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

Microfibre pollution: An emerging contaminant, alarming threat to the global environment

Microfibres, mostly obtained from home laundry, textiles, industrial materials, sewage effluents, and sludge, are considered the main source of environmental pollution, which has become a prevalent threat to terrestrial and aquatic creatures. Global population growth and industrialization have led to a rise in fibre consumption and production, which spread its network in drinking water, beer, and seafood. Focusing on the alarming threat of microfibre towards the natural environment, we have penned an extensive review article about microfibre pollution. The manuscript is divided into various subparts, such as the introductory portion, which briefly summarizes the sources and presence of various hazardous pollutants in the environment, followed by a detailed discussion about microfibre. The second part elaborates on the sources and distribution of microfibreous pollutants and the third portion discloses the toxic chemicals utilized or produced from functionalization, as well as the negative implications of microfibre on the environment. The fourth part discloses the leading application strategies to diminish microfibre pollution by controlling the sources and the development of various remediations. The last portion deals with the future and critical aspects of microfibre contamination. The authors hope this review article will boost its domain in environmental chemistry, sustainable development and environmental engineering from academic to industrial level as it helps researchers in particular and academics in general.

Marine macrolitter and cigarette butts hazard multiple-use marine protected area and fishing community at Brazil

Wide marine litter (ML) contamination impacts human health and economic sectors including fishing, navigation, and tourism. Perequê beach, Brazil, is an authentic fishing community within a touristic multiple-use marine protected area. However, no ML contamination monitoring were so far performed in the region. This study evaluated the spatiotemporal abundance, composition, sources, and associated ML hazards at Perequê beach using a multi-index approach. The 2579 items (0.64 ± 0.72 items.m-2) yielded a high contamination level (CCI = 12.6 ± 14.4) with plastic (44.6-50.9 %) and cigarette butts (20.6-28.4 %) prevalence, while primary sources were smoking (cigarette butts, lighters, others-21.2-30.1 %) and packaging (17.8-22.8 %). Levels of pollutants leaked from cigarette butts (CBPI = 30.5 ± 47.5) and hazardous items (HALI = 3.06 ± 2.64) were among the highest globally. Heightened levels occurred in summer, at dry sand strip, where short-term buoyant items prevailed. Multi-indexing approaches offer valuable insights for local authorities to implement mitigation programs, while contributing to global discussions, promoting awareness, and facilitating replicability.

Alarming cigarette butts contamination on sandy beaches of East Java, Indonesia

Cigarette butts, along with other plastic items, have been extensively studied as the primary source of marine litter in coastal areas around the world. Although there has been extensive research on cigarette butts in coastal areas worldwide, there have been no publications related to this in coastal areas in Indonesia. Therefore, this research is the first to report on the pollution of cigarette butts on different Indonesian beaches, specifically in the East Java Province. The study aimed to assess the abundance, size distribution, and pollution levels associated with cigarette butts from 15 different beaches. Cigarette butts were collected using a 5 × 5 m quadrate transect, placed 20 m apart along the coastline from December 2022 to August 2023. The collected cigarette butts were counted and measured in three different sizes: 0.5-2.5 cm, 2.5-5 cm, and 5-10 cm. A total of 323 cigarette butts were collected, with densities ranging from 0.08 to 3.32 items m-2. The majority of butts were classified as meso-size (0.5-2.5 cm), suggesting incomplete smoking and a higher potential for toxin release. The Cigarette Butt Pollution Index (CBPI) revealed a spectrum of pollution levels, from low to severe, with most beaches exhibiting severe pollution. Factors such as negligent smoking behavior, inadequate waste management infrastructure, and beach environmental conditions were identified as key contributors to this pollution. This study highlights the urgent need for comprehensive strategies, including public awareness campaigns, improved waste management, and beach clean-ups, to mitigate the environmental impact of cigarette butt pollution on Indonesian beaches.

Marine litter along the Peruvian coast: spatiotemporal composition, sources, hazard, and human modification relations

Marine litter (ML) represents an escalating environmental issue, particularly in Latin America, where comprehensive studies are scarce despite critical solid waste management challenges and continuous human modification occurring on the coasts. To contribute to the knowledge of ML in the southeast Pacific, this study examined contamination across 10 beaches on Peru's extensive coast. Overall, ML contamination was categorized as moderate (with an ML concentration of 0.49 ± 0.64 items∙m-2), while significantly differing between summer (dirty with an ML concentration of 0.56 ± 0.66 items∙m-2) and winter (moderate with an ML concentration of 0.47 ± 0.60 items∙m-2). Three beaches were extremely dirty (concentrations of ML exceeded 1.0 items∙m-2). Predominant materials, items, and sources were plastic, cigarette butts (CBs), and mixed packaging. The Peruvian coast faced CB leachate impact (CBPI = 3.5 ± 3.5), reaching severe levels on two beaches, with considerable hazardous litter (HALI = 3.0 ± 2.9). Additionally, a higher degree of human modification was associated with higher ML levels along the coast.

