How leachates from wasted cigarette butts influence aquatic life? A case study on freshwater mussel Anodontites trapesiali

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.

Negative effects of cigarette butt leachate on freshwater phytoplankton communities

We experimentally tested the effects of different concentrations of cigarette butt leachate on freshwater phytoplankton chlorophyll-a, species richness, cell density, and community composition. For this, we sampled the phytoplankton from a eutrophic lake and acclimated it for 24 h in microcosms. We then conducted the experiment in microcosms maintained for 96 h. The experiment consisted of four treatments: control and leachate from 1 butt L-1 (T1), 5 butts L-1 (T5), and 10 butts L-1 (T10), which were prepared by diluting a stock solution of leachate from 50 butts L-1. We found that algal chlorophyll-a content was not affected by different leachate concentrations. In contrast, phytoplankton cell density decreased in a dose-dependent manner as concentrations of the leachate increased. Similarly, the number of species was highest in the control group relative to all other treatments, with T1 and T5 showing higher species richness than T10. Additionally, the exposition to different concentrations of the leachate impacted community composition across all treatments in comparison to the control group. Our results suggest that cigarette butt leachate alters the number of cells and species, as well as the distribution of abundance, without necessarily reducing chlorophyll-a concentrations. Our findings indicate that to gain a comprehensive understanding of the effects of cigarette butt leachate on freshwater ecosystems, it is essential to evaluate more realistic scenarios that incorporate aquatic communities, rather than isolated species.

Toxicity of leachate from smoked cigarette butts to terrestrial animals: A case study on the earthworm Eisenia fetida

Cigarette butts, as easily overlooked littered wastes, have been evaluated for toxicity in various researches. In this study, we investigated the toxic effects of smoked cigarette butt leachate (SCBL) on the earthworm Eisenia fetida. The results showed the following: 1) E. fetida avoided SCBL in artificial soil, and the avoidance rate was positively correlated with the concentration of SCBL but negatively correlated with the exposure time; 2) the LD50 of SCBL on earthworms at 36 and 48 h of exposure were 3.71 × 10-4 and 2.67 × 10-4 butts/cm2, respectively. Moreover, both the body surface and intestinal tissues of E. fetida were damaged after exposure to SCBL; 3) the survival rates of E. fetida exposed to artificial soil with an SCBL of 3.6 butts/kg for 7 and 14 days were 80.00 ± 7.07 % and 68.00 ± 4.47 %, respectively; and 4) the mean biomass of the surviving E. fetida in all treated groups decreased with increasing SCBL concentration and exposure time. We concluded that SCBL exerted significant negative effects on soil animals, and suggested that SCBs should be collected, detoxified, and reused before entering the natural environment.

Toxic effect of cigarette butts leachates on blood markers of Periophthalmus waltoni species from the Persian Gulf region

Cigarette butts (CBs) are one of the most common, long-lasting, and toxic forms of marine and coastal area debris. Although the significance of CBs and the toxic contents of this waste items are well recognized, but there is still a lack of information about the effects of this waste on the aquatic organisms. Therefore in this study, the in-vivo toxic effects of various CBs leachates (smoked cigarette butts with tobacco [SCBs], smoked CBs without tobacco [SFs], and unsmoked filters [USFs]) on cellular and chemical hematologic markers in fish (Periophthalmus waltoni) were evaluated. In three acute, sub-acute, and sub-chronic exposure measurements, P. waltoni exposed to different CBs leachates showed a significant increase in white blood cells, creatine kinase, lactate dehydrogenase, alkaline phosphatase, alanine transaminase, and aspartate transaminase, as well as a decrease in hemoglobin (Hb) levels. The mean ± SD values of Hb in P. waltoni species exposed to different CBs leachates (control, SCBs, SFs and USFs) in acute (1 day) phase were 7.15 ± 0.34, 6.02 ± 0.29, 6.25 ± 0.25 and 6.89 ± 0.1 g/dl respectively. These values in subacute (28 days) phase were 6.70 ± 0.15, 5.19 ± 0.24, 5.67 ± 0.30 and 6.10 ± 0.24 g/dl and in sub chronic exposure (42 days) phase were 7.20 ± 0.40, 5.16 ± 0.30, 5.88 ± 0.34 and 6.60 ± 0.33 g/dl respectively. Our results showed that CBs leachates act as a stressor, leading to changes in some hematologic markers in P. waltoni species. Because of the continued deposition of CBs waste into global aquatic environments, policies to mitigate this waste in coastal areas are needed to prevent potentially negative effects on fish and other aquatic organisms.

