Rod Simpson

The effects of air pollution on hospitalizations for cardiovascular disease in elderly people in Australian and New Zealand cities.

Objective The goal of this study was to estimate the associations between outdoor air pollution and cardiovascular hospital admissions for the elderly Design Associations were assessed using the case–crossover method for seven cities: Auckland and Christchurch, New Zealand; and Brisbane, Canberra, Melbourne, Perth, and Sydney Australia. Results were combined across cities using a random-effects meta-analysis and stratified for two adult age groups: 15–64 years and ≥ 65 years of age (elderly). Pollutants considered were nitrogen dioxide, carbon monoxide, daily measures of particulate matter (PM) and ozone. Where multiple pollutant associations were found, a matched case–control analysis was used to identify the most consistent association. Results In the elderly, all pollutants except O3 were significantly associated with five categories of cardiovascular disease admissions. No associations were found for arrhythmia and stroke. For a 0.9-ppm increase in CO, there were significant increases in elderly hospital admissions for total cardiovascular disease (2.2%), all cardiac disease (2.8%), cardiac failure (6.0%), ischemic heart disease (2.3%), and myocardial infarction (2.9%). There was some heterogeneity between cities, possibly due to differences in humidity and the percentage of elderly people. In matched analyses, CO had the most consistent association. Conclusions The results suggest that air pollution arising from common emission sources for CO, NO2, and PM (e.g., motor vehicle exhausts) has significant associations with adult cardiovascular hospital admissions, especially in the elderly, at air pollution concentrations below normal health guidelines. Relevance to clinical and professional practice Elderly populations in Australia need to be protected from air pollution arising from outdoor sources to reduce cardiovascular disease.

Associations between outdoor air pollution and hospital admissions in Brisbane, Australia

Abstract The authors investigated the effects of ambient air pollution on hospital admissions in Brisbane, Australia. The authors used the Air Pollution on Health: European Approach protocol to examine the effects of particles, ozone, sulfur dioxide, and nitrogen dioxide on daily hospital admissions for asthma and respiratory, cardiovascular, and digestive disorders (control diagnosis) that occurred during the period 1987-1994. Ozone was consistently associated with admissions for asthma and respiratory disease—with little evidence of a threshold. In two-pollutant models, the ozone effect was relatively unaffected by the control for high levels of other pollutants. Particulate pollution (measured by nephelometry) was associated positively with admissions for respiratory disease and admissions for asthma in summer, whereas a negative association was observed for cardiovascular admissions. Although sulfur dioxide was associated significantly with admissions for respiratory and cardiovascular disease, a significant association was also found for the control diagnosis of digestive disorders. No significant associations were found for nitrogen dioxide over the study period, although significantly positive seasonal interactions were found for asthma and respiratory disease in autumn, winter, and spring. It was concluded that current levels of ambient air pollution in Brisbane make a significant contribution to the variation in daily hospital admissions for asthma and respiratory disease.

Maternal exposure to low levels of ambient air pollution and preterm birth in Brisbane, Australia

Background  There is evidence that maternal exposure to ambient air pollution during pregnancy is associated with adverse birth outcomes.

Associations between Outdoor Air Pollution and Daily Mortality in Brisbane, Australia

The results of several studies have indicated significant associations between daily mortality and air pollution, with little evidence of a threshold. In the current study, the authors examined daily mortality during the period 1987-1993 for the Brisbane region, which is the fastest-growing urban region in Australia (annual average concentration of particulate matter less than 10 microm in diameter = 27 microg/m3, maximum hourly sulfur dioxide level = 60 ppb, and maximum daily ozone hourly level = 118 ppb). The authors conducted a general estimating equation analysis, and they used autoregressive Poisson models for daily mortality to examine associations with air pollution variables. The authors used research methods developed in the Air Pollution on Health, European Approach (APHEA), project to control confounding effects of weather and temporal trends. The air pollutants examined included particulate pollution (measured by nephelometry [bsp data]), sulfur dioxide, ozone, and nitrogen dioxide. The results indicated that the associations between total daily mortality and particulate levels found in studies in the United States and other countries may be applicable in Brisbane, Australia. Ozone levels were also associated significantly with total daily mortality. There was little evidence of interaction between the ozone effects (mainly in summer) and particulates or with sulfur dioxide and nitrogen dioxide. The associations between pollutants (ozone, bsp) and daily mortality were significant only for individuals who were older than 65 y of age; positive associations were also found with cardiovascular disease categories, and the regression coefficients--when significant--were higher than those for total mortality. The results indicated a possible threshold for ozone levels, but a similar result for particulate levels was not apparent.

The short-term effects of air pollution on daily mortality in four Australian cities

Objective: To examine the short‐term health effects of air pollution on daily mortality in four Australian cities (Brisbane, Melbourne, Perth and Sydney), where more than 50% of Australians reside.

Associations between ambient air pollution and daily emergency department attendances for cardiovascular disease in the elderly (65+ years), Sydney, Australia.

There are no reported studies on the effects of ambient air pollution on emergency department (ED) attendances in Sydney, Australia. This study aimed to determine associations between ambient air pollutants and ED attendances for cardiovascular disease (CVD) in those aged 65+ years. We constructed daily time series of hospital ED attendances, air pollutants and meteorological factors for the Sydney metropolitan area from 1 January 1997 to 31 December 2001. We used generalised linear models to determine associations between daily air pollution and daily ED attendances and controlled for the effects of long-term trends, seasonality, weather and other potential confounders. Increased ED attendances for all CVD, cardiac disease and ischaemic heart disease were seen with 24-h particulate pollution, 1-h NO2, 8-h CO and 24-h SO2. Air pollutants were associated with decreased ED attendances for stroke. The effects of air pollutants on CVD, cardiac disease and stroke attendances were generally greater in the cool period compared to the warm period. The single-pollutant effects of CO, O3, NO2 and SO2 were essentially unchanged in two-pollutant models. Although air pollution levels in Sydney are relatively low compared to similar cities, we have demonstrated associations between ambient air pollutants and ED attendances for CVD in people aged 65+ years. Our study adds to the growing evidence for the effects of ambient air pollution on CVD outcomes even at relatively low ambient concentrations.

