Study On Effect Of Noise Exposure On Hypertension Among Steel Workers

Objectives To analyze the prevalent rate of hypertension among steel workers exposed to occupational noise and to study the relationship between occupational noise exposure and hypertension, so as to provide a scientific basis for reasonable control of noise hazard and the risk of hypertension.Methods 1150 noise exposure workers by health examination from January to July in 2014 were selected as study group, and 1103 non noise exposure workers were selected as control group. The research was surveyed by questionnaire and measurement of their workplace noise. According to equal-energy rule, the A-weighted sound pressure level and noise exposure duration were incorporated for the cumulative noise exposure. The level of noise exposure were divided into: 75 d B(A) ~, 80 d B(A) ~, 85 d B(A) ~ and ?90d B(A) groups according to the size of CNE.Results 1 In the control group, the systolic blood pressure was 112.03 ± 12.97 mm Hg, and the diastolic blood pressure was 72.53±9.31 mm Hg; The systolic blood pressure of the noise group was 120.51±14.53 mm Hg, diastolic blood pressure was 78.94 ±10.97 mm Hg. The difference between the two groups was statistically significant(t=3.40,P<0.01). 2 The mean systolic blood pressure in each noise exposure group were 119.70±15.75 mm Hg, 124.74 ± 10.66 mm Hg, 126.75±14.64 mm Hg and128.88 ±16.15 mm Hg; The mean diastolic blood pressure was 77.83±5.55 mm Hg, 80.86±5.30 mm Hg, 84.79±9.38 mm Hg, 86.72±11.12 mm Hg respectively. There was statistically significant difference(SBP: F= 5.14, P<0.05; DBP: F= 9.70, P<0.01). 3 After divided into 20 year, 30 year,40 year groups, systolic blood pressure and diastolic blood pressure were both different with statistical significant in each noise exposure level groups. The differences of systolic blood pressures and diastolic blood pressures in each noise exposure level groups involved in 50 year group was not statistically significant. 4 The hypertension prevalence rate among steel workers exposed to noise was 32.3%. 5 With increase of the CNE, the prevalence of hypertension was gradually increased and difference was statistically significant(P<0.01), there was a clear dose-response relationship between the CNE and the prevalence of hypertension. Unconditional logistic regression analysis showed that, after adjusting for age(OR30~40years=1.505,95%CI 1.038~2.471;OR 40 ~ 50 years = 1.824, 95%CI 1.135~2.932; OR50 ~ 60 years = 4.646, 95%CI 2.454~8.794), BMI(OR 24 ~ 28 kg / m~2= 2.402, 95%CI 1.708~3.377;OR?28kg/m~2 = 6.502, 95%CI 4.461~9.478), hightemperature(OR=3.735,95%CI 1.628~5.213),family history of hypertension(OR = 1.410, 95%CI 1.063~1.871), smoking(OR21~40/d=1.262,95%CI 1.128~1.412;OR?41/d=1.657,95%CI 1.336~2.054), alcohol consumption(OR = 1.358,95%CI 1.094~1.685), fried grilled food intake(OR = 1.356, 95%CI 1.058~1.739), salt(OR = 1.465, 95%CI 1.080~1.986), education level(OR = 0.761, 95%CI 0.611~0.947) and other factors, CNE is still a risk factor for the prevalence of hypertension(OR75~85 d B(A)=1.206,95%CI 1.042~1.617,OR85~90d B(A) = 1.362, 95%CI 1.030~1.802;OR?90dB(A) = 2.564,95%CI 1.417~ 4.642).6 The prevalence rate of hypertension was decreased with the increase of noise exposure started age, and the difference was statistically significant(2c =33.75,P<0.001).Conclusions 1 The workers in iron and steel enterprises increased blood pressure was associated with noise exposure; The elevation of noise operator in more than 50 years old group was not associated with the increase in blood pressure. 2 Noise exposure may be a risk factor of hypertension for steel workers. Therefore, strengthening noise protection may be one of the effective measures to reduce the risk of the hypertension among steelworkers. 3 Noise exposure started from older may be a protective factor for hypertension in noise exposure workers in iron and steel enterprises.