Abstract
Chemical toxicants released into the environment during the use of tobacco and nicotine products potentially give rise to an elevated health risk among non-users. The aim of this study was to assess the levels of a wide range of chemical toxicants in the indoor air of an unventilated testing facility during various scenarios of tobacco and nicotine product use, including the use of conventional waterpipes, electronic vaping products (EVPs, also known as e-cigarettes), an electronic waterpipe which uses electrical heating of shisha tobacco instead of conventional charcoal heating, and combustible-cigarettes. In the one-occupant scenarios, increases in PM10 and PM2.5 were greatest during conventional waterpipe use, approximately 40% lower for OOKA electronic waterpipe use, and lowest for EVP use. An increase in the combustion by-product CO was greatest for conventional waterpipe use, and substantially lower for EVP and OOKA electronic waterpipe use, with the latter generating only a negligible amount of CO. The increase in formaldehyde levels was greatest for conventional waterpipe use, and substantially lower for OOKA electronic waterpipe use. In ten-occupant product use scenarios, increases in PM10 and PM2.5 were greatest for EVP use and slightly lower for OOKA electronic waterpipe use, lower during the cigarette smoking scenario, and lowest for the unattended conventional waterpipes scenario. Increases in CO and formaldehyde were highest for the conventional waterpipes scenario, substantially lower during cigarette smoking, and negligible for OOKA electronic waterpipe and EVP use. Increases in several other volatile organic compounds and some polycyclic aromatic hydrocarbons were mainly seen only during cigarette smoking and were negligible during the other product use scenarios. This pattern was similar for the tobacco-specific nitrosamines NNN, NNK, and NAT. These findings have important implications concerning the potential for secondhand toxicant exposure among waterpipe non-users, and for understanding how to potentially reduce health risks associated with such exposure. [Contrib. Tob. Nicotine Res. 34 (2025) 230–241]