Pharmaceutical residues from clinical wastes?

Regulators and those who follow on their every word continue to be exercised by the question of pharmaceutical residues from clinical wastes. Of course, bulk pharmaceutical wastes from the pharmacy department or drug manufacturing facilities must be managed with great care and their disposal must be properly controlled. There is, however, great confusion between this and the trace residues that might be present in soft clinical wastes and even in sharps bins filled with empty, or near entry, syringes.tablets and capsules

A recent conversation with colleagues in the US brought this issue once more to the fore. The proposal was that there exists serious environmental impact from empty syringes and the occasional tablet of IV bag in an orange (red) sack.

Taking this further, the conversation turned to the problem of scavenging of drug residues from clinical waste. When asked, that too was an environmental hazard since those drugs would end up in the environment, without control or proper disposal and treatment. The response perhaps bears repetition here:

 

Have you really swallowed the tale about the dire impact of drug residues from clinical wastes endangering the environment? That a few pharmaceuticals misappropriated from some insecure or unscrupulous waste management facility might precipitate environmental disaster? Or that outflows from domestic sewerage and/or solid wastes into which unwanted prescription drugs have been tipped will change the world?

Though it is no reason to ignore these sources completely, the impact is, without doubt, infinitesimally small when compared with excretion of the administered dose.

We cannot dispute that what goes in will come out, and actually quite quickly. On average, in excess of 95% of the administered dose of any drug is excreted unchanged, with some varying amount and range of metabolites. Half-lives change but most drugs begin to be excreted within a matter of hours and a single dose is usually eliminated within 24-36 hours.

We pass that into sewerage systems designed by Victorians to remove biological hazards but not pharmaceuticals. Yet when we find drug residues in natural water sources we get over-excited about a few street drugs and ignore the obvious.

Wastewater treatment processes are being considered for some hospitals, to reduce the burden of drug residues in their outflow. Quite right. But just why is this being done? Many regulators are taking the rather myopic view that this because hospitals are poor at segregation of pharmaceutical wastes. Yet they ignore completely, or simply cannot comprehend, that those same hospitals are full of patients receiving medications, defecating daily and urinating several times each day thus contributing a massive drug load to the sewer that conventional wastewater treatments cannot address. We make it worse still. Hospital staff are not immune from the need for drug treatments, from a simple cold remedy or painkiller, through to hormone-based contraceptives. And still regulators and those who hang on their words bang a drum for what are effectively the most minute contributions to the global environmental burden of pharmaceuticals, their metabolites and their degradation products.

To broaden the rather gloomy horizon still further, this is not restricted only to prescription pharmaceuticals but to OTC products also, though at least in the UK, and it seems elsewhere too, regulators cannot stretch their mind to this even greater pool of potential environmental contaminants but only to those prescription medicines defined by law and thus satisfying a naïve, or is it brainless, tick box mentality. Cleaning agents too, which though not considered in the same classes as pharmaceuticals share many similarities in biological and ecological impacts, in addition to more direct eco-toxicities.

Improvement in community wastewater treatment facilities may be advantageous, and particularly for outflows deriving from hospital ‘hotspots’. However, let’s not place blame squarely on the Victorian sewage treatment facility since globally many are lacking this basic public health resource and have to rely on cess pits, soak-aways or worse.

If that seems like a dipartite situation separating the have’s and have not’s, consider the veterinary and agricultural (livestock) use of pharmaceuticals . Globally, this is massive. It is largely unspoken as many developing countries use increasing but often undeclared amounts of drug additives to increase profitability in the global food markets.

At least some of us have the option to use a toilet. In the animal kingdom, mans intervention in the intensive livestock industries has not changed the inevitability of excretion directly to land.

Make your own mid up.

There should be concern about drug residues in the environment. When we stop over-prescribing, and curtail the sales of PTC (non-prescription) products, when we make arrangements for the collection of unwanted pharmaceuticals from households, when we stop passing out thousands of tonnes of pharmaceutical residues in urine, and start treating wastewaters accordingly, then there will be some significant reduction in the level of drug residue found in natural waters. The contribution from clinical wastes, and from drug litter, is infinitesimally small and regulators would do well to consider the science, and the logic, of the situation and divert their collective attention to the heart of the problem instead of making mischief around the periphery where their interventions will make little if any difference.

 

 

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