Gerard Neville

Use of HPLC-MS/MS to monitor cylindrospermopsin, a blue–green algal toxin, for public health purposes

Increasing reports of blooms of the blue–green alga Cylindrospermopsis raciborskii (C. raciborskii), which contains the hepatotoxic alkaloid cylindrospermopsin (CYN), have led to public health concerns in Australia. The toxicology of CYN appears complex and is still being elucidated. We have utilized the combination of sensitivity and specificity afforded by coupling high performance liquid chromatography (HPLC) to a tandem mass spectrometer (MS/MS) to produce an assay which is suitable for monitoring low CYN concentrations in water samples. Intact algal cells in the water sample are lysed by a freeze–thaw cycle. After filtration (0.45 μm filter), 110 μL is injected. The HPLC uses an Altima C18 (250×4.6 mm, 5 μm) column at 40°C. Chromatography utilizes a linear gradient from 1 to 60% methanol over 5 min, with a final isocratic stage holding at 60% methanol for 1 min. The mobile phase is buffered to 5 mM with ammonium acetate. The transition from the M+H ion (416 m/z) to the 194 m/z fragment is monitored. Linearity of this assay is 1–600 μg/L [peak area=304×CYN (μg/L)−569; r2=1.000 (n=7)]. Using a single point standard curve, total coefficients of variation were 26.4, 10.5, 12.6, and 10.7% at 0.78, 5.2, 104, and 1040 μg/L. This assay is utilized in conjunction with algal cell counts and mouse bioassays to monitor water bodies for public health purposes. The rationale used in employing these methods is discussed. ©1999 John Wiley & Sons, Inc. Environ Toxicol 14: 151–154, 1999

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.

The impact of heatwaves on mortality and emergency hospital admissions from non-external causes in Brisbane, Australia

Objectives Heatwaves can have significant health consequences resulting in increased mortality and morbidity. However, their impact on people living in tropical/subtropical regions remains largely unknown. This study assessed the impact of heatwaves on mortality and emergency hospital admissions (EHAs) from non-external causes (NEC) in Brisbane, a subtropical city in Australia. Methods We acquired daily data on weather, air pollution and EHAs for patients aged 15 years and over in Brisbane between January 1996 and December 2005, and on mortality between January 1996 and November 2004. A locally derived definition of heatwave (daily maximum ≥37°C for 2 or more consecutive days) was adopted. Case–crossover analyses were used to assess the impact of heatwaves on cause-specific mortality and EHAs. Results During heatwaves, there was a statistically significant increase in NEC mortality (OR 1.46; 95% CI 1.21 to 1.77), cardiovascular mortality (OR 1.89; 95% CI 1.44 to 2.48), diabetes mortality in those aged 75+ (OR 9.96; 95% CI 1.02 to 96.85), NEC EHAs (OR 1.15; 95% CI 1.07 to 1.23) and EHAs from renal diseases (OR 1.41; 95% CI 1.09 to 1.83). The elderly were found to be particularly vulnerable to heatwaves (eg, for NEC EHAs, OR 1.24 for 65–74-year-olds and 1.39 for those aged 75+). Conclusions Significant increases in NEC mortality and EHAs were observed during heatwaves in Brisbane where people are well accustomed to hot summer weather. The most vulnerable were the elderly and people with cardiovascular, renal or diabetic disease.

Do Biometeorological Indices Improve Modeling Outcomes of Heat-Related Mortality?

Various biometeorological indices and temperature measures have been used to assess heat-related health risks. Composite indices are expected to assess human comfort more accurately than do temperature measures alone.Theperformancesofseveralcommonbiometeorologicalindicesandtemperaturemeasuresinevaluating the heat-related mortality in Brisbane, Australia—a city with a subtropical climate—were compared. Daily counts of deaths from organic causes [International Statistical Classification of Diseases and Related Health Problems, 9th Revision, (ICD9) codes 001‐799 and ICD, 10th Revision, (ICD10) codes A00‐R99] during the periodfrom 1 January 1996 to30 November 2004were used. Several composite biometeorological indices were considered, such as apparent temperature, relative strain index, Thom discomfort index, the humidex, and wetbulb globe temperature. Hot days were defined as those days falling into the 95th percentile of each thermal stress indicator. Case-crossover analysis was applied to estimate the relationship between exposure to heat and mortality. The performances of various biometeorological indices and temperature measures were compared using the jackknife resampling method.The results showthat more deathswerelikelytooccur on hot daysthan on other (i.e., control) days regardless of the temperature measure or biometeorological index that is considered. The magnitude of the odds ratios varied with temperature indicators, between 1.08 [95% confidence interval (CI): 1.02‐1.14] and 1.41 (95% CI: 1.22‐1.64) after adjusting for air pollutants (particulate matter with aerodynamic diameter less than 10 mm and ozone). Average temperature performedsimilarly tothe composite indices, but minimum and maximum temperatures performed relatively poorer. Thus, average temperature may be suitable for the development of weather‐health warning systems if the findings presented herein are confirmed in different locations.

