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Humans are exposed to 44 times as much BPA as previously assumed
A new method of measuring human exposure to the potentially toxic chemical calls into question regulatory policy.
- Bisphenol A, or BPA, is produced at a massive scale in order to manufacture plastics.
- It's been linked to a wide variety of negative health effects, but regulatory agencies have mainly left the chemical alone due to its usefulness and the low exposure levels found in humans.
- However, a new study found that the method that most researchers have used to measure BPA exposure in humans drastically underestimates the actual exposure.
Bisphenol A (BPA), a chemical used in the manufacture of plastics, has a nasty reputation. In fetuses, BPA exposure is linked with growth, metabolism, behavior, and fertility issues as well as a greater risk for cancer. It disrupts the endocrine system, mimicking the action of estrogen and blocking androgen, leading some to cite it as a possible cause for lower testosterone rates in men. In the environment, it interferes with the growth of aquatic and plant life as well.
Despite this, over a million pounds of BPA are released into the environment every year. Regulatory agencies have mainly left BPA alone, as it can be used to craft high-performing polycarbonate plastic and epoxy resins for use in food storage containers, automobiles, electronics, and other products. Additionally, it has a rapid half-life of just a few days, and human exposure levels appear to be low. According to the FDA website,
People are exposed to low levels of BPA because, like many packaging components, very small amounts of BPA may migrate from the food packaging into foods or beverages. Studies pursued by FDA's National Center for Toxicological Research (NCTR) have shown no effects of BPA from low-dose exposure.However, a recent study published in The Lancet Diabetes & Endocrinology has determined that regulatory agencies such as the FDA may be drastically underestimating human exposure levels to the potentially toxic compound. Comparing regulatory agencies' measurement methodologies with their own, the researchers found that regulators may be underestimating human exposure to BPA by as much as 44 times
A more precise method
Regulatory agencies rely on an indirect method to measure BPA exposure. The trouble arises from the difficulty of measuring BPA metabolites directly. When our body processes a substance, the end result is a metabolite — in this case, the relevant metabolites are known as BPA glucuronide and BPA sulfate, which are excreted in urine.
But the indirect method does not measure these metabolites; instead, it uses an enzyme solution derived from snails to revert the two metabolites back into regular BPA, which is more easily measured.
The researcher's new method, however, was capable of measuring BPA's metabolites directly, thus providing us with a clearer picture of how much an individual had been exposed.
The research team analyzed samples of synthetic urine spiked with BPA and 39 human samples. Twenty-nine of these came from pregnant women. Since BPA exposure has the most damaging effects on developing fetuses, studying its effects on pregnant women is particularly important. These analyses revealed a troubling feature of the indirect method — the more BPA present in the sample, the worse the indirect method was at predicting the actual level. As a result, the indirect method was revealed to underestimate BPA by up to 44 times in some cases.
Why was this discrepancy so large? The researchers had a few speculations. First, it seems likely that the enzyme solution was imperfect at reverting the BPA metabolites back into BPA. The researchers also argued that this solution could be transforming BPA glucuronide into products other than BPA, although they did not identify any possible alternate products in their samples.
The findings also have a larger implication for regulatory policy beyond BPA. Many other potentially harmful chemicals are measured using similar indirect methods, including phenols and phthalates, which are found in a wide array of products. It's conceivable that the real human exposure to these substances also exceeds safety levels — though more research is needed.
BPA is produced on a massive scale in industry, and there is little consensus about its health effects in the scientific community. Since this recent finding shows that humans are being exposed to far, far more than originally thought, researchers and regulatory agencies must identify how exactly BPA exposure affects the human body and reconsider assumptions regarding the chemical's safety.
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From "if-by-whiskey" to the McNamara fallacy, being able to spot logical missteps is an invaluable skill.
- A fallacy is the use of invalid or faulty reasoning in an argument.
- There are two broad types of logical fallacies: formal and informal.
- A formal fallacy describes a flaw in the construction of a deductive argument, while an informal fallacy describes an error in reasoning.
