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RATIONALE: Identifying high grass pollen days is important for asthma management programs that issue warnings to patients who are at an increased risk of an asthma attack due to grass pollen exposure. We sought to examine the association between increasing ambient concentrations of grass pollen and asthma Emergency Department (ED) presentations in children during the 2003 grass pollen season in Melbourne, Victoria; and whether there was any added influence from thunderstorms. METHODS: A short time series ecological study was conducted of ED presentations for asthma in children in Melbourne, Victoria and grass pollen, meteorological and air quality measurements recorded during the selected 2003 period. A semi-parametric Poisson regression model was used to examine the dose-response associations between daily grass pollen levels and mean daily ED attendances for asthma among children. RESULTS: A smoothed plot suggested a dose-response association -as ambient grass pollen increased to about 19 grains/m 3 the same day risk of childhood ED presentations also increased (p < 0.001). Grass pollen levels were also associated with an increased risk in asthma ED presentations on the following day (lag 1, p < 0.001). CONCLUSIONS: This is the first study to establish a clear relationship between increased risk of childhood asthma ED attendance and increasing levels of ambient grass pollen below 20 grains/m 3 , independent of thunderstorm-associated asthma. Lower levels of pollen may contribute to asthma symptoms, so the limits of the pollen season may need to be reviewed and this in turn could affect the timing of immunotherapy.

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Objectives: To investigate the incidence of respiratory symptoms and changes in pulmonary function in relation to occupational exposures in two aluminium smelters in Victoria, Australia. Methods: The study population consisted of employees who started employment between 1995 and the end of 2003 at two aluminium smelter sites in Victoria, Australia. Participation involved an initial assessment at the start of employment and annual follow-up assessments for the duration of employment at the smelters. These assessments involved an intervieweradministered questionnaire which included questions about cough, shortness of breath, wheeze, chest tightness and rhinitis. In addition lung function was assessed by measuring forced expiratory volume in 1 s (FEV 1 ) and forced vital capacity (FVC). Methacholine challenge testing was performed to identify bronchial hyper-responsiveness (BHR). The occupational exposures investigated in this study were fluoride, sulphur dioxide (SO 2 ), inspirable dust, benzene soluble fraction (BSF) and oil mist. The exposure levels to these substances were calculated for each participant in the study using their job history information and routine personal air monitoring data. The random effects model was used to investigate the association between occupational exposures and health outcomes. Results: In total 446 employees participated in the study. Of the five symptoms, only wheeze and chest tightness, the two symptoms most closely related to asthma, showed associations with exposures at the sites. Workers who were exposed to fluoride, inspirable dust, SO 2 and BSF were more likely to report wheeze. Chest tightness was associated with exposure to dust, SO 2 and BSF. Many of the exposures were highly correlated, but it is most likely that fluoride and SO 2 , known respiratory irritants, were responsible for the symptom effects observed. Fluoride, inspirable dust and SO 2 were the most important agents having an effect on lung function. A significant reduction in the FEV 1 /FVC ratio (an indicator of airflow limitation), and declines in both FEV 1 and FVC over time were associated with these exposures. BHR was also related to exposure to fluoride, SO 2 , inspirable dust and BSF. Conclusion: Some occupational exposures in aluminium smelters are associated with increased wheeze and chest tightness and small decrements in lung function and BHR. Key words: aluminium smelter; pulmonary function; respiratory symptoms PREVALENCE OF CHRONIC BRONCHITIS RELATED TO PROFESSIONAL AND ENVIRONMENTAL EXPOSURE TO HYDROCARBONS IN FEMALE WORKERS E. Viragh. Tg-Mures University of Medicine and PharmacyObjectives: This epidemiological field study was conducted to determine the prevalence of chronic bronchitis in female persons exposed to hydrocarbons in the petrochemical industry and the surrounding environment. Methods: Air monitoring in all workplaces and around the factory of aliphatic (AH) and polycyclic aromatic hydrocarbons (PAH) was carried out during a 7-year period. 147 females aged 38.2 (SD 6.1) years and w...