Acute Toxicity of Commercial Ethanol and Sodium Hypochlorite on Freshwater Species: Potential Implications of the COVID-19 Pandemic Disinfection Measures
摘要
The global response to the SARS-CoV-2 pandemic involved intensified disinfection of public spaces, predominantly using 70% ethanol (EtOH) and bleach (sodium hypochlorite). However, the extensive application of these agents has raised concerns regarding their ecotoxicological impact on aquatic ecosystems, particularly following their entry into drainage systems where they can form hazardous disinfection by-products. This study assessed the acute toxicity of commercial 70% EtOH and bleach on two key freshwater species: the cladoceran Ceriodaphnia dubia and the gastropod Biomphalaria glabrata. The 24-h median effective concentration (EC50) of 70% EtOH for C. dubia was 0.45% v/v (3.91 g/L), while the 24-h median lethal concentration (LC50) for B. glabrata was 3.8% v/v (33 g/L). For bleach, the corresponding toxicity values were significantly lower, at 0.0000024% (0.025 mg/L) for C. dubia and 0.0776% (815 mg/L) for B. glabrata. These results demonstrate that both disinfectants induce acute toxicity at concentrations substantially below their typical use levels. Notably, bleach proved to be more toxic than 70% EtOH by five orders of magnitude for C. dubia and two for B. glabrata. This study underscores the critical need for cautious use and continuous environmental monitoring of these disinfectants to mitigate their ecological impact and highlights the importance of developing sustainable alternatives.