Workforce survey of occupational exposures and health effects in New Zealand : a thesis by publications presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Epidemiology at Massey University, Wellington, New Zealand
This thesis is based on the first workforce survey in New Zealand to assess occupational
exposures and health in a random sample of the working population. The aims of this
thesis were to: i) describe the prevalence and distribution of occupational exposures and
workplace practices in the New Zealand working population; ii) identify gender and ethnic
differences in occupational exposure; and iii) examine which occupational risk factors
contribute to the risk of respiratory disease.
Over a two year period 10,000 individuals aged 20-64 were randomly selected from the
Electoral Roll and invited to take part in a telephone interview. The interview obtained
information on lifetime work history, occupational exposures including dust/chemical
exposures and certain physical and organisational factors, and selected health effects
including respiratory symptoms. A total of 3,003 interviews were completed (37%
Occupational exposure to dust/chemical and certain physical factors were
disproportionately experienced by workers in the agricultural, trades, and manufacturing
sectors, where prevalences were as high as 75%. However, exposures also occurred in
other occupational groups not traditionally associated with hazardous exposures (for
example the legislators and managers group). Substantial differences in exposure
prevalence were observed between males and females and Maori and non-Maori workers.
The occupations positively associated with current and adult-onset asthma included
printers, bakers, and sawmill labourers, as well as several occupations that have not been
previously associated with asthma (for example teachers and certain sales professionals).
Finally, a positive association between work-related stress and asthma was identified.
This thesis indicates that the traditional chemical and physical exposures are common in
the New Zealand working population, and that emerging factors such as organisational and
psychosocial exposures are also prevalent and relevant to occupational health. While the
distribution of occupational exposures and risk factors for asthma were concentrated in
certain occupational groups, they were also more widely spread across the workforce than
previously assumed. Besides occupation, the demographic characteristics of a worker also
appeared to determine their occupational exposure. The findings of this thesis illustrate that
workforce surveys are a valuable tool for assessing a wide range of exposures in a wide
range of workers, and therefore should be carried out on a regular basis.
This is a pre-copy-editing, author-produced PDF of an article accepted for publication in Annals of Occupational Hygiene following peer review. The definitive publisher-authenticated version Eng, A., 'T Mannetje, A., Cheng, S., Douwes, J., Ellison-Loschmann, L., McLean, D., et al. (2010). The New Zealand workforce survey I: Self-reported occupational exposures. Annals of Occupational Hygiene, 54(2), 144-153 is available online at: http://annhyg.oxfordjournals.org/content/54/2/144.full. CH5. Eng, A., t Mannetje, A., Ellison-Loschmann, L., McLean, D., Cheng, S., & Pearce, N. (2011). Ethnic differences in patterns of occupational exposure in New Zealand. American Journal of Industrial Medicine, 54(5), 410-418
The definitive version is available at www3.interscience.wiley.com or http://onlinelibrary.wiley.com/doi/10.1002/ajim.20934/full.
This is a pre-copy-editing, author-produced PDF of an article accepted for publication in The annals of occupational hygiene following peer review. The definitive publisher-authenticated version Eng, A., ‘T Mannetje, A., Douwes, J., Cheng, S., McLean, D., Ellison-Loschmann, L., & Pearce, N. (2010). The New Zealand Workforce Survey II: Occupational Risk Factors for Asthma. Annals of Occupational Hygiene, 54(2), 154-164 is available online at: http://annhyg.oxfordjournals.org/content/54/2/154.full.