Leached Compounds from Smoked Cigarettes and Their Potential for Bioaccumulation in Rainbow Trout (Oncorhynchus mykiss)

Toxicological assessment of cigarette filter-derived microplastics in Daphnia magna

Cigarette filters are the most common form of litter worldwide and pose significant ecological risks because they degrade into microfibers and microplastics in aquatic environments. While previous studies have focused on the acute toxicity of cigarette leachate, the long-term ecological consequences of microplastic release from cigarette filters remain largely unexplored. This study evaluated the toxicity of cigarette filter-derived microplastics, including non-smoked cellulose acetate filters (CAF), smoked cigarette filters (GSF), on Daphnia magna, as well as leachate from smoked filter (LSF) for comparison. Imaging analysis confirmed that D. magna ingested cigarette filter-derived microplastics, which acted as carriers, gradually releasing harmful substances within organisms, a phenomenon consistent with the Trojan horse effect. Acute toxicity tests revealed similar 48-hour EC50 values (∼50 mg/L) for both GSF and LSF; however, GSF induced more pronounced long-term toxic effects. Chronic exposure to GSF significantly impairs reproduction, delays the timing of the first brood, reduces offspring size, and disrupts ecdysteroid-regulated genes. These findings indicate that cigarette filters are a persistent source of chemical pollution, threatening aquatic ecosystems. Specifically, microplastics from discarded cigarette filters act as Trojan horses, continuously releasing toxic chemicals and transporting hydrophobic contaminants, amplifying their environmental impact.

Bioaccumulation of polycyclic aromatic hydrocarbons from leachates of waterpipe tobacco wastes on Peronia peronii species from the Persian Gulf region

This study examines the bioaccumulation factor (BAF) of polycyclic aromatic hydrocarbons (PAHs) in Peronia peronii (as the bio-indicator organism) exposed to the leachate resulting from fruit-flavored and traditional burnt tobacco wastes. The ƩPAHs concentrations in the muscle samples of P. Peronii of exposed group I (organisms exposed to the leachate resulting from fruit-flavored waterpipe tobacco wastes) and exposed group II (organisms exposed to the leachate resulting from traditional waterpipe tobacco wastes) and control group (exposed to natural seawater) were 37.49 ± 12.9, 9.32 ± 3.8, and 3.89 ± 1.9 ng/g, respectively. Furthermore, there was a significant difference between the mean values of all ƩPAHs compounds in the three groups (group I, group II, and control). The mean Log BAFs in P. Peronii exposed to fruit-flavored and traditional tobacco waste leachates were ranged from 1.70 to 3.61 and 2.49 to 3.07, respectively. The mean Log BAFs of none of the PAHs compounds did not exceed 3.7 (the limit set as "bio-accumulative") in none of the leachates (fruit-flavored or traditional). In the organisms exposed to the leachates resulting from fruit-flavored tobacco waste, Log BAFs of Benzo[b] fluoranthene (BbF), benzo(a)anthracene (BaA), and chrysene (Chr) lay within the range of 3.3-3.7 ("potentially bio-accumulative"). However, in the organisms exposed to the leachates resulting from traditional tobacco waste, the mean Log BAFs of all compounds did not reach even 3.3. The findings of our study indicate that leachates from tobacco waste, pose significant environmental and health hazards. Considering the prevalence of tobacco smoking, suitable strategies should be employed for management of these hazardous wastes to protect the environmental health.

Estimating the accumulation and re-accumulation of commercial tobacco, electronic cigarette, and cannabis waste based on a stratified random sample of census blocks

We investigated the amount and distribution of waste generated by commercial tobacco, electronic cigarette, and cannabis (TEC) use to inform policy options aimed at mitigating the environmental harm caused by these products. Using disproportionate stratified random sampling, we selected 60 census blocks from the eight largest cities in San Diego County, California. We twice surveyed publicly accessible areas in these blocks to quantify TEC waste accumulation and its re-accumulation. All collected items were photographed, classified, geocoded, counted, and properly discarded. We identified demographic, land use, and behavioral data from public sources and direct observations. We modeled total cigarette butt quantities for all census blocks across the eight cities and found similar results for Round 1 (8.63 million) and Round 2 (8.66 million) collections. Single-use plastic cigarette filters were the primary contributor to TEC waste (94%). Total TEC waste counts and cigarette butt counts showed strong linear associations (r = +0.86 and r = +0.91). The area surveyed, land use category, resident demographics, smoking prevalence, and walkability explained 78% of the variance in cigarette butt count. The interval between Round 1 and 2 counts did not affect re-accumulation counts, suggesting that baseline TEC waste levels were re-established within 1-2 months after cleanup. Annually, we estimate up to 200 million cellulose acetate plastic filters may be discarded in public areas of the eight cities. Given the continuous deposition, vast quantity, heterogeneous distribution, and rapid re-accumulation of TEC waste after cleanup, increasing removal efforts alone are financially untenable and impractical downstream solutions for TEC waste. Community-wide policies (e.g., filter bans, outdoor smoking restrictions) and individual behavior changes (e.g., reduced smoking rates, proper disposal of cigarette butts) are necessary to effectively mitigate the environmental impact of TEC waste in urban settings.

