University Of Tasmania

File(s) under permanent embargo

Systematic and day-to-day effects of chemical-derived population estimates on wastewater-based drug epidemiology

journal contribution
posted on 2023-05-18, 07:20 authored by Lai, FY, Anuj, S, Raimondo BrunoRaimondo Bruno, Carter, S, Gartner, C, Hall, W, Kirkbride, KP, Mueller, JF, O'Brien, JW, Jeremy PrichardJeremy Prichard, Thai, PK, Ort, C
Population size is crucial when estimating population-normalized drug consumption (PNDC) from wastewater-based drug epidemiology (WBDE). Three conceptually different population estimates can be used: de jure (common census, residence), de facto (all persons within a sewer catchment), and chemical loads (contributors to the sampled wastewater). De facto and chemical loads will be the same where all households contribute to a central sewer system without wastewater loss. This study explored the feasibility of determining a de facto population and its effect on estimating PNDC in an urban community over an extended period. Drugs and other chemicals were analyzed in 311 daily composite wastewater samples. The daily estimated de facto population (using chemical loads) was on average 32% higher than the de jure population. Consequently, using the latter would systemically overestimate PNDC by 22%. However, the relative day-to-day pattern of drug consumption was similar regardless of the type of normalization as daily illicit drug loads appeared to vary substantially more than the population. Using chemical loads population, we objectively quantified the total methodological uncertainty of PNDC and reduced it by a factor of 2. Our study illustrated the potential benefits of using chemical loads population for obtaining more robust PNDC data in WBDE.


Publication title

Environmental Science and Technology








School of Psychological Sciences


Amer Chemical Soc

Place of publication

1155 16Th St, Nw, Washington, USA, Dc, 20036

Rights statement

Copyright 2014 American Chemical Society

Repository Status

  • Restricted

Socio-economic Objectives

Public health (excl. specific population health) not elsewhere classified

Usage metrics

    University Of Tasmania