The fairly depressing picture of pesticide pollution in British rivers

6 September 2013 by Stephanie Swift, posted in Conservation, Ecology, Science

Lots of pesticides – such as the organochlorine insecticide, DDT – that were widely used in the fairly recent past are now banned after having serious effects on the health of humans and other species.

Yet old and new pollution of rivers and streams is still an issue across Europe, since waste water treatment practises don’t remove potentially harmful substances like pesticides, toxins, synthetic hormones and pharmaceutical drugs.

One team of researchers wanted to assess the levels of contaminants and the state of river recovery across 33 rivers in South Wales, UK, that were badly polluted in the past. To do this, they sampled toxin levels in the eggs of the Eurasian dipper (Cinclus cinclus), a waterbird that is well known to act as a pollution bioindicator.

They found that eggs from urban areas contained higher levels of modern pollutants, like toxic PCBs and PBDEs, while eggs from rural areas had higher levels of old agricultural pollutants, such as the pesticides DDE (a breakdown product of DDT) and dieldrin.

When the team compared current pesticide levels with those recorded 20 years ago, there was little or no reduction, and the concentrations of some pesticides – such as HCB and lindane -  had actually increased to levels high enough to affect bird development.

This research indicates that British water wildlife is not being properly protected by current legislation governing levels of toxic substances in rivers, and a new approach to water security is badly needed.


2 Responses to “The fairly depressing picture of pesticide pollution in British rivers”

  1. Reply | Permalink

    This is the sort of thing that needs as much publicising as possible. I read that you are not British so it might be hard to call, but are there any solutions you have in mind for these problems, from your perspective? I'm in the dark.

    • Stephanie Swift Reply | Permalink

      Hi TrueEfficiency!

      Thanks for your comment! And what a tricky question you have posed.

      For me, it would seem like a good plan to remove contaminants and pollutants as the water flows through water processing plants. Filtration strategies to remove synthetic hormones that otherwise feminise fish, and remove chemicals (drugs, pesticides, toxins) that are otherwise environmentally hazardous would be an excellent start. There would be a substantial cost to this, but I think the ladyboy fish (disclaimer: not a real species) would thank us.

      Of course, that doesn't deal with the problem of chemicals lurking embedded in the environment, rather than flowing freely suspended in the water. These sedimented hazards often leach out slowly, and how to deal with those is a tricky question, especially seeing as though pesticides - albeit mild ones compared to DDT - are still frequently used today. Better minds than mine might be needed to solve that dilemma.

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