Plastic Leachates Research Articles

A battery of baseline toxicity bioassays directed evaluation of plastic leachates—Towards the establishment of bioanalytical monitoring tools for plastics

There are increasing concerns regarding the ecological risks of plastics to the natural environment, especially the potential effects of plastic leachates on organisms, which contain various toxic components. However, appropriate methods to assess the overall environmental risks of plastics are limited. In this study, five different plastic products (three conventional and two biodegradable plastics) were immersed in simulated freshwater, and their toxicity was assessed using a battery of bioassays. We evaluated the effects of plastic leachates effects on organisms from four trophic levels of species (nematodes, Caenorhabditis elegans; algae, Scenedesmus obliquus; daphnids, Daphnia magna; and fish, Danio rerio) by measuring their acute and chronic toxicity. Our results indicated that all plastic leachates exhibited poor acute and chronic toxicity to the organisms. The acute toxicity of conventional plastic leachates with EC20 values <1.6 g plastic/L was higher than that of the biodegradable polydioxanone (PPDO) leachate (EC20: 16.2–796.1 g plastic/L); however, the toxicity of PPDO-octane (EC20: 0.04–1.9 g plastic/L) was similar to that of polyethylene or polystyrene (excluding toxicity in D. magna). Similarly, the leachates of the three conventional plastics and PPDO-octane had obvious inhibitory effects on the growth of C. elegans at exposure concentrations higher than 0.01 g plastic/L; however, the toxicity of the PPDO leachates was at least an order of magnitude lower. Therefore, the environmental related concentration of the plastic leachates did not have significant toxic effects. Considering that a single bioassay does not provide comprehensive information on biological implications, this study provided a new integrated and efficient method for the environmental risk assessment (ERA) of plastic leachates. Moreover, the toxicity sensitivity of different organisms varied following exposure to different plastics, thus demonstrating that multiple organisms from different trophic levels should be included in the ERA for plastics.

Chemical characteristics and toxicological effects of leachates from plastics under simulated seawater and fish digest

In recent years, the ecological risks of plastics to marine environments and organisms have attracted increasing attention, especially the leachates from plastics. However, a comprehensive knowledge about the leaching characteristics and subsequent toxicological effects of leachates is still sparse. In this study, 15 different plastic products were immersed in simulated seawater and fish digest for 16 h. The leachates were analyzed through non-target and target analyses and their toxicological signatures were assessed by bioassays. In total, 240 additives were identified from the plastic leachates, among which plasticizers represented the most (16.7%), followed by antioxidants (8.7%) and flame retardants (7.1%). Approximately 40% of plastic leachates exhibited significant inhibitory effects on the bioluminescence using a recombinant luminescent assay. In addition, both the hyperactive and hypoactive behaviors were displayed in the larvae of marine medaka (Oryzias melastigma) exposed to some plastic leachates. In general, the number and amount of identified compounds under simulated fish digest were less than those under simulated seawater. However, the simulated fish digest leachates triggered higher toxicity. Redundancy analysis demonstrated that identified additives did not adequately explain the toxicological effects. Future research should focus on the identification of more additives in the plastic leachates and their potential ecological risks.

A fluorescence indicator for source discrimination between microplastic-derived dissolved organic matter and aquatic natural organic matter

