The other threads on what’s happening in Japan at the Fukushima Daiichi nuclear plant are getting a bit wild and woolly, going off in all sorts of different directions. I wanted to start a thread that just talks about the real health dangers given the known situation, and what the actual risks might be there. It’s probably a GQ question, but I figured that as the other threads are so contentious perhaps it would be better to put it here (definitely don’t want it in the Pit, as those threads have been complete train wrecks).
So, first off, I was reading this article where they were talking about the levels of contamination in beef cattle:
So, what’s the actual level of threat to health here between 500 becquerels per kilogram and 510? What does it actually mean in terms of risk? And why do the Japanese have a different level of what’s acceptable from that in Germany? From the same article:
Also, that’s just talking about cesium, right? What else is contaminating the live stock, and crops in the region…and what do those numbers mean in terms of risk? In some articles they downplay the exposure, saying the health risks are minimal, in others they talk about the area like it’s a dead zone where no one can survive. What’s the realistic view of the actual dangers and risks in the plant? In the immediate vicinity of the plant? In the 20 km evacuation zone? In the 50 km US advisory zone? Outside of that in Japan as a whole?
Next up…sea water. There has been a lot of articles lately about the sea water contamination. Like from here:
What do these numbers mean? 4000 times regulatory limit? 3000 times? 10000 times? What are the health risks? What are the dangers? If you fell into the water there what would happen to you (immediately on falling in, after a few days, over your lifetime)? If you were swimming in the water there, what would be your real world risks? If you ate the fish from there what would be your risks?
With the disclaimer that I am not a credentialed expert in these matters, just a layperson who’s been trying to become informed over the years, this is my best guess/deduction.
A quick run through Wikipedia says the average human experience 4,400 becquerels due to natural radiation in our own bodies. Using 70 kg for an average (admittedly, I’m rounding up a bit from my own weight here, but it’s just an estimate anyway) I get 63 Bq for the average person. So 500 is definitely elevated.
However, the Bq is one of the those small units that look scary because of how quickly the number goes up. Think of the difference between grams and kilograms - 1,000 grams might sound like a lot, 1 kilogram not so much, but they’re really the exact same amount. For example, according to the Wiki most of our natural Bq load is from potassium, which per kilogram has around 31,825 Bq due to the natural incidence of potassium-40 in the food chain. Sounds scary, doesn’t it? But it’s the normal rate, minus nuclear accidents and such.
Of course, no one sits down and eats a kilogram of potassium, we only need minute amounts in our bodies. That’s why 500 Bq in a hamburger is more significant - people do sometimes sit down and eat a kilogram of beef in a sitting. Over the course of a week you might eat several.
So it’s not enough to know just the Bq - you need to know what is causing the radiation, and how much a human might plausibly consume. I don’t know what the normal rate is for a cow, but it’s probably not that much different than a human’s. So 500 is definitely above the norm. However, “legal limits” are usually set to be below a level believed to cause trouble in even the most vulnerable people - children and pregnant women. (This is why the limit for an adult male working at a nuclear plant is considerably higher, among other reasons). As there is no sharp dividing line between “safe” and "not safe in these matters that limit will vary somewhat from country to country. The difference between 500 Bq and 510 Bq is that in the latter ten more atoms per second are decaying. Ten atoms. That’s not a lot. But it’s over the legal line. Realistically no, there’s little difference but a limit needs to be imposed and that which is just over is just a teeny bit more risky than what’s under.
As for the boars in Germany - well, either the German limit for meat in general is higher, or else whoever set that limit reasoned that people don’t eat wild boar nearly as often as some other meats, so a higher limit there might not affect healthy (assuming Germany says it’s OK to eat wild boar - for all I know, they’ve banned it)
Let’s say you accidentally ate a steak with 510 Bq. What would happen? Well, if it only happened one time likely nothing at all. If you ate a steak with 600 Bq what would happen? Likely, nothing at all. The problem is if you eat 600 Bq steak or boar every day, or at least frequently, because the radioactive isotopes tend to accumulate over time, and as you go up the food chain.
Just one slightly more radioactive than average meal isn’t going to hurt you. Making a habit of it might - but slightly over the limit likely won’t, unless you’re looking at decades or even an entire lifetime.
Correct, the figure given above is cesium. Cesium is of concern because it acts much like potassium does in the body, so your body will willingly incorporate cesium into your flesh. On the up side, it doesn’t hang around that long, either, and is excreted in sweat and urine, just like potassium. On the down side, it has a half life of 30 years, which means it takes awhile to go away, and plants will keep it in the food chain if it’s present in the environment.
Which takes us to the crops. Any plant food that’s high in potassium will soak up Cs-137 (the major bad-boy isotope) as readily as it does potassium. Any animal that eats the plant will further concentrate that material. This is why milk and spinach keep figuring in news reports - the contamination in milk is because cows eat vast quantities of plants like grass, concentrating the substance in their meat and milk; and spinach just likes to suck up nutrients, that’s why it’s such a healthy vegetable… unless there’s lead or cesium or something else bad in the environment (spinach has been used to help remove lead from contaminated soil, by growing several years of spinach in such an area it does lower the lead levels. Of course, it would be unhealthy to eat such spinach). Contamination will show up there, first.
