Significance: To date, wastewater-based epidemiology has focused on reporting drug and pharmaceutical consumption patterns by analyzing domestic wastewater. Here we explore the relationships between chemicals in wastewater and social, demographic, and economic parameters of the respective populations. We show the extent to which consumption of chemicals such as opioids and illicit drugs are associated with sociodemographics. We also examine chemicals that reflect individuals’ consumption of food components in wastewater and show that disparities in diet are associated with educational level. Our study shows that chemicals in wastewater reflect the social, demographic, and economic properties of the respective populations and highlights the potential value of wastewater in studying the sociodemographic determinants of population health.

Wastewater contains a large range of biological and chemical markers of human activity and exposures. Through systematic collection and analysis of these markers within wastewater samples it is possible to measure the public health of whole populations. The analysis of effluent and biosolids can also be used to understand the release of chemicals from wastewater treatment plants into the environment. Wastewater analysis and comparison with catchment specific data (e.g. demographics) however remains largely unexplored. This manuscript describes a national wastewater monitoring study that combines influent, effluent and biosolids sampling with the Australian Census. An archiving program allows estimation of per capita exposure to and consumption of chemicals, public health information, as well as per capita release of chemicals into the environment. The paper discusses the study concept, critical steps in setting up a coordinated national approach and key logistical and other considerations with a focus on lessons learnt and future applications. The unique combination of archived samples, analytical data and associated census-derived population data will provide a baseline dataset that has wide and potentially increasing applications across many disciplines that include public health, epidemiology, criminology, toxicology and sociology.

Monitoring smoking prevalence is key to assessing responses to tobacco control measures, and evaluating associated health and economic costs. Estimates of tobacco consumed in Australia are based on various data sources - tax excise clearances, sales, and self-report surveys. There are limitations with each of these data sources which makes triangulation of cigarette use estimates by multiple methods important. Wastewater-based epidemiology, the systematic sampling and analysis of wastewater, is now a routine method to measure and monitor human exposure to a range of chemicals. This study provides a high frequency long-term temporal assessment of exposure to nicotine, the main addictive component of tobacco, using this approach. 291 archived wastewater samples collected from a regional city catchment from 2010 to 2017 were analysed for human-specific nicotine metabolites (cotinine and trans-3'-hydroxycotinine), to estimate per capita nicotine use. Temporal trends in nicotine use determined by wastewater-based epidemiology were compared with national sales and survey data. Wastewater analysis showed a 25% reduction in the mean number of cigarette equivalents consumed from 2010 to 2017, representing a 3% annual decline. These findings are in good agreement with estimates based on surveys and sales data, indicating annual declines of 5% and 4%, respectively. Findings of this study demonstrate WBE to be a relatively cost-effective and objective approach to reporting long-term data on nicotine consumption. When combined with alternative data sources, and valuable sociodemographic information of surveys, wastewater-based epidemiology helps to refine our estimates and understanding of the total impacts of smoking.