Recently, studies have increasingly focused on the occurrence of plastic leachate and its effects on aquatic environments. However, few studies have aimed to identify microplastic-derived dissolved organic matter (MP-DOM) from environmental samples that are often enriched with natural organic matter (NOM). In this study, three MP-DOM (EPS-DOM, PVC-DOM, and PET-DOM) and eight aquatic NOM samples, and their mixtures, were used to identify a unique optical surrogate for MP-DOM within background NOM. Three major fluorescence peaks (peaks P, H, and L) were identified in the excitation emission matrix (EEM) spectra of both DOM sources (i.e., MP-DOM and NOM). The first two peaks were more pronounced for MP-DOM than for aquatic NOM, whereas peak L showed the opposite trend. The summed intensity ratio of the ranges of the first two peaks relative to peak L, namely, (H + P)/L, clearly distinguished between MP-DOM and NOM samples. The MP-DOM source discrimination capability was compared for several selected spectroscopic indices by tracking their changes in the mixtures of two source groups with increasing fraction of MP-DOM via end-member mixing analysis. This was further evaluated based on the three criteria built on the significance of the difference between the two groups, the correlation coefficients of the regressions, and the minimum fraction of MP-DOM in mixtures that can be distinguished from 100% NOM samples. Irrespective of the plastic type and leaching conditions (i.e., UV-irradiated or not), the new optical index, (H + P)/L, was superior at distinguishing MP-DOM from the mixtures when compared to other commonly used optical indices. The new index can serve as a sensitive, robust, and reliable fluorescence indicator with minimal interference from NOM for detecting plastic leachate in aquatic samples.

Plastic leachates lead to long-term toxicity in fungi and promote biodegradation of heterocyclic dye

The hazardous effects of plastic and plastic leachates on organisms, even bacteria, have attracted widespread attention, but only a limited effort has been devoted to explore the response of fungi to plastic leachate induced by light irradiation. Here, we performed plastic leaching experiments to obtain leachates from polyethylene (PE), polyethylene terephthalate (PET) and polypropylene (PP), and optical properties of plastic leachates were analysed to determine the influence of light conditions and plastic materials on that. The effects of plastic leachates on the production of fungal enzyme and the biodegradation of heterocyclic dye by fungi were evaluated. Results indicated that the UV light greatly enhanced the release of leachates from the three plastics. Both plastic polymers and light irradiation affected the plastic-derived dissolved organic carbon (DOC) and their aromaticity, but the molecular weight of plastic leachates showed no dependency on light irradiation types, and PE was the easiest to photo age and leached more DOC. Plastic leachates had no dose-effect on the production of extracellular enzymes by fungi. PE leachates showed long-term toxicities to fungi, and no manganese peroxidase activities were detected after a 42-day incubation, while that of controls were up to 73.64 ± 8.81 U/L. However, the PE and PP leachates greatly promoted methylene blue degradation by the fungi, but PET leachates relieved the decolouration of methylene blue, probably because of the benzene ring structure in the PET monomer. Fusarium oxysporum had a stronger degradation ability than Phanerochaete chrysosporium. Our results indicate that plastic leachates can influence the production and secretion of fungi ligninolytic extracellular enzymes, and regulate the fungal degradation of heterocyclic dye.

Migrating Levels of Toxic Heavy Metals in Locally Made Food Packaging Containers

Abstract Background/Objectives: Earth’s crust contains heavy metals as natural ingredients. Heavy metals create a major health problem for the humans because of their persistence, highly toxic nature and tendency to accumulate in the ecosystem. The main aim of this study was to measure the concentration of heavy metals in the locally made food containers at three different temperatures, using various simulating solvents as per guidelines Bureau of Indian standard (BIS), by using Atomic Absorption spectroscopy (AAS). Methods/Statistical analysis: The estimation of heavy metals such as Cd, Cr, Ni, Cu, Mn, Fe, Pb and Zn of plastic leachates were detected by using Atomic absorption spectrophotometer (AAS). The results were expressed statistically using mean ± standard deviation of triplicate reading of each sample and corresponding control solution. The dunnett comparison were made to assess the level of significance by applying one way analysis of variance (ANOVA) using computer based software ‘Graph Pad PRISM-5’. Findings: The level of migration of heavy metals above the permitted limit was in the following pattern: • At Elevated Condition (60±2˚C for 2 h): Pb(1.9-1.002ppm) > Cu(1.61-1.02ppm) > Ni(1.31-1.01ppm) > Zn(1.02-1.006ppm) > Mn(1.01-1.001ppm). • At Ambient Condition (25±2˚C for 24 h): Pb(1.9-1.01ppm) > Cu(1.61-1.01ppm) > Ni(1.31-1.01ppm) in S3, S5, S2, S4 > Mn(1.01-1.001ppm) >Zn(1.002ppm). Ni(1.01ppm) > Cu(1.009-1.003ppm) > Pb(1.007ppm) > Zn(1.001ppm). • At Refrigerated Condition (4±1˚C for 72 h): Ni(1.01ppm) in S2 > Cu(1.009-1.003ppm) in S4, S5, S2 > Pb(1.007ppm) inS1 > Zn(1.001ppm) in S1. The results show that the amount of migration of heavy metals from food packaging containers followed the pattern: Elevated condition > Ambient condition > Refrigerated condition. Novelty/Applications: This research aims to obtain a better understanding of locally made food packaging plastics having no specification of additives and their related potential hazards.

