Wikipedia:Reference desk/Archives/Science/2013 April 27

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April 27

Legal barriers to blood testing

In the era of digital medical records, Quantified Self, home genomics testing, patient directed laboratory blood tests available at shopping malls and kiosks, and the upcoming Scanadu tricorder, it seems strange that government and medical associations would continue to stand in the way of progress, efficiency, and lower health costs. However, I have just discovered this seems to be the case in sleepy Hawaii, where, "According to State and Federal Regulations" a laboratory "must receive an order from your physician/health care provider before any laboratory tests can be performed". How many states is this still true for anyway and why are these backwards laws still on the books? Viriditas (talk) 05:56, 27 April 2013 (UTC)

Laws vary locally. In some states you can go to a laboratory and have many basic tests done for yourself. You may even be able to do it from Hawaii. http://www.walkinlab.com/?gclid=CLLAhqjg6rYCFa5DMgodgUkANw However, Do not confuse insurance coverage or the specific lab policy with legal constraints however. These are three different things. alteripse (talk) 11:34, 27 April 2013 (UTC)

Honestly, I don't think this is a science question, and I can't really give you very good information. But I honestly believe you're up against a racket, and that medical ethics is defined as whatever maximizes profits for the medical industry. In the continental U.S. it doesn't seem like any trouble to go to Quest Diagnostics for "screening" tests, as long as they're not "diagnostic" (they measure the same things, and are cheaper). From a search I can see that there are locations of this company in Hawaii - if you want, you could ask by phone if you can get an "omega health screen" there; if not, then they should be able to tell you the specific regulation that impedes them. Because of Hawaii's isolation preventing people from alternatives, I suppose their state legislature would be a particularly high-value target, but I don't know anything about their laws. Wnt (talk) 15:53, 27 April 2013 (UTC)

You can also do blood test via mail, e.g. ZRT labs does such tests. You just order a test on their website, they then send you a blood spot card with needles. You have to put some drops of blood on the card, let it dry and sent it back to them via post. Count Iblis (talk) 16:05, 27 April 2013 (UTC)

I'm curious to know why someone would feel the need to get their blood tested, in the absence of a doctor having called for it. ←Baseball Bugs ^{What's up, Doc?} carrots→ 03:16, 28 April 2013 (UTC)

Diabetics do it all the time. Someone might want to cross-check the accuracy of a reading if they have reason to mistrust a specific lab or interpretation. Bielle (talk) 04:18, 28 April 2013 (UTC)

Yes, they use equipment to measure their own blood sugar. That kind of thing has been around for a while. And if they think something's wrong, they should see the doctor that's treating them already, not try to be their own physician. ←Baseball Bugs ^{What's up, Doc?} carrots→ 04:53, 28 April 2013 (UTC)

That's the old way of doing medicine. The new way of doing medicine is for healthy individuals to monitor their health for any unusual problems and then to visit their physician with hard data showing the results of their health monitoring. In the long run, it saves everyone time and money and forces the patient to take control of their own health. Laws that prohibit patient testing in lieu of a physician are out of date. Viriditas (talk) 05:47, 28 April 2013 (UTC)

There are gazillions of different blood tests. I'd like to see some examples of the type of blood test you might ask for. And supposing you got it, what would you do with the results? Also, if anybody could just walk in off the street and ask for a blood test, by what percent would the staff need to be increased? ←Baseball Bugs ^{What's up, Doc?} carrots→ 06:44, 28 April 2013 (UTC)

I approximately get 10,000 IU/day of vitamin D from Sun plus supplements, which is not the current medical recommendation. I don't want to bother my doctor with what I'm doing, so I'm on my own and have to do the calcidiol blood tests myself. I aim at a calcidiol level of 220 nmol/l by adjusting the dose I take. Count Iblis (talk) 13:15, 28 April 2013 (UTC)

Being "on your own" might have something to do with the legal restrictions. There could be liability issues. ←Baseball Bugs ^{What's up, Doc?} carrots→ 14:53, 28 April 2013 (UTC)

Yes, so the doctor is not going to prescribe me 10,000 IU/day to keep my calcidiol level at 220 nmol/l. His medical handbook probably still says that 2000 IU/day is the maximum safe dose for vitamin D, which is completely wrong. The fundamental problem here has to do with medicine in general being focussed on illness and not on health. If you have an obvious medical problem (say a broken leg, heart attack, cancer etc.) you'll probably get the right treatment. However, if you don't have any such problems but you are not in an optimal physical condition, you'll have to fix the problem yourself.

