Waterborne Toxicity to Neotropical Invertebrates and Hazard of Cigarette Butt Leachates in Marine Environments.

Cigarette butts (CBs) are the most common type of beach litter worldwide and contain a complex mixture of chemicals. Given the recent interest in this emerging problem, it is important to assess the toxicity of CB leachates to a range of species from different regions, sensitivities, and ecological traits. We evaluated the waterborne toxicity of smoked CB to tropical invertebrates. Leachates were prepared in the laboratory and characterized for trace elements (Mn, Fe, Co, Ni, Cu, Zn, As, Cd, and Pb), ammonia nitrogen, and polycyclic aromatic hydrocarbons. Then a set of toxicity tests with marine invertebrates was performed as follows: the brine shrimp Artemia sp. (nontoxic); the amphipod Tiburonella viscana (median lethal concentration [LC50] of 0.038 CB/L); the tanaid Monokalliapseudes schubarti (LC50 of 0.126 CB/L); the copepods Tisbe biminiensis (median effect concentration [EC50] of 0.038 CB/L) and Nitokra sp. (EC50 of 0.009 CB/L); pluteus stage larvae of the sea urchin Echinometra lucunter (EC50 of 0.152 CB/L); the sand dollar Mellita quinquiesperforata (EC50 of 0.054 CB/L); and D-stage larvae of the mussel Perna perna (EC50 of 0.005 CB/L). The predicted no-effect concentration was estimated using species sensitivity distribution, producing a 5th percentile hazard concentration of 0.015 CB/L. This preliminary threshold allowed us to estimate the potential impact of a single CB to 67 L of seawater via leaching, contributing to the advancement of knowledge regarding the contamination, toxicity, and ecological risks of cigarette waste. Environ Toxicol Chem 2024;43:374-384. © 2023 SETAC.

Occurrence, characterization, partition, and toxicity of cigarette butts in a highly urbanized coastal area.

Cigarette butts (CBs) comprise one of the most relevant categories of marine litter worldwide. This study was structured as a case study simultaneously assessing (i) the occurrence of CBs in a highly urbanized coastal area, (ii) their partitioning in two environmental compartments (water column and sediments) by laboratory settling tests, and (iii) the toxicity produced by the CBs leachates (measured as copepod reproduction). Marine litter was sampled in beaches of the city of Santos (SW Brazil) and CBs were collected for analysis. The characterization showed that CBs were one of the most prevalent items (51.5% in summer and 34.4% in winter) and 22 cigarettes brands were identified at different stages of decomposition. Laboratory settling tests showed that CBs remain in the water column between 3 and 20 days, subsequently reaching the sediments. The toxicity results indicated that CBs the leachates extracted from a small amount of CBs was sufficient to affect copepod reproduction (0.1 and 0.01 CBs L-1). Furthermore, the approaches adopted by the present study can serve as a preliminary assessment to estimate local impacts resulting from inadequate disposal of cigarette butts in coastal areas around the world.