Chronic effects of domestic and single used plastic leachates on the microcrustacea Daphnia magna

Plastic pollution has become one of the most serious environmental issues worldwide. Plastics can contain high amount of additives (e.g., phthalate, bisphenol A, trace metals), and they could be leached out of plastics, enter the aquatic environment and cause toxic effects to aquatic organisms (including microcrustacean). In this study, we investigated chronic effects of plastic leachates from two popular plastic materials (garbage bag and disposable raincoat) on the survival, maturation and reproduction of the microcrustcean Daphnia magna. The results showed that, the plastic leachates from the two materials at the concentration up to 1000 mg/l did not cause negative effect on survival of D. magna. However, exposed to the leachates from the garbage bag (at the concentrations of 10, 100 and 1000 mg/l) and from the disposable raincoat (at the concentration of 10 mg/l), the animals delayed their maturity ages compared to the control. Besides, the two kinds of leachates at the concentration of 1000 mg/l stimulated the reproduction of D. magna, resulting the increase of 17 – 37% of total offspring compared to the control, during 21 days of experiment. The results of this study contribute to the understanding on the toxicity of popular plastic materials to the microcrustacean, D. magna. Additionally, the plastic usage and emission into the environment should be paid more attention to protect the aquatic ecosystems and human health.

Investigating zinc toxicity responses in marine Prochlorococcus and Synechococcus.

Marine plastic pollution is a growing concern worldwide and has the potential to impact marine life via leaching of chemicals, with zinc (Zn), a common plastic additive, observed at particularly high levels in plastic leachates in previous studies. At this time, however, little is known regarding how elevated Zn affects key groups of marine primary producers. Marine cyanobacterial genera Prochlorococcus and Synechococcus are considered to be some of the most abundant oxygenic phototrophs on earth, and together contribute significantly to oceanic primary productivity. Here we set out to investigate how two Prochlorococcus (MIT9312 and NATL2A) and two Synechococcus (CC9311 and WH8102) strains, representative of diverse ecological niches, respond to exposure to high Zn concentrations. The two genera showed differences in the timing and degree of growth and physiological responses to elevated Zn levels, with Prochlorococcus strains showing declines in their growth rate and photophysiology following exposure to 27 µg l−1 Zn, while Synechococcus CC9311 and WH8102 growth rates declined significantly on exposure to 52 and 152 µg l−1 Zn, respectively. Differences were also observed in each strain’s capacity to maintain cell wall integrity on exposure to different levels of Zn. Our results indicate that excess Zn has the potential to pose a challenge to some marine picocyanobacteria and highlights the need to better understand how different marine Prochlorococcus and Synechococcus strains may respond to increasing concentrations of Zn in some marine regions.

Variability in Toxicity of Plastic Leachates as a Function of Weathering and Polymer Type: A Screening Study with the Copepod Nitocra spinipes.

