Ben Tscharke

Towards finding a population biomarker for wastewater epidemiology studies

Wastewater analysis has the potential to provide objective information on community drug use. Introducing a population biomarker (PB) in the sample analysis may significantly reduce errors in the back-calculation associated with population estimation and wastewater volume measurement. A number of potential PBs have been suggested but no systematic evaluation has been conducted so far. This study evaluated the eligibility of the previously suggested PB candidates (creatinine, cholesterol, coprostanol and cotinine) as well as three new ones (cortisol, androstenedione and 5-hydroxyindoleacetic acid (5-HIAA)) using five criteria. We assessed the quantification method, affinity to particulate matter and stability of candidates in wastewater, as well as the constancy of inter-day excretion and correlation between excretion and census population. All PB candidates were quantifiable in wastewater. Cholesterol and coprostanol were eliminated from further consideration due to affinity to particulate matters in the wastewater. Creatinine, cortisol and androstenedione were disqualified for stability reasons. On a population scale, both cotinine and 5-HIAA were excreted (RSD=8.01 ± 1.13% and 10.20 ± 0.89%, respectively) at a constant rate and concentrations of each correlated well with the census population (r=0.9809 and 0.9442, respectively). Overall, both cotinine and 5-HIAA are eligible PBs, but the neurotransmitter metabolite 5-HIAA may be more suitable for international comparisons.

Estimates of tobacco use by wastewater analysis of anabasine and anatabine

Wastewater analysis, the chemical analysis of municipal sewage, is fast becoming the technique of choice to monitor changes in community consumption of a range of compounds over time. Currently wastewater analyses which estimate tobacco consumption focus on the major alkaloid nicotine and its urinary metabolite, cotinine. As nicotine is also present in replacement therapies such as nicotine gum and patches, this analysis is not specific and hence does not truly reflect the harmful consumption of tobacco. Two alkaloids - anabasine and anatabine - which are specific to dried tobacco, were assessed as biomarkers for tobacco consumption in wastewater, together with nicotine and cotinine. Consequently, solid phase extraction (SPE) and liquid chromatography-mass spectrometry (LC-MS) methods for the detection of anabasine, anatabine, nicotine, and cotinine in municipal wastewater were validated. All compounds were detected in wastewater extracts and found to have satisfactory recovery, accuracy, precision, and stability in wastewater. Daily flow volume and catchment population of the wastewater facility were used to estimate normalized consumption figures of mg/day/1000 people for composite samples collected over one week, in an application of the method. Anabasine and anatabine were found to be suitable wastewater biomarkers of tobacco and can be used to assess tobacco consumption of communities via wastewater analysis. Application of this methodology can be used to collect temporal consumption data which could be used to determine the efficacy of tobacco reduction strategies. Copyright

A prospective study of mediating cognitive mechanisms in impulsive alcohol use by adolescents

Abstract presented at the Australasian Professional Society on Alcohol and other Drugs Conference 2013, 24-27 November 2013, Brisbane, Australiapresented at the Australasian Professional Society on Alcohol and other Drugs Conference 2013, 24-27 November 2013, Brisbane, AustraliaAbstract presented at the Australasian Professional Society on Alcohol and other Drugs Conference 2013, 24-27 November 2013, Brisbane, AustraliaAbstract presented at the Australasian Professional Society on Alcohol and other Drugs Conference 2013, 24-27 November 2013, Brisbane, AustraliaAbstract presented at the Australasian Professional Society on Alcohol and other Drugs Conference 2013, 24-27 November 2013, Brisbane, Australia