Elucidating nicotine transfer into water environments via cigarette butt remaining parts

Unseen streams tracing emerging contaminants from stormwater to surface water: A brief review

Emerging contaminants (ECs) have raised global concern due to their adverse effect on ecosystems and human health. However, the occurrence and transport of ECs in stormwater remain unclear. The impact of ECs from stormwater on surface water quality and ecosystem health is also poorly documented. In this review, we examined the variations in EC concentrations in surface water resulting from stormwater. During the wet weather, the concentrations of most investigated ECs, e.g., microplastics, per- and polyfluoroalkyl substances, and vehicle-related compounds, significantly increase in surface water, indicating that stormwater may be a critical source of these contaminants. Furthermore, the potential pathways of ECs from stormwater enter surface water are outlined. Studies demonstrate that surface runoff and combined sewer overflows are important pathways for ECs, with discharges comparable to or exceeding those from wastewater treatment plants. Illicit connection also plays an important part in elevated EC concentrations in surface water. Overall, our findings underscore the importance of stormwater as a source for ECs in surface waters, and urge for increased emphasis on, and reinforcement of, stormwater monitoring and control measures to minimize the transport of ECs into receiving water bodies.

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.

Satellite Remote Sensing-Implemented Nontargeted Screening of Emerging Contaminant Fingerprints in a River-to-Ocean Continuum through Interpretable Machine Learning: The Pivotal Intermediary Role of Dissolved Organic Matter

Emerging contaminants (ECs) can exert irreversible health impacts on humans, even at trace concentrations. Currently, nontargeted screening of ECs has been developed for their assessment, which requires sophisticated instrumentation. Although satellite remote sensing is a cost-effective technology for water quality assessment, accurately measuring ECs in a river-to-ocean continuum remains a significant challenge due to their trace levels. To address this challenge, we innovate a strategy utilizing satellite remote sensing to achieve high-resolution nontargeted EC screening. By employing DOM as an intermediary variable, bridging the gap between satellite remote sensing and ECs in river-to-ocean continua. DOM, including the total sum of ECs, reflects their distribution and spectral sensitivity, enabling satellite sensing to capture their unique fingerprints. In this study, this strategy has enhanced the accuracy of nontargeted EC screening from 32.2 to 95.7% using machine learning. Interpretable machine learning causal inference and SHAP models reveal that shortwave infrared (SWIR) S2-B11 is crucial for EC screening while emphasizing the importance of avoiding multicollinearity with similar SWIR band S2-B12. Additionally, the band reflectance is influenced by the proportion of polarity-related heterogeneity in the ECs. Furthermore, we developed a real-time remote sensing surveillance system featuring interactive maps for nontargeted screening of ECs and GPT-based contamination interpretation.

Assessment of nicotine and degradation products in cigarette butts leachates after detoxification by white rot fungi

Cigarette butts (CBs) are widespread hazardous waste contaminating the environment due to the recalcitrance of the filter and the toxicity of the contaminants leached. This paper evaluated through analysis of contaminants and toxicity bioassays on Raphanus sativus seeds, the ability of four fungal strains of white rot fungi to treat cigarette butts, including 2 native strains of Trametes sp. (strains BAFC 4765 and BAFC 4767), one of Irpex lacteus (strain BAFC 4766) and one commercial strain of Pleurotus ostreatus (strain BAFC 2034). Each strain was grown in a medium of water-soaked CBs in axenic conditions at Erlenmeyer-scale during six weeks, analyzing leachate samples periodically by HPLC-MSn. Temporal evolution of nicotine as well as the transformations of tobacco alkaloids and other contaminants generated by the different fungal treatments were characterized. Nicotine was degraded significantly by the end of the treatments although variations were found among the fungal strains, proposing a degradation mechanism based on the 12 tobacco alkaloid transformation products identified. Leachates from CBs showed a total inhibition of germination on Raphanus sativus seeds whereas those obtained after 6 weeks of treatment displayed a significant decrease of phytotoxicity (7-20 % inhibition of germination) exhibiting sublethal effects. The results obtained in this work support the development of CBs fungal treatment for waste detoxification on a larger scale.

Impact of cigarette butts elutriates on Artemia franciscana in a climate change context

Cigarette butts (CBs) are major worldwide pollutants, posing environmental challenges, especially in the current climate crisis. Hence, this study examined the biological responses of Artemia franciscana to smoked (SCBs) and non-smoked (nSCBs) cigarette butt elutriates with increased temperatures. Acute (0.188-4.0 CBs/L, 48 h) and sub-chronic (0.03125-0.5 CBs/L, 7 d) assays were performed, exposing nauplii to two temperatures (25.0 ± 1.0 °C, guideline; and 30.0 ± 1.0 °C, according to IUCN (2017) and European Environment Agency (2023) projections). High acute toxicity was observed: LC50 = 3.98 SCBs/L and an LC50 = 0.94 nSCBs/L at 25.0 °C, with increased toxicity for SCBs (LC50 = 1.26 SCBs/L) at 30.0 °C. The sub-chronic exposure showed that the temperature increase affected the organisms' biological responses to CBs by disturbing the activity of acetylcholinesterase (AChE) and the antioxidant enzymes catalase (CAT) and glutathione S-transferases (GSTs), inducing oxidative damage (thiobarbituric acid reactive substances - TBARS) and influencing energy metabolism (lactate dehydrogenase - LDH). A. franciscana's biological responses emphasize the importance of mitigating CBs pollution by understanding these ecotoxicological implications in a warming world.

