Module 2 Climate change and health: vulnerable groups, health impacts and prevention

2.1         Vulnerable groups and health impacts of exposure to heat

Heat extremes have serious impacts on public health worldwide (see figure 2.1). The effects of heat mostly occur on the same day and in the following three days. We distinguish indirect and direct impacts. Indirect impacts are for example disruption of infrastructure and health services or a decrease in air and water quality. Direct impacts are an increase of illness, death and hospitalization. Elderly people are a group who have a high risk at negative health effects due to the increase of the frequency and intensity of heatwaves in combination with the presence of (co)morbidity. People living in cities have a larger risk at negative health effects because of so called heat islands which are often located in socially and economically deprived areas. Other vulnerable groups at greater risk include people with chronic conditions (such as cardiorespiratory diseases, endocrine system disorders, mental health disorders, metabolic disorders and kidney disorders), pregnant women, small children, workers, migrants and travellers. Age, pre-existing medical conditions and social deprivation are key factors that make people experience more adverse health outcomes related to heat and extreme temperatures. In the last decade, the quantity of literature on factors affecting vulnerability to heat (see also figure 2.1) has greatly increased.

We differentiate direct and indirect effects of exposure to heat. Direct effects are heat stress and dehydration or heatstroke. Indirect effects are for example worsening of cardiovascular and respiratory diseases, kidney diseases or electrolyte disorders (WHO Regional Office for Europe, 2018).

 Figure 2.1 Health impacts of exposure to extreme heat

Source: https://www.who.int/news-room/fact-sheets/detail/climate-change-heat-and-health#Overview

Figure 2.2:          Climate Change, vulnerability and climate-sensitive health risks

 

Source: https://www.who.int/news-room/fact-sheets/detail/climate-change-and-health 

 2.2         Heatwaves:  prevention

In order to find the right, useable information on how to deal with heat stress in an effective as well as efficient way, it is helpful to start with a working model. A good example of such a model is the Public Health Model which was developed by the Centers for Disease Control and Prevention:

 

Figure 1. The CDCP Public Health Model (https://www.cdc.gov/violenceprevention/publichealthissue/approach.html)

 The first step is to identify the problem: what is it? What are the possible consequences? How is it caused? In the next step, the risk and protective factors must be identified. These may vary between the various target groups. Once this is clear, it is of important to identify effective prevention strategies, f.e. by literature searches. In case there are none, they need to be developed. Finally, proven effective strategies need to be implemented broadly.

In this e-learning, you can find more information about heatwaves, and the problems that are related to it. It has been briefly described in this introduction, and more elaborated in the database of this e-learning that has been filled with useable articles on this topic. Promising as well as proven effective measurements can be found there.

Many of these interventions can be considered as a form of prevention. Should you want to develop a preventive strategy, you need to have a good understanding of the different types and stages of prevention. Although there is no uniform, generally applicable definition of prevention, the WHO has adopted a description of prevention that has become generally accepted, especially in healthcare. Here, a distinction is made between primary, secondary and tertiary prevention. In this context, primary prevention refers to all measures that can be taken to prevent the occurrence of the basic problem. In this e-learning and depending on the perspective chosen, that could be the appearance of extreme heat or the occurrence of heat-induced problems in the elderly. Secondary prevention includes measures that can be taken in high-risk situations, for example in case a heat wave occurs, and the elderly have symptoms predicting related health problems. Tertiary prevention deals with the reaction of the elderly who actually suffer from heat-related health problems. This type of prevention is directed at reducing complications. In this classical prevention model, there is a clear timeline: no problem, or not yet any problem, (primary), small, beginning problems (secondary), and serious problems (tertiary).

Another and more recent ‘prevention model’ which has been introduced by the Institute Of Medicine (IOM) is widely employed lately. In this model it’s not the timeline, but the target groups that are distinctive: universal prevention which is directed at the overall population, selective prevention which is geared toward high-risk groups, and indicated prevention when individuals are facing (potential) health problems.

Both models (WHO and IOM) can be used separately, but also in combination since the distinctions made are related, which is illustrated in Figure 2.

 

Fig 2. The relation between the WHO and IOM prevention model. (Meili B: Indizierte Prävention bei gefährdeten Jugendlichen. Suchtmagazin 2004, 6:21–25.)

Considering this way, secondary prevention is not only important for individuals at high risk but also for the overall population. Furthermore, tertiary prevention should not only be considered similar to indicated prevention since it can be applied in high-risk groups too.

In order to find and select the appropriate prevention measures it is important to realize at which stage you want to apply the intervention(s), and towards which target group. The database of this e-learning contains possible measurements on all levels and for all target groups mentioned.

 Tasks

Obligatory

Sorensen, C., Hess, J.  (2022). Treatment and Prevention of Heat-Related Illness. In:

N Engl J Med 2022; 387:1404-1413. (in e-learning database)

https://www.who.int/news-room/fact-sheets/detail/climate-change-heat-and-health#Overview

https://www.who.int/news-room/fact-sheets/detail/climate-change-and-health

Chapter 6 of the WHO report Heat and health in the WHO European Region:updated evidence for

effective prevention (2021).  https://www.who.int/europe/publications/i/item/9789289055406

 Suggestion

Μodule 7: Health, Wellbeing and the Changing Structure of Communities https://www.ipcc.ch/report/ar6/wg2/

E-learning Database

E-learning Literature base