The recent coronavirus outbreak and its high transmissibility identified significant issues in the system of measuring air and surface contamination, required to estimate worker exposure to virus particles. An article written by Cherrie et al. (2021), published in the journal Annals of Work Exposures and Health, presents a systematic review of methods used for the measurement of air and surface contamination.
Summary
The report starts with providing informational background on COVID-19 and SARS-CoV-2, where authors emphasize how the virus could be easily transmitted from patients to healthcare workers. The background explains the foundation of the research and its application and connection to actual problems in the healthcare system. The authors state that the article presents a summary of reports on air and surface contamination in workplaces where the virus was located. In addition, the article reviews the sampling and measurements data, makes assumptions about the quality of measurements, and provides recommendations that could be used in measurements and sampling methodology in the future.
The first significant finding from the article is that because there is no standardized procedure for quantifying the concentration of SARS-CoV-2 RNA in the air, the results were different among several reports. In terms of methods used for air sampling, the authors listed the use of gelatin filters, wet cyclone, impingers, dry filters, and water-based condensational samples (Cherrie et al., 2021). The authors also clarified that some reports used a combination of different sampling methods. On the other hand, the sampling methods for surface contamination were consistent through the majority of reports. According to Cherrie et al. (2021), in general, in the surface contamination sampling method, most of the reports followed recommendations provided by WHO. Thus, the article’s findings suggest that due to the absence of recommendations from credible organizations for air sampling procedure, the results from the reports have different non-comparable data from the use of different measurement systems.
In their research, the authors tried to compare results from reports on contamination data but determined that only a small amount of collected data could be used for making further suggestions. In particular, some surface samples identified 0% positive for SARS-CoV-2 RNA, and some identified 74% positive results, with a median of 6% (Cherrie et al., 2021). Additionally, some of the reports did not detect SARS-CoV-2 RNA on any surfaces, while others showed a tendency to show a high number of positive results in air samples (Cherrie et al., 2021). According to the authors, only part of the reports used concertation units for measurements, most suitable for comparison purposes (Cherrie et al., 2021). In analyzing the findings of inconsistencies in data, the authors suggested that most reports have a descriptive character and lack documentation and statistics on air and surface contamination.
In conclusion and discussion of research results, the article suggests that inconsistencies in data and sampling methods could be explained by limitations due to conditions of the pandemic and shortage of equipment. The article states that inconsistencies in data and measurements could not deny that workers’ exposure to high concentration of SARS-CoV-2 RNA in the air presents a risk for workers’ safety. According to the authors, contamination could be dangerous only in cases of high (37% and more) concentration as cultivation of virus requires a high concentration of SARS-CoV-2 RNA in the air (Cherrie et al., 2021). Thus, in low concentrations, the SARS-CoV-2 RNA is relatively harmless to people.
Critique
The research findings indicated a significant issue in the system of measuring air contamination with SARS-CoV-2 RNA. In the article, comparing the inconsistencies in air sampling methods with surface sampling showed how recommendations from credible organizations such as WHO could improve the accuracy of sampling results. The authors suggest that preparing for the next outbreak requires international coordination, which could be fulfilled by WHO. Although WHO previously addressed the recommendations for indoor air sampling and analysis methods, they mainly relate to exposure to chemical pollutants and do not fit SARS-CoV-2 RNA tests (WHO Europe, 2020). Thus, the article emphasizes the critical issue of addressing the need for the development of a standardized procedure of air contamination sampling and measurements. Moreover, the article provides evidence that due to inconsistencies in the data, the collective analysis of different reports lacks accuracy and could only provide depthless results.
The article also points that due to inconsistencies in data, there is no opportunity to provide an accurate value of SARS-CoV-2 RNA in the air that could be dangerous to people in cases of exposure. The authors use previous findings from Lednicky et al. suggesting that successful culture of the virus requires the RNA concentration higher than 38% (as cited in Cherrie et al., 2021, p. 12). Therefore, after comparing the statement with results from different reports, the article states that the contamination of workplace air with SARS-CoV-2 RNA in small concentrations is harmless to people.
The authors acknowledge the fact that their research and reports that the research is based on do not reflect several vital factors. In particular, the authors listed “measurement contextual data” as one of the factors that were missing in the reports. The factor includes additional information about the workers’ room sizes, ventilation systems, use of protective equipment etc. Without centralized sampling procedures and measurement system, the abovementioned factors could potentially add more depth to the existing research. According to the authors, in future development of the centralized processes the new protocols should be formatted with an opportunity to feature such important information. Moreover, the protocols should also provide additional data on workers’ health status, behavior, and remaining social context of workplace interactions.
In terms of the organization’s perspective, I assume that engaging 3rd party organizations in cleaning and disinfecting services is a good intention to provide a safe workplace. Although, in some cases, the initiative could be misinterpreted as relieving oneself from responsibilities, spending additional resources to provide safety for the workers is better than ignoring the cleaning and disinfecting regimen. Moreover, cleaning and disinfecting should be an essential part of any functioning organization, and I think that even after the COVID-19 pandemic, the organizations should carry the cleaning and disinfecting regimen. A clean workplace environment could prevent transmission of other diseases and result in improvement of workers’ health status.
The fact that non-viable virus particles on surfaces could culture the virus emphasizes the need for further research and the development of standardized techniques and protocols that would improve the accuracy of currently available research. There could be more pandemics like COVID-19 in the future, so taking proactive actions now could benefit the efficiency of response to the following situations. New mutations of the COVID-19 virus characterized with a higher level of transmissibility present a significant threat for the population and workers.
References
Cherrie, J.W., Cherrie, M.P., Smith, A., Holmes, D., Semple, S., Steinle, S., Macdonald, E., Moore, G., & Loh, M. (2021). Contamination of air and surfaces in workplaces with SARS-CoV-2 virus: A systematic review. Annals of Work Exposures and Health, 1-14.
WHO Regional office for Europe. (2020). Methods for sampling and analysis of chemical pollutants in indoor air.