Cigarette butts in Vietnam's marine environments: From pollution to solutions and prospects

Cigarette butts contain over 4000 toxic chemicals, including nicotine, tar, and heavy metals. More than 90 % of cigarettes sold today feature single-use plastic filters composed of cellulose acetate fibers and various additives. Cigarette butts are hazardous waste that pose significant risks to ecosystems and human health. Littered cigarette butts can act as an essential vehicle for toxic chemicals in the water environment. Cigarette butts contribute to gradual environmental degradation by releasing heavy metals such as lead (Pb), cadmium (Cd), chromium (Cr), copper (Cu), vanadium (V), nickel (Ni), and arsenic (As). Recent reports highlight the alarming increase in cigarette butt pollution on beaches, emphasizing the significance of commercial cigarette filters as single-use plastics and the primary contributors to this environmental threat. Given their potential toxicity, the research community has increasingly focused on understanding the profound impact of cigarette butt pollution on freshwater bodies, marine ecosystems, and terrestrial environments. However, there remains a considerable gap in knowledge regarding the extent of cigarette butt pollution, especially on Vietnam's beaches. While cigarette butts are a pervasive form of litter globally, little is known about their environmental effects, accumulation patterns, potential toxicity, and impacts on the coastline of Vietnam. This underscores the need for an in-depth investigation into this issue, expressing disappointment over the limited research conducted in coastal areas thus far. This article advocates for active participation from the scientific community to bridge this gap, asserting that collaborative research efforts will bring attention to and address the critical issue of cigarette butt pollution in Vietnam's regions and potential harm to natural ecosystems. Furthermore, enhancing research efforts to understand and mitigate cigarette butt pollution on Vietnam's beaches is crucial for achieving sustainable development goals (SDGs).

Cigarette butts enable toxigenic cyanobacteria growth by inhibiting their lethal fungal infections

Cigarette butts (CBs), of which around 4.5 trillion are discarded annually, are one of the most common types of litter worldwide. CBs contain various chemicals, including metals, nicotine, and polycyclic aromatic hydrocarbons, which can leach into water and pose a threat to aquatic organisms such as cyanobacteria and chytrid fungi. Chytrids, zoosporic fungi that parasitize cyanobacteria lethally, play a crucial role in regulating cyanobacteria blooms by delaying or suppressing bloom formation. Despite the prevalence of CBs in the environment, the impact of their leachates on cyanobacteria-chytrid interactions is not well understood. We assessed the effects of CB leachate on the interaction between the toxigenic cyanobacterium Planktothrix agardhii and its chytrid parasite Rhizophydium megarrhizum. CB leachate inhibited cyanobacterial growth in uninfected cultures. Infection prevalence decreased at 0.2, 2, and 10 CB L-1, with the two highest concentrations completely suppressing infection. Interestingly, at the highest CB concentration, cyanobacterial biomass in infected cultures was comparable to that of uninfected cultures not exposed to CB leachate, suggesting that the presence of chytrids mitigates the impact of the leachate. This study demonstrates that CB leachates are a potential environmental hazard that can enable cyanobacterial growth by inhibiting chytrid infections during epidemics. In addition, our research highlights the importance of assessing the effects of chemical mixtures, such as those leached from CBs, on multi-species interactions, such as host-parasite dynamics. These assessments are crucial to better understand the impact of pollutants on aquatic ecosystems.

A review on cigarette butts: Environmental abundance, characterization, and toxic pollutants released into water from cigarette butts

Every year, trillions of cigarette butts (CBs) are discarded into the environment. CBs are frequently found on beaches and in urban areas worldwide due to their high resistance to physical and biological degradation. Components of CBs, such as heavy metals, polycyclic aromatic hydrocarbons (PAHs), cellulose acetate fibers (microplastics), nicotine, aromatic amines, and BTEX (benzene, toluene, ethylbenzene, and xylene), are released into aquatic environments. Harmful components released into water from CBs cause both water pollution and toxic effects on different aquatic organisms. In the first part of this review, studies investigating the density of CBs in different environments were reviewed. In the second part, the results of studies investigating the characteristics of cigarette filters using characterization techniques were reviewed. Then, studies on heavy metals, PAHs, microplastics (microfibers), nicotine, aromatic amines and BTEX released into water from CBs were reviewed, and factors affecting the types, amounts and release conditions of compounds (pollutants) released into water from CBs were discussed. In the last section, taking into account the studies carried out to date, deficiencies in the research on pollutants released into water from CBs were identified and recommendations were made for future studies. This review highlights the environmental abundance of CBs, the characterization results of CB filters, and the release into water of some substances in CBs that are pollutants for the aquatic environment. This review may serve as a guide to elucidate the environmental abundance of CBs, the characteristics of CBs/filters, and the concentration in water of some pollutants released into water from CBs.