Ingestion of corrosive substances can produce severe injury to the gastrointestinal tract. The extent and degree of tissue injury are dependent on such factors as the type of substance, morphological form of the agent, amount, intention, concentration, pre-ingestion condition of the tissues, and duration of contact. Oxidant agents, such as bleach, are among the corrosives commonly found. These agents can cause serious damage to the gastrointestinal tract, including perforation [6, 7].
Prior to the COVID-19 pandemic, chlorine derivatives products were already commercialized. Specifically, sodium chlorite under the name MMS (Miracle or Master Mineral Solution; Master Mineral Supplement). Distributors claimed that after mixing with an acid, it had antiviral and antibacterial effects, and was supposed to be a treatment for various unrelated diseases, such as autism spectrum disorder, cancer, flu, hepatitis and HIV/AIDS [8,9,10]. Several warnings and communications were published before and after the COVID-19 pandemic by government institutions and regulatory entities including USA, Canada and the UK, aiming to stop commercialization and demanded its withdrawal from the market [11,12,13,14].
Chlorine dioxide is a greenish–yellowish gas, and it is known to be highly effective at alkaline pH . Although this compound is a gas, it is highly soluble in water . Chlorine dioxide has many applications in numerous fields, such as water or wastewater treatment, bleaching, environmental and food disinfection, and sterilization of medical devices. The maximum concentration for chlorine dioxide in the drinking water has been set at 0.8 mg/L by The Environmental Protection Agency (EPA) [3, 17,18,19,20]. Conversely, exposure to higher concentrations might cause serious side effects. It is a respiratory irritant compound; hence, it may cause irritation of eyes, nose, throat and lungs . Also, the ingestion of these products may cause irritation of the mouth, esophagus and stomach, with severe irritative digestive symptoms; nausea, vomiting and diarrhea, in addition to serious hematological (methemoglobinemia, hemolysis and disseminated intravascular coagulation), cardiovascular and kidney disorders, including renal failure [4, 21,22,23]. Therefore, the permitted amount of chlorine dioxide and chlorine levels per volume of water in drinking water is highly regulated . It has been observed that the concentrations of these commercialized products exceed the maximum limits allowed in drinking water in countries where chlorine dioxide or sodium chlorite have been marketed as therapeutic agents .
It is necessary to understand the mechanism of action of oxidizing agents, such as chlorine dioxide and sodium chlorite. As mentioned previously, these substances serve as disinfectants due to their oxidizing properties. This means they can oxidize other compounds via an oxidation–reduction reaction . Ultimately, chemical reactions will induce disruption of protein synthesis and outer membrane permeability due to rapid efflux of potassium ion, leading to the destruction of the transmembrane ionic gradient [25, 26]. This effect is not specific to a particular organism; human cells, like other microorganisms, are also affected .
No study has evaluated the clinical effects of chronic chlorine derivatives ingestion to date. Gradual and low increase in chlorine dioxide concentration may have lessened irritative symptoms until lesion of the mucosa and ultimately, perforation of the gastrointestinal tract occurred. Additionally, chronic inflammation of the serous layer with neutrophilic infiltrate and tissue necrosis in the mucosa caused by chemical destruction was demonstrated by histological findings.
A recent data analysis of the American Association of Poison Control Centers (AAPCC) National Poison Data System (NPDS) identified 53 cases of chlorine dioxide associated exposure between January 1, 2000 and March 31, 2020 . The main reasons for use were infectious disease (13.2%), accidental exposure (9.4%), supplement/cure all (9.4%) and detoxification (7.5%). Ingestion was the most common route of administration (83%). 62.3% cases were female, and the median age was 46 years. The most frequently reported related clinical effects were vomiting (49.1%), nausea (28.3%), abdominal pain (22.6%), and diarrhea (20.8%). The majority of exposures represent acute toxicity (84.9%), as most effects occurred the first 24 h of exposure (75.5%) (Table 1). It is likely to be a greater amount of exposures than are described in this report, as it is subject to limitations common to voluntary reporting systems. Because poison control centers primarily offer advice following acute exposure, the data rarely include late-onset clinical effects or long-term complications. Nevertheless, it grants a fair contrast in regarding the consumption of chlorine derivatives.
The first analysis that linked the geospatial dynamics of social media with public health interventions has been recently published. The study indicates that health misinformation on social media is associated with greater exposure to household cleaners, including bleaching agents . Also, the access to concentrated formulations of chlorine derivatives has increased in recent years due to unsupported claims of efficacy in preventing and treating several medical conditions, now including COVID-19 [16, 30].
To date, there is no scientific evidence to uphold the use of chlorine dioxide or chlorine derivatives as preventive or therapeutic agents against COVID-19 . This case demonstrates that for people searching cleaning products to protect themselves from COVID-19, unregulated access to industrial disinfectants represents a dangerous alternative. The use of products that have not been proven to be safe and effective against COVID-19 not only poses a potential health risk to those who use them, but also to the entire population. By generating a false sense of security due to the presumed but unproven beneficial effect, these products may also incur in the abandonment of prevention and control measures against COVID-19 that have proven to be effective, such as the use of masks, social distancing and hand hygiene. Furthermore, it is critical that public messaging steers clear of promoting these potentially lethal products as we continue to manage the COVID-19 pandemic. We urge consumers to avoid the use of chlorine dioxide derivatives and we expect to make health care providers aware of potential clinical sequelae associated with its administration.