Temperate City Research Articles

Particulate air pollution and cardiorespiratory hospital admissions in a temperate Australian city: A case-crossover analysis

Although ambient air pollution exposure has been linked with poor health in many parts of the world, no previous study has investigated the effect on morbidity in the city of Adelaide, South Australia. To explore the association between particulate matter (PM) and hospitalisations, including respiratory and cardiovascular admissions in Adelaide, South Australia. For the study period September 2001 to October 2007, daily counts of all-cause, cardiovascular and respiratory hospital admissions were collected, as well as daily air quality data including concentrations of particulates, ozone and nitrogen dioxide. Visibility codes for present weather conditions identified days when airborne dust or smoke was observed. The associations between PM and hospitalisations were estimated using time-stratified case-crossover analyses controlling for covariates including temperature, relative humidity, other pollutants, day of the week and public holidays. Mean PM(10) concentrations were higher in the warm season, whereas PM(2.5) concentrations were higher in the cool season. Hospital admissions were associated with PM(10) in the cool season and with PM(2.5) in both seasons. No significant effect of PM on all-age respiratory admissions was detected, however cardiovascular admissions were associated with both PM(2.5) and PM(10) in the cool season with the highest effects for PM(2.5) (4.48%, 95% CI: 0.74%, 8.36% increase per 10μg/m(3) increase in PM(2.5)). These findings suggest that despite the city's relatively low levels of air pollution, PM concentrations are associated with increases in morbidity in Adelaide. Further studies are needed to investigate the sources of PM which may be contributing to the higher cool season effects.

Projected Years Lost due to Disabilities (YLDs) for bacillary dysentery related to increased temperature in temperate and subtropical cities of China

The impact of climate change on enteric infection has been a concern in recent years. This study aims to project disability burdens of bacillary dysentery (BD) associated with increasing temperature in different climatic zones in China. Years Lost due to Disabilities (YLDs) were used as the measure of burden of bacillary dysentery in this study. A temperate city in northern China and a subtropical city in southern China were selected as the study areas. The quantitative relationship between temperature and the number of cases in each city was base on the regression models developed in our previous studies. YLDs for bacillary dysentery in 2000 were used as the baseline data. Projection of YLDs for bacillary dysentery in 2020 and 2050 under future temperature scenarios were conducted. Demographic changes over the next 20 to 50 years in study cities were considered in the projections. Under the temperature scenarios alone, the YLDs for bacillary dysentery may increase by up to 80% by 2020 and 174% by 2050 in the temperate city and up to 75% increase in the YLDs by 2020 and a 147% increase by 2050 in the tropical city. Considering potential changes in both temperature and population size and structure, if other factors remain constant, compared with the YLDs observed in 2000, the YLDs for bacillary dysentery may double by 2020 and triple by 2050 in both the temperate and subtropical cities in China. The temperature-related health burden of enteric infection in China may greatly increase in the future if there is no effective intervention. Relevant public health strategies should be developed at an earlier stage to prevent and reduce the impact of infectious disease associated with climate change.

Meteorological variables and malaria in a Chinese temperate city: A twenty-year time-series data analysis

Objectives This study aimed to examine the impact of climate variation on malaria in a temperate region of China. Methods A 20-year historical time-series data analysis was conducted to examine the relationship between meteorological variables, including maximum and minimum temperatures, rainfall, humidity, and cases of malaria in Jinan, a temperate city in northern China. Data were retrieved from 1959 and 1979 and analyzed on a monthly basis. Spearman correlation and cross-correlation analyses were performed to identify time lag values between each meteorological variable and the number of malaria cases. The Seasonal Autoregressive Integrated Moving Average (SARIMA) model was used to quantify the relationship between the meteorological variables and malaria cases. Results The SARIMA models indicate that a 1 °C rise in maximum temperature may be related to a 7.7% to 12.7% increase and a 1 °C rise in minimum temperature may result in approximately 11.8% to 15.8% increase in the number of malaria cases. A clear association between malaria and other selected weather variables, including rainfall and humidity, has not been detected in this study. Conclusions Temperature could play an important role in the transmission of malaria in temperate regions of China.

