Gaussian Processes in particular can be very useful in regression problems when you don't want to make strong assumptions about the functional form of the relationship between variables. (You can still introduce more general assumptions, like that the relationship is "smooth" to some degree or is periodic, by your choice of GP kernel function.)
Another excellent choice for a LaTex editor is LyX (https://www.lyx.org/). It's not WYSIWYG, but does basic math formatting as you go, which is very helpful for complicated expressions.
Most emerging contaminants have no clinical reference levels for safe vs. unsafe exposure, so often the best you can do is compare your exposure level to a reference distribution to see if you have relatively high levels.
The CDC tests thousands of people in the U.S. every two years for a panel of chemicals (including endocrine disruptors) via NHANES, so at very least you can compare your results to that to see if you are unusual relative to a nationally representative sample of Americans.
I used to work on an endocrine disruptor (EDC) testing program (https://wwww.silentspring.org/detoxmeactionkit/). Analytical laboratories won't deal with individual samples from consumers, so our approach was to collect batches that we sent to the lab all at once. The cost adds up quickly because (1) the analytical chemistry done for the testing requires a mass spectrometer, which need constant expert attention and expensive reference standards, (2) urine needs to be mailed frozen, which requires overnight shipping. The program I worked on didn't test for phthalates because IIRC that would require sending the samples through the mass spec a second time, which substantially increases the price.
I think it would be possible to bring the price down if you had your own dedicated mass spec and high volume, but it's never going to be cheap. Unfortunately the usefulness of this kind of testing increases the more you can get tested, e.g. before and after a dietary intervention. I think the market for this kind of testing could be large if there was a way to bring the price down, but that probably requires the development of new analytical chemistry techniques.
Silent Spring Institute | Newton, MA | ONSITE | Software Engineer
We’re looking for a web application engineer to lead our efforts to design digital tools to communicate research about harmful chemicals in everyday environments.
We measure chemical levels in people’s environments and in their bodies—even a New York Times columnist Nicholas Kristof was tested in one of our studies: http://nyti.ms/2CdcyQ4! We built a web application to help us return individual results in an understandable way to the people who were tested. We need your help turning it into a scalable tool that can be used by more studies to reach tens of thousands of participants. Here’s a description of some of our work so far: https://ehp.niehs.nih.gov/EHP702/.
Silent Spring is relentlessly asking tough questions about the chemicals in our homes and in the products we buy. You’ll be there with us, helping us communicate our findings to create conscious consumers and healthier communities.
You will have opportunities to develop new software tools or lead data science projects, for example, analyzing environmental health data, developing new R packages, or creating novel visualizations of our unique datasets. You will help develop new smartphone tools, like Detox Me (https://silentspring.org/detoxme/) to collect data on the products people are using and track interventions to their reduce exposures.
This is a full time position. We offer competitive salaries, 4 weeks vacation plus holidays, health insurance, and other benefits.
Silent Spring Institute | Newton, MA | ONSITE | Software Engineer
We’re looking for a web application engineer to lead our efforts to design digital tools to communicate research about harmful chemicals in everyday environments.
We measure chemical levels in people’s environments and in their bodies—even a New York Times columnist Nicholas Kristof was tested in one of our studies: http://nyti.ms/2CdcyQ4! We built a web application to help us return individual results in an understandable way to the people who were tested. We need your help turning it into a scalable tool that can be used by more studies to reach tens of thousands of participants. Here’s a description of some of our work so far: https://ehp.niehs.nih.gov/EHP702/.
Silent Spring is relentlessly asking tough questions about the chemicals in our homes and in the products we buy. You’ll be there with us, helping us communicate our findings to create conscious consumers and healthier communities.
You will have opportunities to develop new software tools or lead data science projects, for example, analyzing environmental health data, developing new R packages, or creating novel visualizations of our unique datasets. You will help develop new smartphone tools, like Detox Me (https://silentspring.org/detoxme/) to collect data on the products people are using and track interventions to their reduce exposures.
This is a full time position. We offer competitive salaries, 4 weeks vacation plus holidays, health insurance, and other benefits.
The article seems to play extremely fast and loose with watershed vs waste treatment plant sludge vs drinking water all being the same. Which is it?
I'm particularly interested because I live in a community marked blue and I'm sure our industrially polluted river tested positive, yet our drinking water comes from 800 foot deep wells and is extremely hard although otherwise extremely clean.
