparisons with SNK. Multiple logistic regression was used to compare the differences among subjects with different noise exposure levels after adjusting for confounders such as age, sex, smoking, and drinking status. Odds ratio (OR) and its 95% confidence interval (CI) were calculated for the risk of hypertension by noise exposure, adjusting for potential confounders with reference to the control group, and subjects with lowest levels of noise exposure. All statistical analyses were performed using SPSS 19.0 for Windows (IBM Corporation, Armonk, NY, US).

Results

Basic characteristics of the subjects

This study recruited 1,390 noise-exposed workers and 1399 non-noise exposed control subjects. The basic characteristics of the subjects are shown in Table 1. All the subjects were males with a mean of age was 33.1 years old ± 8.7 (standard deviation). No significant difference was found between the exposed and control groups in term of age (P > 0.05). However, 56.2% of exposed group were smokers and 46.6% in control group (P <0.001), and 68.6% of the exposed group were alcohol drinkers and 41.0% in control group (P <0.001). Therefore, smoking and drinking status were modified in the following analysis. The median of intensity of noise exposure was 87.5 dB (A) (82.5, 87.5) and the duration of noise exposure was 4.21 (1.67, 8.00) years, with a CNE value of 92.28 (88.31, 96.79). 83.8% of the exposed workers used earplug as simple noise protection.
Table 1

Basic characteristics of noise- exposed and control group

variables

Noise-exposed group (n = 1390)

control group (n = 1399)

P value

Age (years) (mean ± SD)

33.1 ± 8.7

33.1 ± 8.6

0.941#

Smoking status (%)

 Yes

56.2

46.6

 

 No

43.8

53.4

<0.001§

Drinking (%)

 Yes

68.6

41.0

 

 No

31.4

59.0

<0.001§

Years to noise exposure, years,*

4.2(1.7,8.0)

  

Noise intensity exposure, dB (A),*

87.5 (82.5,87.5)

  

cumulative noise exposure (CNE)*

92.3(88.3,96.8)

  

Noise protection (%)

83.8

  

CNE, cumulative noise exposure, was calculated as CNE = 10 × log 10SPL × years of noise exposure), where, SPLis the sound pressure level [dB (A)] of noise exposure

*Data are presented as median (P25, P75)

#independent t-test; §, χ 2 test

Effect of noise exposure on the levels of SBP and DBP

The levels of SBP and DBP of the subjects of the noise exposed and non-exposed groups are shown in Table 2. The mean levels of SBP in exposed group were 125.1 ± 13.9 mm Hg and 117.2 ± 15.7 mm Hg in the control group (P < 0.001). Exposed group had significantly higher levels of DBP than control group (P < 0.001). Significant differences were also found among the subgroups of exposed subjects classified by different noise intensity, duration, and CNE of noise exposure. The regression coefficients of noise exposure (different intensities, duration, and CNE of noise exposure) with SBP and DBP are shown in Table 3. Significant correlations were found between noise exposure (different intensity, duration and CNE of noise exposure) and blood pressure (SBP and DBP) (P < 0.001). However, the regression coefficients with DBP appeared larger than those with SBP (Table 3).
Table 2

Levels of SBP and DBP in the subjects of noise exposed and non-exposed groups

Groups

n

SBP

DBP

Mean ± SD

P value*

Mean ± SD

P value*

Non-exposed group

1399

117.2 ± 15.7

 

70.0 ± 10.5

 

Exposed group

1390

125.1 ± 13.9

<0.001

77.6 ± 10.7

<0.001

Noise intensity (dB)

 80-

490

124.2 ± 14.7#

 

75.8 ± 11.1#

 

 85-

571

124.9 ± 12.8#

 

78.1 ± 10.1#,$

 

 90-

237

126.2 ± 14.6#

<0.001

78.8 ± 11.1#,$

<0.001

  ≥ 95

92

129.1 ± 13.8#,$,§

 

80.7 ± 9.5#,$

 

Work-years of noise exposure

 1-

795

123.9 ± 13.4#

 

76.0 ± 10.3#

 

 5-

394

125.7 ± 13.8#,$

 

78.8 ± 10.3#,$

 

