Climate Change and Health [1]

The new findings of the International Panel on Climate Change (IPCC), issued this week, show that “the impact on human health is one of the most important effects of the changing climate. Future health impacts are predicted with high (80%) or very high (90%) confidence. If current trends continue, our grandchildren will be living in a much warmer world with more frequent extreme weather events, higher concentrations of carbon dioxide, and half a meter higher seas.

In this scenario, millions of them are more likely to die, as a consequence of heat waves, floods and droughts; of changes in infectious disease patterns and distribution; of changes in seasonality and increased frequency of water- and food-borne diseases; and of cardio-vascular and respiratory diseases from more extensive and persistent air pollution. There might be benefits like reduction in winter mortality; though they will not be able to balance the negative effects on health of the warmer and more variable climate. Once again, the most affected will be the poor of the world, without access to effective social protection and health systems.” [2]

“It is important to understand that we are not only forecasting deaths and diseases, we are witnessing them now. We are all experiencing at a lower scale what will happen more frequently and more seriously tomorrow. The 35,000 deaths due to the heat wave which hit Europe in the Summer 2003, and changes in the geographical distribution of some vectors are the first alarming examples.” [3]

The longer greenhouse gas reduction measures are not in place, the greater the need to understand how people and systems can effectively adapt to new climate patterns and potential threats, and what needs to be done now to avoid the human suffering and deaths that may result. This paper summarizes the findings of the “Climate change and adaptation strategies for human health in Europe” (cCASHh) project co-coordinated by WHO to assess current health impacts of climate change and responses to it in measures and policies. The study identified a range of options that have been taken or could be taken by European policy-makers now to prevent, prepare and respond to heat-stress-related mortality and morbidity, food-borne (salmonellosis and campylobacteriosis), vector-borne diseases and allergic disorders.

Trends
Current trends, discussed in the studies, point to the likelihood that southern Europe will become drier in the future, while northern Europe is likely to become warmer and wetter. Extreme events are expected to increase in frequency and severity, particularly heat-waves, droughts and intense rainfall events.

The WHO European Region was hit by a major flood in 2002 and by a severe heat-wave in 2003. Lessons learned point to the need for strengthening policies that will help societies adapt better to such extreme climatic changes. Lack of preparedness and weak response systems in the 2003 heat-wave resulted in more than 35,000 excess deaths in Europe. In contrast, structural and non-structural flood protection measures in many European countries have significantly reduced associated deaths over recent decades. cCASHh European surveys confirmed that while the characteristics of the population, access to health services and types of exposure are important determinants of health outcomes, effective policies can make a difference.

Developing effective policies
The cCASHh findings are organized in two sections. The first addresses some pre-requisites of adaptation, such as the need for better linkage between health and climate authorities and enhancing policy-makers’ capacities to act and communicate. The second addresses some specific policy-driven action options (how) to reduce the health impact of heat-waves and floods, and changes in the ranges of vectors, allergens and food-borne diseases attributable to climate change (now).

Integration
Addressing the health impacts of climate change requires integration of public health and climate change knowledge. Integration requires reciprocal understanding of terminology, goals and methods. Beyond this it requires working together to achieve the goal of reducing deaths, disease and disabilities.

Building on existing policies
A key message from the research is that the measures considered in adapting to future climate change are, in general, not new, and that most of them build on well-established public health approaches. In general, early action was found to be most possible and important when: action measures have already been shown to be effective under current climate conditions; severe impacts are possible; multi-sectoral alliances, partnerships, and networks are in place; adaptation measures have a long lead time; decisions have long-term effects; and there is a need to reverse trends that threaten adaptive capacity.

Risk perception and Communication
cCASHh surveys revealed a limited public or policy-maker appreciation of the risks of climate change and variability and what to do about them, partly because of the perception that the problem is too big to manage, outside of the health sector and the impacts are long-term. Awareness-raising and information activities will need to communicate better the “real” threats and preventive actions that can be taken by individuals to reduce their risk of climate-sensitive diseases. In particular, there is a need for a more strategic approach to those at risk and those who can play a part in enhancing adaptability. Crisis and risk communication experiences point to the counter-intuitive aspects of uncertainty communication: namely, if one does not deal with uncertainties with clarity and candour, one risks losing trust and worsening fear and insecurity

Heat waves
Surveys show that Europe is not well-prepared to cope with “unexpected” extreme thermal stress events. In western Europe alone, 35,000 excess deaths were reported in the 2003 heat-wave.