The medical establishment is not interested in these sorts of issues, which leads to medicine itself being perverted. In case of vitamin D, the article I cited explains that the safe upper limit of 2,000 IU/day is wrong (see here for a more theoretical treatment of why this is impossible), so you have to ask yourself how this stupidity made it into the medical handbooks. The reason is that you only need a about 400 IU/day to not get obvious medical problems like rickets. Then whatever the health benefits of higher dosages, if it doesn't have obvious effects like preventing cancer or heart disease, it won't be of interest and the mere possibility that the study where hypercalcemia was detected at the extremely low dosages below 4000 IU/day was correct, merits the upper safe limit of 2000 IU/day.

Only now are fundamental studies being done that look at the effects on muscles, see e.g. here, which confirms what people using vitamin D have known for a long time from their own personal experience. So, given the way medicine functions in practice, the best thing you can do to stay physically fit is to read the relevant medical literature yourself (despite the flaws in the field of medicine, the primary literature is more reliable than what is in the official medical handbooks), draw your own conclusions and act accordingly. The doctor is only useful when you suspect a serious problem; he'll give you a clean bill of health as long as your body is not in imminent danger of falling apart. Count Iblis (talk) 16:01, 28 April 2013 (UTC)

You sound like Wnt's twin. Keep in mind the old saying, "He who doctors himself has a fool for a patient." ←Baseball Bugs ^{What's up, Doc?} carrots→ 22:02, 28 April 2013 (UTC)

It's not about "doctoring" oneself at all. It's all about evidence-based, preventative health maintenance. This is becoming the new norm across the U.S. and the rest of the world, but once again, the government and the legal system are dragging their feet. In the next year or so, when you go to your doctor, you're not going to go because you are sick, you're going to go because you are healthy. I realize that this is a major paradigm shift for a lot of people, but you need to get on board the progress train. It is a waste of time, money, and medical resources for patients to wait until they are sick to see a doctor. That's an old model that no longer works. The new model involves the patient collecting data about their health, data that can be shared with their doctor in real time. Combine this with individualized genomic screening (which familiarizes the patient with their family history) and you can create a roadmap for a single patient that they can follow along at home. If you take good care of your car, then you know that bringing it in to your mechanic for scheduled maintenance when there is nothing wrong with it is the best thing you can do. It is not a surprise that the newest cars coming out have sensors that record maintenance data and tell you when you need to go to a mechanic. This is exactly how healthy people are using new monitoring tools to maintain their health. So the question at hand isn't "how do I cure myself from this disease", the question is "how do I maintain my health and stay healthy". Medicine is transitioning from a system that was solely designed for and based on treating soldiers in the battlefield, to helping people stay healthy before they become sick. Viriditas (talk) 22:57, 28 April 2013 (UTC)

How many extra staff will your local clinic need to hire in order to allow for folks just walking in off the street? ←Baseball Bugs ^{What's up, Doc?} carrots→ 00:45, 29 April 2013 (UTC)

What's interesting, is that the exact opposite is the case. When patients take control of their health with technology, you need less staff to deal with them (Hello, persistent digital medical records?). All that wasted time staff spend taking vitals such as temperature, blood pressure, weight and BMI, will "follow" you around in your digital medical record. In fact, it should be a rule that using medical-approved devices, you should take those readings at your home and have them updated to your global file before you even see your physician. This is doable right now with the proliferation of medical grade scales, thermometers, and BP devices which can communicate their readings to your medical file in real time. And, with doctors spending less time dealing with people who have stuffy noses, they can focus more on actual problems. When you are talking about folks just walking in off the street, you are talking about emergency medicine. Viriditas (talk) 00:57, 29 April 2013 (UTC)

If you take your own tests, how does your doctor know they're genuine? How does your insurance company know they're genuine? And do you really want your medical info on the internet??? ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:04, 29 April 2013 (UTC)