AbstractThe production and use of plastic over many decades has resulted in its accumulation in the world's oceans. Plastic debris poses a range of potential risks to the marine environment and its biota. Especially, the potential hazards of small plastic debris and chemicals associated with plastic have not been extensively studied. When buoyant plastic is exposed to ultraviolet radiation, it will slowly degrade and leach chemicals into surrounding waters. These leachates can include additives, sorbed organic pollutants, and degradation products of the plastic polymers. While most hazard assessments have focused on studying adverse effects due to the uptake of plastic, toxicity studies of the leachates of plastics are less common. To begin to address this knowledge gap, we studied the acute toxicity of leachates from diverse plastics in the harpacticoid copepod Nitocra spinipes. Our results show that leachates caused a higher toxicity after plastic was exposed to ultraviolet light compared to leaching in darkness. We observed differences in toxicity for different polymer types: polyvinyl chloride and polypropylene resulted in the most toxic leachates, while polystyrene and poly[ethylene terephthalate] were least toxic. Furthermore, we observed increased toxicity of leachates from some plastics that had been weathered in the real marine environment compared to matching new materials. Our results indicate that both weathering condition and polymer type influence the toxicity of plastic leachates.

Enhanced in vitro toxicity of plastic leachates after UV irradiation

Plastics can release numerous chemicals and thereby, contribute to the chemical pollution in aquatic systems. To which extent environmental degradation processes influence the release of plastic chemicals, is currently unknown and subject of research. We therefore evaluated aqueous leachates of 12 differently formulated plastics (e.g., pre-production, post-industrial and recycled pellets as well as final products) using in vitro bioassays and chemical analysis via LC-HRMS nontarget approach. We weathered these plastics by UV irradiation (UV-C and UV-A/B) under laboratory conditions in dryness and a subsequent leaching period in ultrapure water (‘atmospheric’ weathering) or directly in water (‘aquatic’ weathering, UV-A/Baq). A dark control (DC) without UV light served as a reference treatment. Some plastics triggered several toxicological endpoints (low-density polyethylene recyclate (LDPE-R), starch blend (SB), bio-based polybutylene succinate (Bio-PBS) and polyvinyl chloride (PVC)), whereas others caused little to no effects (polyethylene terephthalate (PET), polystyrene (PS), polypropylene (PP) and LDPE). UV irradiation enhanced the plastics’ toxicity, even for samples initially evaluated as toxicologically inconspicuous. The plastic samples caused oxidative stress (85%), baseline toxicity (42%), antiestrogenicity (40%) and antiandrogenicity (27%). Positive findings were measured after UV-C (63%) and UV-A/Baq (50%) treatments, followed by UV-A/B (48%) and DC (33%). Overall, we detected between 42 (DC) and 2896 (UV-A/Baq) chemical compounds. Our study demonstrates that differently formulated plastics leach toxic chemicals. UV exacerbates the plastics’ toxicity by either generating active compounds and/or by facilitating their release. UV light even leads to the release of bioactive compounds from plastics of low chemical complexity. To prevent the exposure to plastic-associated chemicals, the application of chemicals could be reduced to a minimum, while on a regulatory level the evaluation of plastic eluates could be another focal point next to singular compounds.

A Critical Review on the Impacts of Nanoplastics and Microplastics on Aquatic and Terrestrial Photosynthetic Organisms.

Microplastic and nanoplastic contamination is widespread and affects aquatic and terrestrial ecosystems. Photosynthetic organisms are present in both media, they are primary producers, sink for CO2 , and they represent a major point of entry in the food chain. Here, the current knowledge on the fate and impacts of microplastics and nanoplastics in interaction with these organisms is reviewed. As a general trend, plastic characteristics (smaller size and positive charge) play a crucial role in their toxicity toward photosynthetic organisms. Plastic leachates (containing additives) also represent a major source of toxicity, and some harmful compounds such as phthalate esters are shown to accumulate in plants and generate a risk for the consumers. Adsorption of plastic particles is evidenced for each type of photosynthetic organism, and uptake and translocation in terrestrial plants is evidenced for nanoplastics, leading to concerns for trophic chain contamination. The available techniques for the detection of microplastics and nanoplastics and their secondary products in biological samples and media are also listed. Finally, the current gaps of knowledge, specific challenges, and future research directions are also discussed.

