Microplastics and biofilms on clinical-use devices as an emerging occupational risk for healthcare workers: a systematic review and meta-analysis.

This project is a systematic review and meta-analysis carried out as part of a master's thesis in Occupational Health at Universidad Iberoamericana del Ecuador. It looks at microplastics and microbial biofilms on clinical-use devices as an emerging occupational risk for healthcare workers. Background and purpose: Healthcare work depends heavily on plastics and synthetic polymers, including medical devices, packaging, personal protective equipment (PPE), textiles and personal items such as mobile phones. These materials can shed microplastics and microfibres. Their surfaces also make it easy for microorganisms to attach and form biofilms. Biofilm-covered plastic particles may act as a "Trojan horse," carrying pathogens and antimicrobial-resistant organisms into the work environment and possibly onto workers. Microbial contamination of devices has been described before, mostly from an infection-control perspective. However, how microplastics and biofilms together expose healthcare workers has rarely been studied as an occupational health problem. This review aims to (1) identify and summarise the evidence on microplastic exposure in clinical settings, (2) estimate the prevalence of microbial contamination on clinical-use devices handled by healthcare workers, mainly stethoscopes and mobile phones, and (3) discuss what these findings mean for occupational risk assessment and prevention. Methods: The review follows PRISMA 2020 and a PECO framework. Population: healthcare workers. Exposure: microplastics, or biofilm or microbial colonisation of clinical-use devices and settings. Comparator: not applicable. Outcomes: presence, concentration or prevalence of contamination. PubMed/MEDLINE, Scopus and SciELO were searched, along with the first 200 Google Scholar results sorted by relevance, for studies published between September 2021 and September 2026 in English, Spanish or Portuguese. The last search was on 26 September 2026. Duplicates were removed in Mendeley, and records were screened in Rayyan in two stages: title and abstract, then full text. Screening was done by one reviewer under the methodological supervision of a second reviewer, who resolved doubtful records. Risk of bias was assessed with the OHAT tool and the JBI checklist for prevalence studies. Prevalence of microbial contamination was pooled with random-effects meta-analysis (REML, logit transformation) in jamovi 2.4.11 (MAJOR module, based on metafor). Heterogeneity was assessed with I² and Cochran's Q, and publication bias was explored with funnel plots and Egger's test. Microplastic studies were synthesised narratively because their methods and outcomes were too different to pool. Expected outcomes: The review is expected to (a) provide pooled prevalence estimates of microbial contamination on stethoscopes and mobile phones used by healthcare workers; (b) map the still limited evidence on microplastics in healthcare environments and materials, including PPE as a possible source of microfibres; (c) identify gaps in knowledge and methods, such as the lack of standard methods for detecting microplastics and the lack of studies that measure workers' exposure directly; and (d) offer practical recommendations based on the hierarchy of controls, such as device disinfection protocols, antimicrobial or easy-to-clean device covers, choosing materials carefully and the correct use of PPE. The findings are meant to support including microplastics and biofilms in occupational risk assessments in healthcare and to serve as a starting point for future primary research. This protocol was registered retrospectively, after data extraction was completed, to make the review methods transparent.