This week, myHSN welcomes a crucial and timely blog from guest author Dr Michael Chadwick, who explains the potential consequences of droughts in the UK on human health. Michael is a Senior Lecturer in Physical and Environmental Geography at King’s College London.
What?
Weather conditions this summer have been unusual to say the least. We have had record temperatures and below-average rainfall across much of the UK. A quick look at any news feed will demonstrate how these conditions are affecting the UK. For example, hosepipe bans are being put in place in many areas and there have even been unprecedented wildfire outbreaks. Current conditions are worrying for a range of reasons, but what are the implications for our rivers, and are there potential knock-on effects for public health?
Why?
Droughts have several obvious effects on the environmental conditions of rivers. Reductions in rainfall cause river flows to slow and, in some cases, even result in dry channels. However, in the UK the natural phenomena linking rainfall, groundwater and river flows are complicated by our reliance on related ecosystem services1. For example, water is abstracted to provide drinking water and rivers receive effluents from wastewater treatment plants. Sustainable rates of abstraction and release of wastewater effluent are linked to available water. Droughts complicate these processes and can have implications for both ecosystem and human health.
In terms of water supplies, over abstraction is problematic as it drives rivers towards conditions which would not occur naturally. In extreme cases, rivers can stop flowing and extended areas can be dewatered. Implications to aquatic life can be catastrophic and long lasting2. To prevent these issues, both rainfall and river flow conditions are monitored by the Environment Agency and weekly summaries are produced3. Additionally, DEFRA (the Department for Environment, Food and Rural Affairs) is reviewing water abstraction plans to put measures in place to stop ecologically damaging activities4. In terms of human health, abstraction for drinking water is highly regulated and water companies are legally required to produce ‘wholesome’ water, which simply means suitable for human consumption.
How (does it affect you?)
Reductions in abstraction can lead to supply issues, which can prompt hosepipe bans to reduce non-essential water use. Of course, drought conditions extended over the long-term may also raise issues related to food production and food security5.
In terms of surface water quality, reductions in river flows reduce the assimilating capacity of surface waters receiving wastewater effluents. This means that pollution is concentrated in a small volume of water, resulting in increased bacterial loads and an elevated risk of getting sick with exposure (a case which was recently reported for the River Medway in Kent6). In fact, only two locations are currently designated as Bathing Waters in England7. Essentially, most of England’s rivers are not fit for swimming during normal conditions due to sewage and the current reduced river flows exacerbate this problem. Algal blooms driven by concentrated nutrients can also give rise to health issues ranging from skin rashes to diarrhoea8. Unfortunately, although beating the heat by cooling off in a local river may seem appealing, it is not recommended!
Overall, when considering the potential ranging of human health implications associated with drought9 risks are currently quite low and avoidable in the UK. However, risks to environmental quality are much more pressing and considerable attention is needed to address and reduce drought-associated threats to our already degraded river ecosystems.
As always, best wishes from myHSN!
You can find out more about the author here:
Michael Chadwick ([email protected])
Supporting Information:
1. Ecosystem services are benefits related to natural processes and include things like the purification of water and air (regulating services), production of food and drinking water (provisioning services), the enjoyment of natural areas for a range of activities (cultural services), and other a range of other functions which allow for the continued stability of ecosystems (supporting services). For more information see: http://uknea.unep-wcmc.org/EcosystemAssessmentConcepts/EcosystemServices/tabid/103/Default.aspx
2. https://theriverstrust.org/key-issues/drought
4. https://www.gov.uk/government/publications/water-abstraction-plan-2017/water-abstraction-plan
5. https://www.france24.com/en/europe/20220721-heatflation-how-high-temperatures-drive-up-food-prices
6. https://inews.co.uk/news/wild-swimming-polluted-river-hospitalisation-pain-1765566
