Elsevier

The Lancet

Volume 353, Issue 9166, 22 May 1999, Pages 1750-1754
The Lancet

Articles
Occupational asthma in Europe and other industrialised areas: a population-based study*

https://doi.org/10.1016/S0140-6736(98)07397-8Get rights and content

Summary

Background

There are no large population-based studies on occupational asthma, and few estimates of the proportion of asthma attributed to occupation, even though asthma is the most common occupational respiratory disorder in industrialised countries.

Methods

We assessed data on 15637 people aged 20–44, randomly selected from the general population of 26 areas in 12 industrialised countries. Asthma was assessed by methacholine challenge test and by questionnaire data on respiratory symptoms and use of medication. Occupation was defined by job-titles and a job exposure matrix was constructed.

Findings

Highest risk of asthma, defined as bronchial hyperresponsiveness and reported asthma symptoms or medication, was shown for farmers (odds ratio 2·62 [95% CI 1·29–5·35]), painters (2·34 [1·04–5·28]), plastic workers (2·20 [0·59–8·29]), cleaners (1·97 [1·33–2·92]), spray painters (1·96 [0·72–5·34]), and agricultural workers (1·79 [1·02–3·16]). Similar risks were shown for asthma defined as reported asthma symptoms or medication. The most consistent results across countries were shown for farmers and cleaners. Excess asthma risk was associated with high exposure to biological dusts, mineral dusts, and gases and fumes. The proportion of asthma among young adults attributed to occupation was 5%–10%.

Interpretation

The prevalence of occupational asthma in women and in specific occupations has been underestimated. Given a mean prevalence of asthma of about 5%, about 0·2%–0·5% of young adults become asthmatics or have their asthma exacerbated because of their occupations.

Introduction

Asthma is the most common occupational respiratory disorder in industrialised countries. About 250 specific occupational exposures are associated with asthma.1 Only some of these exposures have been assessed in epidemiological studies, and only a few studies have assessed occupational asthma in the general population. Studies that have used information from occupational registers in the USA and Japan suggest that about 15%–20% of all asthma may be related to occupation.1, 2, 3 Other studies, including two population-based studies in Spain4 and New Zealand,5 gave lower percentages, and suggested a raised risk of asthma for occupations such as cleaners, which are not generally recognised as high-risk occupations.4, 6

We analysed data from the European Community Respiratory Health Survey (ECRHS). The survey was done in Western European and other industrialised countries, and incorporated information from random samples of the general population of young adults in selected areas.7 Results from two national studies included in our analysis are available elsewhere.4, 5 We aimed to verify which occupations carry a high risk of asthma, and we estimated the proportion of asthma cases in the general population attributable to occupational exposures.

Section snippets

Participants

Information on participants' occupation was available from 26 centres in 12 countries. In the first phase of the ECRHS study, which took place in most of the countries in 1992, a random population sample aged 20–44 years from selected study areas was contacted and asked to complete a short screening questionnaire on respiratory symptoms. Since this sample was drawn from selected areas and towns, it may not have been representative of the general population. In the second phase, a 20% random

Results

Of the 26 848 people contacted in the second phase, 15 637 (58%) completed the questionnaire. Of these, 12 967 were from the random sample and 2670 from the “symptoms” subsample (table 1). 9476 of these people completed the test for bronchial reactivity. There were minimal differences in age and smoking status between the 6161 people who completed only the second questionnaire and the 9476 people who completed both the second questionnaire and the methacholinechallenge test. There were,

Discussion

Our data show that occupational asthma accounts for 5%–10% of asthma in young adults. These estimates are consistent with a study from Spain included in the ECRHS, and with estimates by Xu and Christiani,12 who showed that the excess fraction of physician-diagnosed asthma in China was about 12% for people exposed to dust and 5% for those exposed to gases or fumes. Our study was done in several countries and used the same methods, which suggests that occupational asthma should be an important

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  • Cited by (0)

    *

    Participating centres listed at end of paper

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