First of all, healthy patients establish baseline readings with repeated measurements over time. Using digital medical records, these numbers are graphed as the "normal" range for the individual, so it is very easy to establish what is genuine. As for your medical info, you wouldn't necessarily have it "on" the internet under your name, it could be associated with a unique ID that your doctor associates with your name. There's many ways to do it. Viriditas (talk) 01:11, 29 April 2013 (UTC)

There's many ways for people to commit fraud, too. Why should the insurance company cover your costs if they're uncertain it's really you? Sorry, too many unanswered questions. It sounds good in theory, but it fails in the details. ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:21, 29 April 2013 (UTC)

It's not theory at all; it's in practice right now by thousands of people who are in control of their own health and use this data to help their doctor monitor their health. It's also used every day by sick people. As for "fraud", I'm not sure I know what you are talking about here. Once your baseline is established, how would you commit fraud? Are you talking about someone who is pretending to be sick? Someone who is pretending to be overweight? That's a mental health issue and not really part of this discussion. You are strangely assuming that people will prefer to be sick rather than healthy. That may be true when it comes to rampant disability fraud already at work, with tens of thousands of people claiming disability benefits when they don't really need them. I don't see you asking any questions about disability fraud which is achieved with the help of physicians. Keep in mind, you need a physician to give you disability. No medical device "fraud" required. In any case, most people want to be healthy, active individuals, and it's very easy for medical devices to be queried and tested for accuracy. I'm not seeing any unanswered questions except for my original question: why is the government getting in the way of patients trying to maintain and improve their health by prohibiting patient-directed blood testing? Viriditas (talk) 01:30, 29 April 2013 (UTC)

Who's paying for these tests you're getting or want to get? ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:35, 29 April 2013 (UTC)

Me. Why does that matter? Viriditas (talk) 01:37, 29 April 2013 (UTC)

Viriditas, technically you and I did answer the question: you said that allowing patient-initiated testing would be more efficient ... which means there would be less profit in it ... which means, by definition, it would be "unethical" (as surely as it would be unethical and illegal to have your office building not freezing cold in the summer and roaring with the noise of ASHRAE-mandated HVAC equipment). But this isn't a science question - maybe the Humanities people could do a better job answering. Wnt (talk) 12:56, 29 April 2013 (UTC)

Shouldn't science inform the law? Viriditas (talk) 19:39, 29 April 2013 (UTC)

It should, which is why this idea won't fly. First, you have to establish what a "baseline" is for each patient. I don't think any reputable doctor would let the patient do so themselves. Besides which, what happens when the doctor disagrees with your baseline or preferred treatment? If, for instance, you're taking a dose of medication five times larger than your doctor would prescribe, they're going to wind up dropping you as a patient.

Second, someone both has to purchase and maintain said equipment, not to mention always using it correctly. The number of people I've seen with serious burns because they were smoking while wearing nasal cannula oxygen is not encouraging in that regard. And I wouldn't trust the average person to get a proper blood draw for those tests. It can be difficult for professionals who've been through medical school! Further to that point, some tests must be collected in a specific way, into a specific tube.

Then there's:

You are strangely assuming that people will prefer to be sick rather than healthy.

This actually happens more than you'd think. Being sick gets sympathy from family, sometimes pills and sometimes (as you stated) for fraud. There is no guarantee the blood your machine is testing is from the patient. There's a good reason why hospitals are very particular about labeling samples.

Finally, your statement that this would lessen the need for personnel only applies if all those flaws were somehow eliminated. Otherwise, this is not going to be a method doctors can generally rely on. 66.63.204.26 (talk) 17:38, 30 April 2013 (UTC)

You may use the global market to evade local cartels. As said equipment to measure gets cheaper and smaller, but always assume you are wrong and ensure you aren't when it comes to readings. A baseline may not be reliable because the equipment or it's handling may be consistently wrongly handled. But even if results from said equipment isn't up to insurance and doctor approval. They can still indicate issues that need to be dealt with. And in particular monitor in the long term. Being blind in this matters because "it's always been that way" won't benefit you anyway. Electron9 (talk) 02:59, 2 May 2013 (UTC)

