Skip to main content
Have a personal or library account? Click to login
Wastewater-Based Epidemiology (WBE): Potential Application for Assessing the Use of Conventional and New Generation Tobacco and Nicotine Products Cover

Wastewater-Based Epidemiology (WBE): Potential Application for Assessing the Use of Conventional and New Generation Tobacco and Nicotine Products

Contributions to Tobacco & Nicotine Research
Volume 34 (2025): Issue 2 (May 2025)
By: ,   and    
Open Access
|May 2025
Figures & tables

Figures & Tables

Figure 1.

Flow chart on identification, exclusion and inclusion of studies considered in this systematic review on WBE studies of tobacco/nicotine product use according to the PRISMA guidelines (136).

Table 1.

Population-normalized consumption of nicotine (PNC, mg/d/1000 persons) based on Cot or Cot + OH-Cot levels in WW reported in 170 data sets from 60 publications.

AllEuropeAmericaAsiaAustralia/New Zealand
N (data sets)170107182025
Mean27692947254320282763
SD18661428111215433480
Median23942650267314421800
5% Percentile8071227189564571
95% Percentile56335673394042628588
Min8666916244086
Max1700070564433703417000
Figure 2.

Mean WBE-derived nicotine consumption in 4 continents. Error bars represent the variation between 5% and 95% quantiles.

Table 2.

Studies investigating long-term time trends for WBE-assessed tobacco/nicotine consumption.

StudyCountryPeriod (years)Time trends in nicotine consumption observedComparison to sales/surveysInterpretation by authors
Mackie et al. 2019 (53)Australia2010–2017 (7 years)

  • - Decrease by 25%

  • - ~3% decrease per year

  • - Similar decrease in sales, but at lower level (reasons, see right cell)

  • - Self-reports too low

  • - Illicit tobacco use incompletely assessed

  • - Other Nic sources (NRT, EC) unimportant

Bade et al. 2020 (102)Australia2015–2019 (4 years)

  • - Cot decreased by 3.3%

  • - AB decreased by 30%

  • - None reported

  • - Reason for difference between change in Cot and AB: Increased use of NRT

  • - EC played no role in Australia at that time

Garcia-Lor et al. 2020 (18)Italy2013–2015 (2 years)

  • - Decrease in North and South Italy

  • - Unchanged in Central Italy

  • - In fair agreement with survey data on cigarette consumption

  • - Success of tobacco control policies

  • - Other Nic sources (NRT, EC, snus) considered to be insignificant

Zheng et al. 2020 (63)China2012–2017 (5 years)

  • - Decrease of Cot in WW by 2.1 % per year

  • - AB decreased by 3.0 % per year

  • - Tobacco tax and survey data: decreased by ~4%

  • - Faster decrease in tobacco than in nicotine consumption: other Nic sources play a role

  • - Market share of Nic patches increased from 0.47 to 0.95%

Gao et al. 2020 (31)China2014–2016 (2 years)

  • - Cotinine relatively consistent over time

  • - In agreement with WHO statistics, surveys and sales data for CC

  • - NRT and EC market shares were negligible in China at that time

Boogaerts et al. 2021 (25)Lithuania2018–2019 (1 year)

  • - Stable in Lithuania (whole country)

  • - Unexplained decrease of 25% in the city of Kaunas

  • - Cig sales over time also stable but by 35% lower (various reasons, see right cell)

  • - Outdated sales data (from 2016)

  • - Other Nic sources play a role (NRT, EC, pipes)

  • - Illegal tobacco products in circulation

  • - Disposed cig butts (chemical conversion to Cot and OH-Cot)

Campo et al. 2023 (137)Spain2018–2020 (2 years)*

  • - Decrease by 65% (!) during the study period

* Contradictory statements for study period: 2014–2017 in the text

  • - Unfortunately, the authors gave no explanation or interpretation of their results

Thai et al. 2023 (138)Australia2017–2020 (3 years)

  • - Decrease 2017-2019: 5%/a (slope: −0.035)

  • - Increase 2019-2020

  • - Stronger decrease in sales (slope: −0.12)

  • - Increase in NRT use 2017–2020 (estimated contribution to Nic consumption: < 10%)

  • - EC use of less importance (prohibited in Australia)

Wang et al. 2024 (59)Australia2013–2021 (8 years)

  • - First (until 2018) decrease (−18%), then increase (+40%)

  • - AB: First strong (−21%), then slight (−10%) decrease

  • - Tobacco sales show similar pattern to AB, but at lower consumption levels

  • - Illicit tobacco use suggested

  • - Non-tobacco nicotine use (NRT, ECs, etc.) suggested to increase after 2018

Table 3.

