ISEE-230

An Italian network for the prevention of the health effects of heat waves was established in 2003. The network coordinated by the National Department for Civil Protection in collaboration with a centralised data elaboration center, involves experts from epidemiological departments, local health authorities, and regional agencies for the environment. At the municipal level, local centers (municipality, local health authority) coordinate the workload. Weather forecast data for each city are transmitted daily from the Italian Air Force Meteorological Service to the centralised data center and elaborated. An informative bulletin, graded by the severity of the warning, is then transmitted to the National Department for Civil Protection and published on their website. At the same time, the data elaboration center transmits a city-specific bulletin to the local coordinating center, which is responsible for the local dissemination of the information and, in case of an alarm, the activation of a city-specific prevention programme. This programme is defined based on the guidelines developed by the National Institute of Health and take into account local conditions. Information regarding the warning is transmitted to local health authorities and social services, public and private hospitals, nursing homes, general practitioners, and social centres for the elderly and to the general public via the media. Preventive measures especially aimed at the elderly and other susceptible groups include a telephone help-line, a network of social services, volunteers, street units trained for emergency situations and a campaign to inform the population of air conditioned public facilities. Hospitals are urged to provide air conditioning for patients at risk and to postpone non-emergency surgeries. Specific guidelines are drawn up by the Association for General Practitioners for the general population, and for patients suffering from specific diseases which then are distributed at the beginning of the season. Brochures are distributed to local pharmacies and physicians.

In the summer 2003 the HHWWS was experimented in four Italian cities, namely Turin, Milan, Bologna and Rome. Preliminary results comparing the predicted alarms and the observed excess mortality showed a good ability of the system to predict major peaks in mortality in Rome, whereas an underestimation was observed in Milan and Turin, which can be partly attributable to the extreme meteorological conditions in the summer 2003. In summer 2004, the project will be extended to other cities in order to cover the major urban areas throughout Italy.

ISEE-233

Since 2002, a Heat Health Watch Warning System (HHWWS) and a prevention program have been active in Rome during the summer period (15th May - 31st August) to reduce the impact of heat on mortality. Rome has an estimated population of 2.550.000 of which 14% are over 65 years of age. An evaluation of the performance of the HHWWS in 2003 during heat waves (defined as maximum apparent temperature above the 90th annual percentile and a +2°C compared to the previous day) in terms of excess mortality and the number of warnings predicted was carried out.

The HHWWS is based on a synoptic climatological procedure that classifies each day into meteorologically homogeneous groups (air masses) and identifies oppressive conditions associated with an increase in mortality. Meteorological forecast data is then applied to the system to predict air masses and the related excess mortality three days in advance. The daily excess mortality observed (defined as the difference between observed mortality on a given day and the smoothed average daily value for the reference period, 1995-2002) was compared with excess mortality predicted by the HHWWS.

During the summer of 2003 high temperatures persisted, and record excess mortality was observed during three heat wave periods (June 10th-July 3rd, July 11-31st, August 4-14th) exhibiting a strong association between temperature and daily mortality. Total excess mortality was 1094 deaths (+23%), observed especially among the elderly and increased dramatically with age, with the greatest impact in the over-85 age group (+46%).

The HHWWS called a warning on 43 days (47%), with a maximum of 7 consecutive days during the summer of 2003. The system was efficient in predicting major peaks in mortality, but during heat wave periods it underestimated the total number of excess mortality by 414 units (-47%) for the age group >65. The HHWW system underestimated actual heat wave days (69) by 27, predicting only 42 warnings. This is attributable to the underestimation of forecast temperatures and secondly, the extreme meteorological conditions recorded during heat waves were not accounted for in the meteorological time series used to construct the model. To overcome these underestimations, the HHWWS air mass-based model will be integrated with a temperature-based model in summer 2004. An evaluation of the effectiveness of the HHWWS and the preventive strategies implemented will be performed to further reduce heat-related mortality in Rome.