AUG 03, 2020 7:31 AM PDT

Pollutants, Pathogens and Toxins Found in Shellfish

WRITTEN BY: Carmen Leitch

Scientists used cutting edge technologies to assess how pervasive toxic or household chemicals and pathogens like plastic, kerosene, talc, bacteria, and milk supplement powders are in oysters in Myanmar. Their findings, which examined oysters from a densely populated but nevertheless rural area revealed that these huma- derived substances are widespread. The researchers concluded that urbanization along coastlines and the absence of sewage treatment poses a risk to human health, even when they are far from the source of the pollution. The work has been reported in Science of the Total Environment.

Joleah Lamb, assistant professor of ecology & evolutionary biology at UCI, collecting data on urban reefs in Myanmar. / Credit: Michelangelo Pignani

"While 48 percent of the microparticles were microplastics - a finding representative across numerous ocean ecosystems - many other particles were not plastic and originated from a variety of human-derived materials that are constituents of fuels, paints and cosmetics," noted the senior study author Joleah Lamb, assistant professor of ecology & evolutionary biology at the University of California - Irvine. "We were particularly surprised to find three different brands of milk powder formula, which comprised 14 percent of the microdebris contaminants."

The study focused on nine coral reefs that are about 40 miles away from a city called Myeik, which has a population of about a quarter of a million people. The researchers sampled seawater and oysters, which were examined with DNA sequencing that revealed 87 species of bacteria and 5,459 potential pathogens, about half of which are known to pose a threat to human health.

With infrared microscopy, the scientists identified particles in the oysters. After examining 1,225 individual pieces of debris, they found 78 different kinds of contaminants. Take together, the study showed that runoff from agriculture, animals, and humans is significant, detrimental to water quality, and may be contaminating fisheries worldwide. Because oysters are often consumed raw, this research has suggested that the contamination is dangerous. Developing countries often export seafood, so food safety might be at risk on a wide scale.

"It's important to keep in mind that much of our seafood is imported from overseas, from places that may be contaminated, emphasizing the importance of both adequate testing and improvements to coastal water quality worldwide," said the lead study author Raechel Littman, a postdoctoral scholar in ecology & evolutionary biology at UCI.

The presence of microplastics is also a cause for concern. "Scientists are only beginning to explore the human health consequences from consuming microplastics," said Lamb.

Many plastics contain chemicals that are known to be toxic or carcinogenic. They can enter the food web through fish that take them up as they swim around polluted waters, and then they are transmitted to the people that eat the fish.

Beyond plastic are the known toxins found by the researchers including kerosene and saponin. The abundance of milk supplements also suggests that human waste and sewage is making its way back into the food chain.

"This study is important in its global implications. There is strong evidence of transferability of the findings from Myanmar to other seafood sources around the world," said Douglas Rader, chief scientist for the EDF Oceans program and study collaborator. "These findings highlight both the risks of coastal urbanization and the importance of adequate wastewater and stormwater management. It also shows clearly the need for better science related to the potential impacts of these contaminants, and the need for better testing programs so that seafood consumers can rely on its wholesomeness.


Sources: AAAS/Eurekalert! via University of California - Irvine, Science of the Total Environment

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
JUN 18, 2020
Cardiology
Healthy Eating Habits Lower the Risk of Cardiovascular Disease
JUN 18, 2020
Healthy Eating Habits Lower the Risk of Cardiovascular Disease
The results are in, eat your fruits and vegetables. A truth that society has known for some time, but data now confirms ...
JUL 23, 2020
Plants & Animals
Groups Led by Dominant Males Are Less Cooperative
JUL 23, 2020
Groups Led by Dominant Males Are Less Cooperative
When aggressive males led groups of fish in a complex task, those fish did poorly on the task compared to groups led by ...
AUG 20, 2020
Plants & Animals
Flamboyant Cuttlefish Are Usually Understated
AUG 20, 2020
Flamboyant Cuttlefish Are Usually Understated
Cuttlefish are well known for their incredible camouflaging abilities; they can rapidly change the color and texture of ...
AUG 21, 2020
Cannabis Sciences
Growing Cannabis Indoors is Not Eco Friendly
AUG 21, 2020
Growing Cannabis Indoors is Not Eco Friendly
Indoor cannabis cultivation is considered to produce the highest quality cannabis available, but the elephant in the roo ...
SEP 10, 2020
Plants & Animals
Scientists Document Swimming Styles of Sea Butterflies
SEP 10, 2020
Scientists Document Swimming Styles of Sea Butterflies
Snails, marine and terrestrial, are likely primarily imagined to be attached to a substrate. However, under the waves, t ...
SEP 17, 2020
Genetics & Genomics
Revealing More About the Past With a New Metagenomic Technique
SEP 17, 2020
Revealing More About the Past With a New Metagenomic Technique
Scientists can use advanced genomics techniques to mine samples for all the genetic material they contain.
Loading Comments...