Work-related Respiratory Symptoms and Lung Function in New Zealand Mussel Openers

Am J Ind Med. 1998 Aug;34(2):163-8. doi: 10.1002/(sici)1097-0274(199808)34:2<163::aid-ajim9>;2-y.


Our objectives were to measure the prevalence of work-related and nonwork-related respiratory symptoms in a group of New Zealand mussel openers who open green-lipped mussels, and to relate these to demographic factors, work history, smoking history, and pulmonary function measurements. A cross-section study of respiratory symptoms and lung function was performed on 224 New Zealand mussel openers (99.6% of the study population) at nine work sites. In addition, peak expiratory flow (PEF) change across-shift was measured at one work site in 19 workers. The mean age of all mussel openers was 33.4 years and the mean duration of mussel opening was 5.0 years; 25% were male, 54.7% were current smokers, and 13.9% were ex-smokers. The reported symptom prevalences were: any wheeze, 35%; work-related wheeze, 23%; any chest tightness, 30.5%; work-related chest tightness, 20.2% (work-related symptoms were defined as symptoms improving on rest days or worse at work). Seventy-two mussel openers (32.3%) answered positively to at least 1 of 4 questions concerning work-related symptoms. The mean predicted FEV1 (SD) for this group was 74.3% (14.5), and the mean predicted FVC (SD) was 79.2 (16.0). Nineteen workers completed serial PEF, and the mean percentage change was +1.5% at 7 hr, but 8 workers had falls ranging between 1.1-14% after either 1 or 7 hr of work. Duration of mussel opening of greater than 2 years, but less than 7 years (OR = 2.29; 95% CI, 1.07-4.91), and duration of mussel opening greater than 7 years (OR = 3.72; 95% CI, 1.52-9.11), were significant predictors of work-related respiratory symptoms. Female sex (OR = 1.73; 95% CI, 0.83-3.60) was also associated with the presence of work-related symptoms. No relationship was found with measured hygiene parameters of cleaning agents used. In conclusions, duration of work as a mussel opener was associated with the present of work-related respiratory symptoms, after adjustment of age, sex, and smoking habit. There were marked abnormalities in mean FEV1 and FVC, although no consistent changes across working shift were noted.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Animals
  • Asthma / epidemiology*
  • Asthma / etiology
  • Bivalvia*
  • Confidence Intervals
  • Cross-Sectional Studies
  • Female
  • Food Handling*
  • Humans
  • Male
  • New Zealand / epidemiology
  • Occupational Diseases / epidemiology*
  • Occupational Diseases / etiology
  • Odds Ratio
  • Prevalence
  • Respiratory Function Tests
  • Sex Factors
  • Smoking / adverse effects
  • Surveys and Questionnaires
  • Time Factors