The response of the Montreal Public Health Board to climate change: preventing excess morbidity and mortality due to extreme summer temperatures in vulnerable human populations

A recent publication by the World Health Organization, the World Meteorological Organization and the United Nations Environment Programme states that there is now a widespread consensus that global warming is a real phenomenon and that the last decade has been the warmest since the nineteenth century when temperatures were initially recorded. The impacts of global warming are far ranging and include such effects as extreme weather events, transmission of vector borne diseases and increased temperatures.

The aim of this presentation is to focus on the potential health impacts of extreme summer temperatures in Montreal and to discuss the public health response to this problem. The various levels of intervention aimed at identifying the extent of the problem and at helping the vulnerable population adapt to heat waves without suffering from excess morbidity and mortality will be described. New approaches aimed at mitigating the effects of heat will also presented.

The effects on public health of more frequent and more severe heat waves in temperate climates are well documented. Aside from the direct effects associated with extreme heat, the elderly and chronically ill living in urban environments are particularly vulnerable to the effects of summer heat waves as shown by events in the American mid-west in 1995 and in Europe during the summer of 2003.

The Montreal public health department has been preoccupied with these health impacts for several years now, and we have developed a multifaceted approach aimed at protecting the vulnerable population from the effects of heat waves.

First and foremost, we have mobilised environmental, health care, municipal and community resources as well as the media in order to ensure that our public health message reaches the vulnerable population and those that come into contact with them on a daily basis.

We are also exploring the possibilities of developing a surveillance system in collaboration with Montreal hospitals and emergency services in order to follow the evolution of health events during heat waves in order to determine whether emergency procedures such as opening air-conditioned shelters are necessary. Such a decision requires the collaboration of several levels of municipal resources and must thus be based on credible data.

Research is also being carried out with the collaboration of Montreal universities in order to study how the population of Montreal reacts to heat stress. Determination of threshold levels defining when excesses of morbidity and mortality begin to occur will help us define more accurately when emergency measures must be put into place.

Finally, we are working in collaboration with municipal authorities, community groups and private enterprise in the elaboration of a sustainable development plan for the Montreal area aimed at contributing to the reduction of greenhouse gas emissions and other pollutants and setting up of measures to mitigate the effects of heat waves.