Conditions and assumptions applied in two scenarios of Monte Carlo Simulations (MCSs) for WW concentrations of cotinine (Cot), anabasine (AB) and 2-cyanoethyl mercapturic acid (2CyEMA) of a hypothetical WWTP serving a large city.

Input variablesMean value (unit)UncertaintyDistributionAssumptions and Rationale
Pop: Catchment population size of the WWTP150000015%Normal

  • - Stable over the study period of 10 years

  • - In other studies normal distribution of Pop with uncertainties of 10 (20), 15 (36) and 20% (40) were assumed

F: Flow rate of WWTP350,000,000 (L/d)15%Normal

  • - In other studies normal distribution of F with uncertainties of 10 (20, 166) and 20% (40) were assumed

  • - Reported F values for comparable Pops were in the same range (166)

UERBM: Daily urinary excretion rates of the BMsIn the rows below, the group- and BM-specific UER values are listed. These are derived from a controlled study with 10 subjects per group (159, 160, 169). As uncertainty, the relative standard errors (RSE) are provided. Specifics are indicated in the last column. Most distributions are between normal and lognormal. As a first approach, normal distributions are assumed. It is assumed that UERs are valid for steady-state conditions.
UERCotCC5.736 (mg/d)18%Normal
UERCotEC2.309 (mg/d)23%NormalUECot values were obtained from reported nicotine equivalents (Nic+10) (160) assuming that Nic+10 represents 95% of the absorbed nicotine dose and that 32.3% are excreted as Cot (free + conjugated) (50)
UERCotHTP4.240 (mg/d)17%Normal
UERCotONP6.625 (mg/d)18%NormalNo values for UERCotONP are available. It is assumed that the UER for ONP users is between those of CC and OT users.
UERCotNRT2.220 (mg/d)31%NormalThere were mainly nicotine gum users in the controlled study (160)
UERCotOT7.174 (mg/d)19%NormalThere were mainly snus users in the controlled study (160)
UERCotNU0.020 (mg/d)47%Normal
UERABCC14.6 (µg/d)21%NormalUERAB values were obtained from the published controlled study (169)
UERABEC0.50 (µg/d)25%NormalOutliers were excluded
UERABHTP2.51 (µg/d)22%Normal
UERABONP0.38 (µg/d)32%NormalNo data for ONP were available, the UERAB values for NRT users were applied
UERABNRT0.38 (µg/d)32%Normal
UERABOT22.2 (µg/d)50%NormalThere were mainly snus users in the controlled study (160)
UERABNU0.21 (mg/d)12%Normal
UER2CyEMACC186.4 (µg/d)18%NormalUER2CyEMA values were obtained from the published controlled study (159)
UER2CyEMAEC2.52 (µg/d)39%Normal
UER2CyEMAHTP14.00 (µg/d)28%Normal
UER2CyEMAONP0.58 (µg/d)6%Normal
UER2CyEMANRT0.58 (µg/d)6%NormalDue to obvious outliers, UER2CyEMA values of NU were used
UER2CyEMAOT0.58 (µg/d)6%Normal
UER2CyEMANU0.58 (µg/d)6%Normal
UER for DU (only in Scenario 2)It is assumed that DUs (simultaneous use of CCs and ECs) exhibit the same daily nicotine uptake as CCs do and would have the same UERCot. For a 20 CPD (cigarettes per day) smoker this could be achieved by reducing the consumption to 10 CPD (= 50% reduction) and simultaneously carry out 25 EC sessions per day. UERABDU and UER2CyEMADU were therefore reduced by 50% compared to the corresponding UER levels for CC-only users.
Scenario 1: No dual use of CC and EC is assumed
fCC : Fraction of smokers of CC in the total Pop

  • Year 1 (Y1): 0.14

  • Y10: 0.05

A constant yearly net decrease of 0.01 is assumed

  • - Group fractions are related to the whole Pop (all age groups, both genders)

  • - fCC is based on a smoking prevalence of 16.5% in the population aged 15+ which represent 85% in Pop

fEC : Fraction of vapers (EC) in the total Pop

  • Y1: 0.014

  • Y10: 0.0464

A constant yearly net increase of 0.0036 is assumed

  • - No reliable prevalence data for EC use are available to date

  • - f EC is assumed to be 10% of that of smokers (CC)

fHTP : Fraction of HTP users in the total Pop

  • Y1: 0.007

  • Y10: 0.0232

A constant yearly net increase of 0.0018 is assumed

  • - No reliable prevalence data for HTP use are available to date

  • - f HTP is assumed to be 50% of that of vapers (EC) both in Year 1 and 10

fONP : Fraction of ONP users in the total Pop

  • Y1: 0.0014

  • Y10: 0.0113

A constant yearly net increase of 0.0011 is assumed

  • - No reliable prevalence data for ONP use are available to date

  • - f ONP is assumed to be 10% of that of vapers (EC) in Year 1 and ~50% of that of HTP users in Year 10