So are we contaminated because somehow the deep wells are contaminated with just this unusual pollutant, or is our industrially polluted river (or some old industrial EPA superfund site, who knows) verified as being polluted, or is our waste treatment plant essentially failing us? (Or of course a combination)
In an era of infotainment and clickbait and fake news its sad to see harvard in the domain name, but its the current year, its not the authors fault that someone is profiting off scientific research, etc.
Its surprisingly difficult to figure out the percentage of people who drink deep municipal well water vs groundwater vs near-ground-water (shallow wells often private and contaminated). Therefore I don't know if my situation of drinking deep well water (presumably safe) but living in a contaminated area is unusual or typical.
My understanding is that just because you live in a blue area of the map doesn't mean you have contaminated water.
Also, note that this paper only looks at public water supply testing data, not private well water.
From the linked article:
"From the authors of the study: We have mapped watersheds in the United States that have potentially high concentrations of PFASs based on U.S. EPA data. This does not mean that all drinking water supplies within the highlighted regions contain high PFAS concentrations, but that at least one sample from at least one water supply was reported to be at or above levels considered safe by the U.S. EPA between 2013 and 2015. However, no measurements have been made in many water supplies across the country. We recommend increased monitoring of these contaminants in our drinking water. For more information, please contact the EPA: Cathy Milbourn, Milbourn.cathy@Epa.gov, or Monica Lee, Lee.monica@Epa.gov."
I'll follow up with my colleague to see if she has any thoughts.
I have another request. (You didn't limit us to one)
The article very carefully avoids discussing actual hazard level or a comparison, merely a measured number exceeded a beancounter's number.
Its irresponsible to make policy decisions without knowing the actual risk level... so inform us?
I realize its difficult to compare ochem toxicity between compounds, famously there are obscure reactions where nothing interesting happens to anyone except pregnant women or unborn children, obscure herbicides that slaughter fish but are otherwise mostly harmless, obscure herbicides that selectively kill broadleaf plants, etc.
None the less ... would it be possible to put the risk in a form people (perhaps incorrectly) think they can understand and manage? Something like fill in the blank: "The risk of drinking unfiltered tapwater at the EPA limit on a normal daily basis is roughly as dangerous to your health as consuming X ounces of 100 proof ethanol per day"
I'm curious if EPA defined contaminated tapwater is as risky as drinking four bottles of wine per day WRT cancer risk or if its more like sniffing an open bottle of N.A. beer.
I tried to find some data on that, but it appears that there is no data available showing definite health hazards of these compounds.
Getting such data can be difficult. Animal models can often be wrong: the toxicity may be specific to humans, or the damage may require exposure over time frames than the animals' life span, or it only manifests under rare circumstances (i. e. interactions with drugs).
The best data you can get may be from people who were exposed to the compounds unusually high degrees, usually because they worked with them. But that group of people may be too small, or not diverse enough (we've long avoided exposing pregnant women to industrial chemicals), or the nature of their work exposed them to different chemicals muddling any results.
You say "Its irresponsible to make policy decisions without knowing the actual risk level", but I'd say that you can't not make a decision: taking the view that a chemical is safe until proven otherwise is as much a decision as the opposite. The EU has started to assume new compounds to be dangerous until proven otherwise – I believe the US may still be doing the opposite.
Ethanol (i. e. alcohol) is also a particularly bad unit of measurement, considering its effects on human health are not just somewhat disputed, but apparently highly unusual. There is quite a lot of evidence for beneficial effects of alcohol, possibly even at rather high dosages (although the effects on cancer, which you mention specifically, are probably closer to a standard linear dose-response relationship,)
We had a big debate in Portland about whether we should add fluoride to our water (we voted it down). As far as I can tell, fluoride in the water is beneficial to people who don't brush their teeth with fluoride toothpaste, but for the majority of us who do, it's not particularly helpful.
I think people should generally have a right not to ingest substances that they don't want to, especially when said substances aren't doing anything useful and might be marginally harmful to some.
There's also an argument that all that fluoride eventually ends up accumulating in the environment, and there may be long term negative effects from that. There's no benefit from watering our lawns or flushing our toilets with fluoridated water.
So, I don't really think this is so much of a science versus anti-science debate as a question of how you should weight the costs and benefits of a policy that people can't realistically opt out of if they don't approve of it.
