‘Hi Dear, Someone at Work Said the Lateral Flow Tests Cause Head Cancer?’

Zak Muggleton-Gellas, Year 2

According to recent governmental guidelines, and compliant with the University of Leeds guidelines, LFTs play an integral role in COVID-19 spread prevention. But, contrastingly, as suggested on social media, LFTs can have carcinogenic effects. From a personal standpoint, this ideology was presented as an innocent message from a family member, and this article was born from the research that was carried out to obtain an informed and unbiased response. Anti-vaccinators and COVID-deniers are topical communities in the current climate and therefore are used as ammunition against the governmental guidelines to protect against covid. Statements such as these, to members not included within the scientific community, can be scare-mongering and potentially lead to unnecessary exposure to the virus. One could additionally theorise that it can cause the scientific community to become neglectful, as individuals who support the government become resistant to research any opposing claims, and the NHS are under scrutiny. There is a duty to research these claims, specifically after the thalidomide crisis (Kim, 2011). 

Ethylene oxide has been used for over 60 years, in the hospital environment, as a device to sterilise medical equipment (Mendes et al, 2008). It is a colourless, odourless gas that is used in various cosmetic products. This includes being noted on the back of LFTs for sterilisation of the equipment used (BCPP, 2021). A Facebook user posted a video stating that, due to this sterilisation, the cotton buds used in the test kits cause encephalitis, endocrine dysfunction (neuroendocrine tumours), leukaemia, breast cancer and lymphoma (Reuters Fact Check, 2021). While there is significant evidence that ethylene oxide is a carcinogen (Vincent et al, 2019), and there has been increased breast cancer incidence in female factory workers producing the chemical as well as hospitals (BCPP, 2021), the presence of the gas in the sterilisation process does not pose a harmful risk of cancer to LFT users. Specifically, there is no found evidence that it can lead to brain – it can be interpreted the comment did not refer to other parts of the head – cancer. 

As a basis, sterilised devices undergo preconditioning and humidification, gas introduction, exposure, evacuation, and air washes (Reuters Fact Check, 2021), with several chemicals to wash that include hydrogen peroxide, chloride dioxide, ethylene oxide (FDA, 2021). The objective of the evacuation and air washing section of the process is to remove the harmful chemicals, such as ethylene oxide, from the equipment, before use. In addition, the amount of ethylene oxide decreases to below measurable levels after 3 weeks and is monitored to be below dangerous levels by the International Standard Organisation (ISO). As well as this, the low risk of exposure can be categorised by the limited contact (about 20 seconds per test) and the contact only being the throat and nasal passage (GovUK, 2021). Users can therefore be reassured that it would take 40 year of testing, two times every week (or 4,160 tests with no deviation from that schedule) to be placed into a high-risk category for ethylene oxide exposure. 

Overall, as supported by a freedom of information request answered by the government (GovUK, 2021), the claim stating that they will cause cancer is factually incorrect, and that this harmful claim is not to be taken into the NHS’ consideration when advising others on how to test for covid. They will continue to be an accessible method of testing, as we work globally to find guidelines that decrease the cases in our population. 

References

Kim JH, Scialli AR. Thalidomide: the tragedy of birth defects and the effective treatment of disease. 2011. [Online]. [Available at: https://pubmed.ncbi.nlm.nih.gov/21507989/].

Cunha Mendes GC, da Silva Brandão TR, Miranda Silva CL. Ethylene oxide potential toxicity. 2008. [Online]. [Available at: https://pubmed.ncbi.nlm.nih.gov/18452382/].

BCPPL. Ethylene Oxide. 2021. [Online]. [Available at: https://www.bcpp.org/resource/ethylene-oxide/].

Reuters Fact Check. Fact Check-Lateral flow tests do not cause cancer; ethylene oxide sterilisation is a widely-used process that is regulated by international safety standards. 2021. [Online]. [Available at: https://www.reuters.com/article/factcheck-ethylene-oxide-idUSL1N2LO1YM]

Vincent MJ, Kozal JS, Thompson WJ, Maier A, Dotson GS, Best EA, Mundt KA. Ethylene Oxide: Cancer Evidence Integration and Dose-Response Implications. Dose Response. 2019. [Online]. [Available at: https://pubmed.ncbi.nlm.nih.gov/31853235/ ].

FDA. 2021. Ethylene Oxide Sterilisation for Medical Devices. [Online]. [Available at: https://www.fda.gov/medical-devices/general-hospital-devices-and-supplies/ethylene-oxide-sterilization-medical-devices].

GOVUK. Freedom of Information request about the safety of ethylene oxide (EO) and its use to sterilize the swabs used in lateral flow tests (FOI-21-294). 2021. [Online]. [Available at: https://www.gov.uk/government/publications/freedom-of-information-responses-from-the-mhra-week-commencing-19-april/freedom-of-information-request-about-the-safety-of-ethylene-oxide-eo-and-its-use-to-sterilize-the-swabs-used-in-lateral-flow-tests-foi-21-294]