Medline ® Abstracts for References 36,37
of 'Reactive airways dysfunction syndrome and irritant-induced asthma'
Increased rates of asthma among World Trade Center disaster responders.
Kim H, Herbert R, Landrigan P, Markowitz SB, Moline JM, Savitz DA, Todd AC, Udasin IG, Wisnivesky JP
Am J Ind Med. 2012 Jan;55(1):44-53. Epub 2011 Nov 8.
BACKGROUND: Studies have documented high rates of asthma symptoms among responders to the World Trade Center (WTC) disaster. However, whether there are increased rates of asthma among responders compared to the general population is unknown.
METHODS: The study population consisted of a prospective cohort of 20,834 responders participating in the WTC Medical Monitoring and Treatment Program between July 2002 and December 2007. We calculated prevalence and standardized morbidity ratios (SMRs) of lifetime asthma and 12-month asthma (defined as≥1 attacks in the prior 12 months) among WTC responders. The comparison population consisted of>200,000 adults who completed the National Health Interview Survey in 2000 (for pre-9/11 comparisons) and between 2002 and 2007 (for post-9/11 comparisons).
RESULTS: WTC responders were on average 43±9 years old, 86% male, 59% white, and 42% had an occupation in protective services. The lifetime prevalence of asthma in the general population was relatively constant at about 10% from 2000 to 2007. However, among WTC responders, lifetime prevalence increased from 3% in 2000, to 13% in 2002, and 19% in 2007. The age-adjusted overall SMR for lifetime asthma among WTC responders was 1.8 (95% CI: 1.8-1.9) for men and 2.0 (95% CI: 1.9-2.1) for women. Twelve-month asthma was also more frequent among WTC responders compared to the general population (SMR 2.4, 95% CI: 2.2-2.5) for men and 2.2 (95% CI: 2.0-2.5) for women.
CONCLUSIONS: WTC responders are at an increased risk of asthma as measured by lifetime prevalence or active disease.
Department of Population Health, Hofstra North Shore-LIJ School of Medicine, New York, New York, USA.
Reactive airways dysfunction syndrome induced by exposure to a mixture containing isocyanate: functional and histopathologic behaviour.
Lemière C, Malo JL, Boulet LP, Boutet M
A 31-year-old machinist experienced acute symptoms of rhinoconjunctivitis, coughing, shortness of breath, and wheezing after sudden exposure to fumes containing isocyanates and solvents. Lung function tests carried out 11 days after the event showed reduced flow rates. Forty days after the acute inhalational injury, expiratory flows improved, and the PC20 was 0.8 mg/ml, showing moderate bronchial hyperresponsiveness. Six days later, the subject underwent bronchoscopy. Bronchial biopsies showed a marked loss of epithelial cells, severe subepithelial oedema, and inflammatory cells infiltrate (mainly lymphocytes). The subject was given inhaled steroids. The PC20 was back to normal 42 days later. Bronchial biopsies then showed incomplete regeneration of the epithelial layer with few ciliated cells and persistence of inflammation (lymphocyte infiltrate) in epithelia and connective tissue. We conclude that irritant exposure to a mixture of isocyanates and solvents can cause occupational asthma without a latency period, i.e., reactive airways dysfunction syndrome.
Sacré-Coeur Hospital, Quebec City, Canada.