This post is in response to another community member's post that essentially amounts to fear mongering over the use of plastics. The fact that almost no one in the comments, including multiple ECs, questioned the validity of the linked literature is worrying, and illustrates the need for a quick run-down of scientific skepticism.
First off, let me say that bringing up topics like estrogen-mimicking plasticizers is completely valid and important. However, stating that "plastics are the tobacco of the 21st century" without a wealth of credible primary literature is absurd and akin to stating that "water is a chemical in weed-killer so it must be bad for you".
Why you should trust my judgement: I am a molecular biologist and immunologist who is active in the academic sphere and have expertise in in vitro cellular assays. This is a fancy way of saying that I grow lots of cells in plastic dishes and then look at them in different ways, and it's how most of these studies are conducted. Also, it's my job to evaluate academic literature.
Ok let's do this I'll try to make it as entertaining as possible.
Polymer Chemistry - also known as REEEEEEEEEEEEE
As mentioned in the original article, some specific types of plastic polymer are embedded with plasticizers - essentially molecules added to the polymer matrix to change the physical properties of the material. Now most plastics are really just long carbon chains arranged horizontally with some interlinking vertical bonds, kind of like a the lines on a sheet of paper. Plasticizers insert themselves in the spaces between the lines and push them apart, making the material more flexible.
Knowing that there are many types of plastic and many ways of making each type you might ask - "well what kind of plastics should I watch out for? Am I really being dosed by 'big tampon' with endocrine disruptors until I get a period so they can make even more money?" Well big tampon may be trying, but substances recognized as harmful by the primary literature are really only commonly found in the following materials:
- Polyvinyl chloride (PVC)
- Nitrile (like the rubber gloves your doctor wears for your weekly prostate exam)
- Polyesters (this is more of a class of plastics)
Now keep in mind that polymer chemistry is really a black magic in itself and nothing is as simple as, "yes this water bottle will give you bitch tits" or "no this prostate stimulator will not - unless you stick it in your mouth". So instead of going through a list of plastics, of which there are many, and their production methods let's just get to refuting the literature linked in the OP. If you're dying to talk physical chem you can contact me and we can both pretend like we know what's going on after reading wikipedia.
Das Swedish Study
The first claim the article makes is that a Swedish study (n=200) found a correlation between maternal phthalate levels and "anogenital distance" - that's the distance from the anus to the genitals (commonly referred to as the scrote or undercarriage) after 20 months of life.
First of all, you have to go on a wild goose chase to even understand why anogenital distance was used. It's actually a method of measuring reproductive toxicity as the trait is under androgen-receptor control. However, this method is really only used in animal studies and is not commonly applied to humans. Secondly, looking at Table 5 as presented in the study, the researchers present a model of confidence intervals that are not even close to significant. Not only that, but the article provides no evidence that (1) the pthalates in the maternal urine samples measured were from incidental ingestion of plasticizers or that (2) the correlation between maternal pthalate levels and scrote length has anything to do with the correlation between you drinking water out of a microwaved bottle and your dick shrinking up into an infinitesimally dense and small point, birthing a black hole.
This study is completely irrelevant to the original posters point.
Study #2: The Mysterious Case of Shitty Workers' Rights in China
Luckily I didn't even have to waste my time reading deciphering jargon and ugly figures this time around because this isn't even a research paper. It's a huffington post article that literally says half way down the page, "This data should not raise alarm bells for men who don’t work in chemical factories".
The study the article sites was looking at levels of free testosterone in men who worked in a plastic factory in China- now this may be news to some of you guys but working in a Chinese plastic factory with no OSHA to save you is quite a bit different than drinking from a water bottle. And don't worry, we will get to the water bottle data soon enough.
Study #3: Estrogen-dependent proliferation of MCF7 Cells, or, 18 bottles of bitch tits on the wall
This study is the closest thing linked to actually being somewhat valid. In this study an assay is carried out where MCF7 cells are essentially treated with tap water where the solids in it have been concentrated way down from 1.5L to a few mL. For those who don't like commie units that means whatever is in that water is 1500x more concentrated than in your tap water.
