As Japanese
emergency workers continue to pump out thousands of gallons of
contaminated water from the damaged reactors of the Fukushima Power
Plant, radiation contamination in food and water has emerged as a new
focus of the international media.
Before explaining the risks of food and water
contamination, it’s important to understand the difference between
radiation exposure and radiation contamination. The United States
Center for Disease Control (CDC) defines exposure and contamination with
the following:
A person exposed to radiation is not
necessarily contaminated with radioactive material. A person who has
been exposed to radiation has had radioactive waves or particles
penetrate the body, like having an x-ray. For a person to be
contaminated, radioactive material must be on or inside of his or her
body. A contaminated person is exposed to radiation released by the
radioactive material on or inside the body. An uncontaminated person can
be exposed by being too close to radioactive material or a contaminated
person, place, or thing.”
 |
| Source: U.S. Department of Health |
As the CDC implies, there are many ways that
radiation can enter the body for contamination to occur. Radioactive
materials that enter into digestive tract can do damage while they
reside in the body, but most of these materials pass through quickly.
Radiation that gets trapped in other areas of the body, such as
radioactive dust being breathed in and lodged in the lungs, can cause
serious threats because the longer the radiation resides in the body,
the more harm it can do.
So what are levels of radiation we actually
need to worry about in food or water? The unit of measurement used for
quantifying radiation in food and water is the Becquerel (Bq) and
defined as the activity of a radioactive material in which one nucleus
decays per second. More dangerous sources of radiation give off higher
readings, and amounts decrease as radioactive isotopes decay. The
Becquerel is a very small quantity of radiation; the human body itself
produces over 4000 Bq per second. The standards
set by the United States Food and Drug Administration (FDA) for food
and water is about 375 Bq/lb (170 Bq/kg).
Recently Japan reported
a reading of 463 Bq/lb (210 Bq/kg) in Tokyo’s tap water, leading to
widespread fear and a government advisory against giving tap water to
children (who are more susceptible to radiation and have lower exposure
limits). Since this incident, the radiation in Tokyo’s tap water has
returned to safe limits. Radiation in food has also been a problem,
especially since much of the Fukushima Prefecture near the crippled
nuclear plant is dedicated farmland. Widespread bans have gone into
place on the sale and consumption of crops from affected areas, as well
as seafood caught in the ocean near the plant. Much of the radiation
present in the contaminated food and water is Iodine-131, which has a
half-life (meaning that half of a quantity of the material has broken
down and is not longer radioactive) of only 8 days. This means that this
type of radiation won’t be around for long, but the fear of radiation
is more likely to hurt the Japanese economy as buyers shy away from food
that they think might still have some contamination.
 |
| Source: Associated Press |
Although the fear that Japanese radiation in
dangerous amounts will end up in other countries is often unfounded, we
can’t let down our guard just yet. Japan provides 4% of US food imports,
including many seafood products that can have concentrated levels of
radiation, such as shellfish and seaweed.
So how can we assure that our food and water is
contamination free? Finding trace amounts of radiation in food and
water is often difficult because products are usually shipped in large
containers that shield radiation. Common radiation detectors such as
Geiger Counters just aren’t sensitive enough to detect radiation at
these levels. The FDA works to safeguard our food supply by using the
MiniRad-D, a hand-held radiation detector, to search for radiation. The
MiniRad-D uses a scintillation detector, which is over 100 times more
sensitive than a Geiger counter, and because it can pick up radiation
from tens of meters away, it can be used to scan whole containers of
food at once.
 |
| The MiniRad-D radiation detector |
The procedure of scanning food is becoming
increasing popular as Japan increases its exports. According to a recent
New
York Times article, even some fish markets and high-end restaurants
have begun radiation detection procedures to ensure the safety of their
customers. Knowing for sure that food and water is clean is a big draw
for these businesses as Japan’s nuclear clean-up continues to make
headlines.
So,
although the direct danger of radiation contamination in food and water
is very low, the effects of the nuclear crisis are sure to be felt for
years to come. And as many companies involved with food imports are
discovering, peace of mind is not only attainable, but extremely
valuable. With the right equipment, good information, and correct
procedures, this peace of mind is truly available to everyone.
D-tect Systems is
supplier of advanced radiation and chemical detection equipment sold
around the world. www.dtectsystems.com.