Deaths from heat stroke, cardiovascular, renal, respiratory and metabolic disorders were reported in the over 65 age group. People most at risk suffer from chronic diseases, take certain medications and are not physically fit. Several environmental, social and health-care-related risk factors contribute to higher levels of mortality, most importantly living in the city, being alone, living on the top floors of buildings.

There is some evidence that mortality can be reduced by strengthening and implementing early warning systems (especially to high-risk populations), strengthening health system preparedness and response and better planning of cities and housing.

It was estimated for the city of Rome, that the monetized mortality damages of the heat-waves in the absence of planned adaptation programmes would be €281 million for the year 2020 (in 2004 euros). Policy options include early warning systems, health system preparedness and response, urban planning and housing improvements.

Floods
Floods are the most common natural disaster. They cause death, injury, diseases and mental disorders during the flood event and restoration, along with additional effects brought about by major infrastructure damage and displacement of populations. Furthermore, there are indirect effects such as water-borne and vector-borne diseases, exposure to chemical pollutants released into floodwaters, and food shortages.

Interventions before, during and after floods can reduce short- and long-term health impacts.

Chronic health effects are possible but rarely quantified. Exposure to flooding reportedly results in long-term problems including increased rates of anxiety and depression stemming from the experience itself, troubles brought about by geographic displacement, damage to the home or loss of familiar possessions and stress in dealing with builders and other repair people in the aftermath.

Prevention of floods and flood damage is mainly based on structural (dams, room for the river, etc) and non-structural (early warning, risk communication, etc) measures. Flood prevention plans normally include environmental impact assessments (flood plains), communications strategies and land-use regulations. Providing accurate information on safe management of flood water during evacuation and clean-up is essential. There is a need to shift emphasis from disaster response to risk management, to improve flood forecasting, to establish early warning systems and to include health actors in the communication flow.

Vector-borne diseases

Lyme borreliosis and tick-borne encephalitis (Ixodes ricinus)
cCASHh data and other studies have shown that the tick transmitting Lyme borreliosis and tick-borne encephalitis (Ixodes ricinus) has spread into higher latitudes (in Sweden) and altitudes (in the Czech Republic) in recent decades and has become more abundant in many places.

Based on the results of the extended cCASHh reviews, it seems likely that climate change in Europe will: facilitate the spread of Lyme borreliosis and tick-borne encephalitis (TBE) into higher latitudes and altitudes and contribute to an extended and more intense Lyme borreliosis and TBE transmission season in some areas.

Malaria
Although several models predicted a potential increase of malaria in Europe, there is agreement that the risk is very low under current socioeconomic conditions.

The measures currently available to control vector- and rodent-borne diseases are disease-specific and can be broadly classified into diagnosis and treatment, vaccination, vector control, reservoir host control, information and health education and disease surveillance and monitoring.

Food-borne diseases
Diarrhoeal diseases are one of the most important causes of ill health in Europe, secondary to food-borne and water-borne infections.

Salmonellosis
cCASHh studies on food-borne diseases show that, in general, cases of salmonellosis (the most common food-borne disease) rise by 5-10% for each one-degree increase in weekly temperature, for ambient temperatures above about 5ºC.

Important mechanisms to prevent food-borne and water-borne diseases are surveillance and monitoring, microbiological risk assessment, risk management and risk communication. The number of cases of salmonella can be reduced by controlling and monitoring along the food chain. The level of implementation varies by country. Control measures and information on storage and food handling need to be strengthened.

Allergic illness
Evidence is growing that climate change might facilitate the geographical spread of particular plant species to new climatically suitable areas. Warming is likely to facilitate earlier onset and may extend the duration of flowering and pollen seasons for some grasses and weeds.

Conclusion
Political will and support for public health approaches may be seen as a pre-requisite to reducing health risks and instability. Identifying ways to reduce the causal factors of climate change (mitigation) and effectively help populations and systems deal with risks and threats posed by climate change (adaptation), especially for vulnerable populations, can lead to a greater sense of security and control and result in improved population health. The health sector can and should be at the heart of this.

[1] Excerpts from cCASHh report summary (Apfel and Menne, 2006).

[2] Proposed editorial, Dr Roberto Bertollini, Director of the Special Programme on Health and Environment, and Dr Bettina Menne, Medical Officer, Global Change and Health, both of WHO Regional Office for Europe.

[3] Proposed editorial, Dr Roberto Bertollini, Director of the Special Programme on Health and Environment, and Dr Bettina Menne, Medical Officer, Global Change and Health, both of WHO Regional Office for Europe.