The role of different remaining parts of cigarette butts in the transfer of phenolic compounds into the aquatic environment and their ecological risk

Cigarette butts (CBs), the most prevalent waste material globally, have the potential to leach various toxic substances, including phenolic compounds (PhCs), into the environment and aquatic ecosystems. Nevertheless, there is a lack of knowledge concerning the long-term release of PhCs via the different parts of CBs which are littered into the environment. Hence, the present study was designed to investigate the ecological risk as well as the leachate concentrations of PhCs, including phenol, o-cresol, 2,4-dimethylphenol, pentachlorophenol and 2,3,4,6-tetrachlorophenol via different parts of CBs littered into water at several exposure times. Aged CBs collected from the environment, freshly smoked CBs, filter and paper, and remaining tobacco plus ash of freshly smoked CBs were studied to determine the leachate levels of PhCs. Pentachlorophenol and 2,3,4,6-tetrachlorophenol were not detected and quantified in the leachates of all CB types at all exposure times. The combination of filter and paper from freshly smoked CBs exhibited the highest mass-based leachate levels of phenol, o-cresol, and 2,4-dimethylphenol, whereas aged CBs showed the lowest levels. The mean leachate of phenol, o-cresol, and 2,4-dimethylphenol from all four examined CB types were in the ranges of 0.43-639.56, 0.77-58.61, and 0.25-16.58 μg L-1 per CB, respectively. The ecological risk assessment showed that PhC leachates via all CB types had high risks for algae, Daphnia magna, and fish. The present study elucidated the release behavior of several PhCs and toxic CB-associated contaminants that have been overlooked in the literature.

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).

Improper disposal of cigarette butts in a southeast Asian megacity (Hanoi, Vietnam): Pollution indexes, distribution profiles, and preliminary physicochemical characterization

Although Southeast Asia is among the largest producers and consumers of cigarettes in the world, information about environmental contamination with littered cigarette butts (CBs) in this region is very limited, especially in urban areas. In this study, we collected CBs in 58 locations of 6 categories (i.e., parks, apartments, streets, shopping malls, universities, and relic sites) in Hanoi, a megacity of Vietnam, to elucidate the occurrence, pollution levels, and physicochemical properties of this specific waste type. A total of 25,943 CBs with 86 brands from 16 origin countries was obtained, showing a density range of 0.0056 to 1.16 (mean 0.125) CB/m2 and cigarette butt pollution index (CBPI) range of 0.23 to 86.9 (mean 6.14). CB contamination levels were higher in parks, apartments, streets, and shopping malls than in universities and relic sites, but CB density and CBPI values varied greatly between locations of the same category. Generally, CB contamination levels measured in Hanoi were within a moderate range compared to other countries worldwide. Several physicochemical properties of CBs were preliminarily determined, which partly confirmed the formation of smoking-derived chemicals captured in CBs and their release potentials into surrounding environments. Further investigations are required to evaluate detailed chemical profiles, leaching behavior, and toxic effects of hazardous substances in CBs.

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.

Peronia peronii as a bio-indicator to assess the toxicity of waterpipe tobacco leachates in aquatic and sediment media

This study was aimed to survey toxicity of waterpipe wastes leachates on Peronia peronii in aquatic and sediment environments as two exposure media. For this, leachates of four tobacco types including burnt traditional tobacco (BTT), fresh traditional tobacco (FTT), burnt fruit-flavored tobacco (BFT) and fresh fruit-flavored tobacco (FFT)) were prepared and used to assess their toxic effects on P. peronei in two aquatic and sediment media. The in-vivo toxic effects of five different concentrations of waterpipe tobacco waste leachates on P. peronii were evaluated. The LC50 values of BTTs leachates to P. peronii were 17.50, 16.05, 11.31 and 9.38 g/L at exposure times of 24, 48, 72 and 96 h, respectively in aquatic media. These values for BFTs leachates were 14.86, 12.38, 9.53 and 7.46 g/L at exposure times of 24, 48, 72 and 96 h, respectively. In the case of sediment media, the LC50 values of BTTs leachates were 15.33, 13.70, 9.09 and 6.70 g/L at exposure times of 24, 48, 72 and 96 h, respectively while these values for BFTs leachates were 12.00, 10.32, 8.20 and 5.65 g/L. Fruit-flavored tobacco leachates had significantly higher toxicity than traditional tobacco leachates for P. peronii. The findings also showed significant differences between the LC50 values of different leachates in different media of water and sediment. The results demonstrated that even small amount of tobacco waste (~ 5 to 6 g/L) can lead to P. peronii mortality and may also pose a hazard to other aquatic and benthic organisms. The results obtained from the present study can be used as a baseline data to assess local effects causing from unsafe disposal of post-consumption tobacco waste in beach areas. In addition, these findings can lead to encouraging decision-makers to focus more on the types of tobacco waste in the municipal solid waste management system and to implement a source separation process for these wastes.