Seasonal Occurrence of Immature Mosquitoes in Swimming Pools in Buenos Aires, Argentina

The seasonal variation in the density of swimming pools and the occurrence of immature mosquitoes in these habitats were studied in the temperate city of Buenos Aires, Argentina. The density of swimming pools was highest in the summer (6.0 pools/ha) when temporal pools predominated; it was lowest in the winter (0.9 pools/ha) when only permanent pools were recorded. The presence of immature stages of mosquitoes was mainly associated with the lack of use and maintenance of the pools in the fall season, when temporal pools were still assembled but not intensively used. Seven mosquito species were recorded, among which Culex pipiens and Culex apicinus were the most frequent.

Meteorological Variables and Malaria in a Chinese Temperate City: A Twenty-Year Time-Series Data Analysis

ISEE-0022 Background and Objective: Re-emergence of malaria has been observed in China recently. Although the association between climate variation and malaria has been addressed in many countries, little is known about the impact of climate variation on malaria in temperate regions of China. Methods: A 20-year historical time-series data analysis was conducted to examine the relationship between meteorological variables, including maximum and minimum temperatures, rainfall, humidity, air pressure, and cases of malaria in Jinan, a temperate city in northern China. Data were retrieved for the period 1959 to 1979 and analyzed on a monthly basis. Spearman correlation and cross-correlation analyses were performed between each meteorological variable and the number of malaria cases, to identify time lag values. A Seasonal Autoregressive Integrated Moving Average (SARIMA) model was used to quantify the relationship between the meteorological variables and malaria cases. Results: The SARIMA models indicate that a 1°C rise in maximum temperature may be related to a 4.2% to 13.9% increase, and a 1°C rise in minimum temperature, may result in an approximately 6.8% to 14.8% increase in the number of malaria cases. A clear association between malaria and other selected weather variables, including rainfall, humidity and air pressure, has not been detected in this study. Conclusion: Results suggest that temperature could play an important role in the transmission of malaria in temperate regions of China, and climate change may bring about more malaria cases in this region of China if no action is taken.

The effect of heat waves on hospital admissions for renal disease in a temperate city of Australia

A rarely investigated consequence of heat exposure is renal dysfunction resulting from dehydration and hyperthermia. Our study aims to quantify the relationship between exposure to extreme high temperatures and renal morbidity in South Australia. Poisson regression accounting for over dispersion, seasonality and long-term trend was used to estimate the effect of heat waves on hospital admissions for renal disease, acute renal failure and renal dialysis over a 12-year period. Selected comorbidities were investigated as possible contributing risk factors. Admissions for renal disease and acute renal failure were increased during heat waves compared with non-heat wave periods with an incidence rate ratio of 1.100 [95% confidence intervals (CI) 1.003-1.206] and 1.255 (95% CI 1.037-1.519), respectively. Hospitalizations for dialysis showed no corresponding increase. Comorbid diabetes did not increase the risk of renal admission, however 'effects of heat and light' and 'exposure to excessive natural heat' (collectively termed effects of heat) were identified as risk factors. Our findings suggest that as heat waves become more frequent, the burden of renal morbidity may increase in susceptible individuals as an indirect consequence of global warming.

