Search

Large batches of sibling triploid and diploid juvenile Haliotis rubra were produced to evaluate and compare their production performances. Triploidy was induced by inhibiting extrusion of the second polar body (PB2) using either 150 μM 6-dimethylaminopurine (6-DMAP) or 0.5 mg/l cytochalasin B (CB). Best guess conditions were used in which treatments were started at 25–26 min after fertilization and continued for 20 min at 17.5–18.5 °C. Triploid percentages, survival and growth were examined up to 22 weeks after settlement. Triploid percentages in day 2 larvae were 94% and 92% in 6-DMAP and CB treatments, respectively. Overall survival from eggs to competent larvae was 30.0 and 55.5% for 6-DMAP and CB treatments, respectively, compared to 64.8% for the diploids. Yields of 20 weeks post-settlement juveniles (from competent larvae) were less than 1.9% in the two triploid treatments and the diploid control. A shell length was less than 3.7 mm in all the three cases. At 22 weeks after settlement, triploid rates were 100% for 6-DMAP and 82.5% for CB treatments. [Copyright &y& Elsevier]

Abstract: In this study a small but comprehensive data set from a 24-hourly sampling program carried out during June 2001 in an industrial area in Brisbane was chosen to investigate the effect of inclusion of multiple type composition data and wind data on source apportionment of air pollutants using the Positive Matrix Factorisation model, EPA PMF 3.0. The combined use of aerosol, VOC, main gaseous pollutants composition data and wind data resulted in better values of statistical indicators and diagnostic plots, and source factors which could be more easily related to known sources. The number of source factors resolved was similar to those reported in the literature where larger data sets were used. Three source factors were identified for the coarse particle samples, including ‘crustal matter’, ‘vehicle emissions’ and ‘sea spray’. Seven source factors were identified for the fine particle and VOC samples, including ‘secondary and biogenic’, ‘petroleum refining’, ‘vehicle emissions’, ‘petroleum product wholesaling’, ‘evaporative emissions’, ‘sea spray’ and ‘crustal matter’. The factor loadings of the 16 wind sectors and the calm wind sector from the PMF analysis were also used to quantify the directional contribution of the source factors. While the contributions were higher in the prevailing wind directions as expected, calm winds were also found to contribute up to 17% of the pollutant mass on average. The factor loadings, normalised by the overall abundance of the wind sectors, were also used to assess the directional dependences of the source factors. The results matched well with the location of known sources in the area. There was also a higher contribution potential from calm winds for local sources compared to that for distant sources. The results of directional effect using the PMF factor loading approach were similar to those by using the other approaches. This approach, however, also provides estimates of the mass contribution of source factors by wind sector and also the uncertainty of the results. [Copyright &y& Elsevier]

Abstract: In this study, 437 days of 6-daily, 24-h samples of PM2.5, PM2.5–10 and PM10 were collected over a 12-month period during 2003–2004 in Melbourne, Sydney, Brisbane and Adelaide. The elemental, ionic and polycyclic aromatic hydrocarbon composition of the particles were determined. Source apportionment was carried out by using the positive matrix factorisation software (PMF2). Eight factors were identified for the fine particle samples including ‘motor vehicles’, ‘industry’, ‘other combustion sources’, ‘ammonium sulphates’, ‘nitrates’, ‘marine aerosols’, ‘chloride depleted marine aerosols’ and ‘crustal/soil dust’. On average combustion sources, secondary nitrates/sulphates and natural origin dust contributed about 46%, 25% and 26% of the mass of the fine particle samples, respectively. ‘Crustal/soil dust’, ‘marine aerosols’, ‘nitrates’ and ‘road side dust’ were the four factors identified for the coarse particle samples. On average natural origin dust contributed about 76% of the mass of the coarse particle samples. The contributions of the sources to the sample mass basically reflect the emission source characteristics of the sites. Secondary sulphates and nitrates were found to spread out evenly within each city. The average contribution of secondary nitrates to fine particles was found to be rather uniform in different seasons, rather than higher in winter as found in other studies. This could be due to the low humidity conditions in winter in most of the Australian cities which made the partitioning of the particle phase less favourable in the NH4NO3 equilibrium system. A linear relationship was found between the average contribution of marine aerosols and the distance of the site from the bay side. Wind erosion was found associated with higher contribution of crustal dust on average and episodes of elevated concentration of coarse particles in spring and summer. [Copyright &y& Elsevier]

There is mounting evidence that maternal exposure to ambient air pollution during pregnancy is associated with adverse birth outcomes. We examined birth weight and small for gestational age (SGA <10th percentile for age and gender) among 26,617 singleton full-term births in Brisbane, Australia (July 2000–June 2003), in relation to ambient pollution during pregnancy. We also examined head circumference (HC) and crown–heel length (CHL) among a sub-sample (n=21,432) of the term neonates. Maternal exposure to PM10, visibility reducing particles (bsp), O3 and NO2 was assessed by calculating average exposure estimates over months and trimesters of pregnancy based on a citywide average of the pollutants. Linear and logistic regression models were employed to examine the effect of these pollutants on the birth outcomes after adjusting for potential confounders and season of birth. The regression coefficients were based on an inter-quartile range (IQR) increase in exposure as well as quartiles of exposure with the lowest used as a reference category. Trimester-and monthly specific exposures to all pollutants were not significantly associated with a reduction in either birth weight or HC, or an increased risk of SGA. An IQR increase in NO2 during the third trimester was associated with a reduction in CHL ( cm, 95% CI −0. 25 to −0. 05cm) and this was concentrated around exposure during month nine. No other pollutants were associated with a reduction in CHL. In conclusion, there was no strong evidence suggesting that ambient air pollution during pregnancy is associated with sub-optimal fetal growth in Brisbane. [Copyright &y& Elsevier]

