Why are we still allowing our nurses to be exposed to bioaccumulation?

(1129 words) Published Sept ’22, Updated May ’23

‘Sustainability’ is a growing theme across all areas of clinical treatment – but what impact does it have on the daily lives of front-line staff, especially nurses? Here, Simon Davies, founder of CleanCert Hygiene, continues his ‘Green Solutions’ series, focusing on how eco-friendly products minimise environmental impact today, whilst delivering higher performance.

Wikipedia defines biomimetics as “the emulation of the models, systems, and elements of nature for the purpose of solving complex human problems”. Some of the most ubiquitous technologies in the world today mimic nature to achieve their success. By copying the formation, structure, or function of living organisms, biomimetics synthesise similar products and systems using artificial means. One biomimetic compound increasingly used in dentistry and hospitals (hypochlorous) is not only inspired by nature; it also helps to protect it.

Velcro fabric is one of the oldest and most widely used biomimetic technologies. Its inventor, George de Mestral, was inspired to create it after studying the prickly plant burrs that clung to his dog’s fur. Other examples include the blades of wind turbines, which mirror the aerodynamic efficiency of humpback whale fins, and a recently approved surgical glue based on the secretions of the Californian sandcastle worm. Many biomimetic products are inspired by plants, including water-, oil- and fat-repelling sprays, coatings and sealants that copy the nanoscale surface of the lotus leaf.

Overcoming the challenges of bioaccumulation

Clinical staff and nurses in particular are asked to handle disinfectants many times each day, hence need to be aware of the latest evidence around environmental impact.

One of the ways in which the disinfectant chemicals we use damage the natural world and living organisms is through the process of bioaccumulation. This is where contaminants and chemicals dissolve into water, evaporate into the air and mix into soils, whereby they are ingested or absorbed by plants and animals. In high enough concentrations, certain contaminants can build up and accumulate in the tissues of living things- aka bioaccumulation¹. Often crucial bioaccumulation data takes a long time to build up, by which time the products have become normalised through frequency of exposure.

The problems with quats in particular

Humans have a questionable record when it comes to their choices of disinfectants. In Italy in the 15^th century, mercury derivatives were used to combat an outbreak of syphilis. ² Mercuric chloride was still being used as an antiseptic in the late 1950s, before suggestions that exposure to it was dangerous for humans. We now know, of course, that mercury is highly toxic and can bioaccumulate in humans to cause serious long-term health risks.

Another group of modern chemicals, known as quaternary ammonium compounds (QACs or quats), are one of the most widely used disinfectant molecules that we have been using since the early 20^th century. Their antimicrobial properties mean they are widely used in clinical treatment, found in surface disinfectant wipes and sprays. In dentistry they are found  in composite resin, adhesive systems, acrylic resin, glass ionomer cement and endodontic materials. Across all these applications, QACs play an important role: they promote antimicrobial activity, decrease bacterial attachment in the enamel and prevent biofilm accumulation. But increasing evidence is pointing to emerging risks and since 2016, the use of QACs in consumer hand and body washes throughout the European Union has begun to be limited.³

These chemicals have been detected in wastewater, surface waters, and sediments. ⁴ They have been shown to reduce fertility in male and female mice. ⁵ Research published earlier this year found QACs in human milk for the first time. ⁶ The researchers concluded that this represents potential risk to babies, warranting further research on the toxicity of QACs and their effect on human health. The repeated use of QACs has been shown to result in them bioaccumulating in human blood, ⁷ with levels appearing to increase as a result of heightened disinfectant use during the COVID-19 pandemic ⁸. Another concern worth mentioning here is that bacteria are becoming resistant to QACs, with some biocides also appear to be inducing resistance to QACs.⁹

Non- bioaccumulative products are available now!

Innovative ways to use products with safer and more sustainable chemicals – often those that mimic nature – have environmental benefits, including being non-bioaccumulative to staff and patients. The added bonus is they can be even more powerful (shorter contact time) than their toxic competitors.

One disinfectant biomimetic is produced by the white blood cells of the human immune system in response to infection – and is called hypochlorous. It can eliminate biofilms and free-floating viruses, bacteria, and fungi more effectively than bleach. It has been independently verified as effective in destroying SARS-CoV-2, the novel coronavirus that causes COVID-19. HOCl is used in different formulations for a number of human (oral, skin,ocular) and clinical surfaces (water, medical devices etc) at CleanCert Hygiene (CHL)- both as medical devices and biocides.

This naturally occurring substance is completely non-cytotoxic, non-mutagenic and does not cause reproductive toxicity. It does not irritate the mucosa, skin or eyes and can even be swallowed without causing harm (up to 7500ml). As a result, clinical staff do not need to use personal protective equipment (PPE) to handle the products, making them perfect for immediate use by front line clinical staff today.

SteriDerm skin disinfectant (100ml, 250ml, 1L & 5L), CleanCert waterline disinfectant (5L), OptiZil surface cleaner (1L spray and 5L), OraWize+ mouthwash (250ml, 1L & 5L)

For further info, email sales@cleancert-hygiene.co.uk or visit www.cleancert-hygiene.co.uk

References

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5. Melin et al. 2016. Quaternary ammonium disinfectants cause subfertility in mice by targeting both male and female reproductive processes. Reproductive Toxicology 59:159-166.
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