eea flag

Main pathways through which climate-induced drought and water scarcity affect human health, and potential strategies to manage the risks
Source: adapted from Figure 1 by Salvador et al. (2023) under the Creative commons 4.0 license and with the authors’ permission

Health issues

Drought and water scarcity affect health and well-being in several ways, including via drinking water shortages (via both drinking and sanitary uses), increased likelihood of water-, food- and vector-borne diseases, wildfires and poor air quality, and food insecurity and malnutrition. Drought can also worsen the likelihood of other climate-related extreme events and their associated health impacts. For instance, drought can intensify heat waves leading to more heat stress. It may also amplify risks of flooding or infectious disease outbreaks when heavy rains occurs after periods of  drought (Ebi et al., 2021; Semenza et al., 2012). Water is critical to all aspects of life. Water scarcity can therefore create cascading effects across social and economic systems, which ultimately affects livelihoods, physical health, and mental health and well-being. For farmers and seasonal agricultural workers, drought can lead to loss of income and unemployment and forced internal and cross-border migration, creating mental distress (Stanke et al., 2013; UNDRR, 2021). Due to the complex and cascading role water plays across society and throughout different sectors, drought can cause long-lasting health impacts through for example, changed livelihoods. Drought can also affect areas not directly exposed to drought through increased food prices of imported food products, which’ production suffered from drought.

Health impacts due to drinking water shortages

Reduced domestic water supply, through limits on volume or access time, can induce poor handwashing and hygienic practices, which can lead to gastro-intestinal diseases and skin and eye infections (Stanke et al., 2013). Populations that rely on a private water supply and people seeking an alternative water supply during periods of water scarcity (e.g., from private water collection) are particularly at risk. Cuts in public water supply, including for use in irrigation and food production purposes, can also put people at risk of health impacts if low water availability leads to use of untreated water for irrigation of crops, raising the risk of foodborne disease outbreaks (Semenza et al., 2012). Moreover, the food-processing industry is also at risk as an insufficient supply of water may lead to lower hygienic standards and increased risk of food-borne diseases (Bryan et al., 2020).

Drought conditions can lead to lower dilution of heavy metals and organic pollutants, including drug residues, in water bodies. Resulting health risks arise from direct contact with bathing water or drinking water that is not specifically treated, or indirectly via the food chain (Sonone et al., 2020). Indirectly, water conservation during droughts leads to less water for dilution and higher  concentrations of pollutants in wastewater plant influent, which can overwhelm the treatment capabilities of wastewater systems and lead to negative impacts on water quality (Chappelle et al., 2019).

Water-borne diseases

Droughts can degrade water quality by stimulating pathogen growth and increasing the concentration of pollutants in water sources. European countries typically have a well-regulated and quality controlled public water supply, which mostly prevents disease outbreaks via the delivery of safe drinking water. In bathing water, microbiological health threats arise during dry periods when pathogen concentrations (e.g. harmful E. coli bacteria) in the water increase due to reduced water levels and low flows, higher water temperatures, lower oxygen levels, increased salt and nutrient concentrations, and higher pathogen concentrations in riverbeds and nearby soils (Mosley, 2015; Coffey et al., 2019). Different pathogens (including viruses, bacteria, and parasites) can cause various waterborne diseases that trigger gastro-intestinal symptoms or skin infections (EEA, 2020a). Low flows and higher water temperatures enhance stratification in bathing waters, i.e., separation of warmer and cooler water layers, which favours cyanobacterial and harmful algal blooms  (Mosley, 2015; Coffey et al., 2019). Cyanobacteria (mostly in freshwater) and algae (in marine waters) can produce toxins that are harmful to humans via skin contact, accidentally ingested contaminated bathing, or infected drinking water or seafood. These pathogens can cause skin and eye irritation, allergy-like symptoms, gastrointestinal diseases, liver and kidney damage, neurological disorders and cancer (Melaram et al., 2022; Neves et al., 2021).

