Wastewater-based epidemiology to assess human exposure to personal care and household products – A review of biomarkers, analytical methods, and applications

Abstract

Humans are nowadays exposed to numerous chemicals in our day-to-day life, including parabens, UV filters, phosphorous flame retardants/plasticizers, bisphenols, phthalates and alternative plasticizers, which can have different adverse effects to human health. Estimating human’s exposure to these potentially harmful substances is, therefore, of paramount importance. Human biomonitoring (HBM) is the existing approach to assess exposure to environmental contaminants, which relies on the analysis of specific human biomarkers (parent compounds and/or their metabolic products) in biological matrices from individuals. The main drawback is its implementation, which involves complex cohort studies. A novel approach, wastewater-based epidemiology (WBE), involves estimating exposure from the analysis of biomarkers in sewage (a pooled urine and feces sample of an entire population). One of the key challenges of WBE is the selection of biomarkers which are specific to human metabolism, excreted in sufficient amounts, and stable in sewage. So far, literature data on potential biomarkers for estimating exposure to these chemicals are scattered over numerous pharmacokinetic and HBM studies. Hence, this review provides a list of potential biomarkers of exposure to more than 30 widely used chemicals and report on their urinary excretion rates. Furthermore, the potential and challenges of WBE in this particular field is discussed through the review of pioneer WBE studies, which for the first time explored applicability of this novel approach to assess human exposure to environmental contaminants. In the future, WBE could be potentially applied as an “early warning system”, which could promptly identify communities with the highest exposure to environmental contaminants.

Identification of biomarkers in wastewater-based epidemiology: Main approaches and analytical methods

“…This approach requires the study of the human metabolism, identification of the substances excreted by urine, selection of those representative excreted in a high percentage, development of an analytical method able to determine them, study of their stability in wastewater and then, finally their assessment in wastewater. There are many remarkable and well conducted reviews that treat the topic of potential biomarkers to be used in the WBE for different estimations [ 15 , [24] , [25] , [26] ]. These reviews categorized biomarkers depending a little bit on the authors criterion but in all cases consumption, exposure, health/disease and lifestyle/consumption are main drivers of these classifications.…”

“…One of the areas that is increasing is the evaluation of human exposure [ 20 , 26 ] reflected on a high number of studies regarding exposure to pesticides [ [73] , [74] , [75] , [76] ], mycotoxins [ 77 ], bisphenol A and its analogues [ 78 ], personal care and household products [ 26 ], phthalates [ 79 ], organophosphorus flame retardants and plasticizers [ 14 , 80 ]. Some of these studies are highly useful reviews of the known pharmacokinetics datasets [ 26 , 73 ] that help in the identification of proper biomarkers and highlights the limitation to overcome in this type of studies that is share with consumption studies —many of the biomarkers used are not exclusive to humans and can therefore sometimes come from other sources, making it difficult to assess exposure.…”

“…In WBE the ability to move from theory to practice correlates with the ability to identify biomarkers that attain estimation of drug use, leisure habits, health, disease, exposure, etc … [ 15 , [25] , [26] , [27] ]. This analytical field is dominated by liquid chromatography-mass spectrometry (LC-MS) techniques since the target molecules belongs to the excreted human metabolites that tend to be more polar than parent compounds [ 3 ].…”

“…In recent years there has been a tremendous methodological effort to identify biomarkers in wastewater, in fact there are many essential reviews that have this sole objective [ 15 , [25] , [26] , [27] ]. However, there is a lack of a critical review that outlines the different types of analytical protocols following a systematic approach that includes a description of the methods and techniques applied in each case.…”

Changes in Sewage Sludge Chemical Signatures During a COVID‐19 Community Lockdown, Part 2: Nontargeted Analysis of Sludge and Evaluation with COVID‐19 Metrics

“…In past wastewater‐based epidemiology studies, various compounds/substances have been assessed for monitoring the usage of illicit drugs (i.e., cocaine, heroin, methamphetamine; Khan & Nicell, 2011 ; Zuccato et al, 2008 ) and licit drugs (i.e., caffeine, nicotine, alcohol; Senta et al, 2015 ), pharmaceuticals (e.g., benzodiazepines, opioids, antidepressants, antibiotics, and antimicrobials; Castiglioni et al, 2006 ; Langford & Thomas, 2011 ), and consumer product ingredients (e.g., ultraviolet filters, synthetic musks, pesticides, plasticizers, and flame retardants; Snyder et al, 2003 ). In addition, human pathogens, stress, and diet markers have been investigated in wastewater/sludge to assist with human biomonitoring and assessing, monitoring, and managing population health (Chen et al, 2014 ; Choi et al, 2018 ; Senta et al, 2015 , 2020 ; Yang et al, 2015 ).…”