health and wellness
What parents need to know about Tylenol, autism and the difference between finding a link and finding a cause in scientific research
The article discusses the ongoing debate regarding the potential link between prenatal acetaminophen (Tylenol) use and autism. While some studies show weak associations, establishing causation remains challenging. Factors like dosage response and sibling outcome comparisons are critical for understanding this complex issue, highlighting the need for more thorough research and consulting healthcare professionals.
What parents need to know about Tylenol, autism and the difference between finding a link and finding a cause in scientific research
Claims from the Trump White House about links between use of the painkiller acetaminophen – often sold under the brand name Tylenol in the U.S. – during pregnancy and development of autism have set off a deluge of responses across the medical, scientific and public health communities.
As a father of a child with level 2 autism – meaning autism that requires substantial support – and a statistician who works with such tools as those used in the association studies cited by the White House, I find it useful to think about the nuances of association versus causation in observational studies. I hope that this explanation is helpful to parents and expecting parents who, like me, are deeply invested in the well-being of their children.
Association is not causation, but …
Most people have heard this before, but it bears repeating: Association does not imply causation.
An often-cited example is that there is a very strong association between ice cream sales and incidents of shark attacks. Of course, it goes without saying that shark attacks aren’t caused by ice cream sales. Rather, in the summertime, hot weather drives more appetite for ice cream and beach time. The increased number of people at the beach does, in turn, cause the likelihood of shark attacks to increase.
Yet pointing this out on its own is neither intellectually satisfying nor emotionally appeasing when it comes to real-life medical concerns, since an association does suggest potential for a causal relationship.
In other words, some associations do end up being convincingly causal. In fact, some of the most consequential discoveries of the past century in public health, like the links between smoking and lung cancer or the human papillomavirus (HPV) and cervical cancer, started out as findings of very strong association.
So when it comes to the issue of prenatal acetaminophen use and autism development, it is important to consider how strong the association found is, as well as the extent to which such an association could be considered causal.
Establishing causal association
So how do scientists determine if an observed association is actually causal?
The gold standard for doing so is conducting what are called randomized, controlled experiments. In these studies, participants are randomly assigned to receive treatment or not, and the environment where they are observed is controlled so that the only external element that differs among participants is whether they received treatment or not.
In doing this, researchers reasonably ensure that any difference in the outcomes of the participants can be directly attributed as being caused by whether they received the treatment. That is, any association between treatment and outcome can be considered causal.
Yet oftentimes, conducting such an experiment is impossible, unethical or both. For instance, it would be highly difficult to gather a cohort of pregnant women for an experiment and extremely unethical to randomly assign half of them to take acetaminophen, or any other medication for no particular reason, and the other half not to.
So when experiments are simply infeasible, an alternative is to make some reasonable assumptions on how observational data would behave if the association was causal and then see if the data aligns with these causal assumptions. This can very broadly be referred to as observational causal inference.
Parsing what the studies mean
So how does this apply to the current controversy over the potential for acetaminophen use during pregnancy to affect the fetus in a way that could result in a condition like autism?
Researchers who try to understand causal roles and links between one variable and potential health outcomes do so by considering: 1) the size and consistency of the association across multiple attempts to estimate it, and 2) the extent to which such association has been established under observational causal inference frameworks.
As early as 1987, researchers have been working to measure possible associations between acetaminophen use during pregnancy and autism. A number of these studies, including multiple large systematic reviews, have found evidence of such associations.
For instance, a 2025 review of 46 studies that examined association between acetaminophen use and an array of neurodevelopmental disorders, including autism, identified papers with five positive associations between acetaminophen and autism.
In one of those studies, which examined 73,881 births, the researchers found that children who were exposed to acetaminophen prenatally were 20% more likely to develop borderline or clinical autism spectrum conditions. Another examined 2.48 million births and reported an estimated association of only 5%.
Both of those are weak associations. For context, estimations of increased lung cancer risk from smoking in the 1950s were between 900% to 1,900%. That is, a smoker is 10 to 20 times more likely than a nonsmoker to develop lung cancer. By comparison, in the two autism studies above, a pregnant woman who takes acetaminophen is 1.05 to 1.20 times more likely than one who does not take the drug to have a child who would be later diagnosed with autism.
It’s also important to keep in mind that many factors can affect how well a study is able to estimate an association. In general, larger sample sizes provide both greater power to detect an association if one does exist, as well as improved precision over estimating the value of the association. This does not mean that studies with smaller sample sizes are not valid, only that from a statistical perspective, researchers like me place greater confidence in an association drawn from a larger sample size.
Once an association – even a small one – is established, researchers then must consider the extent to which causation can be claimed. One way to do this is through what’s called dose-response. This means looking at whether the association is higher among women who took higher doses of acetaminophen during pregnancy.
The study mentioned above that looked at 2.48 million births shows an example of dose-response. It found that pregnant women who reported taking higher doses have higher autism risk.
Another way to examine possible causality in this context is to analyze sibling outcomes, which that same paper did. Researchers looked at whether associations between acetaminophen and autism persisted within families with more than one child.
For example, in a family with two children, if the mother used acetaminophen during one pregnancy and that child was later diagnosed with autism, but she did not use it during the other pregnancy and that child was not diagnosed, then this strengthens the causal claim. Conversely, if acetaminophen was used during the pregnancy of the child who was not diagnosed with autism and not used during the pregnancy of the child who was, then that weakens the causal claim. When this was included in the analysis, the dose-response disappeared, and in fact the overall 5% increased risk mentioned before likewise disappeared. This weakens the claim of a causal relationship.