Weather and the Transmission of Bacillary Dysentery in Jinan, Northern China: A Time-Series Analysis

This article aims to quantify the relationship between weather variations and bacillary dysentery in Jinan, a city in northern China with a temperate climate, to reach a better understanding of the effect of weather variations on enteric infections. The weather variables and number of cases of bacillary dysentery during the period 1987-2000 has been studied on a monthly basis. The Spearman correlation between each weather variable and dysentery cases was conducted. Seasonal autoregressive integrated moving average (SARIMA) models were used to perform the regression analyses. Maximum temperature (one-month lag), minimum temperature (one-month lag), rainfall (one-month lag), relative humidity (without lag), and air pressure (one-month lag) were all significantly correlated with the number of dysentery cases in Jinan. After controlling for the seasonality, lag time, and long-term trend, the SARIMA model suggested that a 1 degree C rise in maximum temperature might relate to more than 10% (95% confidence interval 10.19, 12.69) increase in the cases of bacillary dysentery in this city. Weather variations have already affected the transmission of bacillary dysentery in China. Temperatures could be used as a predictor of the number of dysentery cases in a temperate city in northern China. Public health interventions should be undertaken at this stage to adapt and mitigate the possible consequences of climate change in the future.

Projected Burden of Bacillary Dysentery Due to Climate Change in a Temperate City in China

ISEE-211 Objective: This study aims to project the morbidity burden of bacillary dysentery due to climate change, measured in terms of years lost due to disability (YLDs), in a temperate city of China, to provide scientific evidence for policy makers to reduce the impact of climate change on food-borne diseases in the future. Material and Methods: Notified age- and sex-specified incidence cases of bacillary dysentery and demographic data of the study city were collected from relevant local authorities. The calculation of the YLDs was based on the methodologic framework in the Global Burden of Disease study. The quantitative relationship between climatic variables and the number of cases were based on our previous studies. Various scenarios of increasing temperatures (and demographic change) were applied in this estimate. The YLDs of bacillary dysentery in 2000 were estimated first and then the projection for 2020 and 2050 was conducted. Results: The total YLDs of bacillary dysentery in 2000 in the temperate city were more than 600 and the YLDs were slightly higher in men than women. Considering the temperature scenarios alone, the YLDs of bacillary dysentery may increase up to 80% by 2020 and 174% by 2050, compared with 2000. With the consideration of both climate scenarios and demographic change, the YLDs of bacillary dysentery may double by 2020 and triple by 2050, compared with 2000, if other influencing factors remain unchanged. Conclusions: Despite the uncertainties and limitations in the burden of diseases study, our results suggest that global warming may cause a serious increase in the morbidity burden of bacillary dysentery in the temperate city of China. Sustainable policies should be developed and implemented at an early stage for better mitigation and adaptation to the future risk of climate change.

Weather and Notified Campylobacter Infections in Australia

ISEE-239 Objective: To study the relationship between weather variables and Campylobacter infections in 2 Australian cities with different climatic characteristics and to provide scientific evidence for disease prevention. Material and Methods: Notified Campylobacter infections from Adelaide, a temperate city, and Brisbane, a subtropical city of Australia, over the period 1990 to 2005 were collected from the South Australian Department of Health and the Queensland Health. Meteorological variables over the study period were obtained from the Australian Bureau of Meteorology. Spearman correlation coefficients were calculated between weather variables and the counts of the cases on a weekly basis. Time-series adjusted Poisson regression analysis was performed, using STATA, with the consideration of autocorrelation, seasonality, and lagged effect. Results: In Adelaide, rainfall had an inverse but mean weekly maximum and minimum temperatures had a positive association with the weekly number of cases, with relevant lagged effects. In Brisbane, however, weekly mean maximum and minimum temperatures were positively associated with the weekly number of cases, with a 6-week lagged effect. Conclusions: Increase of temperature may be associated with a rise in cases of Campylobacter infections in Brisbane, the subtropical city. However, this is not the case for Adelaide. Many factors may contribute to this distribution of the infections. Weather variables are one of these, together with reservoir, human behavior.