Comparative assessment of marine weathering of ROP-derived biopolymers against conventional plastics

Bio-based plastics were designed to replace single-use plastics and to cause less post-consumer environmental damage. This paper assesses the weathering of four bio-based polymers created by ring opening polymerization (ROP) promoted by a previously reported Ti-based catalyst, to detect any problems before production was scaled up. Samples were aged in seawater to identify degradation products and monitor structural changes. Surfaces evidenced degradation and a range of leaching products was observed. Aside from compounds used in the preparation of the plastics (i.e. residual monomers and benzyl alcohol), the degradation products included carboxylic acids (often found in plastic leachate), oxacyclohexadecan-2-one (potentially toxic to aquatic life) and triphenylmethane (potential carcinogen). Overall, there were fewer structural changes in the fossil fuel based polymer (PS) and in the commercially available bio-based plastic studied for comparison purposes than the lab based bio-based polymers.

Insight into chain scission and release profiles from photodegradation of polycarbonate microplastics

Bisphenol A polycarbonate (BPA-PC) is a kind of widely used engineering plastics. However, excessive usage causes the production of plastic wastes, following property changes of polymers and high risks of released chemicals during outdoor weathering. In this study, we systematically investigated the photoaging behavior of PC microplastics (MPs) in aquatic environment and evaluated the potential risk of released intermediates. Light irradiation along with mechanical abrasion facilitated the fragmentation of PC MPs and stimulated photooxidative modification during 640 h of ultraviolet (UV) exposure. Continuous degradation of the polymer was accompanied with dramatic decline of molecular weight. Also, BPA was released from irradiated PC MPs with a trend of an initial rapid increase followed by a decrease versus the irradiation time, and the maximum concentration of dropped BPA was detected up to 652.80 ± 72.89 μg/g (43.39% and 56.61% respectively in particles and leachates). However, the releasing amount of BPA in the leachate merely occupied 2.7% of the total organic carbon (TOC) leached out, suggesting that a great number of unknown organic products were produced other than BPA. Liquid chromatography-time-of-flight-mass spectrometry (LC-TOF-MS) analysis showed that these organic compounds forming MPs-derived dissolved organic matter (MPs DOM) were partly composed of 4,4’-dihydroxybenzophenone (DHB), p-hydroxybenzoic acid (p-HBA) and methyparaben (MeP), which would also contribute to the estrogenic activity. The degradation pathway of PC MPs was elaborated with the photolysis process of PC dimer and BPA, and the remarkable photoaging of PC MPs was mainly dominated by the generated reactive oxygen species (ROS). The findings of this study indicated that understanding the photoaging process of PC MPs was vital to evaluate their integral cumulative estrogenic activity in aquatic environment, and further highlighted the notable possible risks of plastic leachates to exposed biota.

Assessing the Toxicity of Leachates From Weathered Plastics on Photosynthetic Marine Bacteria Prochlorococcus

Marine plastic pollution is a well-recognized, global problem. Research addressing plastic pollution has largely focused on investigating impacts on macroorganisms, with few studies investigating effects on marine microbes. We previously showed that marine Prochlorococcus, which are important contributors to oceanic primary production, suffer declines in growth and photosynthetic activity following exposure to leachates from new plastic bags (HDPE) and plastic matting (PVC). However, as such plastics reside in the environment they will be subject to weathering processes, so it is also important to consider how these may alter the composition and amounts of substances available to leach. Here we report on how plastic leachate toxicity is affected by environmental weathering (17- and 112-days in estuarine water) of these common plastic materials. We found that while toxicity was reduced by weathering, materials weathered for up to 112-days continued to leach substances that negatively affected Prochlorococcus growth, photophysiology and membrane integrity. Weathered plastics were found to continue to leach zinc, even after up to 112-days in the environment. The two Prochlorococcus strains tested, NATL2A and MIT9312, showed differences in the sensitivity and timing of their responses, indicating that exposure to leachate from weathered plastics may affect even closely related strains to different degrees. As many marine regions inhabited by Prochlorococcus are likely to be subject to continued accumulation of plastic pollution, our findings highlight the potential for ongoing impacts on these important primary producers.