 10-

100

126.8 ± 13.8#,$

<0.001

81.5 ± 11.5#,$,§

<0.001

  ≥ 15

101

130.7 ± 16.5#,$,§

 

81.3 ± 11.1#,$,§,§

 

cumulative noise exposure

 80-

479

123.3 ± 12.9#

 

75.2 ± 10.1#

 

 90-

434

124.8 ± 13.9#

 

77.5 ± 10.5#,$

 

 95-

274

126.0 ± 15.1#,$

<0.001

79.3 ± 11.5#,$,§

<0.001

  ≥ 100

203

128.8 ± 13.9#,$,§,&

 

81.0 ± 9.8#,$,§

 

Noise category

 Stable

451

124.7 ± 12.5

 

77.6 ± 9.2

 

 Unstable

939

125.4 ± 14.5

0.369

77.6 ± 11.3

0.958

Noise protection

 Yes

956

124.4 ± 12.0

 

77.3 ± 9.3

 

 No

185

124.6 ± 13.7

0.855

77.3 ± 10.8

0.983

*P values were calculated by one-way ANOVA, and then followed by SNK for multiple comparison. #significant difference with non-exposed group. $, significant difference with the group of 80- for Noise intensity, 1- for Work-years of noise exposure, and 80- for cumulative noise exposure. §, significant difference with the group of 85- for Noise intensity, 5- for Work-years of noise exposure, and 90- for cumulative noise exposure. &, significant difference with the group of 90- for Noise intensity, 10- for Work-years of noise exposure, and 95- for cumulative noise exposure

Table 3

Regression coefficient of SBP and DBP with noise exposure in the noise exposed subjects

 

SBP

DBP

beta

P value

beta

P value

Noise intensity (dB)

0.107

<0.001

0.149

<0.001

Work- years of noise exposure

0.100

0.005

0.113

0.001

Cumulative noise exposure

0.128

<0.001

0.187

<0.001

When noise exposure was categorized as steady and unsteady noise, no significant associations of SBP and DBP were found between the steady and unsteady noise categories and between subjects wearing an earplug and those not wearing an earplug.

Effect of noise exposure on the risk of hypertension

Table 4 presents the risks of hypertension in the subjects with occupational noise exposure. The prevalence of hypertension was 17.8% in the exposed group and 9.0% in the control group (P < 0.001), respectively. Compared with the control group, the subjects with noise exposure had the risk of hypertension with an OR of 1.941 (95% CI = 1.471– 2.561) after adjusting for age, smoking, and drinking status. Dose–response relationships were found between noise intensity, years of noise exposure, CNE, and the risk of hypertension (all P values < 0.05). Similar results were found when the lowest noise exposure levels in the exposed group was considered as a reference. Consistent results were found after stratifying analyses by age, smoking and drinking status (Data not shown).
Table 4

the risks of hypertension in the subjects with occupational noise exposure

Groups

n

Non-hypertension

hypertension

OR1 (95%CI)*

P value

OR2 (95%CI)**

P value

Non-exposed group

1399

1273(91.0%)

126(9.0%)

1.00(Ref.)

   

Noise-exposed group

1390

1143(82.2%)

247(17.8%)

1.941(1.471-2.561)

<0.001

  

Noise intensity (dB)

 80-

490

411(83.9%)

79(16.1%)

1.411(0.947-2.102)

0.091

1.000(Ref)

 

 85-

571

471(82.5%)

100(17.5%)

2.128(1.535-2.952)

<0.001

1.510(1.005-2.268)

0.047

 90-

237

193(81.4%)

44(18.6%)

2.018(1.326-3.070)

0.001

1.283(0.783-2.102)

0.323

 ≥95

92

68(73.9%)

24(26.1%)

3.002(1.676-5.376)

<0.001

2.018(1.068-3.811)

0.031

Ptrend

    

<0.001

 

0.064

Work- years of noise exposure

 0

1399

1273(91.0%)

126(9.0%)

1.000(Ref)

   

 1-

795

680(85.5%)

115(14.5%)

1.495(1.064-2.100)

0.020

1.000(Ref)

 

 5-

394

321(81.5%)

73(18.5%)

2.029(1.421-2.898)

