The Association between Noise, Cortisol and Heart Rate in a Small-Scale Gold Mining Community—A Pilot Study

International Journal of Environmental Research and Public Health

Allyson Green¹  Andrew D. Jones¹  Kan Sun¹  Richard L. Neitzel¹  Nil Basu²  Susan Keane² 

[1] Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA; E-Mails:Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA;

关键词: small-scale gold mining;    ASGM;    dietary diversity;    salivary cortisol;    stress;    heart rate;    noise exposure;    Ghana;    health determinants;   

DOI  :  10.3390/ijerph120809952

来源: mdpi

【 摘 要 】

We performed a cross-sectional pilot study on salivary cortisol, heart rate, and personal noise exposures in a small-scale gold mining village in northeastern Ghana in 2013. Cortisol level changes between morning and evening among participants showed a relatively low decline in cortisol through the day (−1.44 ± 4.27 nmol/L, n = 18), a pattern consistent with chronic stress. A multiple linear regression, adjusting for age, sex, smoking status, and time between samples indicated a significant increase of 0.25 nmol/L cortisol from afternoon to evening per 1 dBA increase in equivalent continuous noise exposure (L_eq) over that period (95% CI: 0.08–0.42, Adj R² = 0.502, n = 17). A mixed effect linear regression model adjusting for age and sex indicated a significant increase of 0.29 heart beats per minute (BPM) for every 1 dB increase in L_eq. Using standard deviations (SDs) as measures of variation, and adjusting for age and sex over the sampling period, we found that a 1 dBA increase in noise variation over time (L_eq SD) was associated with a 0.5 BPM increase in heart rate SD (95% CI: 0.04–−0.9, Adj. R² = 0.229, n = 16). Noise levels were consistently high, with 24-hour average L_eq exposures ranging from 56.9 to 92.0 dBA, with a mean daily L_eq of 82.2 ± 7.3 dBA (mean monitoring duration 22.1 ± 1.9 hours, n = 22). Ninety-five percent of participants had 24-hour average L_eq noise levels over the 70 dBA World health Organization (WHO) guideline level for prevention of hearing loss. These findings suggest that small-scale mining communities may face multiple, potentially additive health risks that are not yet well documented, including hearing loss and cardiovascular effects of stress and noise.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.