Table 1.

Distributions and inputs for the QMRA.

Parameter	QMRA statistics applied	Comments
Virus concentration in faeces of infected individuals, SARS-CoV-2 (genomes per mL)	Minimum = 2000 Median = 1.7 × 106 Maximum = 4.1 × 107	Consistent with Han et al. (2020), Amoah et al. (2020). Hockey stick distribution, as previously described (McBride, 2007, McBride, 2011, McBride, 2016a, McBride, 2016b). 1000 genomes = 1 PFU
Duration (hours) of occupational exposure of WWTP operators to aerosolized SARS-CoV-2	Minimum = 2 Median = 4 Maximum = 8	Time spent by WWTP operators on a typical workday at the treatment plant. This includes routine activities such as manual cleaning, coarse screening, wastewater sampling for microbiological and chemical analysis, and process supervision.
Wastewater inhalation rate, mL per hour	Minimum = 2 Median = 10 Maximum = 20	PERT distribution for an adult, consistent with previous QMRA studies on inhalation risks associated with aerosolized adenoviruses (McBride, 2007, McBride, 2011, McBride, 2016a, McBride, 2016b, Dada, 2018a, Dada, 2020b, Dada, 2019a, Dada, 2019b, Dada, 2020a)
Air temperature (degC)	Minimum = 1.4 Median = 12.4 Maximum =20.2	PERT distribution. Data from NIWA mean monthly values for the 1981–2010.
Relative humidity	Minimum = 65.0% Median = 81.5% Maximum = 94.2%	PERT distribution. Data from NIWA mean monthly values for the 1981–2010.
Dose response parameters	SARS-CoV-2 exponential model (k = 4.1 × 102).	Watanabe et al. (2010).