Associations of blood pressure and arterial compliance with occupational noise exposure in female workers of textile mill

BACKGROUND: There are few studies on the arterial compliance of noise exposure. The purpose of this study was to understand the relationship between hearing loss, blood pressure and arterial compliance of female workers who exposed to occupational noise in a textile mill. METHODS: The noise levels in the workplace were measured with a HS6288 sound level meter. Cumulated noise exposure (CNE) was calculated according to the noise intensity and the exposure period. Hearing ability and arterial compliance were measured in 618 noise exposed workers. The database was set up with EpiData and the statistical analysis was performed with SAS software 9.1.3. RESULTS: The noise levels were 80.1dB (A) to 113.5dB (A), of which the levels at 92.5% of the noise monitoring sites were over the national standard. The incidence of high frequency hearing loss (HFHL) was 24.43% and language frequency hearing impairment (LFHI) was 0.81%. The incidence of hypertension was 7.93%. Both systolic blood pressure (SBP) and diastolic blood pressure (DBP) in the high frequency hearing loss group were significantly higher than those in the normal hearing group (P < 0.05), while C(1) (large artery compliance) and C(2) (small artery compliance) were significantly lower (P < 0.05). The high frequency hearing threshold (HFHT) of the hypertension group was significantly higher than in the normal blood pressure group (P < 0.05), while C(1) and C(2) were significantly lower (P < 0.05). C(1) and C(2) had a negative correlation with HFHT, SBP, DBP, mean of arterial pressure (MAP), pulse pressure (PP) and pulse rate (PR) (P < 0.05). The multiple regression analyses showed that blood pressure and PR were the main influencing factors on C(1) and C(2). LFHT was an influence on C(2) and HFHT on C(1). CONCLUSIONS: Textile mill noise pollution is very serious and has an obvious influence on worker's auditory function. The female workers with low artery compliance or with high blood pressure might be suffering from hearing loss; those with noise induced hearing loss might be suffering from hypertension if she is constantly exposed to loud industrial noise.