fNRT : Fraction of NRT (any type) users in the total Pop

  • Y1:0.007

  • Y10: 0.007

A constant rate of NRT product use over the 10 study years is assumed

  • - No net change of NRT product use over the study period is assumed

fOT : Fraction of OT (any type) users in the total Pop

  • Y1: 0.007

  • Y10: 0.00133

A constant yearly decrease of 0.00063 is assumed

  • - fOT is assumed to be similar to fNRT in Year 1

  • - A steady decrease to 10% of the Year 1 use after 10 years is assumed, owing to the fact that a replacement product (ONP) is available

fNU : Fraction of non-users (NU) users in the total Pop

  • Y1: 0.8236

  • Y10: 0.8649

Fraction of NU arises as a result of subtracting all user groups from the total Pop
Scenario 2: Dual use of CC and EC is assumed
fCC : Fraction of smokers of CC in the total Pop

  • Y1: 0.14

  • Y10: 0.054

A constant yearly net decrease of = 0.01 is assumed; from Year 7 to Year 10 an increase of 0.001/year is assumed (back-switchers from DU group)See Scenario 1
fEC : Fraction of vapers (EC) in the total Pop

  • Y1: 0.015

  • Y10: 0.055

A constant yearly net increase of 0.004 is assumed; from Year 7 to Year 10 an additional increase of 0.001/year is assumed (DU staying with EC only)

  • - No reliable prevalence data for EC use are available to date

  • - f EC is assumed to be ~11% of that of smokers (CC) in Year 1

fHTP : Fraction of HTP users in the total Pop

  • Y1: 0.010

  • Y10: 0.037

A constant yearly net increase of 0.003 is assumed

  • - No reliable prevalence data for HTP use are available to date

  • - A somewhat higher starting level and increase rate than in Scenario 1 is assumed

fONP : Fraction of ONP users in the total Pop

  • Y1: 0.002

  • Y10: 0.02

A constant yearly net increase of 0.002 is assumed

  • - No reliable prevalence data for ONP use are available to date

  • - A somewhat higher starting level and increase rate than in Scenario 1 is assumed

fNRT : Fraction of NRT (any type) users in the total Pop

  • Y1: 0.010

  • Y10: 0.0055

A constant decrease of 0.0005 of NRT product use over time is assumed

  • - A slightly higher starting level than in Scenario 1 is assumed

  • - A slight decrease over 10 years is assumed due to the availability of alternatives (NGPs)

fOT : Fraction of OT (any type) users in the total Pop

  • Y1: 0.010

  • Y10: 0.0055

A constant yearly decrease of 0.0005 of OT use is assumed

  • - fOT is assumed to be similar to fNRT in Year 1 and 10

  • - A steady decrease is assumed, owing to the fact that a replacement product (ONP) is available

fDU : Fraction of dual users (DU) of CC and EC in the total Pop

  • Y1: 0.015

  • Y10: 0.012

A constant yearly increase of 0.001 until Year 7 followed by a net decrease of 0.002 until Year 10 is assumed

  • - FDU is assumed to be similar to fEC in Year 1

  • - The net decrease from Year 7 onwards is assumed, due to equal transitions to CC, EC and NU

fNU : Fraction of non-users (NU) users in the total Pop

  • Y1: 0.798

  • Y10: 0.813

Fraction of NU arises as a result of subtracting all user groups from the total Pop
Figure 3.

Monte Carlo simulations (MCSs) of Scenario 1 and 2 over 10 years for WW concentrations of cotinine (top), AB (middle) and 2CyEMA (bottom).

Figure 4.

Monte Carlo simulations of Scenario 1 and 2 over 10 years for the WW concentration ratios AB/cotinine (top) and 2CyEMA/cotinine (bottom).

DOI: https://doi.org/10.2478/cttr-2025-0007 | Journal eISSN: 2719-9509 (formerly 1612-9237)
Journal RSS Feed
Language: English, French, German
Page range: 59 - 83
Submitted on: Dec 18, 2024
Accepted on: Apr 7, 2025
Published on: May 16, 2025
Published by: Beiträge zur Tabakforschung GmbH
In partnership with: Paradigm Publishing Services
Keywords:
Wastewater-based epidemiology,
new generation tobacco products,
new generation nicotine products,
combustible cigarettes,
tobacco harm reduction,
Monte Carlo simulation
Related subjects:
Life sciences,
Life sciences, other

© 2025 Gerhard Scherer, Nikola Pluym, Max Scherer, published by Beiträge zur Tabakforschung GmbH
This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 License.

Volume 34 (2025): Issue 2 (May 2025)
Previous article
Next article