Survey data of a traditional communal water irrigation system in Northern Thailand.

This data article contains a description of a dataset collected by a survey on a traditional communal water irrigation system. This is the Muang fai, a 700-years old communal irrigation system in Northern Thailand. The Muang fai is managed through a series of regulations that are close to Ostrom's principles of effective common property resources (Ostrom, 1990). The survival of this long-standing practice, including its knowledge of the water-flow characteristics of the watershed, is under threat as new technologies, such as groundwater pumping, become increasingly accessible. The target population of the survey was the group of Longan farmers who are located within the 12 villages that are engaged in Muang fai Sop Rong in Chiang Mai Province, Northern Thailand. Information was specifically collected about irrigation practices, farmland characteristics and socio-economic variables from 570 longan (their main crop) farmer households. Roughly half of these sampled farmers practise Muang fai, the other half practise underground pumping irrigation. The irrigation information collected includes type of irrigation (surface or underground), the quantity of water used, pumping methods (if pumps are used). Farming characteristics collected include volume and value of the harvests, land size, and distance to irrigation canal. Socioeconomic characteristics included among others: farmers' income, expenditure, education, off-farm employment and Muang-fai membership. This dataset can be a source of baseline information for future research as well as help preserve the knowledge of this tradition.

The impact of the 1952 London smog event and its relevance for current wood-smoke abatement strategies in Australia.

There is a certain complacency about air pollution in rural towns in Australia. An image of crystal clear skies seems to dominate general perceptions, and few locations actually monitor air pollution levels. Nevertheless, where measurements have been made, particulates have been shown to be the major type of air pollution, and they do reach levels expected to impact on human health. In this article, the contemporary attitudes and behaviour of the government and the population in rural and regional Australia are shown to have a strong resemblance to those that were prevalent prior to the smog events in London in December 1952. Wood smoke poses similar significant health issues in many countries. Insights obtained from the London events, together with more recent research results, are applied to the Australian situation to suggest policy options that are likely to be successful in overcoming the health effects of particulate pollution. Implications: The contemporary attitudes and behaviour of the government and the population in rural and regional Australia are shown to have a strong resemblance to those that were prevalent prior to the smog events in London in December 1952. Insights obtained from the London event of 1952, together with more recent research results, are applied to the Australian situation to suggest policy options that are likely to be successful in overcoming the health effects of particulate pollution.

The impact of summer temperatures and heatwaves on mortality and morbidity in Perth, Australia 1994-2008.

Climate change projections have drawn attention to the risks of extreme heat and the importance of public health interventions to minimise the impact. The city of Perth, Western Australia, frequently experiences hot summer conditions, with recent summers showing above average temperatures. Daily maximum and minimum temperatures, mortality, emergency department (ED) presentations and hospital admissions data were acquired for Perth for the period 1994 to 2008. Using an observed/expected analysis, the temperature thresholds for mortality were estimated at 34-36°C (maximum) and 20°C (minimum). Generalised estimating equations (GEEs) were used to estimate the percentage increase in mortality and morbidity outcomes with a 10°C increment in temperature, with adjustment for air pollutants. Effect estimates are reported as incidence rate ratios (IRRs). The health impact of heatwave days (three or more days of ≥35°C) was also investigated. A 9.8% increase in daily mortality (IRR 1.098; 95%CI: 1.007-1.196) was associated with a 10°C increase in maximum temperature above threshold. Total ED presentations increased by 4.4% (IRR 1.044; 95%CI: 1.033-1.054) and renal-related ED presentations by 10.2% (IRR 1.102; 95%CI: 1.071-1.135) per 10°C increase in maximum temperature. Heatwave days were associated with increases in daily mortality and ED presentations, while total hospital admissions were decreased on heatwave days. Public health interventions will be increasingly important to minimise the adverse health impacts of hot weather in Perth, particularly if the recent trend of rising average temperatures and more hot days continues as projected.

Heat and health in Adelaide, South Australia: assessment of heat thresholds and temperature relationships.

