 At some point during the reign of King Cotton, farmers in the South Central US controlled bowl 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. I mean, you can plant rice on contaminated land as a way to clear it from the soil. Of course, then you're supposed to throw it and the arsenic away, but in the South, where 80% of US 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 have 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, 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 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 seaweed 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-sized 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 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. OK, 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 100 times the acceptable cancer risk. The FDA has calculated that one serving a day of the most common rice, long grain white, would cost 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 and 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 U.S. 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 to land, but soil contamination has also come from dumping arsenic-containing pesticides in 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 patties 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 Arsenic Facts, no less, always got to be skeptical of any group that claims facts in their title. Their main argument appears to be luck. 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 professors 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 secondhand smoke in your life is to never breathe, and then you'd asphyxiate, so might as well just start smoking yourself. If you can't avoid it, 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 them, join them.