Analyzing the influence of air temperature on the cardiovascular, respiratory and stroke mortality in Tehran

The quantification of the relationship between daily mortality and air temperature, as a fundamental policy is essential to enhance the accuracy of the warning system of decrease and increase of temperature. The objective of this study was to investigate the relationship between temperature and death rate in Tehran during the period [2002-2005] by combining statistical and geographic information system methods. The Results of this study indicate that there is a strong and meaningful correlation between air temperature and death rate especially between monthly averages ones. The highest rate of mortality has occurred in the cold months of the year [December, January and February]. and as the temperature decrease, the death rate increase. The increase in death rate caused by cardiovascular, respiratory and stroke diseases in the cold months of the year, bears proof to this matter. Among 22 zones of Tehran, zones 9, 6 and 12 have got the highest number of death occurrence. The correlation between daily death rate and daily temperature averages was V-shaped. Results of this study confirm some previous findings such as those in Moscow, United States, Hong Kong, Madrid, Athens and Shanghai. Temperature minimum mortality for Tehran was calculated as 28.5°C. The obtained results also indicate that the higher was the temperature difference from the Temperature minimum mortality, the more the death rate increased. Finally, the optimum policies for the mitigation of mortality in Tehran are presented

Analysis of air temperature influence on mortality in Tehran

A direct relationship exists between air temperature and seasonal and daily variations of mortality. Stressor effect of temperature decrease and increase has a significant increasing impact on death rate. Quantification of the relationship, between daily mortality and air temperature is useful as a fundamental policy for accuracy enhancement of temperature decrease and increase warning system. The objective of this study was determination of the relationship between temperature and death rate and the Temperature Minimum Mortality [TMM] in Tehran during the period 20022005. In a descriptive and analytical study, we statistically analyzed the relationship between temperature and number of total deaths as well as deaths due to cardiovascular diseases, cerebrovascular accidents, and respiratory diseases. Studied population was the reference population for mortality in Tehran from which a 4-year sample of daily mortality was drawn ft r years 2000 to 2005. Relationship between daily death numbers and daily temperature averages was V-shaped during the studied period. TMM for Tehran was calculated as 28.5 C The more different the temperature was form the TMM, the more was the death rate. There was a strong and significant correlation between air temperature and mortality rate, especially with average monthly mortality rate. Determination coefficient was 0.76 with a 99% confidence level. The highest number of deaths had occurred in the cold months of the year [December, January, and February]. The more decrease in temperature had occurred, the more had increased the mortality. Increase in cardiovascular diseases, cerebrovascular accidents, and respiratory diseases mortality rates during the cold months further clarifies this relationship. Amongst 22 zones of Tehran 's Municipality, zones 9, 6 and 12 had the highest death rates