Effect of unboiled water consumption data on sensitivity analysis in quantitative microbial risk assessment

Biological risk assessment in occupational settings currently is based on either qualitative or semiquantitative analysis. In this study, a quantitative microbial risk assessment (QMRA) has been applied to estimate the human adenovirus (HAdV) health risk due to bioaerosol exposure in a wastewater treatment plant (WWTP). A stochastic QMRA model was developed considering HAdV as the index pathogen, using its concentrations in different areas and published dose–response relationship for inhalation. A sensitivity analysis was employed to examine the impact of input parameters on health risk. The QMRA estimated a higher average risk in sewage influent and biological oxidation tanks (15.64% and 12.73% for an exposure of 3 min). Sensitivity analysis indicated HAdV concentration as a predominant factor in the estimated risk. QMRA results were used to calculate the exposure limits considering four different risk levels (one illness case per 100, 1.000, 10.000, and 100.000 workers): for 3 min exposures, we obtained 565, 170, 54, and 6 GC/m3 of HAdV. We also calculated the maximum time of exposure for each level for different areas. Our findings can be useful to better define the effectiveness of control measures, which would thus reduce the virus concentration or the exposure time.

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Sensitivity analysis in quantitative microbial risk assessment

International Journal of Food Microbiology ◽

10.1016/s0168-1605(00)00275-0 ◽

2000 ◽

Vol 58 (3) ◽

pp. 213-221 ◽

Cited By ~ 44

Author(s):

M.H Zwietering ◽

S.J.C van Gerwen

Keyword(s):

Risk Assessment ◽

Sensitivity Analysis ◽

Quantitative Microbial Risk Assessment ◽

Microbial Risk Assessment ◽

Microbial Risk

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Investigation of water consumption patterns among Irish adults for waterborne quantitative microbial risk assessment (QMRA)

Journal of Water and Health ◽

10.2166/wh.2012.025 ◽

2012 ◽

Vol 10 (3) ◽

pp. 453-464 ◽

Cited By ~ 6

Author(s):

Paul D. Hynds ◽

Bruce D. Misstear ◽

Laurence W. Gill

Keyword(s):

Risk Assessment ◽

Drinking Water ◽

Water Consumption ◽

Tap Water ◽

Primary Concern ◽

Quantitative Microbial Risk Assessment ◽

Chemical Contamination ◽

Daily Consumption ◽

Microbial Risk Assessment ◽

Microbial Risk

Microbial and chemical contamination of drinking water supplies can cause human health problems. Microbial pathogens are of primary concern and quantitative microbial risk assessment (QMRA) is employed to assess and manage the risks they pose. Estimates of drinking water consumption, or distributions, are required to assess levels of waterborne pathogen exposure. To establish distributions for the Irish population, water consumption data were collected from 549 rural survey respondents. A further 110 participants completed a five-day water consumption diary. Average daily consumption of tap-water among the primarily rural-dwelling questionnaire respondents was 940 ml day−1 (SD 670 ml day−1) and 1,186 ml day−1 (SD 701 ml day−1) among the principally urban-dwelling diary respondents. Both mean figures are significantly less than the 2,000 ml day−1 default figure currently used for QRMA; therefore its use may lead to overestimation of the waterborne health burden. As the observed daily consumption difference between rural and urban residents is statistically significant, use of separate consumption distributions for QMRA is advocated. Although males reported higher daily tap-water consumption rates than females, these differences were insignificant, so separate consumption distributions are not considered necessary. A log-normal distribution provides the most adequate fit for daily tap-water intake (ml day−1) within both datasets.

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