The effect of climatic variables and techno-structural factors on the water pollution caused by nicotine leakage from littered cigarette butts

Nicotine is one of the main pollutants in cigarette smoke that trapped in the filter. Nicotine leakage from cigarette butts is one of the concerns associated with this hazardous waste. In this study, the concentration of nicotine leaked from cigarette butts into the urban environment was investigated under the influence of three parameters including rainfall, density, and the durability of the littered cigarette butt. The leakage of nicotine into the environment was estimated in six scenarios based on the difference in the durability of cigarette butts in the urban environment and the humidity ratio. The results showed that the density of littered cigarette butts was 0.0019-0.294 number/m2. The density of littered cigarette butts in residential land-use was 52.38% lower than commercial land-use. Nicotine leakage from cigarette butts in commercial, residential, and recreational land-uses was 1.1, 0.484, and .0065 mg/m2, respectively. In the studied scenarios, in the best and worst case, 335,070 and 481,950 gr/year of nicotine will leak from the cigarette butt into the water resources. Considering that cigarette butts are a serious source of toxins including nicotine to the environment, control measures are necessary to reduce its density in the urban environment.

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.

Cigarette butts as a source of phenolic compounds for the environment

Cigarette butts (CBs) are small residues with mixed composition. Produced in large amounts, their accumulation in the environment has become alarming. It is possible to classify more than 7000 chemical components generated either in the burning process or when distilled from the tobacco. The aim of this work was to describe the rate of release of phenolic compounds from CBs, to determine the content of these compounds in freshly smoked CBs and to monitor the release of phenols from CBs into fresh natural waters. The kinetics of release of selected phenolic compounds (hydroquinone, resorcinol, pyrocatechol, phenol, guaiacol, o-cresol, m-cresol, p-cresol) into water was monitored for 48 h. More than 90% of the content was extracted within 10 h for all analytes. The phenolic content was determined in the CBs of five different brands. The total content of phenols determined for each sample of freshly smoked CB was 215-861 µg/CB. For all CBs analysed, phenol, pyrocatechol and hydroquinone were the most abundant analytes, accounting for up to 75% of the content of all phenols determined. Phenol was the most abundant analyte (64.6-267.8 µg/CB) in all analysed samples. The content of pyrocatechol, the second most abundant analyte, was 45.6-221.2 µg/CB and the third most abundant analyte was hydroquinone (41.71-157.5 µg/CB). Monitoring the release of phenols from CBs into fresh natural waters (river, stream, pond) under steady and slight moving conditions showed that the kinetics of release is not influenced by the type of water. On the contrary, the process of decomposition of the released compounds is influenced by the type of water. The maximum concentrations of individual phenols in CBs extracts were comparable to those determined via laboratory extraction, thus indicating that within 72 h, most of the phenolic compounds are released from CBs into natural water. This research provides missing information on the phenolic content in CBs and the rate of release into water. It thus complements previously published information on CBs as a source of environmental contamination.

Quality variations of leachate resulting from cigarette filter recycling as a challenge for its management

Recycling is known as a solution for cigarette filter management, but this may cause the release of trapped pollutants in it. Cigarette smoke toxins and chemicals that trapped in the cigarette filter can accumulate in the recycling leachate. In this study, littered cigarette filters and freshly smoked cigarette filters were recycled and the resulting leachate was analyzed. The results showed that the minimum and maximum Chemical Oxygen Demand (COD) of the studied leachates were 2100 mg/L and 11,300 mg/L, respectively. The maximum temporal variation in the studied leachate quality was 74.28%, but the maximum spatial variation was 314.2%. COD in the freshly smoked sample was 2600-9200 mg/L more than the littered samples. The average concentration of chromium, lead, nickel, and cadmium in littered samples was 0.023, 0.024, 0.045, and 0.019 mg/L, respectively. Environmental conditions such as humidity, the efficiency of the urban cleaning system in reducing the resistance of littered filters, the difference in the quality of the filter and tobacco, and the difference in smoking behaviors were effective in this variation. Reducing the toxicity of cigarette smoke and improving the efficiency of the urban cleaning system can lead to the same quality, but leachate treatment is necessary to reduce the environmental risk.