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. [ABSTRACT FROM AUTHOR]

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.Journal of Exposure Science and Environmental Epidemiology (2006) 16, 225–237. doi:10.1038/sj.jea.7500451; published online 24 August 2005 [ABSTRACT FROM AUTHOR]

Rationale: The strength of the association between outdoor air pollution and hospital admissions in children has not yet been well defined., Objectives: To estimate the impact of outdoor air pollution on respiratory morbidity in children after controlling for the confounding effects of weather, season, and other pollutants., Methods: The study used data on respiratory hospital admissions in children (three age groups: < 1, 1-4, and 5-14 years) for five cities in Australia and two in New Zealand. Time series of daily numbers of hospital admissions were analyzed using the case-crossover method; the results from cities were combined using a random-effects meta-analysis., Measurements and Main Results: Significant increases across the cities were observed for hospital admissions in children for pneumonia and acute bronchitis (0, 1-4 years), respiratory disease (0, 1-4, 5-14 years), and asthma (5-14 years). These increases were found for particulate matter with a diameter less than 2.5 microm (PM2.5) and less than 10 microm (PM10), nephelometry, NO2, and SO2. The largest association found was a 6.0% increase in asthma admissions (5-14 years) in relation to a 5.1-ppb increase in 24-hour NO2., Conclusions: This study found strong and consistent associations between outdoor air pollution and short-term increases in childhood hospital admissions. A number of different pollutants showed significant associations, and these were distinct from any temperature (warm or cool) effects.

Background: This paper examines the short-term health effects of air pollution on daily hospital admissions in Australian cities (those considered comprise more than 50% of the Australian population) for the period 1996-99., Methods: The study used a similar protocol to overseas studies and derived single city and pooled estimates using different statistical approaches to assess the accuracy of the results., Results: There was little difference between the results derived from the different statistical approaches for cardiovascular admissions, while in those for respiratory admissions there were differences. For three of the four cities (for the other the results were positive but not significant), fine particles (measured by nephelometry - bsp) and nitrogen dioxide (NO2) have a significant impact on cardiovascular admissions (for total cardiac admissions, RR = 1.0856 for a one-unit increase in bsp (10(-4) x m(-1)), RR = 1.0023 for a 1 ppb increase in NO2). For three of the four cities (for the other, the results were negative and significant), fine particles, NO2 and ozone have a significant impact on respiratory admissions (for total elderly respiratory admissions, RR = 1.0552 per 1 unit (10(-4) x m(-1)) increase in bsp, RR = 1.0027 per 1ppb increase in NO2, RR = 10014 per 1 ppb increase in ozone for elderly asthma and COPD admissions). In all analyses the particle and NO2 impacts appear to be related., Conclusions: Similar to overseas studies, air pollution has an impact on hospital admissions in Australian cities, but there can be significant differences between 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., Methods: The study used a similar protocol to APHEA2 (Air Pollution and Health: A European Approach) study and derived single-city and pooled estimates., Results: The results derived from the different approaches for the 1996-99 period showed consistent results for different statistical models used. There were significant effects on total mortality, (RR = 1.0284 per 1 unit increase in nephelometry [10(-4).m(-1)], RR = 1.0011 per 1ppb increase in NO2), and on respiratory mortality (RR = 1.0022 per 1ppb increase in O3). No significant differences between cities were found, but the NO2 and particle effects may refer to the same impacts. Meta-analyses carried out for three cities yielded estimates for the increase in the daily total number of deaths of 0.2% (-0.8% to 1.2%) for a 10 microg/m3 increase in PM10 concentration, and 0.9% (-0.7% to 2.5%) for a 10 microg/m3 increase in PM2.5 concentration., Conclusions: Air pollutants in Australian cities have significant effects on mortality.

Grass pollen is an important risk factor for allergic rhinitis and asthma in Australia and is the most prevalent pollen component of the aerospora of Brisbane, accounting for 71.6% of the annual airborne pollen load. A 5-year (June 1994-May 1999) monitoring program shows the grass pollen season to occur during the summer and autumn months (December-April), however the timing of onset and intensity of the season vary from year to year. During the pollen season, Poaceae counts exceeding 30 grains m(-3) were recorded on 244 days and coincided with maximum temperatures of 28.1 +/- 2.0 degrees C. In this study, statistical associations between atmospheric grass pollen loads and several weather parameters, including maximum temperature, minimum temperature and precipitation, were investigated. Spearman's correlation analysis demonstrated that daily grass pollen counts were positively associated (P < 0.0001) with maximum and minimum temperature during each sampling year. Precipitation, although considered a less important daily factor (P < 0.05), was observed to remove pollen grains from the atmosphere during significant periods of rainfall. This study provides the first insight into the influence of meteorological variables, in particular temperature, on atmospheric Poaceae pollen counts in Brisbane. An awareness of these associations is critical for the prevention and management of allergy and asthma for atopic individuals within this region.

Urban air pollution levels are associated with increased mortality and cardiorespiratory morbidity. These health effects occur even at exposure levels below those stipulated in current air-quality guidelines, and it is unclear whether a safe threshold exists. Air pollution in Australia and New Zealand comes primarily from motor vehicle emissions, electricity generation from fossil fuels, heavy industry, and home heating using wood and coal. In individual patients a direct link between symptoms and air pollution exposure may be difficult to establish and may not change their clinical management. However, avoiding exposure during periods of peak pollution may be beneficial. Although there is some evidence that urban air pollution in Australia and New Zealand has been decreasing (through reduced car use, improved emission-control technology and use of more energy-efficient devices in the household and in industry), pollution levels are still unsatisfactory. Further reductions may prevent hundreds of cardiorespiratory hospital admissions and deaths each year.