SWORD '95: surveillance of work-related and occupational respiratory disease in the UK

[The epidemiology of occupational asthma in Belgium]

INTRODUCTION

A national surveillance programme of occupational asthma was set up to estimate the incidence and identify the causes of this disorder in Belgium.

MATERIALS AND METHODS

The programme was based on the voluntary notification of new cases of occupational asthma by chest specialists and occupational physicians during the period 2000-2002.

RESULTS

92% of the reported cases included occupational asthma of an immunological type and 8% bronchial irritability. According to the opinion of the reporting physicians the diagnosis was considered certain in 39%, probable in 29% and possible in 32% of cases. On the basis of these notifications the mean annual incidence of occupational asthma is estimated as 23.5 cases per million workers (95% confidence interval 19.2-28.8). The most frequently incriminated substances were isocyanates (16%), cereals (12%) and latex (10%). At the time of diagnosis 38% of patients had not applied for compensation.

CONCLUSION

The results of this programme of notification of occupational asthma agree with the data available from other countries and provide information complementary to the medico-legal statistics.

Hazard and risk assessment of industrial chemicals in the occupational context in Europe: some current issues

This paper is about industrial chemicals, the manner in which their toxicity is assessed and the use of such assessments in regulatory decision-making. It begins with general points concerning toxicological data availability and hazard identification, then moves on to risk assessment and occupational exposure limits, and finally looks briefly at three specific toxicological issues, asthma, chronic toxic encephalopathy, and "low toxicity" dust effects on the lung, where the science is far from resolved. The overall purpose of the paper is to raise, or perhaps to act as a reminder of a number of issues of particular relevance to industrial chemicals and the occupational setting, and hopefully to prompt further thinking and perhaps some new initiatives directed at the areas in question.

Reported incidence of occupational asthma in the United Kingdom, 1989-97

OBJECTIVES

To examine trends in estimated population based incidence of occupational asthma by age, sex, occupation, geographical region, and causal agents based on 9 years of the Surveillance of Work Related and Occupational Respiratory Disease (SWORD) data.

METHODS

In January 1989 the SWORD scheme for the surveillance of occupational respiratory disease was established in the United Kingdom to make good the lack of epidemiological information on the incidence of these diseases in the United Kingdom. Between 80% and 90% of chest and occupational physicians report voluntarily all new cases they see, on a monthly or random sampling basis. During the 9 years 1989-97, an estimated 25 674 new cases of occupational respiratory disease, including 7387 of occupational asthma, were reported. Suspected causal agents were classified into 44 categories and estimated annual incidences of asthma were calculated with denominators from the labour force survey.

RESULTS

Overall, a third of the suspected causes of asthma were organic, a third chemical, 6% metallic, and the rest miscellaneous, or in 8%, unknown. There was evidence of an increase since 1989 in cases due to latex, and possibly glutaraldehyde, and an apparent drop since 1991 in the proportion of cases attributed to isocyanates. Incidences were higher in men than women and the disparity was especially marked in the population aged 45 years or more in which rates for men were at least twice those for women. Average annual rates per million workers for 1992-7 ranged from 7 (95% confidence interval (95% CI) 5 to 9) for the lowest risk group of professional, clerical, and service workers to 1464 (95% CI 968 to 2173) for coach and other spray painters. Except for laboratory technicians, all other occupations with rates over 100 were concerned with manufacturing and processing that used chemicals, metals, and organic materials. Incidences were two to three times higher in the north and midlands than in East Anglia and the south. The introduction of a sampling scheme in 1992 doubled estimates of reported incidence of occupational asthma, but there was little evidence of other temporal changes.

CONCLUSIONS

The SWORD scheme has produced consistent estimates of the causes and incidence of occupational asthma as seen by chest and occupational physicians. It has allowed the epidemiology of occupational asthma in the population to be studied and high risk occupations to be identified. There is certainly more occupational asthma in the population than that which reaches specialists in occupational and chest medicine; therefore the incidence rates presented here are underestimates, but by how much remains unknown.