Organic additive release from plastic to seawater is lower under deep-sea conditions.

Plastic garbage patches at the ocean surface are symptomatic of a wider pollution affecting the whole marine environment. Sinking of plastic debris increasingly appears to be an important process in the global fate of plastic in the ocean. However, there is insufficient knowledge about the processes affecting plastic distributions and degradation and how this influences the release of additives under varying environmental conditions, especially in deep-sea environments. Here we show that in abiotic conditions increasing hydrostatic pressure inhibits the leaching of the heaviest organic additives such as tris(2-ethylhexyl) phosphate and diisononyl phthalate from polyethylene and polyvinylchloride materials, whereas deep-sea and surface marine prokaryotes promote the release of all targeted additives (phthalates, bisphenols, organophosphate esters). This study provides empirical evidences for more efficient additive release at the ocean surface than in deep seawater, where the major plastic burden is supposed to transit through before reaching the sediment compartment.

Horizontal and vertical distribution of phthalates acid ester (PAEs) in seawater and sediment of East China Sea and Korean South Sea: Traces of plastic debris?

Phthalate acid esters (PAEs) are commonly used as plasticizers in numerous plastic applications. Owing to their high leachability, the occurrence of PAEs can be used to trace plastic pollution. The northwest Pacific marginal seas, including the East China Sea, are suspected not only to be the area that receives the most plastic waste globally but also transit the waste to the ocean worldwide. To identify the potential sources of PAEs in this area, seawater at different water depths and sediment were investigated. The highest level of di(2-ethylhexyl) phthalate (DEHP), which is primarily used in plastic polymers, was observed in the accumulation zone of plastic debris. Moreover, DEHP exhibited not only the highest levels in the bottom layer of water column but also a significant correlation between bottom water layer and bed sediment, which strongly suggests a continuous flow of PAEs from the seafloor to the seawater column in this area.

Phthalate Release from Plastic Fragments and Degradation in Seawater.

Plastic debris in the environment contains plasticizers, such as phthalates (PAEs), that can be released during plastic aging. Here, two common plastic materials, an insulation layer of electric cables (polyvinyl chloride, PVC-cables) and plastic garbage bag (polyethylene, PE-bags), were incubated in natural seawater under laboratory conditions, and the PAE migration to the seawater phase was studied with varying light and bacterial conditions over a 90-day time course. Free PAEs diluted in seawater were also studied for bacterial degradation. Our results showed that, within the first month of incubation, both plastic materials significantly leached out PAEs into the surrounding water. We found that di-isobutyl phthalate (DiBP) and di- n-butyl phthalate (DnBP) were the main PAEs released from the PE-bags, with the highest values of 83.4 ± 12.5 and 120.1 ± 18.0 ng g-1 of plastic, respectively. Furthermore, dimethyl phthalate (DMP) and diethyl phthalate (DEP) were the main PAEs released from PVC-cables, with mass fractions as high as 9.5 ± 1.4 and 68.9 ± 10.3 ng g-1, respectively. Additionally, we found that light and bacterial exposure increased the total amount of PAEs released from PVC-cables by a factor of up to 5, whereas they had no influence in the case of PE-bags.

Distribution of phthalates in Marseille Bay (NW Mediterranean Sea).

Phthalic Acid Esters (PAEs) are a group of emerging organic contaminants that have become a serious issue because of their ubiquitous presence and hazardous impact on the marine environment worldwide. Seawater samples were collected monthly from December 2013 to November 2014 in the northwestern Mediterranean Sea (Marseille Bay). The samples were analyzed for dissolved organic carbon (DOC) as well as the molecular distribution of dissolved PAEs by using solid phase extraction followed by gas chromatography and mass spectrometry (GC/MS) analyses. The results demonstrated the occurrence of six PAEs, including dimethyl phthalate (DMP), diethyl phthalate (DEP), di-isobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP), benzylbutyl phthalate (BzBP) and diethylhexyl phthalate (DEHP), with total concentrations ranging from 130 to 1330ngL-1 (av. 522ngL-1). In Marseille Bay, the highest concentrations were detected in the bottom water from June to November 2014 and in the whole water column during the winter mixing period. This result suggests that resuspension of PAE-rich sediment, in relation to the accumulation of plastic debris above the seabed, or the higher degradation rate in the upper layer of the water column, plays a significant role in the PAE dynamics in coastal water. DEHP was the most abundant PAE in all of the surface samples and the summer bottom samples, followed by DiBP and DnBP, which also represent the largest fractions in the other bottom samples.