<0.001

1.199(0.813-1.767)

0.360

 10-

100

74(74.0%)

26(26.0%)

2.609(1.504-4.527)

0.001

1.412(0.785-2.542)

0.249

 ≥15

101

68(67.3%)

33(32.7%)

4.055(2.318-7.094)

<0.001

2.080(1.114-3.880)

0.021

Ptrend

    

<0.001

 

0.022

cumulative noise exposure

 ≤80

1399

1273(91.0%)

126(9.0%)

1.000(Ref)

   

 80-

479

418(87.3%)

61(12.7%)

1.107(0.712-1.721)

0.652

1.000(Ref)

 

 90-

434

359(82.7%)

75(17.3%)

1.987(1.377-2.869)

<0.001

1.637(1.015-2.638)

0.043

 95-

274

215(78.5%)

59(21.5%)

2.261(1.536-3.328)

<0.001

1.733(1.034-2.904)

0.037

 ≥100

203

151(74.4%)

51(25.6%)

2.829(1.871-4.277)

<0.001

2.006(1.154-3.488)

0.014

Ptrend

    

<0.001

 

0.018

Noise category

       

 Stable

451

388(86.0%)

63(14.0%)

  

1.000(Ref)

 

 Unstable

939

755(80.4%)

184(19.6%)

  

1.324(0.907-1.933)

0.146

Earplug wearing

 Yes

956

801(83.8%)

155(16.2%)

  

1.000(Ref)

 

 No

185

155(83.8%)

30(16.2%)

  

0.910(0.585-1.415)

0.674

Multiple logistic regression was used to compare the differences among the subjects with different noise exposure adjusted by confounders such as age, sex, smoking, and drinking status

*OR1 was calculated taking the non-exposed group as the reference, adjusting for age, smoking, and drinking status

**OR2 was calculated taking the lowest levels of noise exposure as the reference, adjusting for age, smoking and drinking status

No significant difference was found in the prevalence of hypertension between subjects wearing an earplug and those not wearing an earplug, and between the steady and unsteady noise categories (P > 0.05).

Discussion

In this study, we investigated the associations of SBP and DBP with occupational noise exposure in 1,390 occupational noise-exposed workers and 1399 non-noise exposed control subjects. The results indicated that occupational noise exposure associated with higher levels of SBP and DBP and the risk of hypertension. Dose–response relationships were found between noise exposure and blood pressure, and the risk of hypertension.

The associations between occupational noise exposure and hypertension have been extensively investigated [6, 13, 2025], however, the findings are still inconsistent. In this study, using frequency-matched external and internal control groups as references, we found that noise exposure elevated the blood pressure and the risk of hypertension. These findings are consistent with previous studies [13, 20, 21]. After about 10 years of follow up, Chang et al. [20] found that high noise exposure (≥85 dBA) increased the SBP of 3.2 (95% CI: 0.2 – 6.2) mm Hg and the DBP of 2.5 (95% CI: 0.1 – 4.8) (P < 0.05). In the present study, potential confounding factors such as age, sex, smoking, and drinking status were adjusted, and noise exposure was evaluated in term of intensity (dB(A)), years of noise exposure and CNE. The results were consistent with different levels of noise exposure. We also found a dose- response relationship between noise exposure and blood pressure (SBP and DBP)/risk of hypertension. The elevated blood pressure and the risk of hypertension even persisted at the lowest levels of noise exposure with a noise intensity of 80 – 85 dB (A), work-years of noise exposure of 1–5 years and CNE of 80–90. These findings were concordant with previous studies [20, 22]. De Souza et al. [22] found noise exposure at 75–85 dB(A) increased the risk of hypertension with an OR of 1.56 (95% CI: 1.13 – 2.17) compared with exposure at ≤ 75 dB(A). However, no increased risk of hypertension was found in the noise exposure at 80–90 dB(A) in a population study[24]. This study had relatively large sample size, however, the data were obtained from registry system. Recently, with a meta-analysis, Skogstad et al. [16] found that occupational noise exposure increased the risk of hypertension with a hazard ratio (HR) of 1.38 (95% CI:1.01–1.87).

