Plastics, pathogens and baby formula: What's in your shellfish?
New study finds coastal urbanization increases contamination in seafood


Date:
July 30, 2020
Source:
University of California - Irvine
Summary:
The first landmark study using next-generation technology to
comprehensively examine contaminants in oysters in Myanmar reveals
alarming findings: the widespread presence of human bacterial
pathogens and human-derived microdebris materials, including
plastics, kerosene, paint, talc and milk supplement powders.



FULL STORY ==========================================================================
The first landmark study using next-generation technology to
comprehensively examine contaminants in oysters in Myanmar reveals
alarming findings: the widespread presence of human bacterial pathogens
and human-derived microdebris materials, including plastics, kerosene,
paint, talc and milk supplement powders.


==========================================================================
The study -- led by scientists from the University of California, Irvine,
in collaboration with Environmental Defense Fund, Cornell University and
the University of Queensland -- was conducted in the eastern Andaman Sea through partnerships with local researchers in Myanmar in the densely
populated but still rural Tanintharyi region. The study concludes that
coastal urbanization and lack of sewage treatment increases contamination
in seafood and can cause potential health risks to humans, even large
distances from pollution sources.

The area covered by the study spanned nine coral reefs off Myanmar's
Mergui Archipelago, situated roughly 40 miles from Myeik, a city with
a population of over 250,000 people. The study examined contaminants
in seawater and in oysters using next-generation DNA sequencing to
reveal 5,459 potential human pathogens belonging to 87 species of
bacteria. More than half of these pathogens are considered detrimental
to human health. In addition, the scientists used infrared spectroscopy
to examine individual microdebris particles found in the oysters. Of the
1,225 individual microdebris particles examined, 78 different types of contaminant materials were found.

"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," said senior author Joleah Lamb, assistant professor of
ecology & evolutionary biology at UCI. "We were particularly surprised
to find three different brands of milk powder formula, which comprised
14 percent of the microdebris contaminants." Both types of contaminants
-- pathogens and microparticles -- reflect the pervasive presence of
sewage and runoff from human and animal sources. The implications for
other coastal regions are significant, since coastal marine environments worldwide are being increasingly subjected to reduced water quality from urbanization that could be leading to the contamination of important
fishery species on a global scale.

Implications for human health are also significant. Oysters in this
region and elsewhere are part of the local diet and typically consumed
raw and whole. The contaminants found in this study indicate that even
the Mergui Archipelago in largely rural Myanmar has significant and
widespread pollution from runoff of agricultural and human waste that can affect downstream food sources over a wide area far from urban centers.



========================================================================== Today more than half of seafood exports by value originate in developing countries, raising more general concerns about local food safety and
food security worldwide.

"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 lead author Raechel Littman, a postdoctoral
scholar in ecology & evolutionary biology at UCI.

Apart from human bacterial pathogens, the predominance of microplastics
and other types of microparticles present in seafood could have
implications for both the environment and human health.

"Scientists are only beginning to explore the human health consequences
from consuming microplastics," said Lamb.

Many plastic particles can carry toxins, such as persistent organic
pollutants, or POPs, like dichlorodiphenyltrichloroethane (DDT), polychlorinated biphenyls (PCBs) and bisphenol A (BPA), that subsequently
enter the ocean and marine food webs, and can eventually be transferred to people through food. Therefore, the uptake of microplastics in the marine environment could have far-reaching consequences for human consumption
of seafood and can be an emerging risk to public health globally.

Also concerning is that over half of the microdebris contaminants detected
in the Myanmar oyster tissues were composed of non-polymer materials
that can be harmful to human health if ingested, such as kerosene,
saponin and talc.

Moreover, the prominence of milk supplement detected suggests a direct
fecal- oral link between human waste and sewage making its way back
into the food chain, thereby elevating the risk of contamination or
disease transmission.

"This study in 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 collaborator on this study. "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.


========================================================================== Story Source: Materials provided by
University_of_California_-_Irvine. Note: Content may be edited for style
and length.


========================================================================== Journal Reference:
1. Raechel A. Littman, Evan A. Fiorenza, Amelia S. Wenger, Kathryn L.E.

Berry, Jeroen A.J.M. van de Water, Lily Nguyen, Soe Tint Aung,
Daniel M.

Parker, Douglas N. Rader, C. Drew Harvell, Joleah B. Lamb. Coastal
urbanization influences human pathogens and microdebris
contamination in seafood. Science of The Total Environment, 2020;
736: 139081 DOI: 10.1016/j.scitotenv.2020.139081 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/07/200730123704.htm

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