Mass Spectrometry-Based Visualization of Molecules Associated with Human Habitats

Abstract

The cars we drive, the homes we live in, the restaurants we visit, and the laboratories and offices we work in are all a part of the modern human habitat. Remarkably, little is known about the diversity of chemicals present in these environments and to what degree molecules from our bodies influence the built environment that surrounds us and vice versa. We therefore set out to visualize the chemical diversity of five built human habitats together with their occupants, to provide a snapshot of the various molecules to which humans are exposed on a daily basis. The molecular inventory was obtained through untargeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of samples from each human habitat and from the people that occupy those habitats. Mapping MS-derived data onto 3D models of the environments showed that frequently touched surfaces, such as handles (e.g., door, bicycle), resemble the molecular fingerprint of the human skin more closely than other surfaces that are less frequently in direct contact with humans (e.g., wall, bicycle frame). Approximately 50% of the MS/MS spectra detected were shared between people and the environment. Personal care products, plasticizers, cleaning supplies, food, food additives, and even medications that were found to be a part of the human habitat. The annotations indicate that significant transfer of chemicals takes place between us and our built environment. The workflows applied here will lay the foundation for future studies of molecular distributions in medical, forensic, architectural, space exploration, and environmental applications.

High-Resolution Liquid Chromatography Tandem Mass Spectrometry Enables Large Scale Molecular Characterization of Dissolved Organic Matter

“…In addition, low annotation rates also result from the low number of available library spectra that match compounds in DOM. Nevertheless, the reported annotation rate is in a similar range as other non-targeted metabolomic datasets (Bouslimani et al, 2015;Petras et al, 2016;Floros et al, 2017) that are typically less complex than DOM.…”

Mass Spectrometry Based Molecular 3D-Cartography of Plant Metabolites

“…Another advantage of LC-MS based imaging is that the spatial scale is not limited to instrument based dimensions, typically in the cm range. This enables the molecular 3D imaging of humans (Bouslimani et al, 2015) and their habitats (Petras et al, 2016) up to planetary (km) scale. Since the samples are excised, homogenized, and extracted with organic solvents for LC-MS analysis, it is not compatible with direct imaging of plant tissue.…”

MASST: A Web-based Basic Mass Spectrometry Search Tool for Molecules to Search Public Data

“…[27][28][29][30] To look for sunscreen in environmental samples, MASST found matches to the indoor environment or personal objects such as offices, houses, cars, bikes, phones, wallets, keys, mattresses, plants, meat for human consumption, corals, and even in coral reef in remote areas such as Moorea. [31][32][33] While there have been no identifiable toxic effects on humans 34 , these results show that human-made chemicals may be widely distributed without truly understanding the potential long-term impact.…”