The hidden threat of plastic leachates: A critical review on their impacts on aquatic organisms

Plastic products are made from the essential polymer mixed with a complex blend of substances including catalyst remnants, polymerization solvents, and a wide range of other additives deliberately added to enhance the desirable characteristics of the final product. Additives include bisphenols, phthalates, flame retardants, and further emerging and legacy contaminants. With a few exceptions, additives are not chemically bound to the polymer, and potentially migrate within the material reaching its surface, then possibly leach out to the environment. Leachates are mixtures of additives, some of which belong to the list of emerging contaminants, i.e. substances that show the potential to pose risks to the environment and human health, while are not yet regulated. The review discusses the state of the art and gaps concerning the hidden threat of plastic leachates. The focus is on reports addressing the biological impacts of plastic leachates as a whole mixture. Degradation of plastics, including the weathering-driven fragmentation, and the release of additives, are analysed together with the techniques currently employed for chemically screening leachates. Because marine plastic litter is a major concern, the review mainly focuses on the effects of plastic leachates on marine flora and fauna. Moreover, it also addresses impacts on freshwater organisms. Finally, research needs and perspectives are examined, to promote better focused investigations, that may support developing different plastic materials and new regulations.

Anthropogenic dissolved organic carbon and marine microbiomes.

Thousands of synthetic chemicals and hydrocarbons are released to the marine environment composing the anthropogenic dissolved organic carbon (ADOC). Most ADOC is disproportionally hydrophobic, and consequently, its concentrations in the cell membranes are between a thousand and hundred million fold higher than those in the dissolved phase. Marine microorganisms respond to ADOC by multiple strategies ranging from ADOC degradation to detoxifying metabolisms. We argue that the increasing concentrations of ADOC in the oceans deriving from rivers, atmospheric deposition, and plastic leachates can have an effect on the health of the oceans and influence the major biogeochemical cycles, thus influencing the Earth system during the Anthropocene.

Bioassay guided analysis coupled with non-target chemical screening in polyethylene plastic shopping bag fragments after exposure to simulated gastric juice of Fish

In this study, fragments of polyethylene plastic bags were treated with simulated gastric juice of fish for 16 h. Following solid-phase extraction, methanol eluents caused acute toxicity to embryos and larvae of Japanese medaka. Chromatographic fractions (polar to more non-polar with numbers increasing) of the extract were evaluated for toxicity and estrogenic activity using medaka and an estrogen receptor (ER) cell-line. Fractions 6 and 9 had the highest estrogenic effects with relative hydrophobic chemicals. The vtg expression in fraction 6 was 22-fold higher than control, and the ER cellular response in fraction 9 was 8.5-fold higher than controls. Following non-target screening (NTS), several novel phthalates and phenols were identified in the above two fractions. Fractions 1 and 2 appeared to be primarily responsible for the acute toxicity observed with the whole extract. The hatching rate decreased to 36 % in fraction 2, and was not observed following exposure to fraction 1. NTS of these fractions indicated 635 and 808 entities, respectively, most without toxicity information. These results indicate plastic leachates from gastric juices of fish are complex mixtures of many compounds that can have acute reproductive and sublethal endocrine impacts in fish.

Primary and Secondary Plastic Particles Exhibit Limited Acute Toxicity but Chronic Effects on Daphnia magna.

Nanoplastics (NPs; <0.1 μm) are speculated to be a bigger ecological threat due to their predicted wider distribution, higher concentrations, and bioavailability. Primary NPs are manufactured to be that size, while secondary NPs originate from fragmentation of bigger debris. To date, the long-term impact of NPs in freshwater systems, particularly secondary NPs, is not well-understood. Thus, we employed a freshwater invertebrate, Daphnia magna, to investigate the chronic effects of model primary NPs, fluorescent polystyrene nanospheres (PS-NPs; 20 nm), and water leachate of weathered single-use plastics that contained micro- and nanosized particles. In experiment 1, parent Daphnia (F0) were exposed to 1 and 50 mg/L PS-NPs until the production of the neonates (F1) followed by a two-generation recovery. PS-NPs were mainly detected in the intestine and brood chamber in F0 and transferred to F1 and F2. PS-NPs significantly decreased the appendage curling and heartbeat rate in F0 and reduced reproduction in F2. In experiment 2, the plastic leachate also reduced the appendage curling rate but increased growth and reproduction. The results suggest that the acute toxicity of primary and secondary plastic particles is low even at high concentrations, but their chronic and sublethal effects should not be overlooked.

