Comparing the Effects of Microplastics From Conventional Cigarette Butts and Heated Tobacco Device: The Role of...

Despite the widespread presence of cigarette butts in the environment, the potential toxicological effects posed by microplastics (MPs) derived from them remain poorly understood. In this study, we compared the effects of MPs from conventional cigarette butts (cellulose acetate) and heated tobacco devices (cellulose acetate and polylactic acid film), the latter being under-investigated. We also compared their effects before and after UV-accelerated aging. The most notable change in chemical properties of MPs following UV aging was a significant reduction in nicotine content, which fell below detection limits, while elemental composition remained largely unchanged. The surface of particles remained unchanged, but the size of heated tobacco devices cellulose acetate MPs also fragmented to smaller sizes. The effects were evaluated using Daphnia magna (48 h immobilization; 1, 10, 100 mg L^-1), Lemna minor (168 h growth inhibition; 100 mg L^-1), protozoan Tetrahymena thermophila (24 h, 100 mg L^-1) and in vitro cytotoxicity test model using A549 human lung cells (24 h, 100 mg L^-1). Toxicity tests revealed no significant effects of all types of MPs on any of used test models. UV-aging of MPs did not change the toxicological profile. Our findings showed that cigarette butt-derived MPs represent a complex mixture of polymers, residual nicotine, and metals. Comparing this research to previous studies suggests that MPs from different cigarette brands vary in chemical composition and toxicological potential.