Development of health risk-based metrics for defining a heatwave: a time series study in Brisbane, Australia

BackgroundThis study attempted to develop health risk-based metrics for defining a heatwave in Brisbane, Australia.MethodsPoisson generalised additive model was performed to assess the impact of heatwaves on mortality and emergency hospital admissions (EHAs) in Brisbane.ResultsIn general, the higher the intensity and the longer the duration of a heatwave, the greater the health impacts. There was no apparent difference in EHAs risk during different periods of a warm season. However, there was a greater risk for mortality in the 2nd half of a warm season than that in the 1st half. While elderly (≥75 years) were particularly vulnerable to both the EHA and mortality effects of a heatwave, the risk for EHAs also significantly increased for two other age groups (0 – 64 years and 65 – 74 years) during severe heatwaves. Different patterns between cardiorespiratory mortality and EHAs were observed. Based on these findings, we propose the use of a tiered heat warning system based on the health risk of heatwave.ConclusionsHealth risk-based metrics are a useful tool for the development of local heatwave definitions. This tool may have significant implications for the assessment of heatwave-related health consequences and development of heatwave response plans and implementation strategies.

Multi-city studies in Australia and New Zealand: The impact of air pollution on daily mortality and morbidity

We evaluated the short-term effect of Particle Number Concentration (a proxy for ultrafine particles) and PM10 on mortality and hospital admissions between 1998–2002 in a large Italian city. Mortality data were classified by cause of death into three groups: total (ICD9 0–799), respiratory (ICD9 460–519) and cardiovascular (ICD9 390–459) diseases. Hospital admissions data concerns subjects with a primary diagnosis of respiratory or cardiovascular diseases. The collection of PNC data is ongoing since April 2001 with a Condensation Particle Counter (CPC 3022A, TSI Inc). For the period 1998–2000, however, daily PNC values were retrospectively estimated using values of other pollutants and meteorological variables as predictors in a regression model. During the study period, PM10 data were collected in the context of the air quality monitoring system of Rome. A Poisson Generalized Additive Model (GAM) was fitted for each outcome using penalized regression splines of time, pressure, apparent temperature and average apparent temperature of the last four days. Day of the week, holidays, influenza epidemics and an indicator of population reduction were considered as confounders. Lagged effects were accounted for by studying the effect of up to 3 lags, the average of the last two days, and the average of the last 5 days. Stratified analysis was also performed by age groups. To evaluate the sensitivity of our results, Generalized Linear Models using Epidemiology • Volume 15, Number 4, July 2004 Abstracts

The short-term effects of air pollution on mortality and hospital admissions in Brisbane, Queensland, Australia

This poster details the results of a study funded in late 1999 by the SPIRT scheme which examined the short-term health effects of air pollution in Brisbane, Queensland, Australia, for the period 1996-1999. The study used a protocol similar to that used in Europe (Air Pollution and Health: A European Approach-APHEA) to examine the associations between health outcomes, such as daily mortality and daily hospital admissions counts, and air pollutants. The poster details the results for the Brisbane region for the acute health impacts of a range of pollutants-fine particles (as measured by nephelometery), PM10, nitrogen dioxide, ozone, sulfur dioxide, and carbon monoxide-on daily mortality (total, cardiovascular, respiratory), daily cardiovascular hospital admissions, and daily respiratory hospital admissions. Fine particles (as measured by nephelometery) and PM10 have a statistically significant impact on total mortality (all ages), and total cardiovascular mortality (all ages), as well as on total respiratory admissions for the elderly (>65 years). Carbon monoxide and PM10 have a statistically significant impact on IHD admissions (>65 years). Carbon monoxide, nitrogen dioxide and PM10 have a statistically significant impact on cardiac admissions (>65 years). Fine particles and ozone have a statistically significant impact on respiratory admissions in the elderly (especially COPD, asthma, pneumonia and acute bronchitis). The statistical methods used is generalised additive models (GAM) using the S Plus statistical package and loess smoothing. The results for all methods are presented and for lag periods of 0-3 days for all pollutants.