Vector-borne diseases

Drought affects the distribution and abundance of disease vectors, such as mosquitoes and ticks, potentially increasing the risk for vector-borne diseases. Fewer competitors and predators, no egg flushing events and more organic material in remaining stagnant waters during dry periods favour larval development and mosquito populations growth (Stanke et al., 2013; Chase and Knight, 2003). Specifically for West Nile virus (WNV), water scarcity causes birds (reservoir hosts for WNV) and Culex mosquitoes (vectors for WNV) to cluster around remaining water sources and human settlements, which can enhance the transmission of pathogens and increase West Nile fever outbreaks risk among humans (Paz, 2019; Cotar et al., 2016; Wang et al., 2010; Shaman et al., 2005).

Specifically for West Nile virus (WNV), water scarcity causes birds (reservoir hosts for WNV) and Culex mosquitoes (vectors for WNV) to cluster around remaining water sources and human settlements, which can enhance the transmission of pathogens and increase West Nile fever outbreaks risk among humans (Paz, 2019; Cotar et al., 2016; Wang et al., 2010; Shaman et al., 2005).

Health impacts from wildfires and air quality changes

In the absence of precipitation, concentrations of fine particulate matter (PM2.5 and PM10) in the air rise and increase the risk of worsening chronic respiratory problems, developing respiratory infections, and premature deaths (EEA, 2023c). Smoke from drought-related wildfires particularly impairs air quality (mainly through increased PM2.5) including at places far from the fire source. Fires and smoke cause physical and mental health effects including burns, injuries or death, heat-related problems, respiratory and cardiovascular diseases, post-traumatic stress disorder, depression and insomnia (Xu et al., 2020; Liu et al., 2015).

Impacts on nutrition

Drought can decrease crop yields, leading to local shortages of certain food products, which may lead to higher food prices across the whole of Europe (Yusa et al., 2015). Price increases and decreased food availability, particularly of nutritious foods like fruits and vegetables, can cause mental stress and dietary shifts towards cheaper and less healthy foods or lead to meal skipping, especially in low-income groups (UNDRR, 2021; ECIU, 2023; EEA, 2024). Malnutrition also increases healthcare costs and reduces productivity, which can cause health issues and feed into a cycle of poverty (UN, 2021). Most at risk of malnutrition are people with lower socio-economic status, pregnant women and young children.

Mental health & well-being

Droughts can induce both mental health issues (e.g., anxiety, emotional and psychological distress) and mental health illnesses (e.g., depression, post-traumatic stress disorder, suicidal thoughts), particularly for communities that rely on weather-related practices and are therefore vulnerable to drought such as farmers and rural communities (Yusa et al., 2015). Poor mental health outcomes are mostly associated with the economic impacts of droughts. For farmers, drought-related economic impacts are typically driven by crop loss and livestock failure, leading to financial constraints, unemployment, loss of livelihood and further stress, social isolation, anxiety, depression and suicide (Vins et al., 2015; Salvador et al., 2023).

Observed effects

Water scarcity and droughts are increasingly frequent and widespread in the EU (EEA, 2024). In 2019, 38% of the EU’s population was affected by water scarcity (EC, 2023). Drought-related impacts are likely to be worse in regions with high pressure on water resources, such as the Mediterranean.

Health impacts due to drinking water shortages

Due to Europe’s generally well-regulated public water supply systems, health impacts due to drinking water shortages are rare. Nevertheless, drinking water shortage have been more prevalent in Europe in recent years due to severe droughts. For example, in 2022 and 2023 in France, and in 2023 and 2024 in Spain, numerous municipalities faced disruptions to their drinking water supply. By supplying the population with drinking water transported by water tankers or bottled water, gastrointestinal illnesses or other health impacts due to water shortages were largely prevented. In Ireland on the other hand, a long dry spell and associated water use restrictions in 2018 incited the use of untreated water, contaminated with E. coli bacteria, for the irrigation of leafy vegetables. This led to one of the largest food-borne disease outbreaks due to toxin-producing E. coli bacteria (STEC), affecting almost 200 people around the country with some requiring hospitalisation (Health Protection Surveillance Centre Ireland, 2023, personal communication).

Water-borne diseases

In general, Europe’s high-quality drinking water supply and monitoring system mostly prevents disease transmission through contaminated drinking water. Nevertheless, drinking water from private wells has been associated with outbreaks of waterborne diseases. Ireland, for example, where an estimated 15% of the population uses drinking water from private groundwater sources, has the highest rate of STEC infections (by toxin producing E.coli bacteria, causing stomach illness) in Europe per year (ECDC, 2023), of which the majority is associated with drinking water (Health Service Executive, 2021).

