The disadvantages and risks associated with disinfection
Resistance to disinfectants and antibiotics: Numerous studies show that widespread and inappropriate use of disinfectants can lead to resistance of pathogenic microorganisms to disinfectants and antibiotics; commonly termed ‘antimicrobial resistance,’ which is a significant threat to global health (Maillard et al., 2020; Osman, 2020; Ozkan, 2019; Shmerling, 2019; Günter, 2018; Sacha et al., 2018; Miniae et al., 2018; Kim et al., 2018; Carenco, 2017). The misuse of disinfectants would therefore make it increasingly difficult to eliminate pathogenic microorganisms, as the microorganisms can either acquire, or intrinsically generate, genetic elements that are resistant to the effects of antibiotics and disinfectants. These resistant genetic elements can accumulate, leading to multidrug resistant bacteria (Mc Carlie, Boucher & Bragg, 2020).
For example, a bacterial strain has become more than 200 times less sensitive to an antibiotic after being exposed to disinfectants repeatedly (Kim et al., 2018). The misuse of disinfectants can lead to their accumulation in natural environments. In these scenarios, microorganisms are exposed to less than lethal concentrations of disinfectants. This creates a selection pressure, whereby the microorganisms are able to adapt and develop resistance mechanisms that enable them to bypass the biocidal activity of the disinfectants (McBain, Rickard & Gilbert, 2002).
- False sense of security: Even if properly used, disinfectants cannot kill all types of pathogenic microorganisms, including certain bacterial spores, certain fungi, viruses and parasites (Andersen, 2019). Moreover, disinfectants only provide short-term efficacy (Schmidt, Fairey & Attaway, 2019; Frickmann et al., 2017, Attaway et al., 2012). In people’s minds, the disinfected surface becomes safe and free from microorganisms. This perception leads to a false sense of security and leads to the adoption of behaviors that can increase biological risk to our health.
- Massive pollutant load: The thousands of tonnes of disinfectants sold worldwide each year (in 2018, 821,000 tonnes of disinfectants were exported worldwide, with 890,000 tonnes imported [Global Trade, 2020]) eventually end up in the environment (McBain, Rickard & Gilbert, 2002). Many of these disinfectants accumulate in the environment, for example in soil (Bollmann et al., 2017; Chen et al., 2013), as natural microorganisms are unable to effectively biodegrade these biocidal components. These relatively persistent biocidal residues can react with organic matter in soil, water and air, to create highly toxic, carcinogenic and mutagenic compounds that accumulate in the food chain and water cycle, ultimately impacting humans (Surfrider Foundation Europe, 2020).
- Allergies: Evidence suggests significant links between the excessive use of disinfectants and the increasing number of allergies among Western populations (Koch & Wollina, 2014; Krauss-Etschmann, Niedermaier & Beyer, 2009; Petroglou et al., 2007). As such, quaternary amines are among the 8 main allergens among employees in the health sector (Shutty & Scheinman, 2017; Purohit et al., 2000; Bernstein et al., 1994).
- Health risks: The problems posed by the majority of disinfectants for the health of workers are well known, including lung irritation problems, skin corrosion and irritation, eye irritation, asthma, (Casey et al., 2017; Dumas et al., 2017; Fityan & Pees, 2013; Sato et al., 2004). Further to this, certain disinfectants, and the incorrect use of disinfectants, can produce gases that are severely toxic (for example mixing bleach with ammonia, which leads to the formation of chloramine compounds) (Kang, Lauf & Jordan, 2019).
Acknowledgement of source
Steve Teasdale – InnuScience