BACKGROUND: Climate change projections have highlighted the need for public health planning for extreme heat. In Adelaide, South Australia, hot weather is characteristic of summer and heatwaves can have a significant health burden. This study examines the heat thresholds and temperature relationships for mortality and morbidity outcomes in Adelaide. METHODS: Daily maximum and minimum temperatures, daily mortality, ambulance call-outs, emergency department (ED) presentations and hospital admissions were obtained for Adelaide, between 1993 and 2009. Heat thresholds for health outcomes were estimated using an observed/expected analysis. Generalized estimating equations were used to estimate the percentage increase in mortality and morbidity outcomes above the threshold temperatures, with adjustment for the effects of ozone (O(3)) and particulate matter<10 µm in mass median aerodynamic diameter (PM(10)). Effect estimates are reported as incidence rate ratios (IRRs). RESULTS: Heat-related mortality and morbidity become apparent above maximum and minimum temperature thresholds of 30 °C and 16 °C for mortality; 26 °C and 18 °C for ambulance call-outs; and 34 °C and 22 °C for heat-related ED presentations. Most health outcomes showed a positive relationship with daily temperatures over thresholds. When adjusted for air pollutants, a 10 °C increase in maximum temperature was associated with a 4.9% increase in daily ambulance call-outs (IRR 1.049; 95% CI 1.027-1.072), and a 3.4% increase in mental health related hospital admissions (IRR 1.034; 95% CI 1.009-1.059) for the all-age population. Heat-related ED presentations increased over 6-fold per 10 °C increase in maximum temperature. Daily temperatures were also associated with all-cause and mental health related ED presentations. Associations between temperature over thresholds and daily mortality and renal hospital admissions were not significant when adjusted for ozone and PM(10); however at extreme temperatures mortality increased significantly with increasing heat duration. CONCLUSIONS: Heat-attributable mortality and morbidity are associated with elevated summer temperatures in Adelaide, particularly ambulance call-outs, mental health and heat-related illness.

Weather and notified Campylobacter infections in temperate and sub-tropical regions of Australia: an ecological study.

BACKGROUND: The relationship between weather and food-borne diseases has been of great concern recently. However, the impact of weather variations on food-borne disease may vary in different areas with various geographic, weather and demographic characteristics. This study was designed to quantify the relationship between weather variables and Campylobacter infections in two Australian cities with different local climatic conditions. METHODS: An ecological-epidemiological study was conducted, using weekly disease surveillance data and meteorological data, over the period 1990-2005, to quantify the relationship between maximum and minimum temperatures, rainfall, relative humidity and notifications of Campylobacter infections in Adelaide, with a temperate Mediterranean climate, and Brisbane, with a sub-tropical climate. Spearman correlation and time-series adjusted Poisson regression analyses were performed taking into account seasonality, lag effects and long-term trends. RESULTS: The results indicate that weekly maximum and minimum temperatures were inversely associated with the weekly number of cases in Adelaide, but positively correlated with the number of cases in Brisbane, with relevant lagged effects. The effects of rainfall and relative humidity on Campylobacter infection rates varied in the two cities. CONCLUSION: Weather might have different effect on Campylobacter infections in different cities. Further studies are needed for a better understanding of these relationships for they may indicate epidemiologic factors important for control of these infections.

Temperature and direct effects on population health in Brisbane, 1986-1995.

To assess the impact of weather on human mortality, particularly among elderly people and people with diseases, the authors conducted an ecological study in Brisbane, Australia. Correlation and autoregressive integrated moving average (ARIMA) regression analyses assessed the relationship between weather and mortality in the general population and the elderly population (65 years of age and older) over the period 1986-1995. In the summer, both cardiovascular diseases and all-cause mortality in the elderly population had significant positive correlations with monthly temperatures. In the winter, negative correlations were found between monthly mean maximum temperatures and cardiovascular-disease mortality, and between monthly mean minimum temperatures and respiratory-disease mortality. Regression models were developed for various target populations and produced similar results.

Effect of climate change on Australian rural and remote regions: what do we know and what do we need to know?

This paper addresses a very important issue in Australian rural and remote regions: the effects of climate change on various aspects including natural resources, agricultural activity, population health, and social and economic development. The objective is to briefly characterise the consequences of climate change in rural Australia and what we can do to prevent further impact in our rural communities.

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

OBJECTIVE: To identify weather-related risk factors and their roles in Japanese encephalitis transmission and to provide policy implications for local health authorities and communities. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

El Nino-Southern Oscillation and vector-borne diseases in Anhui, China.

This paper examines the relationship between monthly Southern Oscillation Index (SOI) and monthly incidences of hemorrhagic fever with renal syndrome (HFRS) and malaria in Anhui Province, China, over the periods 1971-1992 and 1966-1987, respectively. On the basis of monthly data over a 22-year period, results indicated that there were positive and negative relationships, respectively, between the SOI and monthly incidences of malaria and HFRS. The results suggest that the SOI could be used as an index in the study of the association of climate variability with the transmission of such diseases, particularly over larger areas, such as at a provincial or even state level, where averaging rainfall or temperature data across regions is inappropriate.

