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Perchlorate, used in rocket fuels, may be more hazardous than previously thought
- Metacelsus 6y agoIt's also a big component of fireworks – and every July 4th levels in lakes and rivers spike. That being said, this paper only presents in vitro data. Perchlorate may be more toxic than assumed, but the evidence isn't strong. https://sci-hub.tw/10.1038/s41594-020-0417-5 https://sci-hub.tw/10.1038/s41594-020-0417-5
- alexandercrohde 6y ago>> but the evidence isn't strong. I always feel compelled to point out that absence of evidence isn't evidence of absence. Or chemicals should be presumed unsafe until proven safe, rather than the other way around.
- nickff 6y agoThe problem with precautionary principle arguments (like your latter point) is that the precautionary principle is not self-consistent. You'd need to know the effect of implementing the precautionary principle before using it, which is probably impossible to calculate.
- jackyinger 6y agoThe precautionary principle is the initial condition though! (Ideally speaking, of course.) The idea is to assume new chemicals may be dangerous. Then undertake careful testing programs to determine if they really are dangerous. I think that this is what the grandparent comment was suggesting. There is good precedent for the use of this principle, take for instance drug trials. Furthermore, I think it would be beneficial to assume all new technologies may have detrimental effects, and weigh those effects carefully.
- nickff 6y agoThe precautionary principle could only be the initial condition if it had been followed since the beginning of time; you want it to be our initial presumption, a presumption whose sole virtue is its convenience for PP advocates.
- specialist 6y agoI'm not following you, sorry. Is "let's wait and see" a precautionary move? Are you saying the cost of inaction must be quantified before it's a legitimate choice? In which case, in our world of imperfect understanding, does that lead to bias towards action?
- clumsysmurf 6y ago> In May 2020, the U.S. Environmental Protection Agency (EPA) ruled not to place regulations on the amount of perchlorate that can be allowed in drinking water. Predictable. Just 150 days left to vote.
- ianlevesque 6y agoI don’t get it. Do these people not live in the same country as everyone else? Breathe the same air and drink water? It’s madness.
- vermontdevil 6y agoSee Flint as an example. They know this stuff is bad but they are confident their wealthy town or county will not allow it to impact the drinking water supply. It'll be "someone else most likely poorer areas" problem.
- rayiner 6y agoFlint is an example of what exactly? https://reason.com/2019/07/30/flint-water-crisis-democrat-debate-infrastructure/ https://reason.com/2019/07/30/flint-water-crisis-democrat-de... > Many in the media have parroted the absurd claim that the water crisis was caused by austerity, as if the government cared more about saving pennies than saving lives. The truth is exactly the opposite: Keeping DWSD as Flint's water provider was a cheaper option, but one that would have created zero new infrastructure jobs
- monadic2 6y agoThis is what degrading all understanding of a political economy down to jobs and a stock market price does. Btw, it’s absolutely unacceptable to justify the degradation of water quality with jobs. Regardless the reasoning it was entirely irresponsible given the infrastructure in the area. Anyway it’s not like there’s any shortage of examples that austerity leads to loss of life.
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- JoeAltmaier 6y agoUntil 10 years ago, Dry Cleaners used this for all our clothes.
- steffan 6y agoYou’re thinking of Tetrachloroethylene (perchloroethylene)
- JoeAltmaier 6y agoAm I? Is that different?
- ThePowerOfFuet 6y agoYes. Night and day.
- cbkeller 6y agoBoth contain Cl but perchlorate is a highly oxidizing anion (ClO4-), while perchloroethylene is relatively unreactive (though carcinogenic) organic compound (Cl2C=CCl2)
- mannykannot 6y agoPerchorate is one of those chemicals that I first heard of on account of their use as rocket fuels. It seems that you won't go far wrong by regarding anything in that class as hazardous.
- aasarava 6y agoI covered a Texas Tech study that showed how perchlorate can be passed to babies via breast milk. That was in... 2005. The EPA's recent decision is extremely disappointing. https://www.wired.com/2005/02/rocket-fuel-fed-to-newborns/ https://www.wired.com/2005/02/rocket-fuel-fed-to-newborns/ (An aside: Reporters don't usually choose their own headlines. I fought and lost a battle with my editor on that one.)
- morninglight 6y agoRiverside California also performed tests showing high levels of perchlorate in the drinking water at about the same time. The test results have not slowed residential growth in Riverside. I'd love to see test results from Lompoc. Actually, anyone living within 10 miles of a military base needs to pay attention to their water quality.
- deleted 6y ago[deleted]
- jabl 6y agoSpace rockets should all switch to hydrolox, at least that burns clean. Like Delta IV. (yeah, yeah, terrible impulse density..)
- cryptonector 6y agoWhat's wrong with methane/oxygen?
- jabl 6y ago- methane is a very potent greenhouse gas. What's the effect of methane in the stratosphere? - there are some results suggesting soot emissions in the stratosphere could be a problem if space launches increase a lot. Methane burns a lot cleaner than kerosene, but afaiu some soot is still formed. Now all things considered, given nobody seems interested in a pure hydrolox lower stage due to the poor impulse density, methalox certainly looks better than alternatives.
- chris_va 6y agoGHG emissions from rocketry are so trivially small that it's really not worth optimizing at this point. Maybe if SpaceX flew 500 rockets per day. (disclaimer: I work in a climate research group)
- jabl 6y agoTotal volume is trivial compared to all other human activity, but like I mentioned there is some concern about the effect of rocket emissions in the middle and upper atmosphere given that we're likely to see a substantial increase in launch rate. See https://eos.org/features/the-coming-surge-of-rocket-emissions https://eos.org/features/the-coming-surge-of-rocket-emission... for a recent overview.
- LargoLasskhyfv 6y agoUse rotating detonation engines instead.
- eqvinox 6y agoAw man... perchlorates are also pretty abundant in Martian soil... another hurdle for future terraforming I guess :/ (Last I checked, [some] plants weren't bothered too much by these, but the question then is whether they accumulate in fruit...)
- teruakohatu 6y agoThis may be a stupid question, but can anything be planted in Martian soil, even if the atmosphere was corrected? I always assumed not.
- gpm 6y agoOther than the perchlorate problem (which is a real problem, but they can be baked out with heat as I understand it) I don't think we know any reason why not. You'd have to fertilize the soil of course, but fundamentally plants don't need that much to grow. A lot of hydroponics use a completely inert "gravel" like substance and just wash a nutrient solution through on occasion.
- eqvinox 6y agoDo you know if there's any knowledge on how much fertilization you'd need to bring in? Or: whether it actually makes sense to use Martian soil to grow things on? If it doesn't supply much, one might just stick to hydroponics...
- Ididntdothis 6y agoI can’t imagine Mars soil having any usable nutrients since there are no microbes or any other biological activity. You probably have to bring or produce all fertilization from scratch.
- serf 6y agoMars soil has a ton of required nutrients for vegetation. [0]. It might not all be in amounts easily scavenged, but they're mostly there. [0]: https://www.nasa.gov/feature/can-plants-grow-with-mars-soil https://www.nasa.gov/feature/can-plants-grow-with-mars-soil
- annoyingnoob 6y agoThere is an area outside of Gilroy where a safety flare manufacturer had been dumping perchlorate in a pond for years. It was showing up in local wells years later and bottled water was provided for years until the levels went down enough. Now maybe it wasn't enough? Ouch.