Analysis of university workplace building surfaces reveals usage-specific chemical signatures

Abstract Western people now spend close to 90% of their time indoors, one-quarter of which occurs at their place of employment. As such, interactions between employees and the workplace built environment have significant potential impact on employee health and safety. However, the range of workers’ daily chemical exposures is still poorly understood. Likewise, the influence of workers themselves and of worker behavior on the chemical profile of workplace surfaces is still unknown. In this case study, we used untargeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) to compare the chemical signatures of three different university workplaces: scientific research buildings, office buildings, and one mixed-purpose, high-traffic building housing teaching areas, student training laboratories, and offices. Our results identified differential signatures of public building surfaces based on building purpose and occupant behavior, sampling location and surface materials. Detected chemicals include occupant-derived molecules and molecules linked to human behavior such as cleaning products, medication, and food-derived molecules. The latter were particularly common in areas associated with food consumption such as refrigerators, microwaves and garbage cans. We also observed higher chemical diversity on metal surfaces, likely because these represent frequently-touched building areas such as door handles. Overall, these results are helping define the influence of human behavior on the workplace chemical environment and identify workplace daily chemical exposures.