Secular trends in mortality rates for diabetes in Australia, 1907-1998.

AIMS: To characterise long-term mortality trends for diabetes in Australia during the 20th century, and to provide suggestions to health policy-makers. METHODS: A descriptive study was conducted using existing dataset. Deaths due to diabetes, as underlying cause of death, from 1907 to 1998 were tallied, according to the ICD-9. Trends in diabetes mortality (overall population, under-19 and over 40-year-old age groups) by gender were examined. RESULTS: There was a slightly increasing trend in the mortality rate in males over the study period, from 14.38/100,000 in 1907 to 16.05/100,000 in 1998. Among females, it started from 19.6/100,000 in 1907, reached the peak in early 1940s and then decreased to 10.61/100,000 in 1998. There was a reversal sex ratio after late 1960s with mortality rates among males were higher than females after 1969. There was a significant difference in overall mortality between males and females over study period (p<0.001). The mortality trend among the 40 years and over group was similar to the overall population. The death rates for the under-19 group declined significantly over the study period (p<0.001), but no difference between males and females was detected (p>0.05). CONCLUSIONS: The application of insulin played an important role in the reduction of diabetes mortality among the under-19-year-old group. New medical treatment methods to reduce chronic complications and other public health interventions could have made a recent contribution to reducing death rates. It is also probable that over the study period there has been an increase in the likelihood of diabetes being correctly diagnosed.

Co-existing conditions for deaths from infectious and parasitic diseases in Australia.

OBJECTIVE: To examine the frequency distribution of co-existing conditions for deaths where the underlying cause was infectious and parasitic diseases. MATERIALS AND METHODS: Besides the underlying cause of death, the distributions of co-existing conditions for deaths from infectious and parasitic diseases were examined in total and by various age and sex groups, at individual and chapter levels, using 1998 Australian mortality data. RESULTS: In addition to the underlying cause of death, the average number of reported co-existing conditions for a single infectious and parasitic death was 1.62. The most common co-existing conditions were respiratory failure, acute renal failure - non-specific causes, ischaemic heart disease, pneumonia and diabetes. When studying the distribution of co-existing conditions at the ICD-9 chapter level, it was found that the circulatory system diseases were the most important. There was an increasing trend in the number of reported co-existing conditions from 60 years of age upwards. Gender differences existed in the frequency of some reported co-existing conditions. The most common organism types of co-existing conditions were other bacterial infection and other viruses. CONCLUSIONS: The study indicated that the quality of death certificates is less than satisfactory for the 1998 Australian mortality data. The findings may be helpful in clarifying the ICD coding rules and the development of disease prevention strategies.

Climate variability and transmission of Japanese encephalitis in eastern China.

A time-series analysis was conducted to study the impact of climate variability on the transmission of Japanese encephalitis in eastern China. Correlation and regression analyses were used to examine the relationship between monthly climatic variables and monthly incidence of Japanese encephalitis in Jieshou County, China over the period 1980-96. Spearman's correlation analysis showed that maximum and minimum temperatures and rainfall were all associated with the transmission of Japanese encephalitis in the county. Regression analysis suggested that monthly mean minimum temperature and monthly precipitation had a significant relationship with the transmission of Japanese encephalitis, with a 1-month lag effect. The results indicated that these climatic variables might be treated as possible predictors for regions with similar geographic, climatic, and socio-economic conditions to Jieshou County.

Climatic variables and transmission of malaria: a 12-year data analysis in Shuchen County, China.

OBJECTIVE: The objective of this study was to explore the impact of climate variability on the transmission of malaria, a vector-borne disease, in a county of China and provide suggestions to similar regions for disease prevention. METHODS: A time-series analysis was conducted using data on monthly climatic variables and monthly incidence of malaria in Shuchen County, China, for the period 1980-1991. RESULTS: Spearman's correlation analysis showed that monthly mean maximum and minimum temperatures, two measures of monthly mean relative humidity, and monthly amount of precipitation were positively correlated with the monthly incidence of malaria in the county. Regression analysis suggested that monthly mean minimum temperature and total monthly rainfall, with a one-month lagged effect, were significant climatic variables in the transmission of malaria in Shuchen County. Seasonality was also significant in the regression model and there was a declining secular trend in the incidence of malaria. CONCLUSION: The results indicate that climatic variables should be considered as possible predictors for regions with similar geographic, climatic, and socioeconomic conditions to those of Shuchen County.