Weather variables and Japanese encephalitis in the metropolitan area of Jinan city, China

To identify weather-related risk factors and their roles in Japanese encephalitis transmission and to provide policy implications for local health authorities and communities. Data on notified cases of Japanese encephalitis and weather variables over the period 1959-1979 were collected from Jinan city, a temperate city in China. Due to seasonality of the disease, the data analysis was restricted to five months from June to October each year. Spearman correlation analysis and time-series adjusted Poisson regression analysis were performed to quantify the relationship between weather and the number of cases. The Hockey Stick model was used to detect potential threshold temperatures. Monthly mean maximum and minimum temperatures, monthly total rainfall and monthly mean relative humidity were positively correlated to monthly notification of Japanese encephalitis, while monthly mean air pressure was inversely correlated. Lag times varied from one to two months. All these weather variables were significant in the adjusted Poisson regression model. Thresholds of 25.2 degrees C for maximum temperature and 21.0 degrees C for minimum temperature were also detected. Weather variables could have affected the transmission of Japanese encephalitis in this urban area of China. Public health interventions should be developed at this stage to reduce future risks related to climate change.

Weather and Salmonella Transmission in an Australian Temperate City

Weather and Salmonella Transmission in an Australian Temperate City

Impact of dietary and lifestyle on vitamin D in healthy student girls aged 11-15 years

To study daily intake of calcium, phosphorus and vitamin D, to determine the biochemical findings of rickets and the effect of sunlight exposure and vitamin D supplementation in school girls with hypovitaminosis D. A cross-sectional study was conducted on school girls aged 11-15 years selected randomly from various areas of Tehran, Iran. Dietary information and amount of sunlight exposure were estimated by a 7 day recalling method using self-reported questionnaire. Hypovitaminosis D defined as low serum 25-hydroxyvitamin D concentration with two or more others abnormal biochemical findings. Girls with hypovitaminoses D were randomly divided into two groups. The faces and hands of girls in group 1 were exposed to sunlight for one hour per day for twenty days, while those in group 2 were administered vitamin D capsules, 50,000 IU per day for the same period. four-hundred fourteen girls evaluated, mean daily calcium intake, sunlight exposure and vitamin D acquirement were 360 mg, 10 minutes and 119 IU, respectively. Mean serum 25-hydroxyvitamin D concentration was 30 ng/ml among all girls whereas in 15 (3.63%) of 414 girls was 7.8 ng/ml. Abnormal biochemical findings in these girls included hypocalcemia (n=4), hypophosphatemia (n=5), raised serum alkaline phosphatase (n=13), and parathyroid hormone (n=15). After intervention, mean serum 25-hydroxyvitamin D concentration in sunlight exposure (n=8) and vitamin D (n=7) supplementation increased to 14.4+/-4 ng/ml and 23+/-4 ng/ml respectively. There was a significant difference between the two groups (p<0.05). Vitamin D deficiency developed in rapid growth period of girls without clear clinical rickets in sunny temperate climate city in Iran which vitamin D supplementation improved biochemical findings better than sunlight exposure.

AIR POLLUTION AND DAILY HUMAN MORTALITY IN A TEMPERATE CLIMATE CITY OF AUSTRALIA

ISEE-320 Introduction: Many studies have provided evidence on impact of air pollution on human health outcome. Aim: The project was to explore the association between air pollution and daily death numbers in Adelaide, a temperate city with a 1.1 million population, in Australia. Methods: Daily disease data (ICD-10) in Adelaide over 1986–1999, with overall deaths and deaths in different age and disease groups, were retrieved from the Australian Bureau of Statistics. Daily climatic variables were obtained from the Australian Bureau of Meteorology. Daily air pollution data, including SO2 over 1992–1999, NOx over 1986–1996, CO over 1988–1999, O3 over 1986–1996, PM10 and TSP over 1986–1994, were provided by the SA Environment Protection Authority. Poisson regression analysis (GAM procedure), performed by the SAS, was used in the analyses. Results: Both correlation and regression analyses showed that SO2,NOxand CO are positively associated with total daily death numbers, indicating that the death numbers increased with a rise in these three air pollution indicators. There is no significant relationship between TSP, PM10and daily death numbers. Surprisingly, O3was negatively related to the death numbers in some groups. Conclusion: Total death numbers increased with air pollution. However, some results were not consistent with other similar studies. This could be due to the very limited data (only about 400 days of TSP and PM10 data were available in Adelaide) and/or the lower values of TSP and PM10 and O3 in Adelaide. These results should be clarified in further studies.