Recovery of cellulose acetate bioplastic from cigarette butts: realization of a sustainable sorbent for water remediation

Cigarette butts, one of the most common forms of litter in the world, represent a source of chemical and plastic pollution releasing thousands of toxic compounds and microfibers of cellulose acetate (CA). Besides the correct waste management, the recovery of CA from cigarette filters is a way to cushion their negative effects on the environment. Thus far, recycling strategies have been limited to industrial applications, while not many solutions have designed for water remediation. This work describes a strategy to valorize this harmful waste and to reverse its environmental impact, proposing a simple and effective procedure of reclamation of CA and its reuse to prepare a composite sorbent for the treatment of polluted water. The first step entails the washing of filters with hot water (T = 90 °C) and hot ethanol (T = 58-68 °C) to remove the impurities produced during cigarette burning, as verified by means of UV and attenuated total reflection-Fourier-transform infrared (ATR-FTIR) spectroscopy, thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC). The second step involves the use of the regenerated CA to prepare porous cylinder-shaped cryogels (15 mm × 10 mm) whose sorption properties are enhanced by the combination with AC (15 % w/w). The synthesis takes advantage of the sol-gel transition of the polymer dispersion (5 % w/V) in a solution acetone/water 5 mM in NH3 (60/40, v/v). After characterization by dynamic mechanical analysis (DMA), TGA, FT-IR, and scanning electron microscopy (SEM), the adsorption capability of the physical cryogel was studied in terms of treated environmental water volume, contact time and concentration of the selected pollutants. The results have shown that the proposed strategy is a low-cost way to recycle CA from cigarette butts and that the designed sorbent is a promising material for water treatment, allowing quick removal times and yields >79.6 %.

Abundance and distribution of cigarette butts on the sand of five touristic beaches in Latin America during the COVID-19 pandemic

Cigarette butts (CB) and cigarette butt fibers (CBF) are highly abundant and frequent residues on beach sand. Also, they are hazardous waste due to their significant toxicity and potential risk to the ecosystems' biota and the health of beach tourists. This study aimed to determine the abundance and density of CB and CBF found on the active, rest, and service zones of five pilot beaches in Argentina, Colombia, Brazil, Ecuador, and Mexico. The methodology involved collecting CB and CBF in 500 m2 transects of urban tourist beaches using a citizen science-adapted methodology between June 2021 and May 2022, during the COVID-19 pandemic. The abundance and density of CB and CBF, and the Cigarette Butt Pollution Index (CBPI) were calculated. The highest proportion of CB was found in service and rest areas. Bocagrande (CO) reported the highest generation of CB and CBF and a severe CBPI.

Cigarettes butt littering: The story of the world's most littered item from the perspective of pollution, remedial actions, and policy measures

Cigarettes butt (CB) is one of the most littered items on the planet. This paper critically analyzes the factors responsible for CB littering, and associated environmental ramifications, and reviews all the possible technical, behavioural, and policy-based solutions. Even while smoking has declined globally, middle-income nations have seen an increase in consumption, which may be related to increased affordability and a lack of public awareness. The smokers' individual beliefs and habits, environmental ignorance, covert littering as a result of social taboos associated with smoking, and behavioural gaps between intention and action might all be contributing factors to CBs' littering behaviour. The low biodegradability of cellulose acetate filters and toxic chemical leaching from CBs are the most important aspects of CB environmental toxicity. The small size and low economic value of CB contribute to the inefficiencies of current waste collection and management systems. The current research on CB valorisation includes fired-clay bricks, asphalt concrete, biofilms, sound absorber, cellulose pulp, pesticides, and insecticides as downstream mitigation strategies. This study highlights the urgent need for policymakers to enforce regulations enabling innovative cigarette designs, the creation of deposit-refund schemes, extended producer responsibility and stringent waste collection mechanisms. Adopting gentler marketing strategies and non-confrontational behavioural nudges could result in an overall reduction in CB pollution.

What potential does the EU Single-Use Plastics Directive have for reducing plastic pollution at coastlines and riversides? An evaluation based on citizen science data

To address environmental pollution by plastic litter, the European Union adopted EU Directive 2019/904, the so called "Single-Use Plastics Directive" (SUPD), which bans several single-use plastic products and addresses additional items with measures such as extended producer responsibility and obligatory requirements for product redesign. This study assessed the potential of the SUPD to reduce litter pollution in the environment with three scenarios. The "best case" scenario assumed that all measures of the SUPD completely prevent targeted items from getting into the environment. Another scenario assumed that no measures besides bans were effective. An intermediate scenario assumed partial effectiveness of measures. Data of almost 5,000 sampling events from citizen science protocols (Plastic Pirates, International Coastal Cleanup, Marine Litter Watch) and the OSPAR protocol were used to analyse litter at riversides and coastlines in Germany and the European Union. 44 to 68% of litter items in citizen science protocols consisted of single-use plastics (cigarette butts were the most prominent items). At coastlines sampled by the OSPAR protocol, fishing gear and undefined plastics prevailed. The scenario analysis revealed that substantial litter reductions could be achieved in the "best case" scenario (upwards of 40%), while the intermediate scenario resulted in litter reductions of 13 to 25%. The marginal effect of the "only bans" scenario achieved a reduction of 2-6% in Germany and the European Union, respectively. Thus, depending on implementation and enforcement, the current SUPD can be an important first step, yet further legislative actions are needed to effectively prevent plastic waste pollution.

