Flooding

Health issues

Flooding can affect both physical and mental health. During the flooding, direct physical health effects include drowning, injuries caused by contact with objects in floodwater, hypothermia and electrical injuries.

Sewage overflow caused by flooding increases the risk of infectious disease, particularly in children (EEA, 2020). Floods increase the risk of viral infections such as norovirus, hepatitis A and rotavirus; infections caused by parasites Cryptosporidium spp. and Giardia (to a lesser extent); and bacterial infections due to Campylobacter spp., pathogenic E. coli, Salmonella enterica and, to a lesser degree, Shigella spp. (ECDC, 2021).

Stagnant water remaining after floods (e.g. in basements, gardens, parks, agricultural fields) may create suitable sites for mosquito breeding, increasing the risk of mosquito-borne diseases. Furthermore, the risk of heart attacks, respiratory problems and poor pregnancy outcomes may increase (ECDC, 2021; Paterson et al., 2018).

Indirect effects of flood events, both during and after flooding, include health issues caused by  disruption of medical treatments; physical workload associated with clean-up and reconstruction; shortages of medical aid, electricity or safe water; and problems with supply chains of food, electricity or sanitation (Paterson et al., 2018). Floodwaters can cause property damage, which can lead to displacement and overcrowding. Living in housing affected by flooding can lead to pulmonary and systemic fungal infections (e.g. from airborne and dustborne Aspergillus) and mycotoxin exposure.

Flooding can also lead to loss of employment, lack of access to childcare and school services, and increased domestic violence (Mason et al., 2021). Up to 75% of people affected by flooding suffer from mental health problems: trauma, mental distress in the short term to posttraumatic stress disorder (PTSD), anxiety, insomnia, psychosis and depression (Munro et al., 2017; WHO Regional Office for Europe, 2013).

Populations that are particularly vulnerable to adverse effects of flooding include the elderly, children, people with chronic illnesses or physical impairments and pregnant women (WHO Regional Office for Europe, 2017). People accommodated in temporary shelters are more prone to acquire health problems due to the higher probability of exposure to infectious disease pathogens in communal accommodations and the disruption of their regular healthcare provision. Emergency and ambulance service workers are at higher risk of waterborne diseases due to elevated occupational exposure, as they come into contact with contaminated flood water, debris and mud (ECDC, 2021).

Observed effects

According to JRC, 172 000 people in Europe (EU-27 + UK) are currently exposed to river flooding on an annual basis (Dottori et al., 2020) and 100 000 are exposed to coastal flooding (Vousdoukas et al., 2020). A tenth of Europe’s urban population is currently living in areas potentially at risk of flooding (EEA, 2020). More than one third of the European population lives in coastal regions (EEA, 2021c).

Over the period 1980-2017, flood events have resulted in over 4 300 fatalities in EEA member countries (EEA, 2021a). According to Paprotny et al. (2018), flood trends between 1870 and 2016 show a steady increase in annually inundated area and number of persons affected. However, the number of fatalities has been decreasing over this period, suggesting an increased preparedness of emergency and health care systems. Nonetheless, the 2021 summer flooding in Central and Western Europe with at least 212 documented deaths was the deadliest weather-related flood in Europe in more than 50 years (ECDC, 2021).

Projected effects

The risk of flooding under the changing climate is likely to increase for many regions across Europe. Projections under both high- and medium-emissions scenarios show high confidence in extreme precipitation increase in the northern, central and eastern European regions and in the Alpine area whereas projections for southern Europe are more mixed (IPCC, 2021; EEA, 2021b).

Under the changing climate, at the end of the century, the number of people exposed to annual river flooding in Europe is projected to be 252 000 under 1.5 °C global warming scenario; 338 000 under the 2 °C scenario; and 484 000 – more than three times the current numbers - under the 3 °C scenario. However, with adaptation measures, the population exposed can be limited to 100 000 or less under all global warming scenarios (Dottori et al., 2020).

The relative sea level of Europe’s seas will continue to rise throughout this century under all emissions scenarios, driving more frequent coastal floods along the majority of the European coastlines (EEA, 2021c). Up to 2.2 million people are projected to be exposed to coastal flooding by 2100 under a high emissions scenario and 1.4 million under a moderate mitigation scenario, in the absence of additional adaptation measures. With adaptation measures, these numbers are expected to be reduced to 0.8 million and 0.6 million, respectively (Vousdoukas et al., 2020).

The European ageing population, suffering from chronic diseases and social isolation, is increasingly vulnerable to both physical and mental health problems associated with flooding. Increasing urbanisation, involving continuing development of floodplains and increased surface sealing in cities, is also likely to contribute to increased exposure of Europeans to flooding.

Policy responses

Measures to protect population health from flooding can be divided into those relevant to prevention, preparedness, response, and recovery (WHO Regional Office for Europe, 2017). Long-term prevention includes, among others, identification of flood risk areas, flood-sensitive urban planning with focus on urban greening and permeability of surfaces. Other flood prevention measures include relocation of human activities away from floodplains; upgrading sewer systems; and use of flood protection infrastructure such as dikes or dams (EEA, 2020). Examples of preparedness and response measures are resilient water supply and sanitation systems; flood-proof buildings; availability of evacuation centers; having a flood-health preparedness plan in place. This includes contingency plans for health facilities, enabling them to continue functioning with respect to work organization, patient care, supply management, water and sanitation (WHO Regional Office for Europe, 2017).

At the European level, the effective use of early warning systems such as the European Flood Awareness System (EFAS), a component of the Copernicus Emergency Management Service (CEMS), can reduce the impact of flooding. The EU RescEU programme offers collaborative support to countries in case of disasters (such as critical flooding) by protecting citizens and management of risks.

Recovery measures include mental health aftercare, provisions for vulnerable people, avoiding electrical hazards during recovery and cleaning, and epidemiological/hygienic/sanitary surveillance.

References

Links to further information