Longitudinal wastewater sampling in buildings reveals temporal dynamics of metabolites

Abstract

Direct sampling of building wastewater has the potential to enable "precision public health" observations and interventions. Temporal sampling offers additional dynamic information that can be used to increase the informational content of individual metabolic "features", but few studies have focused on high-resolution sampling. Here, we sampled three spatially close buildings, revealing individual metabolomics features, retention time (rt) and mass-to-charge ratio (mz) pairs, that often possess similar stationary statistical properties, as expected from aggregate sampling. However, the temporal profiles of features-providing orthogonal information to physicochemical properties-illustrate that many possess significantly different feature temporal dynamics (fTDs) across buildings, with rapid and unpredictable deviations from the mean. Internal to a building, numerous and seemingly unrelated features, with mz and rt differences up to hundreds of Daltons and seconds, display highly correlated fTDs, suggesting non-obvious feature relationships. Data-driven building classification achieves high sensitivity and specificity, and extracts building-identifying features with unique dynamics. Analysis of fTDs from many short-duration samples allows for tailored community monitoring with applicability in public health studies.Wastewater sampling presents a means to monitor the general health 1 , chemical exposure 2,3 , and size 4 of a population in a rapid and noninvasive manner. Many studies have been performed at wastewater treatment plants (WWTPs), as these sites are relatively easy to sample, and yield aggregate information on large populations, e.g. from an entire city 2 . As an example of the correlations that can be captured by such studies, an increase in antipsychotics, antidepressants and other therapeutic drugs was observed in wastewater between 2010 and 2014 in Athens, Greece during a time of significant economic turmoil in the country 5 . Given the proper sampling and analysis methods, wastewater can provide meaningful, community-specific public health information.Most wastewater epidemiology and metabolomics studies have focused on the aggregate chemical load on large populations, typically using targeted metabolomics to acquire highly