Small Butt Harmful: Individual- and Population-Level Impacts of Cigarette Filter Particles on the Deposit-Feeding Polychaete Capitella teleta

In the marine environment, discarded cigarette filters (CFs) deteriorate and leach filter-associated chemicals. The study aim was to assess the effects of smoked CFs (SCFs) and non-smoked CFs (NCFs) particles on individual life-history traits in the deposit-feeding polychaete Capitella teleta and extrapolate these to possible population-level effects. C. teleta was exposed to sediment-spiked particles of NCFs and SCFs at an environmentally realistic concentration (0.1 mg particles g^-1 dw sed) and a 100-fold higher (10 mg particles g^-1 dw sed) concentration. Experimental setup incorporated 11 individual endpoints and lasted approximately 6 months. There were significant effects on all endpoints, except from adult body volume and egestion rate, in worms exposed to 10 mg SCF particles g^-1 dw sed. Although not statistically significant, there was ≥50% impact on time between reproductive events and number of eggs per female at 0.1 mg SCF particles g^-1 dw sed. None of the endpoints was significantly affected by NCFs. Results suggest that SCFs are likely to affect individual life-history traits of C. teleta, whereas the population model suggests that these effects might not transform into population-level effects. The results further indicate that chemicals associated with CFs are the main driver causing the effects rather than the CF particles.

Aromatic amines leachate from cigarette butts into aquatic environments: Is there risk for water organisms?

There are many toxics, such as aromatic amines (AAs), in cigarette butts (CBs). As CBs are the most abundant litter worldwide, these chemicals may leach into water bodies. In the present work, for the first time, the levels of AAs leachates from CBs in distilled water (DW) and river water (RW) samples were evaluated at different exposure times ranging from 15 min to 30 days. The mean leachate levels of AAs in DW and RW samples were in the range of 0.2-566 and 0.2-596 ng L^-1, respectively, with overall mean values of 569 and 556 ng L^-1. There was no significant difference (p > 0.05) between the total AAs levels as well as the level of each examined AA in DW and RW samples. Aniline (ANL) had the highest leaching rate from CBs into water. The mean leachates of AAs from CBs into water were ranked as: ANL> 1-naphthylamine (1-NA)> 2-naphthylamine (2-NA) > 2,6-dimethylaniline (2, 6-DMA)> ∑toluidine (∑TOL)> o-anisidine (o-ASD)> ∑aminobiphenyl (∑ABP). Ecological risk assessment showed that ∑7AAs, ANL, p-TOL, o-TOL, 2-NA, and ∑ABP had medium risks to sensitive crustaceans and fish. As AAs are not the only hazardous chemicals which may leach from CBs into aquatic environments, restrictions on littering CBs into the environment are required due to the release of different toxics ultimately causing adverse effects on aquatic organisms.

Chemical contents and toxicity of cigarette butts leachates in aquatic environment: A case study from the Persian Gulf region

Cigarette butts (CBs) are one of the most commonly found types of litter contaminating the aquatic environment. However, the environmental risks posed by CBs need further investigation. In this study, the in-vivo toxic effects of various concentrations of CB leachates on juvenile (5.45 ± 1.36 gr and 7.08 ± 1.12 cm) fish (Periophthalmus waltoni) were evaluated. The LC50 values of CB leachate from smoked cigarette butts with tobacco (SCB) were 3.75, 3.0, 1.94, and 1.37 CBs/L in 24, 48, 72, and 96 h exposure times, respectively. The LC50 values for leachate of smoked CBs without tobacco (SF) were 7.58, 6.22, 4.73, and 2.9 CBs/L at 24, 48, 72, and 96 h exposure times, respectively. In the case of leachate from unsmoked filters (USF), LC50 values were 14.68, 12.44, 10.19, and 7.46 CBs/L in 24, 48, 72, and 96 h exposure time, respectively. The mean concentrations of heavy metals and polycyclic aromatic hydrocarbons in SCBs leachates were higher than in SF and USF leachates. Our findings report that even low concentrations of CBs leachates can led to lethality of P. waltoni and may pose a threat to their population density.

