11 MUST-READ PAGES OF GOOD HEALTH
As a top scientist warns of the potential health timebomb from drugs washed down drains . . .
THERE’S something in the water and Professor Michael depledge, one of the UK’s leading scientists, has an earthy explanation for how it got there. The ‘something’ is the broad range of medicines we ‘pass’ via the loo into the environment and, indirectly, into our drinking water — from heart drugs to depression and hormone pills.
‘We are being exposed to a growing number of chemicals, and mixtures of chemicals during our increasingly lengthy lives,’ the former chief scientist at the Environment Agency told Good health.
‘Low concentrations of highly active pharmaceuticals and pharmaceutical residues are being excreted into sewage works, where one would hope they would be broken down into harmless substances. But in fact they are not,’ says Professor depledge, now chair of environment and human health at Exeter University medical school.
Some drugs found in water supplies are more worrying ‘because of their potential to affect wildlife or people’, said a report published this year by the Royal Pharmaceutical Society. It identified antibiotics, antidepressants, anti-inflammatories and painkillers, beta-blockers, oral contraceptives and hormone replacement therapies as the worst culprits.
Traces of many of these drugs find their way into the sewage system through our urine, but it’s not the only way medicines get into water supplies.
Some have been found downstream from pharmaceutical plants, while drugs such as antibiotics given to farm animals can find their way into lakes and rivers.
NEVER PUT TABLETS DOWN THE LOO
UNKNOWN amounts of unused drugs are also disposed of down our loos every day, even though the NHS says they should be returned to pharmacies for safe disposal.
But are the drugs in our water doing us any harm? The worrying answer, says Professor depledge, is that no one really knows. ‘ Most of this debate has been conducted in a sea of ignorance,’ he told Good health.
however, there are growing fears that while, say, your morning cuppa might not prove fatal, the build-up of chemicals in our bodies could be responsible for many of the health problems that plague us as we grow older.
And now a Un body — which represents countries, the drug industry and other non-governmental groups — has just passed a resolution that for the first time recognises ‘ environmentally persistent pharmaceutical pollutants as a new emerging policy issue’ that demands greater understanding.
In its report prepared for the International Conference on Chemicals Management in October, the watchdog’s officials warned that such drugs were already found in water all over the world, and ‘may pose a threat of important magnitude for public health’.
FISH AND CROPS CONTAMINATED
EVIDENCE that these drugs can have a serious impact on the environment and wildlife can be found in research dating back more than 30 years. Anglers fishing near a sewage discharge pipe in north London on the River Lea, which joins the Thames, noticed that roach they were catching were ‘intersex’ — neither male nor female.
The culprit was natural and synthetic oestrogens used in the Pill. Since then, many more examples have been found around the world affecting other fish. A study published in the journal Science in 2013 reported that concentrations in water of the anti- depressant oxazepam altered the behaviour of wild perch, causing ‘increased activity, reduced sociality, and higher feeding rate’.
As recently as April this year, a study by the University of Wisconsin-Milwaukee found that metformin, a common treatment for type 2 diabetes, now found in freshwater systems around the world, was stunting the growth and changing the sex of fish in Lake Michigan.
And it’s not just fish. Antibiotics given to humans and animals can travel from water supplies to the soil, and have been found to restrict growth, prevent germination and even kill off a range of plants and crops.
A 2011 study by Germany’s Federal Environment Agency reported that the antibiotics enrofloxacin, used on animals, and ciprofloxacin, prescribed for respiratory infection in humans, were toxic to various freshwater plankton and plants. In 2012, a lab study at the University of Padova, Italy, found sulfadiazine, an antibiotic used to treat urinary infections, accumulated in maize plants, killing them off.
ARE WE AT SERIOUS RISK?
WHILE we are unlikely to suffer the same fate as sex- changing fish, says Professor depledge, equally disastrous problems could be heading our way.
A worrying example, he says, is the rise of antibiotic-resistant organisms, caused by the over-use of antibiotics. In 2011, the chief medical officer Sally davies predicted that by 2050 ten million people worldwide would be dying every year from infections associated with such bugs.
Professor depledge and his colleagues at Exeter are looking at whether antibiotics in the environment are capable of producing antibiotic-resistant bugs which can then infect people.
Any such bugs ‘may not cause an immediate problem’, he says. ‘But they may be living within and on our bodies for years — until you get a disease that suppresses the immune system, such as cancer, and that’s when you run into problems.’
And, he says, with an ageing population, the problem is only going to get worse as many more people will be taking drugs to treat conditions such as diabetes, cholesterol, high blood pressure and cancer.
‘These chemicals aren’t killing us,’ he says. ‘But are they influencing the kinds of illnesses we live with as we get older and older? Are there going to be more people living with diabetes, neurological disorders, all the things that higher body burdens of chemicals may be contributing to?’
The story of the Oriental whitebacked vulture may prove salutary. In 2004, the reason this bird was dying in large numbers in India was found: they were eating carcasses of animals treated with a veterinary version of the drug diclofenac, a non- steroidal antiinflammatory or painkiller, and their kidneys were packing up.
