Drug residues from wastes – the impact on the environment?

tablets and capsulesThere is much debate surrounding the impact of pharmaceutical residues on the environment, and appropriately regulators are looking at control and remediation measures.

But as we know, that goes off at a sharp tangent when regulators fuss about a few stray tablets, an empty blister pack of empty syringes from clinical wastes and it has been a common complaint on the Clinical Waste Discussion Forum that such reasoning is scientifically invalid, ignoring as it does the major impact from the excreted does which we pass into the sewage system without any real expectation of effective treatment.

Regulators misuse data concerning data which demonstrate residual drug levels in natural and drink waters, seeking to make a link to those resides from this particular fraction of our waste. By ignoring the bulk of the dose which is ingested and excreted, from drugs used in hospitals and other prescription medicines such as oral contraceptives prescribed by GPs and health clinics, by ignoring the need for better community drug collection facilities and take-back schemes, and failing completely to consider over the counter products that can have the same environmental impact but which escape regulatory control, regulators fail to address these issues at our peril. For we will all face the implications of pharmaceuticals in the environment, whatever they will be.

Of particularly great concern is impact of antibiotic residues in wastewater, with the observations that these may be associated with the further development of antibiotic resistance. We might receive a prescription for a relatively straightforward infection, say ciprofloxacin tablets 500 mg orally twice daily for 7 days. Thus 7 grams of ciprofloxacin ingested and excreted in urine, with the most tiny amount left in a plastic pill bottle that might be tossed into domestic waste. Of course, that isn’t a problem, but toss it into an orange sack as clinical waste and there will be questions asked, about source segregation but also the impact of that minor residue that might be detected only with the best of forensic micro-analysis.

Sometimes, the impact of more obvious, since any drugs administered to farm animals for the purposes of husbandry and stock management will pass straight to the environment and bypass even the sewage disposal system that we inherited from the Victorians. Today’s BMJ carries a really nice discussion piece, where two authors go head to head with opposing views about the implications of drug administration, largely as feed additives, to farm (food) animals. The debate is still out, but for those concerning themselves with the impact of trace drug residues in empty bottles and bags etc should read it, and ponder on the quantities of drug substance routinely given to the national herd as feed additives.

Where does it go? And what is the fate of the thousands of tonnes of prescription only medicines administered to man? And don’t forget all of those non-prescription drugs? And the cleaning products and disinfectants, antiseptics and other medicated products?

We must not overlook the impact of any source for environmental contamination, but prioritisation is both necessary and essential. Presently, the waste sector and the clinical waste subsector remains troubled by pettifogging over these minor drug residues that stifles development and increases costs unnecessarily. It is scientifically redundant, when attention might be refocused on more relevant issues that presently do not excite the same bee in the bonnet.


Wallinga D & Burch DSG. Does adding routine antibiotics to animal feed pose a serious risk to human health? BMJ 2013; 347: f4214 doi: 10.1136/bmj.f4214



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