Rice is a cereal grain that
is the most widely consumed staple food for a large part of the world’s human
population, especially in Asia. It is the agricultural commodity with the third
highest worldwide production after sugar cane and maize.
With the recession in our
part of the world, rice has now become one of the cheapest and most readily
affordable and available staple food, despite being mostly imported.
Even our own locally grown
crops like yam, cassava and beans are a lot more expensive to buy. Gone were
the days in Nigeria when rice was a festivity meal, it is now eaten in many
homes and by many people on a daily basis.
Apart from its relative
affordability, it is quite loved by many, a comfort food par excellence. What
is chicken stew without rice?
Unfortunately, our ‘dear
rice’ has its hitches and those who love it and want to eat should know how to
eat it safely. Arsenic, a toxic and highly dangerous chemical element with
symbol As, has stealthily invaded our food supply, especially rice. Arsenic in
rice has tested at levels capable of triggering symptoms of arsenic poisoning!
How does arsenic get to
food?
It shows up in our food
through three main sources.
First, it naturally occurs
in the earth’s crust, coming in at the 33rd most abundant substance that makes
up the outer layer of the earth. It often occurs in higher concentrations with
other precious or industrial metals, like gold and tungsten.
Thus, a certain amount of
exposure is unavoidable and normal. Some areas, though, have naturally elevated
and thus problematic base arsenic levels, especially areas known for mining.
Second, some industries
release arsenic into the environment. While those industries connected to
mining and refining appear to be the largest emitters, they are not alone.
Depending on their proximity to these industries, arsenic can end up in its
water and soils, and then in the food grown there.
Third, some pesticides and
other agricultural chemicals contain arsenic, which builds up over time in
soils where they are used.
For many decades, farmers
cultivated cotton using arsenic containing agricultural chemicals.
Unfortunately, some of the best places to grow rice today are the same places
farmers once grew cotton using arsenic-laced chemicals. In addition, commercial
chicken farms used arsenic for a long time as a poultry feed additive.
More problematic is the
fact that, the type of arsenic often, though not exclusively, used in
agricultural processes is inorganic (meaning it is not bound to carbon but
other elements and chemicals) and is far more dangerous to human health than
the kind that naturally occurs in the earth’s crust.
Certain parts of the United
States have startlingly high levels of arsenic contamination in the soil and
water. California and Texas, two of the primary places rice is grown, rank as
some of the worst in their nation. Mississippi and Arkansas, also major rice
producing regions, show problematic arsenic levels in their soils too.
However, it is not limited
to these regions as arsenic contamination is incredibly widespread and
problematic across any modern major agricultural region. This is especially the
case with areas that have high concentrations of concentrated animal feeding
operations, otherwise known as CAFO poultry production.
Poultry litter (chicken
manure mixed with bedding) is a major source of arsenic contamination. For many
years, industrial factory farms used arsenic as a growth stimulant for
chickens. The arsenic causes the chickens to eat more, which means they grow
faster, which means the big industrial farms make more money. The problem is
that the chicken’s faeces is laced with lots of arsenic. All that manure is
then used to fertilise grain and vegetable fields.
The arsenic also ends up in
groundwater, which people drink and use to irrigate their crops in many
regions.
This results in foods,
especially those that tend to uptake more arsenic than others, becoming
dangerously high in this contaminant. Rice is one such food.
Rice loves arsenic
Unfortunately, arsenic
easily contaminates rice crops for two reasons. First, rice appears to have an
innate penchant for picking up this chemical element from the soil. By some
estimates, rice is 10 times more efficient than other plants at arsenic uptake.
Second, farmers almost
always grow rice in flooded paddies. This method exposes rice to far more
arsenic than other grain crops since arsenic is highly water soluble. It is
also found in irrigation and other water sources, such as well water.
In 2013, the FDA finally
banned arsenic as an additive to chicken feed but the environmental and human
damage from decades of use is already done.
What does arsenic do to us?
According to a review of
arsenic poisoning and its effect on human health by the United States
Environmental Protection Agency, soluble inorganic arsenic can have immediate
toxic effects. This means that ingestion of a one-time heavy load can lead to
acute gastrointestinal symptoms such as severe vomiting, disturbances of the
blood and circulation, damage to the nervous system, hallucinations, psychosis
and eventually death. When not deadly, it may reduce blood cells production,
break up red blood cells in the circulation, enlarge the liver (causing chronic
hepatitis or hepatic cirrhosis), colour the skin (melanosis, hyperkeratosis,
desquamation and eventually carcinoma), produce tingling and loss of sensation
in the limbs, and cause brain damage.
Long-term exposure to
inorganic arsenic in drinking water in Taiwan has caused Blackfoot disease, in
which the blood vessels in the lower limbs are severely damaged, resulting
eventually in progressive gangrene. However, arsenic exposure has caused other
forms of blood vessel disease in the limbs in several other countries.
It can present with
non-specific symptoms, which can be present in many other diseases such as
palpitations, fatigue, headache, dizziness, insomnia, weakness, nightmares,
numbness in the extremities and anaemia
There is strong evidence
supporting arsenic playing a part in elevated blood pressure, heart attacks and
another circulatory disease. It may also be implicated in diabetes,
infertility, stroke and cancers, especially that of the skin, lungs, bladder,
kidneys and long-term neurological effects.
In the lungs, asthmatic
bronchitis (a cough, expectoration, breathlessness, and restrictive asthma) are
common symptoms in long-term insidious exposure. Symptoms of the clinical phase
are associated with different complications as the other organs like lungs,
liver, muscles, eyes, vessels are affected. Clinical symptoms are associated
with biochemical evidence of organ dysfunction as well as high concentrations
of arsenic in different organs involved. Liver enlargement (hepatomegaly),
spleen enlargement (splenomegaly) and fluid in the abdomen (ascites) are seen
in several cases.
To be continued….
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