Total and bioavailable polycyclic aromatic hydrocarbons in unused and operated heat-not-burn tobacco products and conventional cigarettes

Tobacco product waste poses a global environmental issue, affecting urban and coastal areas alike. The present studies report, for the first time, the total and bioavailable polycyclic aromatic hydrocarbons (PAHs) concentrations in unused and operated heat-not-burn (HnBs) tobacco products. To enable direct comparisons, identical sets of studies were conducted using conventional cigarettes (CCs). Five low-molecular PAHs were determined in HnBs at total concentrations that were of the same order before and after operation (Σ₅PAH = 47.37 ± 3.44 ng unit^-1 and Σ₅PAH = 69.36 ± 5.78 ng unit^-1 in unused and used HnBs, respectively). The incomplete combustion of organics during smoking of CCs, yielded substantially higher amounts of PAHs with their sum (Σ₁₀PAHs = 1449 ± 113 ng unit^-1) being >20 times larger than those in HnBs. The tobacco and filter were the most contaminated parts in HnBs. In unused CCs, tobacco had the highest PAHs load and after smoking, the spent filter was the most contaminated part, containing ∼80% of the total amount of PAHs. Naphthalene was the most abundant PAH detected in all tobacco products. Despite the high total PAH concentrations found in smoked CCs, the sums of the bioavailable PAH concentrations were of the same order in all tested tobacco products (Σ₅PAH = 61.38 ± 1.79 ng unit^-1 in unused HnBs, Σ₅PAH = 70.87 ± 7.67 ng unit^-1 in used HnBs, Σ₄PAH = 66.92 ± 5.95 ng unit^-1 in unused CCs, and Σ₆PAH = 47.94 ± 1.26 ng unit^-1 in smoked CCs). This finding was related to smoking affecting PAHs' leachability from CCs and delaying their desorption from the solid matrix. Adjusting the pH, salt and humic acids content at environmentally relevant values did not affect PAHs leaching at 24 h of soaking. Finally, the leaching behavior of PAHs in natural waters (river water, rainwater, and seawater) was found similar to that in ultrapure water, experimentally verifying the ability of tobacco product waste to leach PAHs into the aquatic environment.

Giving New Life to Waste Cigarette Butts: Transformation into Platinum Group Metal-Free Electrocatalysts for Oxygen Reduction Reaction in Acid, Neutral and Alkaline Environment

Following the core theme of a circular economy, a novel strategy to upcycle cigarette butt waste into platinum group metal (PGM)-free metal nitrogen carbon (M-N-C) electrocatalysts for oxygen reduction reaction (ORR) is presented. The experimental route was composed of (i) the transformation of the powdered cigarette butts into carbonaceous char via pyrolysis at 450 °C, 600 °C, 750 °C and 900 °C, (ii) the porosity activation with KOH and (iii) the functionalization of the activated chars with iron (II) phthalocyanine (FePc). The electrochemical outcomes obtained by the rotating disk electrode (RRDE) technique revealed that the sample pyrolyzed at 450 °C (i.e., cig_450) outperformed the other counterparts with its highest onset (Eon) and half-wave potentials (E1/2) and demonstrated nearly tetra-electronic ORR in acidic, neutral and alkaline electrolytes, all resulting from the optimal surface chemistry and textural properties.

Chemical Elements, Flavor Chemicals, and Nicotine in Unused and Used Electronic Cigarettes Aged 5-10 Years and Effects of pH

The concentrations of elements/metals, nicotine, flavor chemicals and acids were compared in the e-liquids of unused and used first-generation electronic cigarettes (ECs) that were stored for 5-10 years. Metal analysis was performed using inductively coupled plasma optical emission spectroscopy; nicotine and flavor chemical analyses were performed using gas chromatography/mass spectroscopy. Of the 22 elements analyzed, 10 (aluminum, chromium, copper, iron, lead, nickel, selenium, silicon, tin, zinc) were often found in the e-liquids. Five elements had the highest average concentrations: copper (1161.6 mg/L), zinc (295.8 mg/L), tin (287.6 mg/L), nickel (71.1 mg/L), and lead (50.3 mg/L). Nicotine concentrations were always lower than label concentrations indicated. Of the 181 flavor chemicals analyzed, 11 were detected in at least one sample, with hydroxyacetone being present in all samples. In used products, some flavor chemicals appeared to be by-products of heating. E-liquids with the highest concentrations of acids and the lowest pH levels also had the highest concentrations of elements/metals. Metal concentrations in e-liquids increased after use in some products, and some metal concentrations, such as nickel, were high enough to be a health concern. Leachates from discarded ECs could contribute toxic metals/chemicals to the environment, supporting the need for better regulation of atomizer design, composition, and disposal.