What else is in the soil around Fukushima? Well, radioactive iodine. It’s not healthy to eat that, either, but because of a short half life it decays into harmlessness in a few months. In other words, just wait a year and the problem for iodine no longer exists… unlike cesium which takes much, much longer to decay. There are probably a few other contaminants, but in much, much lower amounts than the iodine and cesium. They did find some plutonium samples very near the plant… but based on the ratio of isotopes they determined that several of them weren’t from the recent accident but *may *have been from the atomic bombs we dropped in 1945 (the Nagasaki bomb had a plutonium core, so it’s a likely source) so while it’s not a good thing it’s been around quite awhile and people aren’t dropping like flies from it, so probably not an emergency either.
For a brief exposure - that once in a lifetime 510 Bq of steak, for example - the risks ARE minimal. The problem is that people live there and thus exposures wouldn’t be “once in a lifetime” but throughout a lifetime, at least potentially.
It’s not a “dead zone” at all, but people are long-lived creatures. One year’s exposure might have minimal health impact, but living there for 50 years might have significant impacts. The area around Chernobyl is teeming with plants and wildlife, but most creatures in the wild aren’t going to live long enough to reach old age and cancer. People do live that long.
Right now, in the power plants themselves, there is a real danger of overexposure sufficient to cause short term illness (radiation sickness or poisoning) or, in some areas, perhaps enough to be lethal in days to weeks. One can only hope those working there are able and willing to take precautions to safeguard themselves.
In the immediate vicinity of the plant children and pregnant women should not be allowed. There is probably an elevated lifetime risk of cancer for those in the vicinity. That’s risk - just because you’re exposed does not mean you will get cancer, just that you’re more likely to do so.
The 20 km evacuation zone is probably unhealthy for pregnant women and children. Probably not good for young adults, either. But if you’re 70 or 80 you’ll most likely die of old age before you get cancer from the exposure, and it’s not nearly enough to make you sick short-term. This is one reason elderly people who insist on living in the contaminated area around Chernobyl are no longer shoo’ed away - yes, they’re consuming radioactive contamination every day, but given their ages it’s highly unlikely it will shorten their lives, so why harass them?
The US actually has a 50 mile zone, which is something like 80 km. Let’s just say that’s likely an abundance of caution. It’s also relatively easy to encourage a few foreigners, almost all of them visitors, to leave the area. It’s more difficult to tell tens of thousands of people who live there to move.
As for outside of Japan - as you’ve no doubt heard, there has been some elevation of radioactivity around the world, detected in rain in New England and such. It’s detectable, that’s not inherently the same as “hazardous”. There’s a bump in global background radiation any time you have a nuclear accident. There was one after Chernobyl. There is one after any above-ground nuclear test, which, actually, has been unheard of since the 1960’s. In fact, since we stopped above-ground bomb tests the background radiation has declined in recent decades, and even this incident has not put it back up to what the levels where in the 1950’s and 1960’s. Most countries are inspecting anything come to their shores from the region around Japan, particularly foods, so it is unlikely anything contaminated beyond legal limits will hit the grocery shelves. I don’t believe this is going to cause a problem for folks outside of Japan.
Seriously - I’m fully intending to plant a big garden again this year, including - >gasp!< - spinach, the plant that sucks up radioisotopes like there’s no tomorrow. I’m far more concerned about heavy metal contamination from the local coal fired power plants than I am about radiation from Fukushima.
Unless you know what the regulatory limit for sea water is, those numbers are of limited utility. However, at this point I’m going to take a wild guess and say you probably don’t want to eat the fish swimming just offshore of the nuclear plants.
The ocean is a huge place, it WILL dilute the radioactive water down to harmless levels by the time it reaches, say, Los Angeles. The Pacific is not going to glow in the dark (well, actually, it can due to bioluminescent organisms, but it won’t glow from radiation). It’s right next to the plant, where the water is not or only slightly diluted, that it becomes a problem.
At the plant itself, it’s likely quite hazardous. Remember the two workers who received superficial burns from radioactive water that leaked into their boots? Yes, some of that water is harmful enough to cause immediate harm. Swimming in it could potentially cause skin irritation/burns or short term illness, possibly severe. Even if it didn’t, you’d get a hefty dose of radiation, possibly the “safe” lifetime limit or above, which would increase your risk of cancer in 10-20 years. It’s not doing the local sea life any good whatsoever, and dead fish washing up on the beaches nearby in the next month or so is likely. Don’t eat the local fish, m’kay? Even if it doesn’t kill them outright they’ll be absorbing iodine and cesium and anything else in the water.
The further you get from the plant the less severe the problem is. Seafood catches ARE being monitored for radiation. On NHK (Japanese broadcasting) in English I caught a piece on enterprising restaurant owner purchasing their own geiger counters show they could double-check the fish they bought. Assuming this inspection is done, it is unlikely that anything unhealthy will end up in the commercial food chain. Far more at risk is the amateur fisherman whose catch is not subject to inspection, but that hazard is easily avoided by not fishing near Fukushima.
The Japanese nuke experts said this weekend that they can begin to remove the fuel rods …in about 10 years. So they will be percolating for a long time.
