. Author manuscript; available in PMC: 2015 Apr 1.

Published in final edited form as: Risk Anal. 2014 Feb 27;34(4):602–613. doi: 10.1111/risa.12178

Table I.

Distributions and fit parameters used in the models. AIC = Akaike information criterion.

Model parameter	Unit	Distribution type (values)^a ~ Median^b	References and Fit Statistics
C = rotavirus concentration in secondary treated wastewater at Beijing wastewater treatment plants	viral unit/L	Mixture (A, B) with 60% recovery efficiency ~ 0.02 A = Lognormal (−2.53, 1.33) B = Lognormal (−13.69, 4.45)	^(34-36)
V = volume of water captured by vegetable	mL/g
Bok choy		Lognormal (−3.79, 0.37) ~ 0.02	Chi Sq = 12.8600 AIC = −668.2724
Choy sum		Lognormal (−3.08, 0.48) ~ 0.05	Chi Sq = 10.7917 AIC = −457.7444
Gai lan		Lognormal3 (−2.99, 0.45, 0.005) ~ 0.06	Chi sq = 10.2222 AIC = −461.97
Lettuce		Lognormal3 (−4.57, 0.50, 0.006) ~ 0.02	Chi Sq = 9.0309 AIC = −739.0825
M = per capita consumption of vegetable in China	g/person day
Bok choy		Lognormal (3.03, 2.12) ~ 4.59	⁽³⁷⁾
Choy sum		Lognormal (2.87, 1.99) ~ 16.25	⁽³⁷⁾
Gai lan		Lognormal (3.69, 0.58) ~ 39.33	⁽³⁷⁾
Lettuce		Lognormal (4.35, 1.27) ~ 76.64	⁽³⁷⁾
k = in-field virus kinetic decay constant	days⁻¹	Normal (1.07, 0.07) – truncated at zero ~ 1.07	^{(7, 38)}
t = withholding period	days	Uniform (0, 2) ~ 0.97
W = reduction of virus concentration by post-harvest vegetable washing	log₁₀ unit	PERT (0.1, 1, 2) ~ 1.01	^{(39-41, 9)}
Rotavirus dose-response parameters		Hypergeometric Beta Poisson α = 0.167, β = 0.191	⁽⁴²⁾
I = proportion of rotavirus-infected persons in developing countries who become ill	proportion	0.90	⁽³²⁾
D = rotavirus disease burden for China	DALY per case	Uniform (5.79 × 10⁻², 2.13 × 10⁻¹) ~ 0.11	^{(43, 44)}
S_F = susceptibility fraction	proportion	0.059	^{(45, 21)}

Distribution types and values: Lognormal(μ, σ), where population parameters $\hat{μ}$ and $\hat{σ}$ are calculated as follows: $\hat{μ} = \ln \bar{x} - 0.5 \ln (1 + {(\frac{s}{\bar{x}})}^{2})$ and $\hat{σ} = \sqrt{\ln (1 + {(\frac{s}{\bar{x}})}^{2}),}$ , where $\bar{x}$ is the sample mean and s is the sample standard deviation; Lognormal3(μ, σ, location), where location is a shift parameter; Normal(mean, standard deviation); PERT(minimum, mode, maximum); and Uniform(minimum, maximum).

Median values calculated after 10,000 iterations