TY - JOUR
T1 - The Relationship between Occupational Exposure to Lead and Hearing Loss in a Cross-Sectional Survey of Iranian Workers
AU - Ghiasvand, Masoumeh
AU - Mohammadi, Saber
AU - Roth, Brett
AU - Ranjbar, Mostafa
N1 - Funding Information:
We acknowledge with thanks HSE department of battery manufacturing factory for helping to data collection (arrangement the time and place for interview with workers and lab clinical studies).
Publisher Copyright:
Copyright © 2016 Ghiasvand, Mohammadi, Roth and Ranjbar.
PY - 2016/2/16
Y1 - 2016/2/16
N2 - Objectives: Ototoxic effect of exposure to lead has been reported by many researchers. This study was undertaken with a view to investigate the relationship between blood lead level (BLL) and hearing loss in workers in a lead-acid battery manufacturing plant in Tehran, Iran. Methods: In a cross-sectional study, 609 male workers were recruited from different locations in the factory. Association between BLL and hearing loss in different frequencies were measured. Relationships were analyzed by logistic regressions. Statistical significance was defined as p-value <0.05. Results: Six hundred nine male workers with mean age 40 ± 7 years and mean noise exposure level of 80 (75–85) dB were evaluated. BLLs were categorized into four quartiles, and hearing loss in each quartile was compared to the first one. In our regression models, BLL was associated significantly with high frequency hearing loss, adjusted odds ratios for the comparison of the fourth, third, and second quartiles to the first one are respectively: 3.98 (95% CI: 1.63–9.71, p < 0.00), 3.05 (95% CI: 1.28–7.26, p < 0.01), and 2.89 (95% CI: 1.11–7.51, p < 0.03). Conclusion: This study showed a dose–response relationship between BLL and hearing loss, after adjusting for potential confounders (age, body mass index, work duration, smoking, and occupational noise exposure) in logistic regressions. It is concluded that periodic hearing assessment by pure tone audiometry in workers exposed to lead should be recommended. However, additional studies are required to clarify the mechanisms of lead ototoxicity.
AB - Objectives: Ototoxic effect of exposure to lead has been reported by many researchers. This study was undertaken with a view to investigate the relationship between blood lead level (BLL) and hearing loss in workers in a lead-acid battery manufacturing plant in Tehran, Iran. Methods: In a cross-sectional study, 609 male workers were recruited from different locations in the factory. Association between BLL and hearing loss in different frequencies were measured. Relationships were analyzed by logistic regressions. Statistical significance was defined as p-value <0.05. Results: Six hundred nine male workers with mean age 40 ± 7 years and mean noise exposure level of 80 (75–85) dB were evaluated. BLLs were categorized into four quartiles, and hearing loss in each quartile was compared to the first one. In our regression models, BLL was associated significantly with high frequency hearing loss, adjusted odds ratios for the comparison of the fourth, third, and second quartiles to the first one are respectively: 3.98 (95% CI: 1.63–9.71, p < 0.00), 3.05 (95% CI: 1.28–7.26, p < 0.01), and 2.89 (95% CI: 1.11–7.51, p < 0.03). Conclusion: This study showed a dose–response relationship between BLL and hearing loss, after adjusting for potential confounders (age, body mass index, work duration, smoking, and occupational noise exposure) in logistic regressions. It is concluded that periodic hearing assessment by pure tone audiometry in workers exposed to lead should be recommended. However, additional studies are required to clarify the mechanisms of lead ototoxicity.
KW - blood lead level
KW - hearing loss
KW - lead ototoxicity
KW - pure tone audiometry
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U2 - 10.3389/fpubh.2016.00019
DO - 10.3389/fpubh.2016.00019
M3 - Article
C2 - 26909343
AN - SCOPUS:85029885937
SN - 2296-2565
VL - 4
JO - Frontiers in Public Health
JF - Frontiers in Public Health
M1 - 19
ER -