Drought conditions in 2015-2018 contributed to elevated concentrations of chloride and sulphate, heavy metals, arsenic and pharmaceuticals such as metoprolol and ibuprofen in Elbe, Rhine and Meuse rivers (Wolff and van Vliet, 2021), leading to increased health risks.

Vector-borne diseases

In 2018, the increase of West Nile virus infections in Europe was linked to a wet spring followed by drought (Semenza and Paz, 2021; ECDC, 2018). With changing climatic conditions over the past few decades, the risk of West Nile virus transmission has been steadily increasing across Europe. The relative increase in West Nile virus outbreak risk in 2013-2022 compared to 1951-1960 baseline was 256%, with the highest relative risk increase seen in eastern Europe (516%) and southern Europe (203%) (EEA, 2022).

Health impacts from wildfires and air quality changes

Air pollution from fine particulate matter was responsible for 238,000 premature deaths in the EU-27 in 2020 (EEA, 2023b). While air pollutant concentrations are declining overall in the EU (EEA, 2023b), prolonged dry conditions and wildfires are slowing down this decline (CAMS, 2023). Wildfires cause numerous deaths and health problems in Europe, especially in the Mediterranean region. A study of 27 European countries estimated that, in 2005 and 2008, there were respectively 1,483 and 1,080 premature deaths attributable to vegetation fire-originated PM2.5, with greater impacts in southern and eastern Europe (Kollanus et al., 2017). In 2021, 376 premature deaths were estimated in the eastern and central Mediterranean basin due to short-term exposure to wildfire-caused changes in ozone and PM2.5 (Zhou and Knote, 2023). Between 1980 and 2022, there were also 702 fatalities directly caused by wildfires recorded in the 32 EEA member countries. Populations affected by wildfires may also consume higher amounts of drugs to treat sleeping and anxiety disorders (Caamano-Isorna et al., 2011).

Impacts on nutrition

Drought conditions reduce the availability and affordability of fresh and healthy food in the EU (EEA, 2023a). The heat wave and drought in Spain in 2022 led to substantial price rises due to severe crop losses, e.g. almost +50% for olive oil (ECIU, 2023). Also in Spain, prices for tomatoes, broccoli and oranges increased by 25% to 35% due to drought-related crop losses in the summer of 2023 (Campbell, 2023). The Lancet Countdown in Europe estimates that in 2021, hot and dry days caused moderate to severe food insecurity for almost 12 million people in 37 European countries, i.e., one fifth of the nearly 60 million people facing at least moderate food insecurity in total. In 2021, drought pushed 3.5 million more people into food insecurity as compared to the 1981-2010 average, with a higher likelihood among low-income families (Dasgupta and Robinson, 2022; van Daalen et al., 2024).

Mental health & well-being

While the potential negative mental health impacts of droughts are known, few studies quantify these impacts. Farmers – and their partners – tend to have significantly higher rates of depression, anxiety, and suicide compared to the general population. In France, the suicide rate of farmers is almost 40% higher than the general population (Euractiv, 2022).

Projected effects

Health impacts due to drinking water shortages

The current, very low prevalence of health impacts related to restrictions to public water supply due to water shortages, even during major European droughts, seems to suggest that health impacts in the future will remain limited.

Water-borne diseases

Droughts are expected to continue to decrease water quantity and flow locally and temporarily, hence increasing the risk for waterborne diseases in recreational waters. If good monitoring practices for both drinking and bathing water are maintained, impacts on human health and well-being can be prevented and limited. However, risks of infection may increase when water users shift to alternative drinking water sources, like private wells or harvested rainwater due to water scarcity and associated restrictions to water use.

Vector-borne diseases

Drought conditions coupled with creative water harvesting techniques among population exposed to drought may increase the likelihood of mosquito larvae development due to an increase in stagnant water. Increased drought conditions, in combination with the climate-induced change in range expansion of mosquitos, is expected to increase the incidence of mosquito-borne diseases in certain regions (Liu-Helmersson et al., 2019). In contrast, the expected rise in summer droughts in Southern European countries that currently provide suitable habitats for tiger mosquito populations (Aedes albopictus), such as Northern Italy, will create less suitable conditions for the mosquito in the future, and decrease the transmission risks of diseases like chikungunya or dengue (Tjaden et al., 2017).