Occurrence, Loading, and Exposure of Atmospheric Particle-Bound POPs at the African and European Edges of the Western Mediterranean Sea.

A comparative study for 62 toxic chemicals based on the simultaneous monthly collection of aerosol samples during 2015-2016 in two coastal cities at both the African (Bizerte, Tunisia) and European (Marseille, France) edges of the Western Mediterranean basin is presented. Legacy polychlorinated biphenyls (∑18PCBs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (∑17PCDD/Fs) show generally higher median levels at the African edge (2.1 and 0.2 pg m-3, respectively) compared to the European coastal site (1.0 and 0.08 pg m-3, respectively). Contrarily, the "emerging" polybrominated diphenyl ethers' (∑27PBDEs) median concentrations were higher in Marseille (∼9.0 pg m-3) compared to Bizerte (∼6.0 pg m-3). Different past usages and current emission patterns were found at both edges of the Western Mediterranean, most probably linked to the respective different regulatory frameworks for toxic chemicals. Our results indicate that the total organic carbon (TOC) and/or the elemental carbon (EC) contents in the atmospheric aerosol may have a stronger effect than the total suspended particle (TSP) content as a whole on the spatial-temporal variability and the long-range atmospheric transport potential of the studied POPs. A "jumping" of the PBDE local atmospheric stocks from the Northwestern European Mediterranean edge to the Northwestern African coast seems to be possible under favorable conditions at present. While a higher PBDE median loading is estimated for the Marseille area (∼550 ng m-2 y-1) compared to Bizerte (∼400 ng m-2 y-1), the median PCB and PCDD/F dry deposition fluxes were higher at the African site, resulting in a 3-fold higher toxic equivalent (TEQ) loading of dioxin-like pollutants (400 pg TEQ m-2 y-1) compared to Marseille (∼140 pg TEQ m-2 y-1), with potential implications for aquatic organisms. However, the inhalation exposure assessment points to a minimum risk for human health at both sites.

Occurrence, fate, behavior and ecotoxicological state of phthalates in different environmental matrices.

Because of their large and widespread application, phthalates or phthalic acid esters (PAEs) are ubiquitous in all the environmental compartements. They have been widely detected throughout the worldwide environment. Indoor air where people spend 65-90% of their time is also highly contaminated by various PAEs released from plastics, consumer products as well as ambient suspended particulate matter. Because of their widespread application, PAEs are the most common chemicals that humans are in contact with daily. Based on various exposure mechanisms, including the ingestion of food, drinking water, dust/soil, air inhalation and dermal exposure the daily intake of PAEs may reach values as high as 70 µg/kg/day. PAEs are involved in endocrine disrupting effects, namely, upon reproductive physiology in different species of fish and mammals. They also present a variety of additional toxic effects for many other species including terrestrial and aquatic fauna and flora. Therefore, their presence in the environment has attracted considerable attention due to their potential impacts on ecosystem functioning and on public health. This paper is a synthesis of the extensive literature data on behavior, transport, fate and ecotoxicological state of PAEs in environmental matrices: air, water, sediment, sludge, wastewater, soil, and biota. First, the origins and physicochemical properties of PAEs that control the behavior, transport and fate in the environment are reviewed. Second, the compilation of data on transport and fate, adverse environmental and human health effects, legislation, restrictions, and ecotoxicological state of the environment based on PAEs is presented.

Reliable quantification of phthalates in environmental matrices (air, water, sludge, sediment and soil): a review.

Because of their widespread application, phthalates or phthalic acid esters (PAEs) are ubiquitous in the environment. Their presence has attracted considerable attention due to their potential impacts on ecosystem functioning and on public health, so their quantification has become a necessity. Various extraction procedures as well as gas/liquid chromatography and mass spectrometry detection techniques are found as suitable for reliable detection of such compounds. However, PAEs are ubiquitous in the laboratory environment including ambient air, reagents, sampling equipment, and various analytical devices, that induces difficult analysis of real samples with a low PAE background. Therefore, accurate PAE analysis in environmental matrices is a challenging task. This paper reviews the extensive literature data on the techniques for PAE quantification in natural media. Sampling, sample extraction/pretreatment and detection for quantifying PAEs in different environmental matrices (air, water, sludge, sediment and soil) have been reviewed and compared. The concept of "green analytical chemistry" for PAE determination is also discussed. Moreover useful information about the material preparation and the procedures of quality control and quality assurance are presented to overcome the problem of sample contamination and these encountered due to matrix effects in order to avoid overestimating PAE concentrations in the environment.