What impact do seas, lakes, and rivers have on people’s health?

New research has found that ‘blue space’ including sea, rivers, lakes, and even urban water features can have a positive impact on wellbeing, writes Tim Smedley

canal walk
The impact of water on health: new research suggests that ‘blue space’ can reduce stress and have a positive effect on wellbeing. Photograph: David Levene for the Guardian

Most of us recognise the calming effect of a walk by the river or along a beach. Victorian doctors used to prescribe the “sea air” as a cure for an assortment of agues and ailments. But while the health benefits of green space are now well known, thanks to the pioneering research of Roger Ulrich and the Kaplans among others, little analysis has been made of “blue space” – the impact of the sea, rivers, lakes, and even urban water features on our health and wellbeing.

On Devon’s south coast, Professor Michael Depledge and his team are attempting to put that right. Depledge was formerly the chief scientist for the Environment Agency before founding the European Centre for Environment and Human Health (ECEHH) in Plymouth in 2011 and launching the Blue Gym project in 2012 to study the health and wellbeing benefits of aquatic environments.Advertisementhttps://dda381fadf7de591ada367c2e8823da5.safeframe.googlesyndication.com/safeframe/1-0-38/html/container.html

Teaming up with environmental psychologist Mat White, Depledge began by repeating one of Ulrich’s early studies. By showing photographs of a variety of landscapes to a group of participants, Ulrich was able to demonstrate that stress levels were lowered according to how much greenery was in the picture. The difference this time was that “we started introducing water into the images”, says Depledge, “going from a pond right through to a coastline, with increasing amounts of water in the images, and we found that people showed a strong preference for more and more water in the images.

“We repeated that with urban scenes, from fountains in squares to canals running through the city, and once again people hugely preferred the urban environments with more water in them.”

Images with green space received a positive response, as Ulrich has found. But images with both green and blue got the most favourable response of all.

This was enough to suggest that they might be on to something and their next study, published in September, was more conclusive. Using data from Natural England with anonymous self-reported health information by postcode, a team from ECEHH were able to see if health varied according to proximity to water.

“Self-reported health correlates very well with real health,” says Depledge. “For the first time, we have had this information according to postcode, and we found that the closer you live to the English coast the healthier you are. There was some evidence that other aquatic environments helped too.”

Future research at the ECEHH includes studies looking at the effect of video screens showing aquatic environments in elderly care homes, and the benefits of views over sea or water from home or hospital windows. PhD student Deborah Cracknell is also looking into the effects of watching fish in aquariums and tanks. “There have been studies in the past looking at the health benefits of fishtanks, often in healthcare settings for Alzheimer’s patients or the elderly, says Cracknell.

“But we’re also looking at the effect of what’s in the tank, from a biodiversity aspect … We’ve looked at the effect of [aquarium] exhibits on heart rate, blood pressure and mood. Early results are quite encouraging. We even found that people responded well just watching the water without any fish.”

All of which prompts the question, why? Just what is it about water that attracts us in such a way that could improve our mental wellbeing and even our physical health? “The simple answer, is we don’t know,” says Depledge, “but we are trying to find out.”

“There are all sorts of intriguing possibilities. One is that human beings have evolved in intimate contact with nature, and it is only really in the last 200 years that people have been increasingly removed from nature. Professor Sir Alister Hardy first suggested that the big step in human evolution was not necessarily when hominids came out of the trees and into the savannah but was when they got to the coast and were able to access seafood rich in omega 3 fatty acids … there is something deeply profound about water and humans, and it may reflect evolutionary history.”

Someone else who is trying to find the answer is Jenny Roe, lecturer in the School of the Built Environment at Heriot-Watt University in Edinburgh. At the forefront of research into “green health”, Roe is looking at cortisol as a physiological measure of how the body responds to different environments.

“We’ve also just published a study using a mobile neural cap which taps into brain activity and can give an objective measure of stress in different [green] environments,” Roe says. “But ‘blue health’ really lags way behind – it has started a bit like green health did, with laboratory experiments using photographic images and there’s nothing wrong with that, but we’ve got other methods now, and that’s what we’re keen here in Scotland to press on with.”

Roe highlights the potential for geographic differences. “It does require geographic studies in specific climate zones to tease out whether the effect of water is as great under a cloudy sky as it is in sunny climes. The southwest of England is very different climatically from a country like Scotland.

“For me, [the research] needs to ground itself in issues of climate change. Our scoping study looked at the psychological trauma of living in a flood risk zone and the effect on very vulnerable populations so it’s not just the positive, health-improving benefits of being close to or having access to water, it’s also about how we manage that water flow and how we use sustainable design strategies to minimise the risk of flood-damaged communities.”

Both Roe and Depledge are keen to look at the impact of water within urban environments too, with potential practical applications for planners and developers. Depledge argues that “we have spent a lot of time putting green spaces into urban environments – and 85% of the UK population now live in urban environments – but are we paying any attention to designing in blue space?”

She adds: “I think water features, in general, are beneficial; fountains in cities, ponds in parks … Birmingham restored the canal running through the city, and that has been hugely successful.”

Roe also cites Sheffield and Manchester as cities that have introduced popular water features to their city centres with potentially regenerating effects.

There is also the prospect of economic benefits. Both ECEHH and Heriot-Watt University are enlisting the help of health economists to understand the cost benefits of access to green and blue space if the benefits effects are such that they reduce GP visits. It’s a tantalising prospect, but there’s a long way to go.