title: Hearing impairment and contributing factors among fertilizer factory workers.
abstract: BACKGROUND
  Hearing impairment remains the main occupational health problem in the manufacturing industry, and its contributing factors have not been well controlled.
  
  
  METHODS
  Unmatched case control and comparative studies were carried out among fertilizer factory workers in Sarawak with the aim of determining contributing factors for hearing impairment. Respondents consisted of 49 cases that were diagnosed from 2005 to 2008 with 98 controls from the same work places. Chi-square test and Mann-Whitney test were used in a univariate analysis to determine the association between hearing impairment and the contributing risks being studied.
  
  
  RESULTS
  The results of the univariate analysis showed that hearing impairment was significantly (p<0.05) associated with older age, lower education level, high smoking dose, high occupational daily noise dose, longer duration of service, infrequent used of hearing protection device (HPD), and low perception of sound on HPD usage. Multivariate logistic regression of hearing impairment after controlling for age found the following five variables: occupational daily noise dose ≥50% (OR 3.48, 95% CI 1.36-8.89), ≥15 years of services (OR 2.92, 95% CI 1.16-7.33), infrequent use of HPD (OR 2.79, 95% CI 1.15-6.77), low perception of sound on HPD (POR 2.77, 95% CI 1.09-6.97), and smoking more than 20 packs per year (OR 4.71, 95% CI 1.13-19.68).
  
  
  CONCLUSIONS
  In conclusion, high occupational noise exposure level, longer duration of service, low perception of sound on HPD, infrequent used of HPD, and smoking more than 20 packs per year were the contributing factors to hearing impairment, and appropriate intervention measures should be proposed and taken into considerations.
authors.affiliation: Department of Community & Family Medicine, Faculty of Medicine & Health Science, University of Malaysia Sabah.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Saffree Jeffree
authors.forename: Noorhassim
authors.initials: N
authors.lastname: Ismail
authors.forename: Khamisah
authors.initials: K
authors.lastname: Awang Lukman
mesh_terms: D000328:Adult; D001299:Audiometry; D016022:Case-Control Studies; D004430:Ear Protective Devices / Q000706:statistics & numerical data; D005308:Fertilizers; D034381:Hearing Loss / Q000209:etiology* / Q000517:prevention & control; D006317:Hearing Loss, Noise-Induced / Q000209:etiology* / Q000517:prevention & control; D006801:Humans; D016015:Logistic Models; D008296:Malaysia / Q000453:epidemiology; D008297:Male; D000072499:Manufacturing and Industrial Facilities; D008875:Middle Aged; D009623:Noise, Occupational / Q000009:adverse effects*; D009784:Occupational Diseases / Q000209:etiology* / Q000517:prevention & control; D016273:Occupational Exposure / Q000009:adverse effects*; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D005308:Fertilizers