Professor depledge says the fate of species such as the vulture should be treated as ‘a red flag, because what other pharmaceuticals are out there, wiping out stuff we don’t even know about?’
diclofenac is also widely used in humans — in 2014, it was one of the ten most commonly prescribed drugs in England.
A DANGEROUS COCKTAIL
IS IT in our tap water? Alarmingly, no one seems to be checking regularly. The regulator, the drinking Water Inspectorate (DWI), has looked at drug residues in water just twice in the past eight years.
The first investigation, in 2007, was a ‘desk-based’ review of current research, so no new samples of water were taken for analysis. The review concluded that, in view of ‘the dearth of measured data’ on concentrations of pharmaceuticals in UK drinking waters, ‘it would be prudent to carry out a small-scale survey’.
That was undertaken in 2011, when samples were taken from just four sites in the UK ‘expected to be at high risk’. Exactly where these sites are has not been disclosed.
Two of the study’s authors told Good health they were ‘ not allowed’ to name them. There are more than 3,000 active pharmaceutical ingredients in use in the UK — the Inspectorate looked for traces of only 17 drugs, chosen partly because they were in common use.
diclofenac was one and was found in rivers and reservoirs — ‘source water’ — at the sites, along with nine other commonly prescribed drugs, including atenolol, a betablocker used to treat angina and high blood pressure; furosemide, a diuretic; and trimethoprim, an antibiotic for bladder infections.
One of the scientists who conducted the study told us that they were ‘pretty confident’ the diclofenac results would be echoed across the country.
Four other drugs among the 17 were detected in source water and drinking water, although usually in lower concentrations. These were benzoylecgonine, a prescription painkiller; carbamazepine, for epilepsy and pain; ibuprofen and anti-inflammatory drug naproxen.
The report’s conclusion seemed reassuring. Because concentrations of the drugs in drinking water were much lower than doses prescribed to patients, their presence ‘[does] not pose an appreciable risk to
human health’. But there was a major caveat. Admitting this comparison was ‘a very simple approach’, the authors said that ‘more detailed evaluation of the toxicological risks’ was needed. Such a study, they said, should also recognise ‘the exposure will be long-term and that consumers will be exposed to a mixture of substances in their drinking water’.
This is the ‘cocktail’ effect — where combinations of drugs may have an effect where each drug separately would not.
The follow-up to the Inspectorate’s study, carried out last year by environmental consultants Ricardo Energy & Environment, appears not to have addressed these two critical issues. It looked at only the four drugs in the 2011 report. It, too, concluded there was no ‘appreciable risk to public health’.
UNCLEAR EVIDENCE
ON THE surface, the Government, water companies and pharmaceutical industry all seem pretty relaxed about the issue. On its website, industry body Water UK admits that ‘pharmaceutical residues may be found in very low quantities in water used as sources for drinking water’, but says the levels are ‘hundreds of thousands of times below human therapeutic doses’.
The Association of the British Pharmaceutical Industry (ABPI) told Good Health the Drinking Water Inspectorate had ‘concluded that any appreciable adverse health impacts on human health . . .are extremely unlikely’, adding ‘there is no evidence of population level effects in fish in the environment that can be solely attributed to pharmaceuticals’.
Its evidence? A paper published last year in the Royal Society’s journal Philosophical Transactions, which states that, with ‘the literature on pharmaceuticals and fish . . . dominated by laboratory and caged fish studies’, the risk to fish populations ‘remains hypothetical’.
But it warned that the ‘apparent absence of evidence’ for damage to fish populations from pharmaceuticals ‘should not . . . lead us to complacency’. The authors say: ‘The evidence may be there, but we have not collected it in a systematic way’.
631 ROGUE CHEMICALS
WORRYINGLY, they also reported that no one seems to be taking into account the combined effects of cocktails of drugs.
And if there really is nothing to worry about why, as the Department for the Environment, Food and Rural Affairs (Defra), revealed, are water companies ‘reviewing the levels of pharmaceuticals at water treatment works to develop an understanding of what the situation is’?
Defra is also ‘doing some research to consider the social and economic impact’.
The drugs industry body, the ABPI, says: ‘The substantial safety margins involved with these products mean that even with a doubling of the human population and usage, the risk of any adverse impact on drinking water which would be harmful to humans would still be extremely low’.
But that’s not how the UN’s International Conference on Chemicals Management sees it. Its October report on research findings from 71 countries identified 631 different chemicals detected in the ‘aquatic environment’, including antibiotics, painkillers and statins. The most common drug was diclofenac, the vulture killer.
And while concentrations of chemicals might now be low, added the report, ‘they may persist for long periods of time, contributing to chronic and persistent exposure’.
WHAT CAN BE DONE?
THE technology to clean up waste water exists, says Professor Depledge, ‘but it increases the cost of sewage treatment’.
What is needed now, he says, is for the Government ‘to take a longer term view of emerging problems’. But he warns: ‘This problem is likely to become worse and worse, gradually and insidiously.’