Anyway, so to 1500 MCF7 cells is added all the different water "extracts" (this is a highly simplified explanation) and a week or so later they look at the proliferation of the cells. What the hell, you may be asking? Why would you even measure the proliferation of these cells in response to water? Well, as it turns out, MCF7 is an immortal breast cancer cell line that expresses high levels of estrogen receptors and proliferates in response to activation of those receptors. Now if you scroll down to the results you can see that WOAH, the relative proliferation increased almost 80% when the evil dire-aids bottled water was used (but only sometimes when DMSO or dimethylsulfoxide is used as a solvent, which could very well be significant because DMSO makes anything dissolved in it pass through cellular membranes)! Big tampon strikes again boys. But wait... Lets think about this for a second.
This is an assay carried out in a cell culture dish on a cancerous immortal cell line. Now I have a lot of experience with cancerous cell lines, I work with them every day, and I can tell you that these aren't normal cells. Cancerous cell lines are the kind of thing that you can look at the wrong way and they start dividing- it's literally cancer my dudes. Not only that, but the estrogenic activity is only even significant when DMSO is included (although highly diluted), and the water is "concentrated" (look up solid phase extraction if you want in-detail info on this process it's actually fascinating) in a specific way!
Even if we put all of these potential flaws of methodology aside we can see in the results section that the relative estrogenic activity is equal to that of 1-12 picrograms (pg) per liter. For reference, a picogram is 1x10-12 grams. Putting this in perspective, a liter of water from Tampon-Corp has a truly devestating mass of 0.0000000018% the mass of a single grain of fucking sand. Guys. Oh, and that relative increase in proliferation was all that with just 1500 cells (avg. human has upwards of 15 trillion, or 15x1012 cells or 10 factors of 10 more).
Now, my dudes. I understand that not everybody can be or wants to be a scientist. If you don't have first-hand experience working with cells and these kinds of methodologies, there would be no possible way to even read through some of these articles (the first one in particular is grueling as hell). However, we all have a responsibility to think critically about what we're reading instead of jumping to the conclusion that the government wants to cuck you. Think about it, if plastics were a government conspiracy like some of you apparently think, why would they use them on their own fucking armed forces?!
Next time you read something that tells you you're going to get dire-vagina-period-out-your-dickhole, use the following process to assess the evidence:
Look at the model organism in the study. How close is it to human? In scale? Genetically? Is it cancerous? In these cases, rodent models would have been far superior to established cancer cell lines in my opinion.
Read the results section first, the introduction second, and the methods last. Look at the figures, do they look right? Are they clear?
Where is this info coming from? HuffPo? Or is it a legitimate scientific journal. Is it in all Chinese?
Make sure that anyone who disagrees with your uninformed opinions is called a shill, as this argument has been passed down through the ages.
Anyways, my dudes, you're not going to grow bitch tits because you drink out of a water bottle. Is it possible there could be picogram levels of estrogen-mimicking molecules in your water? Yup. But guess what, there's probably about 100x more cockroach jizz in everything you eat, because a picrogram is literally such a small amount that I can't even describe it without scientific notation. So sack up and read the primary literature so you don't look like a dumb ass.
Thanks for reading. Mistakes in this article are a result of late-night writing.
UPDATE: Many community members have been asking me to provide scientific context to related issues such as steroid use and aluminum in deodorant.
I'm happy to see this kind of curiosity but can't address all of the questions. I've decided to make a series of posts where I will review the literature on a specific topic from both sides in plain speak, as well as demonstrate how to assess the literature without having to have 3 degrees. A huge problem with academia is the jargon that locks the public out of the discussion, and the shoddy quality science "reporting" that makes it to the public. Let's do something about that.
You can vote for the first topic we will address together, or select other and send me a private message with your suggestion.
Thank you all and I look forward to continued learning within this unique community.