Effects of ambient particle pollution on daily mortality in Melbourne, 1991-1996.

This paper presents the results of a study in Melbourne, Australia, of the short-term effects of ambient fine particle pollution on daily mortality occurring between 1991 and 1996. The methodological approach used Poisson regression and Generalized Additive Models (GAM) with LOESS smoothing to control for temporal and meteorological effects. The association between particles and increases in daily mortality was examined using nephelometry data (bsp, mean 24 h average=0.26×10−4 m−1, mean 1 h maximum=0.60×10−4 m−1), PM2.5 (24 h mean=9.42 µg/m3) and PM10 (24 h mean=19 µg/m3). Both the PM10 and PM2.5 data were estimated from nephelometry data using previously derived relationships for the Melbourne airshed. Significant positive associations between the particle measures considered and all cause and respiratory mortality were found in the warm season (November–March). A 1×10−4 m−1 increase in maximum 1-h bsp levels was associated with a 2.19% (95% CI=0.01–4.43%) increase in risk of death for all cause mortality and a 10.40% (95% CI=2.44–18.97%) increase in risk for respiratory mortality in the warm season. A 1 µg/m3 increase in 24-h PM2.5 in the warm season was associated with a 0.38% (95% CI=0.06–0.70%) increase in risk of death for all cause mortality and a 1.18% (95% CI=0.05–2.32%) increase in risk for respiratory mortality. For PM10, a 1 µg/m3 increase was associated with an increased risk of 0.18% (95% CI=0.03–0.33%) for all cause mortality and 0.59% (95% CI=0.06–1.13%) for respiratory mortality. Significant associations were also found in the 65+ age group in the warm season. However, for these warm periods, the effects of ozone (average 1 h maximum=127 ppb) and nitrogen dioxide (average 1 h maximum=70.7 ppb) were also significant and, due to high correlations between these pollutants, it was not possible to separate the particle effects from those of O3 and NO2. Sulfur dioxide was not examined as concentrations of this pollutant in Melbourne are very low (max 1 h=15–24 ppb, annual average 0.8 ppb). Comparison with other Australian studies in Sydney and Brisbane indicates different results for particle pollution.

Survey of airspora in Brisbane, Queensland, Australia

Environmental monitoring of airspora components at two sites in the Brisbane area was carried out for an 18 month period, to cover two peak periods for asthma incidence in this region. Fungal spores, especially those assigned to the Fungi Imperfecti, comprised the most numerous group, and pollen numbers in all samples were consistently low with grass the most abundant pollen. Cladosporium was the most abundant single taxon found throughout the year. Daily spore and pollen counts showed great variability over time. Spore and pollen levels at the two sites tended to show similar temporal patterns, although the magnitudes varied, possibly reflecting differences in microclimate and vegetation. Most fungal spora were present throughout the entire period with total spore counts peaking in late summer/autumn. Pollen groupings showed distinct peaks with Poaceae and Compositae abundant in autumn, Myrtaceae, Cupressaceae and Plantago peaking in spring and Pinus present only in winter. Overall numbers of spores were...

Use of a modified walkley-black method to determine the organic and elemental carbon content of urban aerosols collected on glass fibre filters

Abstract An analysis based on the Walkley-Black method is a rapid and effective means for determining the organic carbon, elemental carbon and total organic carbon content of urban aerosol samples collected on glass fibre and teflon-backed glass fibre filters. The estimated accuracy of the method is + 18%, −33% and −8% for OC, EC and TOC, respectively, the precision is ±7%, ±21% and ±4%, and the detection limit 0.33 μg m−3, 0.54 μg m−3 and 0.29 μg m−3.

Airborne Pinus pollen in the atmosphere of Brisbane, Australia and relationships with meteorological parameters

Relationships between weather parameters andairborne pollen loads of Pinus inBrisbane, Australia have been investigated overthe five-year period, June 1994–May 1999.Pinus pollen accounts for 4.5% of the annualairborne pollen load in Brisbane where thePinus season is confined to the winter months,July–early September. During the samplingperiod loads of 11–>100 grains m3 wererecorded on 24 days and 1–10 grains m3 on204 days. The onset and peak dates wereconsistent across each season, whereas the enddates varied. The onset of the Pinuspollen season coincided with the coolestaverage monthly temperatures (< 22°C),lowest rainfall (< 7mm), and four weeks afterdaily minimum temperatures fell to 5–9°Cin late autumn. Correlations obtained betweendaily airborne Pinus pollen counts andtemperature/rainfall parameters show thatdensities of airborne Pinus pollen arenegatively correlated with maximum temperature(p < 0.0001), minimum temperature (p < 0.0001)and rainfall (p < 0.05) during the mainpollination period. The mean duration of eachpollen season was 52 days; longer seasons wereshown to be directly related to lower averageseasonal maximum temperatures (r2 = 0.85,p = 0.025). These results signify that maximumand minimum temperatures are the majorparameters that influence the onset andduration of the Pinus pollen season inthe environs of Brisbane. Respiratory allergyis an important health issue in Brisbane,Australia, but it remains unknown whether ornot airborne Pinus pollen is acontributing factor.