No significant difference was found between the steady and unsteady noise exposure categories in levels of SBP, DBP and risk of hypertension. These results indicated the similar biological effects of noise exposure on blood pressure between the steady and unsteady noise. We also found no difference in the blood pressure and risk of hypertension between subjects wearing an earplug and subjects not wearing an earplug. Usually, subjects wear the earplug for noise protection, however, the result suggested low effectiveness of wearing an earplug in noise protection. This finding was similar to previous finding of noise induced-hearing loss with earplug wearing [27]. Commonly used earplugs may have a low efficiency for noise protection. On the other hand, due to discomfort, the compliance of earplug wearing among the workers is low during noise exposure in the workplace. Therefore, the low efficiency and compliance rate might lead to the decreased effectiveness of earplug wearing.

Although significant correlations of noise exposure with both SBP and DBP were observed (P < 0.01), however, the regression coefficients with DBP appeared larger than those with SBP. Probably, DBP is more sensitive to the reaction of noise stress than SBP. The mechanism underlying this difference needs further investigation.

The mechanism underlying the higher levels of blood pressure due to occupational noise exposure remains unclear. Acute exposure to noise is associated with short-term changes in blood pressure, heart rate, cardiac output and vasoconstriction along with increased levels of stress hormones (e.g., epinephrine, norepinephrine and corticosteroids) [16]. However, chronic and long-term noise exposure activates the sympathetic and endocrine systems, thereby affecting the humoral and metabolic states of human beings [7, 8, 10]. This could explain the higher cardiovascular risk with noise exposure. In this study, blood pressure was measured following a gap of more than 12 h after noise exposure, therefore, reflects the long-lasting biological effect.

This study had a relatively large sample size and two referent groups of external and internal control. The external control was recruited from the general population and frequency-matched with the exposed group in term of age and sex distribution. Two reference groups could increase the consistency of the results. We also adjusted for potential confounding factors such as smoking and drinking status in addition age and sex. However, there were some limitations in this study. Due to many missing data of height and weight, BMI was still not adjusted in the analysis. One limitation was environmental noise assessment. Noise exposure was evaluated with LEX,8 h, and not individual assessment of noise exposure. LEX,8 h was used according to the Occupational Health Standard of the People’s Republic of China: Measurement of Noise in the Workplace (GBZ/T189.8–2007) (China, 2007). This evaluation of noise exposure based on representative locations at the workplace at different work times and is then weighted as sound pressure levels to nominal 8 h/day. This evaluation is the routine method used for occupational noise surveillance in China. However, the evaluation might be incorrect if a worker often changes his workplace and shift time. It would be better if individual assessment of noise exposure was used. However, individual assessment of noise exposure was very difficult for field investigation with a relatively large sample. The second limitation was that the subjects were restricted to males because the majority (about 91.7%) of the noise-exposed workers in our cross-sectional study were males, which was as similar distribution of gender with the general noise-exposed workers in China. There might be a difference in the biological effects on blood pressure and risk of hypertension with respect to sex. Previous studies have indicated that females are more susceptible to occupational noise exposure than males [18, 21, 28]. Considering the gender difference, the findings in this study should be mainly focused on males. In additionally, these findings were based on a cross-sectional design and should be validated with a prospective study. The last limitation is that the subjects of external control were recruited participants from the cross-sectional survey of general population on metabolic syndrome. Although these population have no specific noise exposure in workplace and resident area, they may have reference exposure. They may also have bias with the exposed subjects group although we used frequency-match on age, sex, and resident area.

Conclusions

In summary, the present study suggested that occupational noise exposure had higher levels of SBP and DBP and the risk of hypertension. There were dose–response relationships between noise exposure and blood pressure and the risk of hypertension. DBP appeared to be more sensitive to occupational noise exposure. These findings indicate that effective and feasible measures should be implemented to reduce the risk of hypertension and cardiovascular diseases.

Abbreviations

CNE: 

Cumulative noise exposure

DBP: 

Diastolic blood pressure

OR: 

Odds ratio

SBP: 

Systolic blood pressure

Declarations

Acknowledgements

Not Applicable.

Funding

This study was supported by the Science and Technology Project of Zhejiang Province (2015C33255) and Zhejiang Provincial Program for the Cultivation of High-Level Innovative Health Talents.