Aristotelia chilensis/Chilean Wineberry/Maqui

Are Chilean Wineberry seeds or seedlings available in the United States, specifically online or in California at all? It is also known as Maqui or Aristotelia chilensis. They are great antioxidants and my Chilean grandfather was telling me about their anti-cancer effects and medicinal qualities. I know guarana and yerba mate and coca tea and other herbal products from South America are now available so I was wondering if anyone knows if they are approved for export into the United States by the FDA or department of customs and department of agriculture. If so does anyone know where one may buy some seeds or a clone or a sapling? I am an avid homesteader and grow my own berries, avocados, grapes, lemons, oranges, potatoes, onions, carrots, lettuce, corn, tomatoes, basil, wild onions, artichokes, saffron, cannabis, roses, nusturium, jasmine, peppermind, mint, oregano, thyme, agapanthus, carnations, cala lillies, gladyolas, dill, marjoram, beets, pumpkins, watermelons, alcayotas, cucumbers, mushrooms, and the list goes on, at home in addition to forraging, fishing, and hopefully when I have a hunting cabin some hunting trapping logging and husbandry and bee hives and bat houses too. I would love to have this chilean plant here in california and possibly sell it at a farmer's market as an exotic fruit such as lúcuma or cherimoya both chilean delacacies, cherimoya being grown in california now as well. Thank you for any info or if you can lead me to the right place to ask. Thanks! Maybe I can send you a bottle of maqui (wine). Cheers. — Preceding unsigned comment added by 108.212.70.237 (talk) 07:06, 27 April 2013 (UTC)

I put "chilean wineberry usa" into Google, and two out of the first three results led me to growers' websites offering Maqui seeds for sale. Both appeared to be mainstream retailers publishing plenty of information about themselves; one was based in Oregon and the other in California, and both had email contact details on their websites. The answer to "are seeds available in the USA/CA?" would seem to be yes - I can't offer any information about the law in your jurisdiction, but contacting a potential supplier directly and asking them would probably be the logical next step. Karenjc 09:30, 27 April 2013 (UTC)

If you can manage coca and cannabis you must know more than we do about the legalities. You might want to try the Humanities desk about how DSHEA deals with wines or other alcohol-containing supplements, being careful to avoid requesting specific legal advice ... beyond the basic questions for orientation, this does sound like something where genuine expert consultation would be useful... Wnt (talk) 15:42, 27 April 2013 (UTC)

Static electricity powering my lights?

Each winter, the static electricity is not to be believed and thoughtlessly touching a light switch with the tip of one's finger can cause the loudest "snap" and quite painful shock for every few steps I take crossing a room. For the sake of simplicity, if the light switch is only powering a 100 watt bulb, am I helping to power that bulb, if even for an infinitesimal amount of time? Or is the static electricity zipping away from the light to some other source? Am I causing a power surge (even if tiny)? – Kerαunoςcopia^◁_galaxies 18:39, 27 April 2013 (UTC)

Almost certainly you'll have created a (very brief) current flow to the ground wire...so probably not. Even if you did somehow discharge the electricity through the bulb, the amount of energy involved is in the realms of millijoules. To power a 100 watt bulb for one second requires 100 Joules of energy - so you'd be able to supply power to the bulb for a few millionths of a second...nowhere near enough time for it to heat up to the temperature required to emit light. That's not to say that this brief and tiny amount of power has no effects though. If you create a static discharge into a computer chip or other electronic device, even that tiny amount of power can destroy the device because of the huge voltages involved. SteveBaker (talk) 18:48, 27 April 2013 (UTC)

... you might like to avoid metal switches (try plastic) so that the static you generate has nowhere to discharge to (though you will still get a shock when you touch water taps). Adding humidity might allow the static to discharge naturally, or you might prefer to add a slow discharge circuit (experiment with a connection to earth through a resistor of many megohms). What sort of carpets do you have? They are probably generating the static. I have a similar problem with my car in dry weather (rare here). Dbfirs 19:00, 27 April 2013 (UTC)