CLIMATE VARIATION AND SALMONELLOSIS TRANSMISSION IN A TEMPERATE CITY OF AUSTRALIA

ISEE-318 Introduction: Food-borne diseases affect population health both in developed and developing countries. The cost has been estimated at over $2.6 billion each year in Australian communities, with about 4 million notified cases annually. Climatic variables make a significant impact on the transmission of food-borne diseases. Salmonella is one of the most important food-borne pathogens affecting human beings including the Australian population. Methods: To quantify the relationship between climatic variables and transmission of salmonellosis, a historical data analysis was conducted over the period 1990–2004 in Adelaide, a city with temperate climate, with a population of 1.1 million, in Australia. Poisson regression analysis, performed by Stata, was used for the time-series data, using both weekly and monthly count cases as the dependent variable. The effect of large outbreaks was controlled for in the analyses. Results: A positive relationship was identified between salmonellosis transmission and climatic variables such as temperatures and the SOI. This applies to monthly and weekly datasets. Conclusion: The increase of weekly or monthly average temperatures had a positive impact on salmonellosis transmission in the temperate city. The results indicate that relevant public health intervention, should be carried out in the community, especially during the summer season.

WEATHER AND DAILY HUMAN MORTALITY IN A TEMPERATE CITY OF AUSTRALIA

ISEE-319 Introduction: Many studies indicate the association of weather with population health, but most have used monthly human mortality as the health outcome. Aim: We examined the relationship between daily weather indices and daily mortality in Adelaide, a temperate city with a population of 1.1 million, in Australia. Methods: Daily disease data (ICD-10) in Adelaide over 1986-2001, overall deaths and deaths in different age and disease groups, were retrieved from the Australian Bureau of Statistics. Daily climatic variables were obtained from the Australian Bureau of Meteorology. Main analytic methods include time series analysis, conducted by the SPSS, and Poisson regression analysis (GAM procedure), performed by the SAS. Results: After controlling for long-term trends and seasonal influences, the results showed that maximum temperature, minimum temperature, maximum dew point temperature, wind direction at 9am, and average wind speed had a negative impact; relative humidity and wind direction at 3:00 pm had a positive impact on the total daily mortality in Adelaide, with a relevant lagged effect. These potential risk climatic variables, however, varied in the groups with different causes of deaths. For example, the factors for heart diseases include maximum temperature, maximum dew point temperature and minimum temperature. While for respiratory diseases, they factors were maximum temperature, total cloud amount, wind direction speed at 3:00 pm and average wind speed. Conclusion: Daily climate indices do influence the human deaths. The mortality increased with reduction of temperature and rise of maximum relative humidity. These results are consistent with other studies.

Fever in Obstetric and Gynecologic Patients

To the Editor.— Klimek et al reported an interesting study of fever in hospitalized obstetric and gynecologic patients. Of the obstetric patients, 52% did not satisfy bacteriologic or presumptive clinical or laboratory criteria to establish the diagnosis of infection. However, no viral studies were reported nor was there a comment concerning the seasonal distribution of the incidence of fever. This study covered at least one summer in a temperate city when enterovirus shed is usually prevalent. Enterovirus disease may often occur as a nonspecific febrile illness 1 or with symptoms indistinguishable from those of early labor, ie, abdominal pain or mild diarrhea. Although Klimek et al classified all the obstetric patient infections as nosocomial, since there were no signs of incubating disease at admission, it seems probable that some of these postpartum fevers may have been attributable to enterovirus infection. The importance of such a diagnosis lies in the outlook