Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Pathways for degradation of plastic polymers floating in the marine environment
Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
Number of Authors: 32015 (English)In: Environmental Science: Processes & Impacts, ISSN 2050-7887, E-ISSN 2050-7895, Vol. 17, no 9, p. 1513-1521Article, review/survey (Refereed) Published
Abstract [en]

Each year vast amounts of plastic are produced worldwide. When released to the environment, plastics accumulate, and plastic debris in the world's oceans is of particular environmental concern. More than 60% of all floating debris in the oceans is plastic and amounts are increasing each year. Plastic polymers in the marine environment are exposed to sunlight, oxidants and physical stress, and over time they weather and degrade. The degradation processes and products must be understood to detect and evaluate potential environmental hazards. Some attention has been drawn to additives and persistent organic pollutants that sorb to the plastic surface, but so far the chemicals generated by degradation of the plastic polymers themselves have not been well studied from an environmental perspective. In this paper we review available information about the degradation pathways and chemicals that are formed by degradation of the six plastic types that are most widely used in Europe. We extrapolate that information to likely pathways and possible degradation products under environmental conditions found on the oceans' surface. The potential degradation pathways and products depend on the polymer type. UV-radiation and oxygen are the most important factors that initiate degradation of polymers with a carbon-carbon backbone, leading to chain scission. Smaller polymer fragments formed by chain scission are more susceptible to biodegradation and therefore abiotic degradation is expected to precede biodegradation. When heteroatoms are present in the main chain of a polymer, degradation proceeds by photo-oxidation, hydrolysis, and biodegradation. Degradation of plastic polymers can lead to low molecular weight polymer fragments, like monomers and oligomers, and formation of new end groups, especially carboxylic acids.

Place, publisher, year, edition, pages
2015. Vol. 17, no 9, p. 1513-1521
National Category
Chemical Sciences Earth and Related Environmental Sciences
Research subject
Applied Environmental Science
Identifiers
URN: urn:nbn:se:su:diva-121702DOI: 10.1039/c5em00207aISI: 000361146500001OAI: oai:DiVA.org:su-121702DiVA, id: diva2:860869
Available from: 2015-10-14 Created: 2015-10-13 Last updated: 2018-04-27Bibliographically approved
In thesis
1. Chemical Pollutants Released to the Marine Environment by Degradation of Plastic Debris
Open this publication in new window or tab >>Chemical Pollutants Released to the Marine Environment by Degradation of Plastic Debris
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Since the beginning of the mass production in the 1940s, plastic has been manufactured in quickly increasing amounts. Plastic debris accumulates in the environment and lately much attention has been drawn to the pollution in the world’s oceans. Despite the rapid development and ubiquitous presence of plastic, degradation in the marine environment and potential risks associated with plastic are not fully understood. Thus, these knowledge gaps were addressed in this thesis, which adds information about exposure and hazards of marine plastic debris.

Although sampling studies have been conducted all over the world, the concentrations of plastic debris in the Baltic Sea have hardly been investigated. In Paper I, the level and distribution of plastic debris in the Stockholm Archipelago were assessed. Plastic concentrations were higher close to suspected point sources compared to remote areas. Fibers accounted for the most common form and the predominant polymer types were polypropylene (PP) and polyethylene (PE).

In Paper II, the literature was critically reviewed for the most important degradation pathways for plastic under environmentally relevant conditions. Ultraviolet (UV) radiation, leading to photo-oxidation, is the most important initiating factor for buoyant plastic. Consequently, a UV lamp was used in Paper III for an artificial weathering setup in the laboratory to degrade pristine plastics and analyze the chemical leachates by liquid chromatography-mass spectrometry (LC-MS) for degradation products using a nontarget approach. Carboxylic acids and dicarboxylic acids of polymer fragments were the most commonly identified degradation products of the plastic polymers, confirming predictions made in Paper II.

To evaluate potential hazards posed by leachates from weathering plastic debris to marine organisms, an acute toxicity screening study with Nitocra spinipes was conducted in Paper IV. Field-exposed plastic and the corresponding newly purchased plastic were artificially aged with the same weathering setup as in Paper III. Poly(vinyl chloride) (PVC) and PP leachates were generally most toxic, while leachates from polystyrene (PS) and poly(ethylene terephthalate) (PET) were least toxic among the tested materials. For plastics, which were supposed to contain only few additives, we observed no difference in toxicity between leachates from the field-exposed and the newly purchased plastic. However, the other plastic products exposed to the marine environment were more toxic than their corresponding newly bought products. This indicates that the toxicity of the leachates not only depends on the polymer type, but also on the weathering condition of the plastic.

Place, publisher, year, edition, pages
Stockholm: Department of Environmental Science and Analytical Chemistry, Stockholm University, 2018. p. 36
Keywords
Plastic, microplastic, degradation, leachates, weathering, photo-oxidation, marine environment, toxicity
National Category
Environmental Sciences
Research subject
Applied Environmental Science
Identifiers
urn:nbn:se:su:diva-155581 (URN)978-91-7797-167-2 (ISBN)978-91-7797-168-9 (ISBN)
Public defence
2018-06-12, Nordenskiöldsalen, Geovetenskapens hus, Svante Arrhenius väg 12, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Manuscript.

Available from: 2018-05-18 Created: 2018-04-25 Last updated: 2018-05-09Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full text

Search in DiVA

By author/editor
Gewert, BeritPlassmann, Merle M.MacLeod, Matthew
By organisation
Department of Environmental Science and Analytical Chemistry
In the same journal
Environmental Science: Processes & Impacts
Chemical SciencesEarth and Related Environmental Sciences

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 43 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf