Delta Life 7

DELTARES, MARCH 2017 11 How can you convince policymakers about the size and urgency of the problem? 'In the West, we have distanced ourselves from water: we only need to turn on the tap. We hardly think at all about how it gets there. But your thinking about water changes radically when you have to use a river not only for washing and drinking, but for waste disposal and as a lavatory. In the meantime, the relationship between water and welfare are also becoming clear in the West. In Miami, for example, the sea level is rising because of climate change and floods are common there now so the city has to remove the salt from its drinking water! ’ Can you give us some examples of situations where human activities have impacted water and health in unexpected ways? 'Human actions always have unforeseen consequences. Positive, negative or both. I was involved once in an inter­ disciplinary study about harmful algae, the Florida red tide . From time to time, it blooms near the beaches, releasing a toxin called "brevetoxin" that works like teargas. Our research was meant to learn more about how these toxins work. In that way, we hoped to predict blooms better so that we could warn tourists when there was a risk. By coincidence, one of the researchers also found an anti- toxin, brevenal, that can tackle the symptoms of cystic fibrosis, which used to be an untreatable illness. On the one hand, then, there can be a positive relationship between water and health, but at the same time water exposes us to all sorts of dangers. Together we can chart those risks better.' Isn't it difficult to combine all those disciplines? 'It takes a lot of time and effort. I once stood on a beach for two hours talking to other researchers about the right term for a particular piece of beach we were studying. Eventually we agreed to the term swash zone . It's still not the right term but we all settled for a compromise. That's when I learned that we have to keep asking each other questions in order to understand each other better. And my questions have become simpler over the years.' Water, ecology and health are separate subjects at university. Is that a bad thing? 'Coming from a single discipline, you can't ask the right questions about complex issues such as the relationship between health and water. Let alone answer them. That's something I learnt early on in my career, when I conducted company inspections as a doctor. Inside the factory, people had to handle chemicals extremely carefully. But once outside, they could just dump the waste on the ground. The toxic chemicals seeped into the water system, contaminating the village nearby. We also have artificial boundaries in science. That's why we set up teams with people from different backgrounds. We work with microbiologists, economists, and epidemiologists: that produces new insights.' If you have no data about a location, where do you start? 'We are currently working on the EU Horizon 2020 BlueHealth project (bluehealth2020.eu ). Our aim is to produce the BlueHealth survey, a questionnaire for over 11,000 Europeans in eleven countries. We are going to ask people how they use water, where and for what purpose. These data will be combined in the future with information from meteorological institutes like the MET Office or research institutes such as Deltares so we can monitor the effects of interventions. Do they change biodiversity, promote algal growth, or lead to an increase in the number of surfers carrying resistant bacteria? It is about creating a starting point, a baseline that will hopefully allow us in the future to predict the consequences of large or small changes in our blue infrastructures.' What insight should be at the top of the agenda? 'In the seventies and eighties, we believed that hospitals were the main source of antibiotic resistance , but now we know that it is created much more in the natural environment. Medicines given to humans and animals find their way to the environment in urine and faeces. We are programming nature to tell it what microbes to evolve. It's Darwin, stupid! ' Are there insights that can help us now? 'The main thing is: it's not just about the risks, but also the possible benefits of water for our health and well-being. But how do you tell people that something can be good and bad at the same time? When we started researching toxic algae in Florida, the tourist branch was not happy. But later they realised that tourists never come back if they get rashes or breathing difficulties after swimming in the sea. Our study actually made it possible to warn people and provide them with alternatives so they could enjoy their stay and possibly even come back again. That's the type of study business likes to get involved in.'