Disinfection in the time of COVID: Safe solutions are critical for schools.

Surface disinfection is part of school protocols designed to decrease the risk of students and staff contracting COVID-19. However, exposure to disinfectants can have short- and long-term health consequences. Given that the risks are well-described and safer products are readily available, it is critical that schools consciously employ safer disinfection strategies.

INTRODUCTION

After lockdowns in the early part of the COVID-19 pandemic and multiple school outbreaks, particularly since the emergence of the Delta and Omicron variants, it is apparent that children need to be able to attend school safely (1). As well as clean air, mask use and immunization, in spite of evidence that COVID-19 transmission is predominantly airborne, surface cleaning, disinfection and hand hygiene are strategies that are widely employed to decrease school-based spread of COVID-19 (2). Unfortunately, many commonly used disinfectants are respiratory irritants implicated in the incidence and prevalence of asthma (3–7), posing a potential risk to all children in school with disproportionate impacts on children with respiratory diseases such as asthma.

DISCUSSION

Chronic exposure to some commonly used disinfectants increases the incidence of asthma and, with acute exposure, its prevalence (3–5,8–10). While most reports focus on adults involved in cleaning as a profession (4,8–10) or who use disinfectants frequently at home (5), similar observations have been made for children exposed at home (3,7). Pandemic-level school disinfection routines have increased children’s exposure to these chemicals at school. While reports of exposure to Poison Control in the United States rose in the under-5 group from home settings (11), studies examining school-based exposures are lacking in the literature.

School administrators face multiple and constantly evolving challenges to provide a safe in-person learning environment for teachers and children (1). A widely adopted strategy is frequent disinfection of high-use surfaces, including desks (12). Multiple classes of disinfectant are available for individual and institutional use (4,5,9,13,14). They can be grouped by chemical type. Some common agents are linked to respiratory irritation, inflammation, and asthma exacerbation (5,6,9). Quaternary ammonium compounds (e.g., benzalkonium chloride) and aldehydes are strongly linked with asthma (5,6,9,13); chlorine-releasing compounds such as hypochlorite (bleach) also increase respiratory problems including asthma (4,6,8). The mode of use is also important, with spray application increasing respiratory problems compared to other forms of administration (5).

Safer and effective solutions, including those that employ hydrogen peroxide, citric acid, or ethanol as active disinfection agents and safer application formats that avoid spraying, are already commercially available and well described in the literature (5,6,13). Information designed for clinicians, school and other administrators, and the general public is available (11,14).

Asthma is the most common chronic disease in Canadian children. Typical factors associated with asthma triggers at school include poor ventilation, dust, pets, and exposure to viral infections. Exacerbations in children lead to child and parental anxiety, unanticipated physician visits, and school and work absences (15). Exacerbations triggered by school factors risk creating negative associations for children who may already be marginalized by their chronic disease. By increasing the use of common and well-known asthma triggers in schools while they are in session, we are not only failing a large and vulnerable population of children, we also may be promoting unnecessary risk for the entire school cohort. Children with respiratory disease may act as the proverbial “canary in the coal mine” with respect to potentially harmful respiratory exposures.

CONCLUSION

Disinfectants are an important part of public health strategies to control the spread of viral infections, including COVID-19. While some disinfectants can present health hazards, particularly to children with asthma and other respiratory conditions, safer alternatives, and safe practices, are broadly available and well-described. For children experiencing respiratory issues such as asthma exacerbations in school, disinfectants should be considered as a potential cause. Physicians, schools, and parents will benefit from working together to address this preventable issue.