Introduction.
Amongst the many issues that the Trust has been involved with over the last twenty eight years the issues of pharmacological pollution, the waste often of hospitals and large conurbation medications has been high on the list of our desires to find affordable solutions. Residues of medical drugs and synthetic organic compounds, such as herbicides, that are found in small concentrations in rivers but affect endocrine activity, metabolism, and development in humans, other mammals and birds. This outweighs the large volumes of waste illicit drug residues that enter the wider environment via the users’ bodies excreting it daily.
We have expended much time and energy looking at possible low tech low cost routes by which to channel the pills and potions that lessen or cure the illnesses, aches and pains of society whilst altering the chemistry of our rivers and seas.
It is a remarkable journey of faith. The answers, we have always known are there and in the past such as reverse osmosis have been expensive, too much so, plus involving chemically complex engineered solutions. Over the last nearly thirty years many organisations have been networking and experimenting. Delving in corners of the mind and finding obscure papers that might lead to answers.
The developing understanding of new methodologies of remediating much that is poisonous to our world using plants and natural processes, now known as phytoremediation (bioremediation) has drawn more and more attention to its nature and its vast array of possibilities. The principal that nature is able to cure itself has now allowed it to step into the mainstream and is no longer only the realm of ‘cranks and oddballs’.
The tabloid ‘silly season’ perennial story of fish changing sex has not been read for the last time but the writing is on the wall with regard to the reality that the answers are now in focus and in the realm of costs the solutions are not either expensive engineering or chemical dosing. The answer lies in the use of wetlands and light, preferably sunlight but artificial will suffice.
Currently, there are no US regulations for medicinal drugs under the Safe Drinking Water Act, and only a few for the residues from consumer products: in the EU regulation is equally sparse. However, the U.S. Environmental Protection Agency’s Contaminant Candidate List, which establishes what chemicals should be evaluated for possible regulation, in 2009 included several endocrine disruptors called estradiols, found in products such as birth control pills. The list also included erythromycin, an antibiotic. The European Commission placed two types of estradiols and a painkiller called diclofenac on a similar watch list in 2013. In the UK the Environment Agency and previously the National Rivers Authority were concerned that estrogenic materials and their mimics were gaining a growing and significant role in the pollution of rivers in England and some Welsh and Scottish rivers. UK research has for thirty years outlined many of the problems and the plethora of sources.
In the UK as in Europe the national agencies felt and still do feel powerless till some independent agency found a solution the costs of which could not be used as an excuse to duck out of taking responsibility for the clean-up of such pollutions. The polluter pays principal allowed for debate as to who might foot the bill; sewage treatment companies, pharmaceuticals companies, the NHS (UK) the consumer with a levy on each drug prescription. Even if a fiscal formula might be acceptable the methodologies had to be assessed for value for money and efficacy.
Clean Rivers Trust has been working at the centre of this set of debates and encouraged research by industry and academics to delve into any idea that raised its head. Willows take up the acetylsalicylic acidthat is the small but effective active ingredient that is used in Aspirin tablets and was found originally in willows, though now for more than 100 years produced synthetically (Wood H 1998).
Issues.
As already mentioned fish changing sex has perennially amused the UK tabloid press. The reality is that male trout and other fish have been found by anglers to have developed female genitalia and research including that carried out by the University of Hull (1995/6) demonstrated that this was brought about by increases of estrogen in their body mass.
Research.
One of the early indications that constructed wetlands could help treat pharmaceuticals and other synthetic contaminants came from a study of nonylphenol, which is widely present in laundry detergents. Nonylphenol is an endocrine disruptor and has been shown to have potent toxicity in fish. When a research team led by the USGS was testing the ability of a small-scale wetlands system outside of Phoenix, Arizona, to diminish nitrogen levels in the wastewater treatment effluent, they noticed that nonylphenol and its breakdown products were also reduced, some by 90 percent.
In the last few years work has begun in this area led by several research groups and in the last few months their findings are being made known.
Research carried out at Yale University (US) outlines research showing the breakdown of many pharmacological active treatments are captured in reedbed and wetland sewage treatment facilities. The list of drugs being extensive and including the most common estrogenic manipulators plus antibiotics, pain killers and tranquilisers. Such methods have also been found to remove antibiotic pollutions both from human and animal waste streams.
Yale University Wetland lagoons in Arizona and California, US.
A smaller piece of research carried out at Wageningen Agricultural University in the Netherlands, demonstrates that Ibuprofen is removed from water into the tissue of Common reed(Phragmites australis). This mechanism the holds the active drug residue within both its stem and its rhyzomeshere.
Present Limitations.
Yale University have found that up to 95% of medical prescription drugs and pain killers and at worst 50% of the endocrine disrupters are removed from waste water flow from major waste water treatment works passing through reed/wetland schemes, and as much as 98% of others. The lower than 65% removal rate is not a failures as the probable reason for such low take up of some endocrine materials is likely to be water management issues related or the wrong species of aquatic or marginal groups of wetland plants being used. The use of Typha and Phragmites being almost universal in the US.
Clean Rivers Trust Actions.
The Trust is in contact with both universities cited above and others who we have long standing working relationships with. The work planned is to include:
- Sampling established UK wetlands that are tertiary treating city scale waste water discharges.
- Trial a range of plant and tree species that are possible partner plants to be added to the present US reed bed flora, this being to raise the rate of removal and broaden its range of chemical absorption. The need to diversify plant species allows for unforeseen species die off.
- Raise funding for trials in the UK.
Harvey Wood July 2018.