Toward a sustainable circular economy for cigarette butts, the most common waste worldwide on the coast

The circular economy is based on the maximum use of resources by reducing, reusing, and recycling the elements used. Currently, the items littered most frequently in the world are cigarettes butts (CB) as these debris are freely disseminated in the marine habitat, they are generally difficult to collect and very complex to recycle. Litter CB is a great social problem that generates excessive economic costs and serious environmental problems. CB is also not biodegradable and highly toxic to marine organisms and presents a distinctive mixture of physical and chemical contamination. However, little research has been done on the management and recycling of this dangerous waste. Several proposals have been made to incorporate this waste into high-volume articles of direct production or recycling, but collection logistics are lacking since the current system is inefficient, in addition to the poor environmental behaviour of citizens. This work presents a current synthesis of the CB problem from all its possible aspects in order to have a global vision of the life cycle of the CB, indicating both the known and the gaps in the knowledge of each of them, and intends to give a general outline of the steps to follow to try to end such a worrying problem at the global level.

Aromatic amines contents of cigarette butts: Fresh and aged cigarette butts vs unsmoked cigarette

Cigarette butts (CBs) are some of the most abundant waste items in the environment and may contain high levels of different toxic chemicals, such as aromatic amines (AAs). However, to this date, there is no comprehensive study on the role of CBs in the emission of AAs into the environment. The present study investigated for the first time the concentration levels of 10 primary aromatic amines (PAAs), including ANL, p-TOL, m-TOL, o-TOL, 2,6-DMA, o-ASD, 2-NA, 1-NA, 3-ABP, and 4-ABP that were measured and compared in unsmoked cigarette, freshly smoked CBs, and CBs collected from urban streets (named here aged CBs). The mean levels of ∑PAAs in different sample categories were statistically significantly different and the mean level order was as freshly smoked CBs > aged CBs > unsmoked cigarette with the values of 3.43, 2.12 μg g-1, and 0.28 μg g-1, respectively. The levels of ∑PAAs, ANL, o-ASD, 2,6-DMA, 2-NA, and ∑TOL dramatically increased by 12.26, 4.05, 8.46, 10.41, 4.78, and 28.84 times, respectively, right after smoking comparing the freshly smoked CBs samples and unsmoked cigarette. The results also showed a substantial decrease in the levels of PAAs (except o-ASD) in the aged CBs samples compared to freshly smoked CBs. The levels of ∑PAAs, o-ASD, 2,6-DMA, ∑TOL, ANL, 2-NA, 1-NA, and ∑ABP decreased 1.62, 1.09, 1.91, 3.20, 3.42, 2.63, 2.00, and 1.88 times, respectively. Considering the average PAAS content and estimated CBs littered worldwide every year, freshly smoked CBs can theoretically emit 2.9 tons of ∑PAAs into the environment annually. Considering other chemicals that may also be released into the environment via CBs (beside PAAs), we can consider CBs as a critical source of toxic compounds into the environment and water bodies.

ECORISK2050: An Innovative Training Network for predicting the effects of global change on the emission, fate, effects, and risks of chemicals in aquatic ecosystems

By 2050, the global population is predicted to reach nine billion, with almost three quarters living in cities. The road to 2050 will be marked by changes in land use, climate, and the management of water and food across the world. These global changes (GCs) will likely affect the emissions, transport, and fate of chemicals, and thus the exposure of the natural environment to chemicals. ECORISK2050 is a Marie Skłodowska-Curie Innovative Training Network that brings together an interdisciplinary consortium of academic, industry and governmental partners to deliver a new generation of scientists, with the skills required to study and manage the effects of GCs on chemical risks to the aquatic environment. The research and training goals are to: (1) assess how inputs and behaviour of chemicals from agriculture and urban environments are affected by different environmental conditions, and how different GC scenarios will drive changes in chemical risks to human and ecosystem health; (2) identify short-to-medium term adaptation and mitigation strategies, to abate unacceptable increases to risks, and (3) develop tools for use by industry and policymakers for the assessment and management of the impacts of GC-related drivers on chemical risks. This project will deliver the next generation of scientists, consultants, and industry and governmental decision-makers who have the knowledge and skillsets required to address the changing pressures associated with chemicals emitted by agricultural and urban activities, on aquatic systems on the path to 2050 and beyond.

Bivalve Haemocyte Subpopulations: A Review

Bivalve molluscs stand out for their ecological success and their key role in the functioning of aquatic ecosystems, while also constituting a very valuable commercial resource. Both ecological success and production of bivalves depend on their effective immune defence function, in which haemocytes play a central role acting as both the undertaker of the cellular immunity and supplier of the humoral immunity. Bivalves have different types of haemocytes, which perform different functions. Hence, identification of cell subpopulations and their functional characterisation in immune responses is essential to fully understand the immune system in bivalves. Nowadays, there is not a unified nomenclature that applies to all bivalves. Characterisation of bivalve haemocyte subpopulations is often combined with 1) other multiple parameter assays to determine differences between cell types in immune-related physiological activities, such as phagocytosis, oxidative stress and apoptosis; and 2) immune response to different stressors such as pathogens, temperature, acidification and pollution. This review summarises the major and most recent findings in classification and functional characterisation of the main haemocyte types of bivalve molluscs.

