"Cancer Risk from Arsenic in Rice and Seaweed"
"At some point during the reign of King Cotton,
farmers in the south central U.S. controlled boll weevils
with arsenic-based pesticides,
and residual arsenic still contaminates the soil."
Now, different plants have different reactions to arsenic exposure.
For example, tomatoes don't seem to accumulate much,
but rice plants are really good at sucking it out of the ground,
so much so that rice can be used for arsenic phytoremediation,
meaning you can plant rice on a contaminated land
as a way to clear it from the soil,
Of course then you're supposed throw it and the arsenic away,
but in the South, where 80% of U.S. rice is grown, we instead feed it to people.
But national surveys have shown that most arsenic exposure
has been measured coming from meat, poultry, and fish in our diet,
rather than grains, but most of that is from the fish.
So if seafood is contributing 90% of our arsenic exposure from food,
then why are we even talking about the 4% from rice?
Because the arsenic compounds in seafood are mainly organic—
used here as a chemistry term, nothing to do with pesticides—
and organic arsenic compounds,
because of the way our body can more easily deal with them,
have historically been viewed as relatively harmless.
Now recently, there's been some questions about that assumption,
but there's no question about the toxicity of inorganic arsenic,
which you can get more of from rice.
As you can see, rice contains more of the toxic inorganic arsenic
than seafood--- with one exception.
Hijiki, an edible seaweed, 100 times more contaminated than rice,
leading some researchers to refer to it as the so-called 'edible' seaweed.
Governments have started to agree.
In 2001, the Canadian government advised the public not to eat hijiki.
Then the UK, the rest of Europe, Australia and New Zealand,
then China advised the public not to eat hijiki
and banned imports and sales of the stuff.
Japan, where they actually have a hijiki industry, just advised moderation.
What about Maine coast seaweed,
domestic, commercially harvested seaweed from New England?
We didn't know until now.
Thankfully only one type had significant levels of arsenic, a type of kelp,
but it would take over a teaspoon to exceed the provisional daily limit
for arsenic, and at that point you'd be exceeding the upper daily limit
for iodine by like 3,000%, 10 times more than reported
in this life-threatening case report attributed to a kelp supplement.
So I'd recommend to avoid hijiki due to its excess arsenic content,
and avoid kelp due to its excess iodine content,
but all other seaweeds should be fine
as long as you don't eat them with too much rice.
What does a number like this mean though?
88.7 micrograms of inorganic arsenic per kilogram of raw white rice?
I mean that's only 88.7 parts per billion.
That's like 88.7 drops of arsenic in an Olympic-size swimming pool of rice.
So how much cancer risk are we talking about?
Well, just to put it in context, the usual level of acceptable risk
for carcinogens is one extra cancer case per million.
That's how we typically regulate cancer-causing substances.
Whenever some industry wants to release some new chemical,
we want them to show that it doesn't cause more
than 1 in a million excess cancer cases.
Now we have 300 million people in this country,
so that doesn't make the 300 extra people who get cancer feel any better,
but you have to cut it off somewhere.
The problem with arsenic in rice is that the excess cancer risk
associated with eating just about a half cup of cooked rice a day
could be closer to 1 in 10,000.
That's a hundred times the acceptable cancer risk.
The FDA has calculated that one serving a day
of the most common rice, like long grain white, would cause
not 1 in a million extra cancer cases, but 136 in a million.
And, that's just the cancer effects of arsenic.
What about all the non-cancer effects?
The FDA acknowledges that in addition to cancer,
the toxic arsenic found in rice has been associated
with many non-cancer effects including heart disease, diabetes,
skin lesions, kidney disease, hypertension, and stroke.
The only reason they just stuck to calculating the cancer risks
is that assessing all the other risks would take a lot of time
and that would delay taking any needed action
to protect the public's health from the risks of rice.
Yes, physicians can help patients reduce their dietary arsenic exposure,
but regulatory agencies, food producers, legislative bodies
may have the most important roles in terms of public health scale changes.
Arsenic content in US-grown rice has been relatively constant
throughout the last 30 years, which is a bad thing.
Wherever arsenic concentration is elevated due to ongoing contamination,
the ideal scenario is to stop the contamination at the source.
Some toxic arsenic in foods is from natural contamination of the land,
but soil contamination has also come from dumping
arsenic-containing pesticides, and the use of arsenic-based drugs
in poultry production,
and then spreading the arsenic-laced chicken manure on the land.
Regardless of why southern rice paddies are so contaminated,
maybe we shouldn't be growing rice in arsenic contaminated soil.
What does the rice industry have to say for itself?
Well, they started a website called ArsenicFacts, no less.
Always got to be skeptical of any group that claims
"facts" in their title. *Ahem*
Their main argument appears to be,
look, arsenic is everywhere; we're all exposed to it every day.
It's in most foods.
So, what, we shouldn't try to cut down on the most concentrated sources?
Isn't that saying like, look, diesel exhaust is everywhere,
so why not suck on a tailpipe?
They quote some nutrition professor saying, look, all foods have a little bit.
So eliminating arsenic would decrease your risk, but you'd die of starvation.
That's like Philip Morris saying, look, the only way you're going
to completely avoid second-hand smoke in your life is to never breathe,
and then you'd asphyxiate; so you might as well just start smoking yourself.
If you can't avoid it, you might as well consume
the most toxic source you can find?
That's the same tact the poultry industry took.
Arsenic and chicken?
No need to worry because there's a little arsenic everywhere.
See? So that's why it's OK that we fed our chickens
arsenic-based drugs for 70 years.
If you can't beat 'em, join 'em.