Motion behavior and metabolic response to microplastic leachates in the benthic foraminifera Haynesina germanica

Plastic is one of the major sources of pollution in modern oceans. When in seawater, toxic plasticizers (the additives incorporated in plastic polymers during manufacturing processes) typically diffuse and accumulate in sediments and in benthic and pelagic organisms' tissues. These plastic leachates affect survival, behavior and metabolism of various marine metazoans, but little effort was placed in studying their effect on protists. In this contribution we monitored the short-term effect of polypropylene (PP) leachates at both environmentally realistic and chronic concentrations on Haynesina germanica locomotion and metabolism. We found that PP leachates has no lethal nor effects on this species activity. Taken together, these results suggest that benthic foraminifera may be more resistant than marine metazoans to plasticizers pollutants.

Adverse effects of oxo-degradable plastic leachates in freshwater environment.

The production of biodegradable plastics is considered to be a way to reduce plastic waste issue. Among others, oxo-degradant additives enable a faster degradation of plastics in the environment. However, the introduction of these new materials could provoke the release of substances potentially toxic in the environment. This work determined and compared the toxicity of leachates from various additivated polymers (polyethylene, PE; polypropylene, PP; polystyrene, PS) upon different test organisms: plants (Sorghum saccharatum, Lepidium sativum, Sinapis alba, and Vicia faba), crustacean (Daphnia magna), and luminescent bacteria (Vibrio fischeri). Daphnia magna survival was mainly affected by PS and PP leachates (72% and 61% effect, respectively) while PS notably reduced the reproduction rate. On plants, only PP exerted a negative effect (S. saccharatum IG% 32.4), while V. fischeri always showed values around 50%. The data integration, through the Toxicity Test Battery Integrated Index (TBI) approach, allowed to rank the leachates toxicity as PE > PS > PP. This result could be mainly ascribable to the highest metals content in PE since no difference with organic compounds analysis was evidenced. In conclusion, since the polymers exerted dissimilar toxicity, the additive could not be considered the sole responsible of the measured toxicity, but its role in the enhancement of the virgin polymers leachates effects can be solidly hypothesized.

A Simple and Effective Liquid-Liquid-Liquid Microextraction Method with Ultraviolet Spectrophotometric Detection for the Determination of Bisphenol A in Aqueous Matrices and Plastic Leachates

This study shows the development and application of an analytical method for the determination of bisphenol A (BPA) in aqueous samples such as tap, river and mineral water and plastic leachates, based on an extensive literature search to understand the gaps for the determination of BPA in aqueous samples. We found that most of the methods in the literature employ some chromatographic strategy, and, to a much lesser extent, non-chromatographic instrumentation. In this scenario, we show an ultraviolet spectrophotometric-based method that can be used for routine analysis. Sample preparation was conducted by means of solvent extraction followed by back-extraction into an alkaline aqueous solution (liquid-liquid-liquid microextraction) and the detection was performed by UV spectrophotometry at 294 nm. Optimization of variables affecting both extraction and back-extraction was conducted, and the optimal extraction conditions were obtained: 85 mL aqueous sample buffered at pH 10, ionic strength adjusted with NaCl to a 2 mol L-1 final concentration, extraction with 6 mL of ethyl ether for 10 min and back-extraction into 0.5 mL of 2 mol L-1 aqueous NaOH. The following quality parameters were obtained: determination coefficient (R2) > 0.999, intra and inter-day repeatability better than 7.8% and 300 enhancement factor. The method was applied in different aqueous samples with excellent recovery and precision results, and no BPA was detected in natural water, even with the excellent limit of detection (3.5 μg L-1) and limit of quantification obtained. Limitations of this method involve analysis of samples with humic acid concentrations higher than 2 mg L-1 or high concentration of phenols and/or phthalate esters.