Potentially toxic elements leachates from cigarette butts into different types of water: A threat for aquatic environments and ecosystems?

Trillions of cigarette butts (CBs) are released into the environment and the leached potentially toxic elements (PTEs) from CBs may contaminate the environments. In this study, the leaching of PTEs including both heavy metals and metalloids (metal(loid)s) from CBs into deionized water (DW), tap water (TW), and seawater (SW) was checked during the different contact times (from 60 min to 60 days). According to the results, PTEs were leached from CBs into different water samples. However, there were no significant differences between leachates in DW and TW samples (p > 0.05). The results of the distribution coefficient indicated the high tendency of most PTEs to enter the liquid phase. The levels of leached PTEs into DW and TW exceeded the standards of surface freshwater to maintain aquatic life. Although the maximum level of leached metal(loid)s into DW, TW, and SW occurred at different times, for each type of water sample no significant differences were found among the levels of most PTEs at various contact times. Based on the results, the levels of leached metal(loid)s from CBs in seawater peak soon after being released into the water, while for the freshwater, they occur after some days. This phenomenon could possibly have short-term and long-term effects on marine and freshwater organisms, respectively. Due to the ability of the dissolved PTEs to integrate into the aquatic/terrestrial food web and threaten human health, some control measures regarding the disposal of CBs are necessary.

The ecological impacts of discarded cigarette butts

Cigarette butts, one of the most littered items globally, present a unique challenge to ecosystems due to their ubiquity, persistence, and potential for harm. Over 35 studies have examined the toxicity of cigarette butts in biota from aquatic and terrestrial habitats from microbes to mice, but many organisms and habitats have not been tested. Two-thirds of studies are on aquatic organisms, and lethal effects were common. Research on the impacts on terrestrial life is lagging behind. Cigarette butts can affect the growth, behaviour, and reproductive output of individual organisms in all three habitats, but research on wider effects on biodiversity and ecosystem functioning is lacking. Here, we summarise the ecotoxicological concerns and identify important knowledge gaps for future research.

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.

Environmental fate of cigarette butts and their toxicity in aquatic organisms: A comprehensive systematic review

Cigarette butts (CBs) are the most frequently littered pieces of environmental wastes which are released both directly and indirectly into the environment and finally may reach aquatic environments and contaminate aquatic biomes. However, to date, there is no comprehensive review on the extent and magnitude of the potential effects of CBs on aquatic organisms. Hence, a systematic review of published studies was conducted in this paper to survey the fate of CBs in the aquatic environments and also the impacts of exposure to CBs on survival, growth, and reproduction of aquatic organisms. The gathered data showed that the leachates of CBs in the aquatic environment could extremely be toxic for various organisms and increasing the exposure time, increases the mortality rate. In addition, smoked filtered CBs with tobacco remnants have higher mortality rate compared to unsmoked filtered butts (USFs) for Hymenochirus curtipes, Clarias gariepinus, tidepool snails, Atherinops affinis and Pimephales promelas. The fate of CBs in the aquatic environments is affected by various factors, and prior to sinking they are floated for a long time (long distance). Hence, CBs and their associated toxic chemicals might be ingested by diverse aquatic organisms. However, further studies are necessary to understand the exact toxicity of CBs on different freshwater and marine organisms and also their fate in the aquatic media. The results of this review showed the essentiality of regulations to prevent the release of chemical and toxic compounds into the aquatic environments.

Toxicity of cigarette butts and possible recycling solutions-a literature review

Tobacco is a worldwide-consumed product, which in addition to causing public health-related issues is responsible for the most common form of litter in the world-smoked cigarette butts (CBs). A large attention has been drawn to this question, since this specific waste type tends to end up in terrestrial and aquatic ecosystems, posing serious threat to a range of life forms. Decomposition may take several years to occur because cellulose acetate is hardly accessible, before deacetylation, by bacteria and fungi. This review concerns the toxicity derived from smoked cigarette butts, as well as innovative ecological solutions for solving the CB litter problem. Toxicity studies have demonstrated the critical influence of chemicals present in smoked CBs to the environment as a whole, but also the physical contaminating potential considering micro- and nanoparticles derived from CB material. Nevertheless, several technological approaches were aimed at unveiling hidden value within used CBs, as well as propositions for incorporation of this residue in large volume production items or direct recycling. In summary, several methods are available to alleviate CB pollution, while appropriate and efficient collection logistics by consumers appears as the main bottleneck for an effective recycling. It is also clear that while considerable progress has been made recently in light of CB recycling solutions, there is still a vast research capacity in this regard.

