Several
years ago, microplastics were found in sea salt by the Joint Group of Experts on the Scientific Aspects of Marine
Environmental Protection but this new study shows the microplastic problem
is now sitting on most our tables in sea, rock and lake salts.
The study tested 39 sea salt brands from 21
countries over six different continents, 36 of the 39 salts contained
microplastics. The findings, published in the journal of Environmental Science & Technology, found that only three salt
brands were free of microplastics, a refined sea salt from Taiwan, a refined
rock salt from China and unrefined sea salt produced by using solar evaporation
in France.
What are microplastics?
Microplastics, the result of the degradation
of larger plastic products, are small pieces of plastic that measure less than
5mm. They are found throughout the world in rivers, oceans and soil and the
study showed a correlation between places with higher plastic emissions and
those with more plastic in their salt.
Seung-Kyu Kim, Incheon Nation
University, said: “The finding suggests that human ingestion of
microplastics via marine products is strongly related to emission in a given
region.”
Asia was shown to have the highest levels of
contamination, with Indonesia showing the highest mass of microplastics across
the study. These fndings echoed in a seperate study on microplastic by the Jambeck Research Group back in 2015.
However, the plastic traces were found in salt from across five continents. Sea
salt was found to contain the highest levels, followed by lake salt and rock
salt.
How harmful is this?
The journal publication suggests that the
average human consumes approximatly 2,000 pieces of microplastic every year
through salt, but there is litle data available on what effect this has. The University of York conducted a study on
the impact of the consumption of plastic in salt on humans, they suggested the
data available at the moment is inconclusive.
Alistair Boxall, one of the co-authors of the study, said there is large
a “knowledge gap” in existing research and that there so many different types
of microplastics monitored across 320 seperate studies that any type of data
comparision is very hard to do.
Boxall said, "Based on our analysis,
there is currently limited evidence to suggest microplastics are causing
significant adverse impacts,” but this points more to a lack of data and a
mismatch of data on the topic rather than any conclusive findings. Boxall
added, “There is an urgent need for better quality and more holistic monitoring
studies alongside more environmentally realistic effects studies on the
particle sizes and material types that are actually in the environment.”
By FDL