Clean, safe water for everyone, even in a changing climate

Infectious diseases in water, soil and air

Ana Maria de Roda Husman combines three roles, all in the field of prevention and control of infectious diseases that are transmissible via the environment – i.e. via water, soil and air.  Her focus at RIVM is on environmentally transmitted infectious diseases. At RIVM, she is the director of the Collaborating Centre for Risk Assessment of Pathogens in Food and Water, which supports the World Health Organization (WHO).
And she also works at Utrecht University, as a professor of global change and environmentally transmitted infectious diseases. 

How are climate change, water and infectious diseases related?

“Pathogens are affected by weather conditions. Ambient temperature, precipitation and humidity all have an influence on pathogens – and that could work either way. Some pathogens thrive at high temperatures, while others do not like the heat at all. Take legionella, which spreads through water and air. When the weather is warm, but dry, there is less legionellosis (also known as ‘Legionnaire’s disease’, a form of atypical pneumonia caused by Legionella bacteria). 

When the weather is warm but wet, with high humidity, we see more frequent reports of legionellosis. We have seen an increase in the number of cases in the Netherlands and many other countries in recent years. And climate change seems to affect that. Other infectious diseases such as cholera and other vibrioses have also been found to be associated with weather conditions.” 

Too much water and not enough are both problematic for water quality. If there is too much precipitation, insufficient water storage can lead to flooded streets. Floodwater can contain pathogens. For example, contact with this polluted water could cause people to develop diarrhoea. Not enough water can also impact water quality. When water is in short supply, you are sometimes forced to settle for inferior quality – and all the consequences that entails.

What opportunities are there for solving problems involving water and water quality? 

“Water safety plans are good tools. These plans enable us to arrive at accurate estimates of the water quality needed to produce drinking water. Employees at our WHO Collaborating Centre, such as Harold van den Berg, received special training from the WHO, and now they help people all over the world to implement the WHO water safety plans. Wherever we go, we assess the risks of local water extraction. We share our knowledge in the African, Asian, and wider European regions. We are also working with the WHO on climate-proofing the tool. In December 2019, we had a meeting in Sri Lanka to contribute to those efforts. 

In January of this year, we were in Myanmar, contributing knowledge about the entire water chain, from source to tap.  Wherever possible, we also address the local needs right away. For example, the people in Myanmar had questions about algae growth in water reservoirs, and we responded immediately, so they would be able to develop their own solutions from there. 

"Reusing or reclaiming water can be a good solution. One initiative of the Joint FAO/WHO Expert Meetings on Microbiological Risk Assessment (JEMRA), part of the United Nations, is a project involving water reclamation in food production. It has to be safe, and the food chain is very complex. Water is used in every aspect: in growing food in the fields, in consumer kitchens before the food ends up on the plate, and all sorts of steps in between. In every step, you want to achieve the right quality for the right application -that principle is called 'fit-for-purpose'-, and that’s what we’re working on. In this project, we are compiling the knowledge about water quality accumulated by the WHO and experts and providing it to professionals in the food domain. Our WHO Collaborating Centre is well-equipped to playing a leading role in the context of such a request on the interface of food and water.

"A basic framework for water safety plans has also been adapted for use in the Netherlands, working closely with the Human Environment and Transport Inspectorate (ILT) and the Dutch water companies. Much of what we do at the WHO Collaborating Centre can be applied regionally, nationally and internationally.”

You mention solutions that contribute to Sustainable Development Goal 6: clean water and sanitation. Are we well on our way to meeting the targets for 2030?

“We are making steady progress on safe drinking water. However, sanitation is lagging behind in various countries – including countries in Europe. We’re talking about people who have no access to toilets, or only poor-quality toilets. A great deal still needs to be done in the whole process from human waste to safe sanitation. Our activities in this area are covered by the Protocol on Water and Health ratified by the Netherlands, on behalf of the Ministry of Infrastructure and Water Management and in close cooperation with the Ministry of Health, Welfare and Sport.”

In your opinion, what will it take to meet the targets?

“Do not seek solutions only in technical fixes, which often do not work at all, or only offer temporary relief. Invest in people’s knowledge as well. What makes water safety plans so powerful is that they work best if you get all sorts of people involved. My goal is to connect dossiers, domains and people. As messaged by WHO on this World Water Day 2020 everybody has a role to play. Wastewater exposure involves contact through air, touch or ingestion. That makes it important to take a broader perspective in finding solutions. As is exemplified in the current COVID-19 crisis. Among many other tools, a Technical brief was developed by WHO on Water, Sanitation, Hygiene and Waste Management for COVID-19 to which our WHO CC has contributed. This approach is fully in line with the multidisciplinary work at RIVM. It brings us closer to what we want to achieve: clean, safe water for everyone, even in a changing climate.”