Appeal to privacy<p>When someone behaves in a way that negatively affects (or could affect) others, but then gets upset when others criticize their behavior, they're likely engaging in the appeal to privacy — or "mind your own business" — fallacy. Examples:<br></p><ul><li>Someone who speeds excessively on the highway, considering his driving to be his own business.</li><li>Someone who doesn't see a reason to bathe or wear deodorant, but then boards a packed 10-hour flight.</li></ul><p>Language to watch out for: "You're not the boss of me." "Worry about yourself."</p>
Sunk cost fallacy<p>When someone argues for continuing a course of action despite evidence showing it's a mistake, it's often a sunk cost fallacy. The flawed logic here is something like: "We've already invested so much in this plan, we can't give up now." Examples:<br></p><ul><li>Someone who intentionally overeats at an all-you-can-eat buffet just to get their "money's worth"</li><li>A scientist who won't admit his theory is incorrect because it would be too painful or costly</li></ul><p>Language to watch out for: "We must stay the course." "I've already invested so much...." "We've always done it this way, so we'll keep doing it this way."</p>
If-by-whiskey<p>This fallacy is named after a speech given in 1952 by <a href="https://en.wikipedia.org/wiki/Noah_S._Sweat" target="_blank">Noah S. "Soggy" Sweat, Jr.</a>, a state representative for <a href="https://en.wikipedia.org/wiki/Mississippi" target="_blank">Mississippi</a>, on the subject of whether the state should legalize alcohol. Sweat's argument on prohibition was (to paraphrase):<br></p><p><em>If, by whiskey, you mean the devil's brew that causes so many problems in society, then I'm against it. But if whiskey means the oil of conversation, the philosopher's wine, "</em><em>the stimulating drink that puts the spring in the old gentleman's step on a frosty, crispy morning;" then I am certainly for it.</em></p>
Slippery slope<p>This fallacy involves arguing against a position because you think choosing it would start a chain reaction of bad things, even though there's little evidence to support your claim. Example:<br></p><ul><li>"We can't allow abortion because then society will lose its general respect for life, and it'll become harder to punish people for committing violent acts like murder."</li><li>"We can't legalize gay marriage. If we do, what's next? Allowing people to marry cats and dogs?" (Some people actually made this <a href="https://www.daytondailynews.com/news/national/cats-marrying-dogs-and-five-other-things-same-sex-marriage-won-mean/dLV9jKqkJOWUFZrSBETWkK/" target="_blank">argument</a> before same-sex marriage was legalized in the U.S.)</li></ul><p>Of course, sometimes decisions <em>do </em>start a chain reaction, which could be bad. The slippery slope device only becomes a fallacy when there's no evidence to suggest that chain reaction would actually occur.</p><p>Language to watch out for: "If we do that, then what's next?"</p>
"There is no alternative"<p><span style="background-color: initial;">A modification of the </span><a href="https://en.wikipedia.org/wiki/False_dilemma" target="_blank" style="background-color: initial;">false dilemma</a><span style="background-color: initial;">, this fallacy (often abbreviated to TINA) argues for a specific position because there are no realistic alternatives. Former British Prime Minister Margaret Thatcher used this exact line as a slogan to defend capitalism, and it's still used today to that same end: Sure, capitalism has its problems, but we've seen the horrors that occur when we try anything else, so there is no alternative.</span><br></p><p>Language to watch out for: "If I had a magic wand…" "What <em>else</em> are we going to do?!"</p>
Ad hoc arguments<p>An ad hoc argument isn't really a logical fallacy, but it is a fallacious rhetorical strategy that's common and often hard to spot. It occurs when someone's claim is threatened with counterevidence, so they come up with a rationale to dismiss the counterevidence, hoping to protect their original claim. Ad hoc claims aren't designed to be generalizable. Instead, they're typically invented in the moment. <a href="https://rationalwiki.org/wiki/Ad_hoc" target="_blank">RationalWiki</a> provides an example:<br></p><p style="margin-left: 20px;">Alice: "It is clearly said in the Bible that the Ark was 450 feet long, 75 feet wide and 45 feet high."</p><p style="margin-left: 20px;">Bob: "A purely wooden vessel of that size could not be constructed; the largest real wooden vessels were Chinese treasure ships which required iron hoops to build their keels. Even the <em>Wyoming</em> which was built in 1909 and had iron braces had problems with her hull flexing and opening up and needed constant mechanical pumping to stop her hold flooding."</p><p style="margin-left: 20px;">Alice: "It's possible that God intervened and allowed the Ark to float, and since we don't know what gopher wood is, it is possible that it is a much stronger form of wood than any that comes from a modern tree."</p>
Snow job<p><span style="background-color: initial;">This fallacy occurs when someone doesn't really have a strong argument, so they just throw a bunch of irrelevant facts, numbers, anecdotes and other information at the audience to confuse the issue, making it harder to refute the original claim. Example:</span><br></p><ul><li>A tobacco company spokesperson who is confronted about the health risks of smoking, but then proceeds to show graph after graph depicting many of the other ways people develop cancer, and how cancer metastasizes in the body, etc.</li></ul><p>Watch out for long-winded, data-heavy arguments that seem confusing by design.</p>
McNamara fallacy<p>Named after <a href="https://en.wikipedia.org/wiki/Robert_McNamara" target="_blank">Robert McNamara</a>, the <a href="https://en.wikipedia.org/wiki/United_States_Secretary_of_Defense" target="_blank">U.S. secretary of defense</a> from 1961 to 1968, this fallacy occurs when decisions are made based solely on <em>quantitative metrics or observations,</em> ignoring other factors. It stems from the Vietnam War, in which McNamara sought to develop a formula to measure progress in the war. He decided on bodycount. But this "objective" formula didn't account for other important factors, such as the possibility that the Vietnamese people would never surrender.<br></p><p>You could also imagine this fallacy playing out in a medical situation. Imagine a terminal cancer patient has a tumor, and a certain procedure helps to reduce the size of the tumor, but also causes a lot of pain. Ignoring quality of life would be an example of the McNamara fallacy.</p><p>Language to watch out for: "You can't measure that, so it's not important."</p>
A new study looks at what would happen to human language on a long journey to other star systems.
- A new study proposes that language could change dramatically on long space voyages.
- Spacefaring people might lose the ability to understand the people of Earth.
- This scenario is of particular concern for potential "generation ships".
Generation Ships<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="a1e6445c7168d293a6da3f9600f534a2"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/H2f0Wd3zNj0?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
Many of the most popular apps are about self-improvement.
Emotions are the newest hot commodity, and we can't get enough.