Occupational Exposure Assessment of alpha-Pinene and related Monoterpenes

National Institute Of Environmental Health Sciences

Investigators

Abstract

Monoterpenes are a class of naturally occurring volatile organic compounds (VOCs) that consist of 10 carbons and 16 hydrogens in varying arrangements. Along with being constituents of various coniferous tree species, monoterpenes are also present in cannabis plants, and several citrus species. Because monoterpenes are organic compounds that contain distinct, often pleasant and intense, aromas and flavoring profiles; they have, with increased frequency, been integrated into various consumer products, including food and beverages as flavoring agents, and perfumes, cleaning solutions, and air fresheners as fragrance enhancers. Studies that have assessed the effects of monoterpene exposure on human health have reported associations between monoterpene exposure and acute decreases in lung diffusion capacity, bronchial reactivity, contact allergy and eye irritation. Recent investigations into the association between monoterpene levels and sensory irritation of the nose and throat have suggested that the current OSHA PEL and NIOSH REL may not be adequately protective. While several Northern European studies have examined exposure to monoterpenes in woodworking settings, the range of exposures to monoterpenes in other occupational settings are poorly understood. In FY22, the protocol has proceeded through peer and tripartite review and is currently awaiting final approval by the NIOSH IRB. Several analytical methods are currently under development, including: (a) air method: Storage capacity and humidity evaluation conducted, (b) urine Method: Initial testing of several urinary metabolites conducted utilizing LC-MS/MS method, and (c) blood Method: Parent monoterpene method has been fully validated and is in the reporting stage. The study team also established connections with relevant trade associations and unions and have begun study recruitment with anticipation of beginning field visits in Spring 2023. More than 150 companies have been identified as potential sites for recruitment.