Heat waves forecasting in Turin (Italy) urban area: a new approach with the use of HSI index to mitigate the impact of high temperatures on Human Health

The summer 2003 in North Italy will be remembered for the high temperatures and for the strong impact of these on the human health, e.g. a sharp increase of the mortality and morbidity. The weather conditions were exceptional with very long period of high temperature, both in the daytime and in the night-time. Epidemiological studies indicates that these weather conditions affect the people with cardio-respiratory diseases, that often bring the person to death. In this work we present, at first the data and the analysis of the relationship between weather and mortality during the summer of 2003 in Turin (Italy), then the proposed solution at this problem with a new approach that besides which use the index HSI (Heat Stress Index). Data and analysis of summer 2003 in Turin urban area: heat related deaths during summer 2003 were 592 more than the average value calculated by a regression model; respect to summer 2002 the difference has been calculated in +502 person, but summer 2002 was rather cold since many days of precipitation. On the contrary the summer 2003 was characterized by an almost continue presence of a North African anticyclone over the North Italy, only briefly interrupted by some T-storms and 1 or 2 days of cool weather. Highest temperatures were recorded during the period 4-14 August, while high values of humidity affected the area during June. To evaluate the human discomfort has been calculated the Heat Stress Index all over the period and compared with other common weather indexes and epidemiological data. New approach to mitigate the problem: a joint project between Weather Office and Epidemiological Office of ARPA Piemonte has created a new mathematical model to estimate the impact of heat waves on Mortality. The model calculates the maxima temperature, the highest and lowest Heat Index (Steadman, 1984), the number of consecutive days with hot apparent temperature, the value of the city Ozone, and other meteorological parameters to predict a HSI - Heat Stress Index (Kalkstein, 2003) in Turin urban area. Built on the HSI index, an epidemiological model forecasts the heat related deaths and by these data the project develops people’s awareness of danger by the following kind of information coded “No Alarm”, “Weather Attention”, “Health Attention”, “Weather + Health Attention”, “Weather Alarm”, “Health Alarm”, “Weather + Health Alarm”, “Emergency”.