Interestingly, all the switches here are plastic, and there aren't carpets where the static electricity is most abundant, just hardwood floors. I notice I discharge more static electricity when wearing nylon (or polyester?) wind/jogging pants (not sweat pants; the kind that make a sort of "zippy" sound as you walk), with less static electricity when wearing jeans. I do scrape along the floor with socks though. I can also discharge static electricity with the granite (or gneiss) countertop, which connects to the metal sink. The rooms with carpeting don't seem to create static electricity. Weird, eh? – Kerαunoςcopia^◁_galaxies 20:28, 27 April 2013 (UTC)

Yes, nylon is known for generating static. I'm surprised that plastic switches discharge the static, but it must be tracking along the surface to the wires inside. Have you tried putting your hand on the wall to discharge slowly before touching the switch? Installing some humidification equipment (even just a dish of water on a radiator) might help. Dbfirs 20:48, 27 April 2013 (UTC)

Extending Kerαunoςcopia's idea, would it be realistic to build outdoors panels in a particular material, being able to accumulate static electricity simply from air friction (triboelectric effect)? Could then this electricity be retrieved? 141.30.214.203 (talk) 19:43, 27 April 2013 (UTC)

• In case on one thought of it yet, the Van de Graaff generator runs on static electricity. --Jayron32 19:50, 27 April 2013 (UTC)

(edit conflict)Theoretically possible but, as SteveBaker mentioned above, the amount of current generated is very tiny, and harvesting a static charge at high voltage is tricky, so not a practicable option. Wind and sun can be used in more conventional ways to produce thousands of times as much power. I assume Jayron's reply (above) was a joke! The Van de Graff generates static but runs on mechanical power (a handle or a motor). Dbfirs 19:59, 27 April 2013 (UTC)

The thing about plastic switches is that (at least for the most common types here in the US and in the UK) they are held to the wall with a metal screw - which screws into the frame that holds the actual switch - which in turn is grounded. So with a plastic switch and switch plate, the static spark is going to jump to that screw-head and thence to ground. SteveBaker (talk) 15:11, 28 April 2013 (UTC)

Yes, perhaps that's more likely than tracking along the surface. It can easily be tested by putting a finger near the switch in the dark and watching where the spark jumps to. I've never experienced a static spark of more than about half a centimetre (around 15,000 volts) except from a Van de Graaff generator. Keraunoscopia must have a much dryer atmosphere. Dbfirs 15:43, 28 April 2013 (UTC)

Radiation hazards in drilling, mining and aviation

Hello everyone,

I'd like to know if the exposure to radiation for humans and/or equipment in the area of oil drilling (presence of traces amounts of natural radionuclides), mineral and coal mining (naturally occuring radiation in the earth crust) and aviation (cosmological radiation) was high enough to require monitoring with particle detectors or atomic emission spectroscopy.

Thanks in advance, 141.30.214.203 (talk) 19:27, 27 April 2013 (UTC)

Wow. That was one hell hell of a question. Let us break it down. Yes, both mineral oil and natural gas will come out of the lower stratus with radionuclide’s. Natural gas is probably the most important in this context, because in processing for the domestic market the radio-active components can get concentrated in parts of the gas processing equipment. This is known about. Thus, radon etc., can be vented so that the domestic gas supply provides not radiation hazard. Other interesting gases like helium can also be recovered but I don't think this is what the OP is asking.--Aspro (talk) 19:50, 27 April 2013 (UTC)

As for mining, I would have thought that other minerals other than coal would have a greater need for radionuclide assay of their spoil. The percentage of Thorium for instance can increase, as the sort for elements, are removed from the ore. Yet don't panic. Gas mantles are impregnated with the same radio active thorium. OK, unless you spend your life sleeping on a mattress stuffed with gas-mantle fabric there is no health hazard. A thorium gas mantle however, can make one Geiger counter buzz like a hive of inquisitive bees. Go round a very old house that had once gas lighting with a Geiger and you can find where the original gas lamps were situated. Oh, I have forgotten what your question was.--Aspro (talk) 20:15, 27 April 2013 (UTC)

As for aviation, Our article radiation concerns may answer it.--Aspro (talk) 20:15, 27 April 2013 (UTC)

Oh yes, back to your question. These industries you mention monitor radiation, not because its 'high enough' but to ensure that it doesn't become high enough to matter. Even scrap metal yards have scintillators now to ensure that radionuclides don't end up in your recycled cast iron patio-chairs. --Aspro (talk) 20:44, 27 April 2013 (UTC)

