Increased disinfection byproducts in the air resulting from intensified disinfection during the COVID-19 pandemic

Intensified use of disinfectants to control COVID-19 could unintentionally increase the disinfection byproducts (DBPs) in the environment. In indoor spaces, it is critical to determine the optimal disinfection practice to prevent the spread of the virus while keeping DBPs at relatively low levels in the air. The formation of DBPs exceed 0.1 μg/mg while hypochlorite dosed at >10 mg/m(3). The total DBP concentrations in highly disinfected places (100–200 mg/m(3) hypochlorite) were as high as 66.8 μg/m(3), and the Hazard Index (HI) was up to 0.84, and both values were much higher than those in less disinfected places (<10 mg/m(3) hypochlorite). Taking into account the HI, formation yields and the origin of the DBPs, we recommended 10 mg/m(3) as the suggested hypochlorite dose to minimize DBPs generation during routine disinfection for controlling the coronavirus. DBPs in indoor air could be eliminated by ventilation, reducing the usage of personal care products, and wiping the solid surface with water before or after disinfection. These results highlighted the necessity to control air-borne DBPs and their associated health risks arising from intensified disinfection, and will guide the further development of evidence-based regulation on DBP exposure during disinfection and improve public health protection.