The best way to prevent this, in my opinion, is to be clear that the research has nothing to do with fluoridated water.
From my colleague:
"The highly fluorinated chemicals that we discussed are organic compounds, meaning that they contain carbon atoms. They are called highly fluorinated or per- and polyfluoro alkyl substances because they have many fluorine atoms, and the carbon atoms are entirely or often bound to fluorine (There may be highly fluorinated chemicals that aren't strictly PFASs, but that's a minor point). These highly fluorinated chemicals have unique chemical properties that give them their characteristic grease and water resistance (typically one end of the molecule is more soluble in oil, and the other end is more soluble in water, similar to other surfactants). The concerns about PFAS toxicity stem from the properties of the whole molecule and not just because they contain fluorine."
Yeah, but people just hear "flouride" and think "OMG That's what they're putting in the water!" Just like they hear about mercury in vaccines and assume they cause nerve damage.
The masses understand at the soundbite level only. I don't know what to do about this.
As an "anti-fluoride person", I just want to go on the record to state that it's ridiculous to be more concerned with riling up a particular group than having safe drinking water.
In fact, counter to common opinion, we have a solidly science-based view on this issue--I'm not sure how we got grouped in with anti-vaxxers and others.
There simply isn't good evidence that adding fluoride to drinking water is a justifiable public health method to reduce cavities, which is why 97% of Western Europe doesn't do it[0]. And because there's no opt-out, it may be dangerous for bottle-fed babies [1].
I'm not saying it's the world's biggest problem right now (by a long shot), but dispensing medicine in water is not good policy.
If I understand correctly, I'd rather have cavities than cancer.
That is: Flouride is supposed to help prevent tooth decay. This stuff, on the other hand, "has been linked to" cancer (how strongly, I'm not sure). But if warning about a cancer-causer kills flouridation as collateral damage, well, I prefer that to the other way around (not doing anything about the cancer-causer to protect people's teeth).
This is extremely non-scientific, but I am an american living outside of the us - and I often wonder 'what's wrong with us' when I meet Americans. Maybe we just have it too easy, maybe we don't have to open up our minds to other cultures (we are the dominant one). But I've met enough people that just make me think c'mon man! That said, we're the dominant culture for a reason - we have some super talented people. At the end of the day, 'flouride' probably isn't the root-cause of our 'unique'-ness.
"The contamination of drinking water in Hoosick Falls is an example of the shortcomings of the UCMR3 program. As part of the UCMR program, all large public water supplies that serve over 10,000 residents, and a small percent of smaller public water supplies, are required to conduct water testing. Most smaller public water supplies and private wells are not required to conduct water testing as part of the UCMR program. The public water supply in Hoosick Falls serves less than 10,000 residents, so it was not required to conduct testing for PFOA as part of the UCMR program, nor were residents in the area who relied on private wells."
I can add that we're also following several other communities with PFAS contamination issues, like Newburgh, NY; Bennington, VT; and Pease, NH.
“What are the chances of falling off the roof?” he argued vociferously when we tried previously to hash it out. Have I ever known anyone who has fallen off a roof? Anyway, he said, it’s not as if he doesn’t give his kids any limits: They are not allowed to play ball or tag up there."
Yes, but most kids are not allowed or encouraged to play on their roofs. If they were, the rate of injury would likely be much higher.
> Yes, but most kids are not allowed or encouraged to play on their roofs. If they were, the rate of injury would likely be much higher.
I used to play on the roof of our shed. I have no idea what I did up there but I think it was mostly being deliberately up high. I dangled and jumped many times and jumped at least once before deciding that kind of hurt and deciding not to do it again. You overestimate the stupidity of children who are familiar with the concept of consequences. I also had my thumbnails fall off multiple times after hitting them with hammers and burned off the skin on my little finger once on a stovetop seeing exactly what these burns were that were so scary. I never even broke a bone and I have less than five wounds that should have received stitches. I had a boring, safe childhood.
Sounds like your roof was not all that high. In the article I think they said the roof was 25 feet, which would very severely injure you (at least) if you fell off.
As a kid, me and my friends would climb any roof we could. Of course adults would chase us down if they saw us, but we would just do it again when they were gone. This was rural Sweden in the 80s.
You don't want to raise conformist children, you want to raise rebels.