I was previously the Radiation Safety Officer at a large fly-in fly-out mining operation in Australia. There was essentially no radiation hazard from the minerals we were mining (sphalerite, pyrite, galena, silica, chalcopyrite, etc). The three major sources of radiation were (in order of the doses received by the workers); cosmic radiation from flying to and from work, ionising radiation from the industrial radiography instruments used on site (density gauges, XRF, multi-stream analysers), and radiation from the X-ray scanners and explosives detectors used at airport security screening. All of these doses had to be calculated from known source strengths, distance from the source, and time spent near them, as direct measurement with the TLD badges was impossible due to the extremely small levels of radiation. 202.158.112.87 (talk) 01:30, 28 April 2013 (UTC)

Well, that's nice to know your mine did not have a radionuclide problem from the ore itself but there are other mines were this causes problems. This essential mineral resource example, is possibly the worst case scenario. [1]. Chose this video because it is very balanced and down to earth and non-alarmist. Thorium occurs naturally in other economically valuable ores as well and so has to taken into consideration.--Aspro (talk) 17:49, 28 April 2013 (UTC)

While there are a few non-radioactive economic minerals that tend to occur with radioactive ones (like the rare earths in your video above), they're relatively niche. I'm actually a process metallurgist by profession and I've never encountered a mine that used a scintillation detector for making sure that ROM ore wasn't radioactive. I done work for gold, bauxite, coal, iron ore, nickel laterite and base metal sulfide projects. Without having any sources to back me up, I'd guess that something like 90% or more of the ore mined in the world is from those minerals. I'm also very doubtful that oil and gas projects bother with continuous radiation monitoring, but I could be wrong. When I was reading the instructions for an Amdel density gauge once it noted that you can actually use the scintillation detector without the radioactive source if you're processing something like uranium, where the ore provides its own gamma rays, but I've never even worked in that area. 202.155.85.18 (talk) 00:36, 29 April 2013 (UTC)

Basically, to answer the questions as asked for the mining part; where a radiological hazard exists, it is generally identified through the geological exploration process (i.e. assays of rock core) long before the mining process begins, so no continuous radiation monitoring takes place during the mine's operation unless a hazard is known to exist. A common ICP-OES/MS exploration assay suite that I have in front of me includes thorium and uranium, and if either of those were present, further investigation would need to take place. Simple scintillation detectors are used for detecting ionising radiation hazards. Particle detectors are more complicated and sensitive than what is required for that application, and atomic emission spectroscopy doesn't detect radiation per se, but rather identifies the elements present, which can indicate that radioisotopes may be present. 202.155.85.18 (talk) 02:07, 29 April 2013 (UTC)

Stop twisting my words around. Were did I say mines use Scintillation counters? – I said 'scrap yards'. >http://www.google.com/url?q=http://deqtech.com/Resources/PDF/Radiation_and_the_Scrap_Yard.pdf&sa=U&ei=yWx-UZjQKoPR0QWLoICADw&ved=0CCwQFjAF&usg=AFQjCNFmT2WNfy0f1eYNHU0rH4pmHJtXOw< I'm not disagreeing with you that for the most part, natural radionuclides are not practical hurdle at source of recovery. However the OP is asking are these monitored – that answer I reiterate yet again is 'yes'. Further down the line from you, there are people that have to convince the necessary authorities that your product and other geological resources won't result in their customers 'glowing in the dark'. With all due respect, I don't think a regulator would accept their statement that “Oh 202.155.85.18 doesn’t know of a problem so we don't need to monitor.” The industry are bound to submit the proof as part of their operating licences. Natural gas also gets to be monitored through out its recover, distribution and end user consumption just to make sure [2]. At, or near to a well head, the amount of radon in a liquefaction plant can accumulate alarmingly do to its boiling/liquefaction point. But by monitoring, the magnitude of the hazard can be quantified and steps taken to mitigate the problem for the people running the plant. Also, field recover estimates also employ radionuculoid isotope tracers which get injected in the the wells. Although the curie load is small, the authorities need to know these are being used responsibly – so monitoring and record keeping is again is needed... Today, geological mineral recover, processing and refining and distribution involves a lot of different skills and expertise. Individuals with in the industry, are often ignorant at what other individuals are doing to get the product to market. Through out the whole industry, monitoring is going on somewhere or other - all the time.Aspro (talk) 13:56, 29 April 2013 (UTC)

