Epsilon Archive for Student Projects

Abstract

The COVID-19 pandemic and the related measures have highly impacted our daily lives through social distancing and the general restriction of our mobility. This resulted in distress for the population and led to behavioral changes, for instance in our eating behavior. A wastewater-based epidemiology (WBE) study was performed to study changes in the eating behavior during the pandemic by analyzing artificial sweeteners in the wastewater of Uppsala (Sweden), using direct injection and high performance liquid chromatography coupled to a tandem mass-spectrometer (HPLC-MS/MS). The results showed that no changes in the consumption pattern of artificial sweeteners were relatable to the COVID-19 pandemic and the national regulations. The temporal comparison revealed however an increased trend of artificial sweetener loads in Uppsala over time, showing an annual increase rate of 8.6% for saccharin, 12.3% for acesulfame and 20% for sucralose between 2019 and 2022. A spatial comparison showed that different locations in Sweden have a similar usage pattern, but that the amount of consumed artificial sweeteners varies spatially. In a second part of the thesis, one of the biggest uncertainties of WBE studies were addressed: the correct estimation of the population size. The second part focused on finding suitable population biomarkers for Sweden. 23 candidates were analyzed in the wastewater and their mass loads were correlated to varying population sizes in Sweden in order to assess their suitability as population markers. Seven out of these 23 candidates were assessed for the first time in the context of population estimation: saccharin, surcralose, metformin, theophylline, citalopram, venlafaxine and its metabolite O-desmethylvenlafaxine. The results showed that 21 compounds, including the seven new propositions, showed a good correlation to the population size and were therefore considered suitable population markers. This knowledge will be helpful to develop a population model that can be used to dynamically estimate the population size for future WBE studies.