Availability of data and materials

Enquiries regarding the availability of primary data should be directed to the principal investigator Professor Yimin Zhu (zhuym@zju.edu.cn).

Authors’ contributions

XZ and YZ conceived and designed the study. YZ drafted and refined the manuscript. SC, YN performed laboratorial determination and statistical analyses. SC, LZ, YZ, L.K., LL, ZY, LY and XZ participated in the epidemiological investigation. All authors approved the final version of the manuscript for submission.

Competing interests

The authors declare that they have no competing interests.

Consent for publication

Not applicable.

Ethics approval and consent to participate

The study protocol was approved by the Research Ethics Committees of Hangzhou Center for Disease Prevention and Control, Zhejiang, China. Written consent was obtained from all participants after they had been informed of the objectives, benefits, medical items and confidentiality agreement regarding their personal information.

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Authors’ Affiliations

(1)
Hangzhou Center for Disease Control and Prevention
(2)
Department of Epidemiology and Biostatistics, Zhejiang University School of Public Health
(3)
Hangzhou Hospital for Prevention and Treatment of Occupational Diseases
(4)
Department of Epidemiology and Biostatistics, Zhejiang Chinese Medical University

References

  1. Tak S, Davis RR, Calvert GM. Exposure to hazardous workplace noise and use of hearing protection devices among US workers--NHANES, 1999–2004. Am J Ind Med. 2009;52(5):358–71.View ArticlePubMedGoogle Scholar
  2. Gomes J, Lloyd O, Norman N. The health of the workers in a rapidly developing country: effects of occupational exposure to noise and heat. Occup Med. 2002;52(3):121–8.View ArticleGoogle Scholar
  3. Nelson DI, Nelson RY, Concha-Barrientos M, Fingerhut M. The global burden of occupational noise-induced hearing loss. Am J Ind Med. 2005;48(6):446–58.View ArticlePubMedGoogle Scholar
  4. Masterson EA, Bushnell PT, Themann CL, Morata TC. Hearing impairment among noise-exposed workers - United States, 2003–2012. MMWR Morb Mortal Wkly Rep. 2016;65(15):389–94.View ArticlePubMedGoogle Scholar
  5. Babisch W. The noise/stress concept, risk assessment and research needs. Noise & health. 2002;4(16):1–11.Google Scholar
  6. Goyal S, Gupta V, Walia L. Effect of noise stress on autonomic function tests. Noise & health. 2010;12(48):182–6.View ArticleGoogle Scholar
  7. Munzel T, Sorensen M, Gori T, Schmidt FP, Rao X, Brook FR, et al. Environmental stressors and cardio-metabolic disease: part II-mechanistic insights. Eur Heart J. 2016.Google Scholar
  8. Recio A, Linares C, Banegas JR, Diaz J. The short-term association of road traffic noise with cardiovascular, respiratory, and diabetes-related mortality. Environ Res. 2016;150:383–90.View ArticlePubMedGoogle Scholar
  9. Concha-Barrientos MC-LD, Steenland K. Occupational noise: assessing the burden of disease from work-related hearing impairment at national and local levels. In: Environmental burden of disease SeriesSeries. Geneva: World Health Organization; 2004.Google Scholar
  10. Munzel T, Gori T, Babisch W, Basner M. Cardiovascular effects of environmental noise exposure. Eur Heart J. 2014;35(13):829–36.View ArticlePubMedPubMed CentralGoogle Scholar
  11. Sorensen M, Hvidberg M, Andersen ZJ, Nordsborg RB, Lillelund KG, Jakobsen J, et al. Road traffic noise and stroke: a prospective cohort study. Eur Heart J. 2011;32(6):737–44.View ArticlePubMedGoogle Scholar
  12. Sbihi H, Davies HW, Demers PA. Hypertension in noise-exposed sawmill workers: a cohort study. Occup Environ Med. 2008;65(9):643–6.View ArticlePubMedGoogle Scholar