Health impacts from wildfires and air quality changes

The negative health impacts of air pollutants in the EU are expected to decline over time, but drought-related dust and wildfire smog is expected to slow down this process. Droughts and temperature increases are expected to increase the frequency and intensity of forest fires and prolong the wildfire risk season, especially in Mediterranean countries but also in temperate regions of Europe (EEA, 2024). More people in Europe are expected to be exposed to forest fires as fire-prone areas expand and extend to urban areas (EEA, 2020b).

Under the high emissions climate change scenario, a substantial increase in deaths caused by wildfires is expected by 2071-2100 (138%); on average, 57 lives a year are projected to be lost (Forzieri et al., 2017).

Impacts on nutrition

Droughts in- and outside Europe will continue to reduce crop yields. This may lead to reduced food availability and accessibility in Europe, particularly for low-income households, creating nutritional risks and associated health impacts (EEA, 2024).

Policy responses

Overarching policies addressing drought preparedness, such as drought management planning, water resource management and water demand management, can have positive implications for many drought-related health impacts. Integrated and proactive approaches to drought risk management improve societal preparedness and contribute to better prevention and limitation of health impacts, rather than the traditional, short-term and reactive approach to drought crises. The World Meteorological Organization’s Integrated Drought Management Programme includes three pillars: (a) drought monitoring and early warning, (b) vulnerability and impact assessment, and (c) drought preparedness, mitigation, and response (Salvador et al., 2023), each reducing the risk of drought impacts and the related health impacts. Also adaptation strategies focused on the water cycle can strengthen the health sector’s preparedness for drought-related impacts, e.g., heat-health action plans and improved climate-sensitive disease surveillance and control.

Water availability and quality

The Protocol on Water and Health is an international legally binding agreement for countries in the pan-European region to protect human health and well-being through sustainable water management and by preventing and controlling water-related diseases. The EU Strategy on adaptation to climate change includes commitments to ‘improve coordination of thematic plans and other mechanisms such as water resource allocation and water permits’ and ‘help guarantee a stable and secure supply of drinking water by encouraging the incorporation of the risks of climate change in risk analyses of water management’. The EU Directive on the quality of water intended for human consumption, which replaces the Drinking Water Directive, regulates public water supplies, addressing risks associated with water restrictions and their effects on water quality, which requires additional monitoring during droughts. The EU Water Framework Directive focusses on ensuring pollutant concentrations in surface and groundwater stay below levels unsafe for human health and the environment. The Regulation on minimum requirements for water reuse aims to encourage and facilitate the safe reuse of treated urban wastewater for agricultural irrigation, in response to water scarcity and deterioration in water quality due in part to climate change. The EU Bathing Water Directive monitors contaminants like E. coli and Enterococci, as well as cyanobacteria and algal blooms in recreational waters. Only 8 member states have so far developed drought management plans for some or all of their river basin districts (i.e. Cyprus, Spain, Italy, Greece, Czechia, the Netherlands, Slovakia).

Other health threats associated to drought

To prevent and protect people from vector-borne diseases, awareness campaigns, technical guidance on rainwater harvesting and operational surveillance systems should be installed. Overall, a comprehensive and multi-faceted approach is essential to address the diverse health impacts of drought. To address air quality issues caused by drought related wildfires, land use planning, regulation of activities in undeveloped land, and early warning systems, such as EFFIS at the EU level and text messages at the national level and local level, are vital (ECHO, 2023).

To reduce impacts through nutrition, adaptation in the agricultural sector, such as water-efficient farming methods, can contribute to become more resilient to climate extremes, including droughts. Incentives for healthy and sustainable food choices will also reduce heath impacts. For mental health and well-being, awareness and training programs, and community-focused initiatives for farmers, including suicide prevention, are helpful (Yusa et al., 2015).

Further information

References

Language preference detected

Do you want to see the page translated into ?

Exclusion of liability
This translation is generated by eTranslation, a machine translation tool provided by the European Commission.