Climate change impact on health
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Climate change impact on health

A more humid climate can have consequences for health. More heavy downpours can lead to water entering our buildings through leaking roofs, foundations, basements, doors and windows, resulting in moisture damage. Moisture damage in buildings can be a breeding ground for mould, which can cause health problems in the form of mucous membrane irritation, headache, coughing and fatigue.


Increased indoor air humidity in buildings can increase the occurrence of dust mites, which could mean that people who are allergic to dust mites will experience more symptoms and that more people will become allergic.


Climate change affects the spread of contagious diseases
Since the impact of climate change on contagious diseases develops relatively slowly, Denmark will have good possibilities to adapt to the expected changes. All in all, the consequences for public health will therefore probably be fairly limited.

Diseases spread by insects
Some contagious diseases are spread from animals to humans or between humans and insects.


So far in Europe spread and increased incidence of certain vector-borne diseases have been observed. Examples of these are tick-borne diseases such as Lyme disease (Borreliosis), tick-borne encephalitis (TBE) and Crimean-Congo hemorrhagic fever (CCHF), as well as Chikungunya fever and West Nile fever, which are transmitted via different species of mosquito.


Ticks in Sweden, the Baltic and on the Danish island of Bornholm have for several years been vectors of TBE. Last year, in Sweden around 200 people were infected with TBE. In Denmark, so far only one incidence in a forest north of Copenhagen has been recorded.


Water-borne infections
Water-borne infections are diseases transmitted via drinking water and via contact with bathing water or similar.


After longer periods with warm seawater, an increased concentration of certain marine bacteria such as Vibrio vulnificus will comprise an infection risk for fishermen and swimmers.


Weil's disease (Leptospirosis) is an example of a disease which can be transmitted from rats and other animals to humans. Legionella bacteria can be found in fresh water and other wet or humid environments. Transmission occurs most commonly via inhalation of aerosols of Legionella-contaminated water. Apart from tap-water, transmission can occur through cooling towers or air conditioning systems. Being aware of this is therefore important in relation to climate change and higher temperatures.


Very heavy downpours can result in overflow of sewers and flooding of gardens, pools, lakes, while sludge in watercourses after flooding with sewage water contains bacteria harmful to health with an accompanying increased risk of infections.


Food-borne infections
Most food-borne infections such as Salmonellosis, Campylobacteriosis and Verotoxin-producing E. coli (VTEC) show clear seasonal variations. This dependence on temperature could signify that efforts to prevent food-borne infections have to be strengthened in order to make consumers safe in future.


Better growth conditions means more pollen
Warmer summers and milder winters can mean that pollen seasons for allergens such as hazel, alder, birch, grass and sageworts are prolonged.


Furthermore, a changing climate can provide better growth conditions for pollen-bearing plants which have so far not gained ground in Denmark. For example ragweed (Ambrosia) has gained a footing in Denmark in recent years.


A warmer climate can increase the risk of sunburn and dehydration
For most people, warm and dry summers mean more time spent outdoors and more physical activity. For example, heatwaves could encourage more people to go to the beach where rays from the sun are particularly strong due to reflection from the water and sand. Increased exposure to the sun's ultraviolet rays can cause more sunburn and increase the risk of skin cancer.


Extra water during hot periods can save lives
Higher temperatures expose more people to the risk of dehydration and heatstroke. People who are especially at risk are described in a report from WHO. The report is based on a study of deaths due to heatstroke, including during the heatwave in France in 2003. You can find a link to the report in the box to the right.

According to WHO, people who require special attention during hot weather periods are:


• elderly living alone;


• people with dementia;


• people suffering from mental illness;


• people with an illness or who take medicine which makes it difficult for them to feel thirsty and to sweat. This includes people with diabetes, cardiovascular and lung diseases;


• young children who are not able to drink by themselves, or who will forget to drink.

Climate change can affect the risk of accidents
Powerful storms can lead to accidents due to overturned trees, falling roof tiles and scaffolding, as well as more traffic accidents due to squalls, especially when riding a bicycle. All types of outdoor activity during powerful storms and hurricanes can be linked to danger from flying objects and falling trees. Indirectly, warmer weather will increase the number of accidents in outdoor activity.


Heavy downpours and thunder storms can lead to more road accidents due to flooded roads and risk of aquaplaning as well as reduced visibility. Furthermore, we will be seeing more episodes with thunder and lightning, with an increased risk of being struck by lightning.


However, overall we can expect only a slight increase in the occurrence of accidents, since other factors than the climate will have a far greater significance for accident figures.