Study warns disease-causing parasites pour into the ocean by hitching rides on plastic

By Tom Campbell via SWNS

Disease-causing parasites could be pouring into the ocean after hitching a ride on microplastics, warns a new study.

The tiny pieces of plastic could spread dangerous diseases to humans - some of which can prove fatal for kids, say scientists.

Plastic particles, no bigger than a grain of rice, known as microplastics, have contaminated the four corners of the ocean, even the most remote waters in Antarctica.

The amount of plastic trash that flows into the oceans every year is expected to nearly triple by 2040.

Now scientists in the United States have found plastic pollution could be harmful in more ways than one.

Author Dr. Karen Shapiro at the University of California, Davis said: "It’s easy for people to dismiss plastic problems as something that doesn't matter for them, like, ‘I’m not a turtle in the ocean; I won’t choke on this thing.

"But once you start talking about disease and health, there’s more power to implement change.

"Microplastics can actually move germs around, and these germs end up in our water and our food.”

Three disease causing pathogens were included in the study which can infect both humans and animals.

Toxoplasma gondii, a parasite found in cat faeces, which infects many sea creatures and causes a disease called toxoplasmosis.

The illness has been linked with deaths among sea otters and critically endangered wildlife like Hector’s dolphins and Hawaiian monk seals.

In humans, the condition can cause life-long illnesses, as well as developmental and reproductive disorders.

Cryptosporidium (Crypto) and Giardia, two pathogens that can be deadly in young children and people with underlying health conditions, were also examined by the researchers.

First author graduate student Emma Zhang said: "This is very much a problem that affects both humans and animals.

"It highlights the importance of a One Health approach that requires collaboration across human, wildlife and environmental disciplines.

"We all depend on the ocean environment.”

Experiments were carried out to see whether these harmful parasites could piggyback off of microplastics in seawater.

Two different types of plastic were tested, including polyethylene microbeads, which are found in many cosmetics, including exfoliants and cleansers.

They also looked at polyester microfibres, commonly used to make clothing and fishing nets.

More parasites stuck to the fibres than the breads, although both were suitable, the researchers found.

Dr. Shapiro said: "Plastic makes it easier for pathogens to reach sea life in several ways, depending on whether the plastic particles sink or float."

Pieces of plastic on the surface can travel long distances and spread diseases far from their original source on land.

But those which sink could concentrate pathogens near the ocean floor, known as the benthos environment.

This is where filter feeding animals like plankton, clams, mussels, oysters and other shellfish live.

Dr. Shapiro said: “When plastics are thrown in, it fools invertebrates.

"We’re altering natural food webs by introducing this human-made material that can also introduce deadly parasites.”

A singe cloth wash can shed up to 700,000 microplastic fibres which reach waterways through waste systems.

But there are several ways that people can reduce their microplastic footprint, the researchers say.

Choosing clothes made from natural fibres and avoiding cosmetic products made with plastic beads is one example.

Co-author Dr. Chelsea Rochman at the University of Toronto said: "This work demonstrates the importance of preventing sources of microplastics to our oceans.

"Mitigation strategies include filters on washing machines, filters on dryers, bioretention cells or other technologies to treat stormwater, and best management practices to prevent microplastic release from plastic industries and construction sites.”

The findings were published in the journal Scientific Reports.