Impact of cigarette butts on bacterial community structure in soil

Cigarette butts contribute significantly to global pollution present on the planet. The filters found in cigarette butts contain a microplastic, cellulose acetate, as well as toxic metals and metalloids which are responsible for pollution in the environment. Although cigarette butt litter is prevalent in many soils, research on the effects of these cigarette butts is limited. In this study, we used Automated Ribosomal Intergenic Spacer Analysis (ARISA) to generate DNA fingerprints of bacterial communities in soil before and after the addition of cigarette butt leachate treatments. An ICP-MS analysis of the biodegradable and non-biodegradable cigarette butts revealed the presence of various elements: Al, As, B, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, Se, Sn, Sr, V, and Zn. The analysis also specified which metals were present at the highest concentrations in the biodegradable and non-biodegradable cigarette butts, and these were, respectively, Al (1,31 g/kg and 2,35 g/kg), Fe (2,03 g/kg and 1,11 g/kg), and Zn (3,18 mg/kg and 15,70 mg/kg). Our results show that biodegradable cigarette butts had a significant effect on bacterial community composition (beta diversity), unlike the non-biodegradable butts. This effect can be attributed to higher concentrations of certain metals and metalloids in the leachate of biodegradable cigarette butts compared to the non-biodegradable ones. Our findings suggest that biodegradable and non-biodegradable cigarette butts can significantly affect bacterial communities in soil as a result of the leaching of significant quantities of certain elements into the surrounding soils.

Smoked cigarette butt leachate impacts survival and behaviour of freshwater invertebrates

Smoked cigarette filters a. k.a. "butts", composed of plastic (e.g. cellulose acetate) are one of the world's most common litter items. In response to concerns about plastic pollution, biodegradable cellulose filters are being promoted as an environmentally safe alternative, however, once smoked, both contain toxins which can leach once discarded. The impacts of biodegradable butts as littered items on the receiving environment, in comparison with conventional butts has not yet been assessed. A freshwater mesocosm experiment was used to test the effects of leachate from smoked cellulose acetate versus smoked cellulose filters at a range of concentrations (0, 0.2, 1 and 5 butts L^-1) on the mortality and behaviour of four freshwater invertebrates (Dreissena polymorpha, Polycelis nigra, Planorbis planorbis and Bithynia tentaculata). Leachate derived from 5 butts L^-1 of either type of filter caused 60-100% mortality to all species within 5 days. Leachate derived from 1 butt L^-1 of either type resulted in adults being less active than those exposed to no or 0.2 butts L^-1 leachate. Cigarette butts, therefore, regardless of their perceived degradability can cause mortality and decreased activity of key freshwater invertebrates and should always be disposed of responsibly.

The fate of cigarette butts in different environments: Decay rate, chemical changes and ecotoxicity revealed by a 5-years decomposition experiment

Cigarette butts (CBs) are the most common litter item on Earth but no long-term studies evaluate their fate and ecological effects. Here, the role of nitrogen (N) availability and microbiome composition on CBs decomposition were investigated by a 5-years experiment carried out without soil, in park grassland and sand dune. During decomposition, CBs chemical changes was assessed by both ¹³C CPMAS NMR and LC-MS, physical structure by scanning electron microscope and ecotoxicity by Aliivibrio fischeri and Raphidocelis subcapitata. Microbiota was investigated by high-throughput sequencing of bacterial and eukaryotic rRNA gene markers. CBs followed a three-step decomposition process: at the early stage (∼30 days) CBs lost ∼15.2% of their mass. During the subsequent two years CBs decomposed very slowly, taking thereafter different trajectories depending on N availability and microbiome composition. Without soil CBs showed minor chemical and morphological changes. Over grassland soil a consistent N transfer occurs that, after de-acetylation, promote CBs transformation into an amorphous material rich in aliphatic compounds. In sand dune we found a rich fungal microbiota able to decompose CBs, even before the occurrence of de-acetylation. CBs ecotoxicity was highest immediately after smoking. However, for R. subcapitata toxicity remained high after two and five years of decomposition.