Plastic pollution has found its way from our consumer products into
the ocean, and now it may have found its way back to our table. We know
our oceans are polluted by giant trash gyres and tiny bits of micro
plastics that prove harmful to aquatic life, but researchers have
recently found that these micro plastics may also be contaminating our
table salt. According to
this article from
the Telegraph, researchers in China tested 15 different brands of table
salt and found traces of plastics from water bottles, cellophane, and
other sources. Not only was this plastic pollution found in table salt
from ocean sources (though sea salt did contain the most plastic), but
salt from lakes and rock salt from wells were also contaminated. These
tiny pieces of plastic, most too small to see, would result in the
average consumer eating about 3 pieces of plastic a day. The article
also shared a quote from one of the researchers who published the
original study in Environmental Science & Technology, who said that
though this study only looked at Chinese salt samples, similar results
could be expected elsewhere, like the US, because plastic pollution is
prolific in oceans and lakes world-wide.
The ES&T article measured the plastic content in 15 salt samples in particles/kg. The most common plastics detected were
polyethylene terephthalate,
polyethylene, and cellophane. The details of sample collection and
analysis were discussed. The researchers found no significant different
between brand of salt in terms of overall micro plastic content, though
some variation in plastic types was observed. The study also compared
these results to previous measurements of plastic pollution in China
water bodies, which would be common sources of the salt.
Something
the journal article mentioned which the Telegraph did not is how
exactly plastics end up in the salt. Sea salt is usually produced by a
crystallization process, essentially concentrating the salt by
evaporating the water containing it. Typically, not additional processes
are used to remove contaminants from the salt, plastic or otherwise.
The ES&T article also had a short discussion of the implications for
human health and aquatic life from ingesting these micro plastics,
something the media article simply implied. The journal article did not
include any discussion of this issue translating to other areas besides
China, though it was mentioned that plastic pollution is a widespread
problem.
Overall, I thought the Telegraph article did a
good job of summarizing the study's findings without sensationalizing
the issue too much. I think the study itself could be shocking, in that
this pollution issue has become so widespread. The implications of table
salt containing plastics were implied by both the study and news
article. Plastic pollution in our oceans and lakes is definitely an
issue that needs to be addressed.
Post by Rachel Kirpes on 11/22/2015
