Friday, December 26, 2014
YOLO COUNTY NEWS
99 CENTS

Chemicals plastics absorb may increase threat to marine life

UC Davis doctoral candidate Chelsea Rockman, right, and colleagues Stephanie Celustka, left, and Meggie Moore tie bags of plastic pellets onto piping to be hung from a dock in San Diego Bay and measured for contaminants. Chelsea Rochman, UC Davis/Courtesy photo

By
From page A1 | January 16, 2013 |

Marine creatures that ingest plastics in the ocean might suffer from a double whammy of the plastic itself and the pollutants those plastics have absorbed while floating in the open seas, according to research led by UC Davis doctoral student Chelsea Rochman.

The study found that the most commonly produced plastics also absorbed the most chemicals, and for longer periods of time than previously thought.

Products made from the particular plastic used to make water bottles — polyethylene terephthalate, or PET — might have fewer detrimental chemical impacts than products made from other types of plastic, according to the study, published online this month in the journal Environmental Science & Technology.

Rochman’s research, conducted for 12 months at five locations in San Diego Bay, was the first controlled, long-term field experiment measuring the absorption of contaminants by the five most common plastics:

* Polyethylene terephthalate (PET). Recycling symbol #1. Ex: Water bottles.

* High-density polyethylene (HDPE). Recycling symbol #2. Ex: Detergent bottles.

* Polyvinyl chloride (PVC). Recycling symbol #3. Ex: Clear food packaging.

* Low-density polyethylene (LDPE). Recycling symbol #4. Ex: Plastic shopping bags.

* Polypropylene (PP). Recycling symbol #5. Ex: Yogurt containers, bottle caps.

Rochman and her colleagues deployed pellets of each plastic type in mesh bags tied to a dock at each study site. They retrieved them periodically to measure the plastics’ absorption of persistent organic pollutants.

“Consistently in our study, we found polyethylene (HDPE and LDPE) and polypropylene (PP) absorbed much greater concentrations of contaminants than PET or PVC, and those are the most commonly mass produced and consumed plastics,” said Rochman, who is a Ph.D. student in marine biology seeking a joint degree from UCD and San Diego State University. “They are also the most commonly recovered as marine debris.”

In 2007, HDPE, LDPE and PP accounted for 62 percent of all plastics produced globally, while PVC and PET represented only 19 percent and 7 percent, the study said.

The data imply that products made from HDPE, LDPE and PP may pose a greater chemical risk to marine animals that ingest plastics than products made from PET and PVC. The study notes that, although PVC did not absorb as many contaminants as did other plastics, vinyl chloride is classified as carcinogenic and toxic.

Rochman expected the pellets would absorb an increasing amount of pollutants for the first several months of the study before reaching equilibrium — the point at which they could not absorb further toxic substances. However, Rochman found that HDPE and LDPE continued to absorb contaminants throughout the 12 months.

The study estimated that, at the Shelter Island study site, it would take 44 months for HDPE and 19 months for LDPE to stop absorbing toxic substances.

“It surprised us that even after a year, some plastics would continue to take up contaminants,” Rochman said. “As the plastic continues to degrade, it’s potentially getting more and more hazardous to organisms as they absorb more and more contaminants.”

The study was funded by the National Science Foundation’s Graduate Research Fellowship Program, with additional funding from the Society of Environmental Toxicology and Chemistry, the San Diego State University Research Foundation and the Padi Foundation.

— UC Davis News Service

Comments

comments

  • Recent Posts

  • Enter your email address to subscribe to this newspaper and receive notifications of new articles by email.

  • .

    News

    Transit survey: 47 percent ride bikes to UCD campus

    By Special to The Enterprise | From Page: A1 | Gallery

     
    Exchange students bring the world to Davis

    By Anne Ternus-Bellamy | From Page: A1 | Gallery

     
    Pastor has many plans for CA House

    By Jeff Hudson | From Page: A1 | Gallery

    Playing Santa

    By Enterprise staff | From Page: A2 | Gallery

     
    Goats help recycle Christmas trees

    By The Associated Press | From Page: A2 | Gallery

     
    Special holiday gifts

    By Sue Cockrell | From Page: A3

    Woodland-Davis commute bus service expands

    By Enterprise staff | From Page: A3

     
    Learn fruit tree tips at free class

    By Enterprise staff | From Page: A3

    Davis Bike Club hears about British cycling tour

    By Enterprise staff | From Page: A3

     
    Pick up a Davis map at Chamber office

    By Enterprise staff | From Page: A3

    Sierra Club calendars on sale Saturday

    By Enterprise staff | From Page: A3

     
    Explorit: Get a rise out of science

    By Lisa Justice | From Page: A4

    NAMI meeting offers family support

    By Special to The Enterprise | From Page: A6

     
    Yoga, chanting intro offered

    By Enterprise staff | From Page: A8

    .

    Forum

    Blamed for her sister’s rage

    By Creators Syndicate | From Page: B5

     
    How much for the calling birds?

    By Creators Syndicate | From Page: B5

    Steve Sack cartoon

    By Debbie Davis | From Page: A10

     
    Many ensured a successful parade

    By Letters to the Editor | From Page: A10

     
    Thanks for putting food on the table

    By Letters to the Editor | From Page: A10

     
    .

    Sports

     
    Two more for the road for 9-1 Aggie men

    By Bruce Gallaudet | From Page: B1 | Gallery

    Patterson is college football’s top coach

    By The Associated Press | From Page: B1 | Gallery

     
    Clippers get a win over Golden State

    By The Associated Press | From Page: B1 | Gallery

    NBA roundup: Heat beat Cavs in LeBron’s return to Miami

    By The Associated Press | From Page: B10 | Gallery

     
    .

    Features

    .

    Arts

    ‘Unbroken': A bit underwhelming

    By Derrick Bang | From Page: A11 | Gallery

     
    Folk musicians will jam on Jan. 2

    By Enterprise staff | From Page: A11

    .

    Business

    Passat: Roomy, affordable sedan with German engineering

    By Ann M. Job | From Page: B3 | Gallery

     
    .

    Obituaries

    James J. Dunning Jr.

    By Special to The Enterprise | From Page: A4

     
    Floyd W. Fenocchio

    By Special to The Enterprise | From Page: A4

    .

    Comics

    Comics: Friday, December 26, 2014 (set 2)

    By Creator | From Page: B7

     
    Comics: Thursday, December 26, 2014 (set 1)

    By Creator | From Page: A9