Mortality, morbidity and occupational exposure to airway-irritating agents among men with a respiratory diagnosis in adolescence.

OBJECTIVES: To examine the influence of an airway diagnosis in adolescence on future health and occupation in Swedish men. METHODS: Data were collected from the linkage of four Swedish national registers: the Military Service Conscription Register, the Population and Housing Censuses, the Inpatient Care Register and the National Cause of Death Register. A job-exposure matrix for airway-irritating substances was developed for application on the conscription cohort. The cohort included 49 321 Swedish men born 1949-51. Three groups-(1) healthy, (2) asthmatics (mild and severe asthma) and (3) subjects with allergic rhinitis without concurrent asthma-were identified at conscription and analysed for mortality, in-patient care and strategies for choice of occupation with emphasis on airway-irritating job exposure. Analyses were adjusted for smoking and childhood socioeconomic position. RESULTS: The prevalence of total asthma was 1.8%, severe asthma 0.45% and allergic rhinitis 2.7%. Mortality for all causes was significantly higher in total asthma, hazard ratio (HR) 1.49 (95% CI 1.00 to 2.23), and lower in allergic rhinitis, HR 0.52 (95% CI 0.30 to 0.91). Asthma was a risk factor for inpatient care while allergic rhinitis was associated with less in-patient care (odds ratio (OR) for total asthma 1.16 (95% CI 1.00 to 1.34), severe asthma 1.38 (95% CI 1.04 to 1.85), allergic rhinitis 0.92 (95% CI 0.82 to 1.03)). Those with asthma tended to avoid jobs with a high probability for airway-irritating exposure (OR 0.88, 95% CI 0.71 to 1.09), but not to the same extent as subjects with allergic rhinitis (OR 0.58, 95% CI 0.47 to 0.70) (ORs from 1990). CONCLUSION: Subjects with asthma did not change their exposure situation to the same extent as subjects with allergic rhinitis. Further, asthmatics had an increased risk for morbidity and mortality compared to healthy subjects and subjects with allergic rhinitis.

Negligible clearance of ultrafine particles retained in healthy and affected human lungs.

Ambient particles are believed to be a specific health hazard, although the underlying mechanisms are not fully understood. There are data in the literature indicating fast and substantial systemic uptake of particles from the lung. The present authors have developed an improved method to produce ultrafine particles with more stable radiolabelling and defined particle size range. Fifteen subjects inhaled technetium 99m (99mTc)-labelled carbonaceous particles of 100 nm in size. Radioactivity over the lung was followed for 70 h. The clearance of these ultrafine particles from the lungs and specifically translocation to the circulation was tested. Lung retention for all subjects at 46 h was mean+/-sd 99+/-4.6%. Cumulative leaching of 99mTc activity from the particles was 2.6+/-0.96% at 70 h. The 24-h activity leaching in urine was 1.0+/-0.55%. No evidence of a quantitatively important translocation of 100-nm particles to the systemic circulation from the lungs was found. More research is needed to establish if the approximately 1% cleared activity originates from leached activity or insoluble translocated particles, and whether a few per cent of translocated particles is sufficient to cause harmful effects.