The short-term effects of air pollution on respiratory admissions: A meta-analysis for 4 Australian cities

This poster complements the paper in this area (A description of the SPIRT study for Brisbane, Melbourne, Perth and Sydney: Simpson et al) and details all the results referred in summary in the paper on the short-term health effects of air pollution on respiratory admissions in four Australian cities-Brisbane, Melbourne, Perth and Sydney. The study used a protocol similar to that used in Europe (Air Pollution and Health: A European Approach-APHEA) to examine the associations between health outcomes, such as daily mortality and daily hospital admissions counts, and air pollutants. This poster details all the results for the period 1996-1999 of a meta-analysis for the four cities for the acute health impacts of the pollutants-fine particles, nitrogen dioxide, and ozone. The meta-analyses often show statistically significant differences between the cities indicating the results can be quite different in different cities. Fine particles (as measured by nephelometery) and nitrogen dioxide both have a significant impact on cardiac admissions (14-65 years, greater than 65 years) and IHD admissions (all ages, > 65 years), while ozone has a significant impact on cardiac admissions (14-65 years, greater than 65 years) (although the results are sensitive to how temperature is used in the models). The sensitivity of the results to different statistical methods used in the meta-analyses have been carried out using a combination of three approaches: generalised additive models (GAM) using the S Plus statistical package and loess smoothing, generalised additive models using the S Plus package and natural spiines, and penalised splines using the R statistical package. The results for all methods are presented and for periods of lags of days 0-3 for all pollutants.

The short-term effects of air pollution on mortality: A meta-analysis for 4 Australian cities

This poster complements the paper in this area (A description of the SPIRT study for Brisbane, Melbourne, Perth and Sydney: Simpson et al) and details all the results referred in summary in the paper on the short-term health effects of air pollution on respiratory admissions in four Australian cities-Brisbane, Melbourne, Perth and Sydney. The study used a protocol similar to that used in Europe (Air Pollution and Health: A European Approach-APHEA) to examine the associations between health outcomes, such as daily mortality and daily hospital admissions counts, and air pollutants. This poster details all the results for the period 1996-1999 of a meta-analysis for the four cities for the acute health impacts of the pollutants-fine particles, nitrogen dioxide, and ozone. The meta-analyses often show statistically significant differences between the cities indicating the results can be quite different in different cities. Fine particles (as measured by nephelometery) and nitrogen dioxide both have a significant impact on cardiac admissions (14-65 years, greater than 65 years) and IHD admissions (all ages, > 65 years), while ozone has a significant impact on cardiac admissions (14-65 years, greater than 65 years) (although the results are sensitive to how temperature is used in the models). The sensitivity of the results to different statistical methods used in the meta-analyses have been carried out using a combination of three approaches: generalised additive models (GAM) using the S Plus statistical package and loess smoothing, generalised additive models using the S Plus package and natural spiines, and penalised splines using the R statistical package. The results for all methods are presented and for periods of lags of days 0-3 for all pollutants.

The short-term effects of air pollution on cardiovascular admissions: A meta-analysis for 4 Australian cities

This poster complements the paper in this area (A description of the SPIRT study for Brisbane, Melbourne, Perth and Sydney: Simpson et al) and details all the results referred in summary in the paper on the short-term health effects of air pollution on cardiovascular admissions in four Australian cities-Brisbane, Melbourne, Perth and Sydney. The study used a protocol similar to that used in Europe (Air Pollution and Health: A European Approach-APHEA) to examine the associations between health outcomes, such as daily mortality and daily hospital admissions counts, and air pollutants. This poster details all the results for the period 1996-1999 of a meta-analysis for the four cities for the acute health impacts of the pollutants-fine particles, nitrogen dioxide, and ozone. The meta-analyses often show statistically significant differences between the cities indicating the results can be quite different in different cities. Fine particles (as measured by nephelometery) and nitrogen dioxide both have a significant impact on cardiac admissions (14-65 years, greater than 65 years) and IHD admissions (all ages, > 65 years), while ozone has a significant impact on cardiac admissions (14-65 years, greater than 65 years). The sensitivity of the results to different statistical methods used in the meta-analyses have been carried out using a combination of three approaches: generalised additive models (GAM) using the S Plus statistical package and loess smoothing, generalised additive models using the S Plus package and natural splines, and penalised splines using the R statistical package.