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

Abstract

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. (Occup Environ Med 2000;57:823-829)

Eye and airway symptoms in low occupational exposure to toluene diisocyanate

“…In western industrialized countries, the incidence of isocyanate-induced asthma has decreased (6,23,24). In recent years, at most, a handful of cases per year have been registered in Sweden.…”

Controversies in epidemiology of occupational asthma

“…The other voluntary scheme, Midland Thoracic Society9s Rare Respiratory Disease Registry Surveillance Scheme of Occupational Asthma (SHIELD), covers only the West Midlands (reports received from the specialists reporting to both schemes inevitably overlap) [57,58]. Results of the 1989-1997 period for SWORD have recently been published [57]. The most recent figures show stabilisation in the number of new cases with limited variation in the number of cases due to specific agents.…”

“…The Surveillance of Work-Related and Occupational Respiratory Disease (SWORD) draws on reports of newly diagnosed occupational lung disease from specialists in occupational or respiratory medicine in the UK. The other voluntary scheme, Midland Thoracic Society9s Rare Respiratory Disease Registry Surveillance Scheme of Occupational Asthma (SHIELD), covers only the West Midlands (reports received from the specialists reporting to both schemes inevitably overlap) [57,58]. Results of the 1989-1997 period for SWORD have recently been published [57].…”

Allergic Fungal Airway Disease

“…Sensitization to fungi, particularly Alternaria species, has been associated with life-threatening acute asthma attacks [90] and asthmarelated deaths [91], and fungi have been considered to cause asthma [92][93][94].…”