  13. Sorensen M, Hoffmann B, Hvidberg M, Ketzel M, Jensen SS, Andersen ZJ, et al. Long-term exposure to traffic-related air pollution associated with blood pressure and self-reported hypertension in a Danish cohort. Environ Health Perspect. 2012;120(3):418–24.View ArticlePubMedPubMed CentralGoogle Scholar
  14. Sorensen M, Hvidberg M, Hoffmann B, Andersen ZJ, Nordsborg RB, Lillelund KG, et al. Exposure to road traffic and railway noise and associations with blood pressure and self-reported hypertension: a cohort study. Environ Health. 2011;10:92.View ArticlePubMedPubMed CentralGoogle Scholar
  15. Dzhambov AM. Comment on: ‘Systematic review of the cardiovascular effects of occupational noise’ by Skogstad et al. Occup Med. 2016;66(6):498–9.View ArticleGoogle Scholar
  16. Skogstad M, Johannessen HA, Tynes T, Mehlum IS, Nordby KC, Lie A. Systematic review of the cardiovascular effects of occupational noise. Occup Med. 2016;66(6):500.View ArticleGoogle Scholar
  17. Meline J, Van Hulst A, Thomas F, Chaix B. Road, rail, and air transportation noise in residential and workplace neighborhoods and blood pressure (RECORD Study). Noise & Health. 2015;17(78):308–19.View ArticleGoogle Scholar
  18. Chang TY, Lai YA, Hsieh HH, Lai JS, Liu CS. Effects of environmental noise exposure on ambulatory blood pressure in young adults. Environ Res. 2009;109(7):900–5.View ArticlePubMedGoogle Scholar
  19. Chang TY, Liu CS, Bao BY, Li SF, Chen TI, Lin YJ. Characterization of road traffic noise exposure and prevalence of hypertension in central Taiwan. Sci Total Environ. 2011;409(6):1053–7.View ArticlePubMedGoogle Scholar
  20. Chang TY, Hwang BF, Liu CS, Chen RY, Wang VS, Bao BY, et al. Occupational noise exposure and incident hypertension in Men: a prospective cohort study. Am J Epidemiol. 2013;177(8):818–25.View ArticlePubMedGoogle Scholar
  21. Lee JH, Kang W, Yaang SR, Choy N, Lee CR. Cohort study for the effect of chronic noise exposure on blood pressure among male workers in Busan, Korea. Am J Ind Med. 2009;52(6):509–17.View ArticlePubMedGoogle Scholar
  22. de Souza TC, Perisse AR, Moura M. Noise exposure and hypertension: investigation of a silent relationship. BMC Public Health. 2015;15:328.View ArticlePubMedPubMed CentralGoogle Scholar
  23. Gan WQ, Davies HW, Demers PA. Exposure to occupational noise and cardiovascular disease in the united states: the national health and nutrition examination survey 1999–2004. Occup Environ Med. 2011;68(3):183–90.View ArticlePubMedGoogle Scholar
  24. Stokholm ZA, Bonde JP, Christensen KL, Hansen AM, Kolstad HA. Occupational noise exposure and the risk of hypertension. Epidemiology. 2013;24(1):135–42.View ArticlePubMedGoogle Scholar
  25. Inoue M, Laskar MS, Harada N. Cross-sectional study on occupational noise and hypertension in the workplace. Archives Environ occup Health. 2005;60(2):106–10.View ArticleGoogle Scholar
  26. Zhang X, Liu Y, Zhang L, Yang Z, Shao Y, Jiang C, et al. Genetic variations in protocadherin 15 and their interactions with noise exposure associated with noise-induced hearing loss in Chinese population. Environ Res. 2014;135:247–52.View ArticlePubMedGoogle Scholar
  27. Zhang XZ L, Xia YY, Wang Q, Xu YY, Chen JC, Shu LP, Zhu YM. A study on dose–response relationship between human hearing loss and non- stationary noise among workers. Zhejiang Prev Med. 2015;27(5):4.Google Scholar
  28. Jarup L, Babisch W, Houthuijs D, Pershagen G, Katsouyanni K, Cadum E, et al. Hypertension and exposure to noise near airports: the HYENA study. Environ Health Perspect. 2008;116(3):329–33.View ArticlePubMedGoogle Scholar

Copyright

© The Author(s). 2017

Advertisement