I'm not trying to twist your words around, so sorry if it came across that way. I knew you were only referring to scrap yards, and I was just trying to contrast the measures that they take to the measures that we take, to show the difference in risk. Also, I'm not sure at which point you're saying radiation testing takes place. For example, I've been involved in the process of gold production from ore to certified 1kg 99.99% cast bars being sold to investors and at no point did we do any sort of testing to make sure it wasn't radioactive, save for the aforementioned exploration that ruled out U or Th being in the ore to start with. The Radiation Management Plan for the mine only briefly mentioned that radiation from the ore was not considered a hazard. Radon from ground water was not considered at all (for open cut mines it doesn't have any shafts to accumulate in). 202.155.85.18 (talk) 00:34, 30 April 2013 (UTC)

Atomic emission spectroscopy is used to determine the chemical composition of a substance. It's not generally useful as a radiation dosimeter. As for the radiation from cosmic rays on aircraft, this link has a decent amount of measured data. A typical dose on a transoceanic flight is 0.1 milisievert. That's far higher than what you get by spending the equivalent amount of time on the ground, but it's around the dose from a skull X-ray and several times lower than the dose from a CT scan. --Bowlhover (talk) 06:03, 28 April 2013 (UTC)

Wow, that was worth asking! Thanks for all this information. Naturally occuring radiation isn't as hazardous as I would have believed. Kind of good news. 141.30.214.203 (talk) 20:00, 28 April 2013 (UTC)

Radon gas is one thing to look out for in mines even if the minerals are safe. Dmcq (talk) 21:55, 28 April 2013 (UTC)

ICAO Annex 6 contains a standard that each civil aircraft that flies at or above 50,000 feet altitude should be equipped with a means for measuring cosmic radiation when the aircraft is used in commercial aviation across national borders. Concorde had such equipment installed. There are now numerous aircraft types approved for flight at or above 50,000 feet but many of them don't have equipment for measuring cosmic radiation because national legislation doesn't require it. This is an example of where an ICAO standard is not incorporated into the relevant legislation in countries where transport category aircraft are manufactured. Dolphin (t) 12:18, 29 April 2013 (UTC)

Do sea horses really 'burp' in order to change their buoyancy?

My 5-year-old son asked, after watching an episode of Octonauts, do sea horses really 'burp' in order to change their buoyancy? I looked at our article on sea horses and found no answer there.82.31.133.165 (talk) 23:38, 27 April 2013 (UTC)

Sea horses are fish. So they have swim bladders. Therefore, ergo, etc., if they need to lose buoyancy, the gas has to escape from some where. Burp! --Aspro (talk) 00:05, 28 April 2013 (UTC)

That's not common in salt-water fish, they often have closed air bladders which adjust only through blood absorption and release. (I.e., there's no direct connection from the bladder to the esophagus.) We'll need a better source than an animated children's TV show. μηδείς (talk) 00:11, 28 April 2013 (UTC)

Don't try and confuse. Those are demersal fish. Sea horses inhabit sallower waters – so what I said still goes. The pressure differential diminishes per foot as one goes deeper. (partial pressure come into this as well but lets not complicate). That is why divers (of the human type) dwell in their assent, below the surface for a while, to diffuse the nitrogen in their blood. Water pressure is about 1/2 a pound per foot of depth, so when feeding time comes at the aquarium, little Nemo who swims up from the bottom of a two foot tank and opens his mouth in anticipation of those lovely mealy worms you about to feed him with, lets out two or three bubbles. Those are the burps!--Aspro (talk) 00:49, 28 April 2013 (UTC)

Minor correction: Water pressure is about 1/2 a pound per square inch (AKA PSI) per foot of depth. Dauto (talk) 15:19, 28 April 2013 (UTC)

Are you saying you've witnessed this, Aspro? μηδείς (talk) 15:56, 28 April 2013 (UTC)