Consult your doctor
At present, there is clearly not enough evidence to establish a causal association between prenatal acetaminophen use and autism.
Yet as a parent who wonders if my daughter will ever be able to write her name, or hold a job or raise kids of her own, I understand that such explanations may not appease the fears or concerns of an expecting mother who is suffering from a fever.
Naturally, all of us want absolute certainty.
But that’s not possible when it comes to acetaminophen use, at least not at this time.
Your doctor will be able to provide you with much sounder advice than any existing study on this topic. Your OB-GYNs are very likely aware of these studies and have much better judgment as to how these results should be considered in the context of your personal medical history and needs.
Researchers, meanwhile, will continue to dig deeper into the science of this critically important issue and, hopefully, provide greater clarity in the years to come.
Mark Louie Ramos, Assistant Research Professor of Health Policy and Administration, Penn State
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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health and wellness
Heat waves can leave homes dangerously hot – even for young, healthy adults
Heat waves can turn homes into dangerous heat traps—especially during blackouts or in houses without AC—pushing indoor temperatures and humidity into lethal territory even for young, healthy adults, not just the elderly.
Heat waves can leave homes dangerously hot – even for young, healthy adults
Zoltan Nagy, Eindhoven University of Technology
Most people know that heat waves can be dangerous, but what they may not realize is that the heat indoors can be much worse than outdoors.
When the power goes out and air conditioning stops, or in homes without cooling, a house starts to function like a greenhouse during a heat wave. Heat enters through windows and walls and has nowhere to go. Air stagnates.
Within hours, indoor temperatures can climb well above what the thermometer shows outside, especially on upper floors and in rooms with south-facing windows. Over longer periods, especially if temperatures don’t cool off overnight, conditions can become lethal.
Most heat-related deaths occur indoors. When a heat dome sent temperatures soaring in the Pacific Northwest in 2021, 98% of the more than 600 deaths in British Columbia happened inside homes. Washington and Oregon also saw high numbers of deaths in homes that lacked air conditioning.
In Europe, where only 1 in 10 households have air conditioning, heat waves killed an estimated 60,000 people in 2022 and 47,000 in 2023, largely inside buildings never designed for these temperatures.
People of all ages are at risk in heat waves like these. I spent eight years at the University of Texas at Austin studying how buildings respond to extreme heat. In a recent study, my team assessed the heat risk in every single-family home in Austin.
We found that even younger, healthy adults face far more risk than they realize.
How hot is too hot for a human body?
Your body maintains a core temperature of about 98.6 degrees Fahrenheit (37 degrees Celsius). To cool down, it pushes blood to the skin and sweats. But when air temperature is high, that convective cooling weakens. When humidity is also high, sweat cannot evaporate.
If the body has no way to release heat, core temperature rises. If the core temperature increases past about 104 F (40 C), the body’s thermoregulation starts to fail. Past 109 F (42.8 C), death becomes likely.
What makes indoor heat especially dangerous is that it does not let up at night in homes that lack air conditioning. Outdoor temperatures typically drop after sunset, and someone outside can get a few hours of recovery. But a poorly insulated home that has been absorbing heat all day releases that heat slowly, keeping indoor temperatures elevated through the night. A person inside the home never gets a break.
After two or three nights of this, even healthy people start to be at serious risk for heat-related illnesses.
Why homes heat up more than people expect
People tend to underestimate indoor heat for a few reasons.
One is that the thermostat typically sits on one wall in one room. It does not tell what the temperature is in an upstairs bedroom or near a sun-facing window. In older, underinsulated homes, the actual felt temperature can exceed 90 F (32.2 C) even when a thermostat reads 75 F (23.9 C). The hot walls, ceilings and windows can radiate heat directly onto your body.
Another reason is that people assume all homes respond to heat the same way. However, a newer home with double-pane windows and good insulation acts like a thermos, keeping heat out for a longer time. An older home with single-pane windows and cracks in the walls heats up fast.
Two houses on the same street, exposed to the same outdoor conditions, can have completely different temperatures inside. And in a blackout, where neither home has cooling, those differences can become a matter of life and death.
What we found in Austin
Our study combined two datasets. From Austin’s tax appraisal records, we pulled basic property information, such as the year the home was built, the size and the number of stories for each of the city’s 213,000 single-family homes. We then matched each home to the most similar energy simulation models in a U.S. Department of Energy database that contains thousands of detailed, physics-based building energy models representing the U.S. residential building stock.
Using those models, we simulated each building’s indoor temperatures over time during a three-day heat wave and power outage with outdoor temperatures above 110 F (43 C).
We found that 85% of homes got hot enough to pose a significant risk of death for an elderly occupant. But what surprised us was the risk to younger people.
Under today’s climate conditions in Austin, about 15% of homes already have the potential to get hot enough without air conditioning to pose serious heat risks to healthy adults. Under future warming scenarios, that number jumps to as high as 65% if average summer highs reach 104 F (40 C). Further, climate projections for Austin show that heat waves will double in frequency by the end of the century.
We found three types of buildings and accompanying risks:
- Resilient homes, which are newer and well insulated, tended to have temperature and humidity conditions that would be survivable for an elderly occupant throughout the simulated heat wave with blackout.
- Critical-risk buildings, which are mostly older homes, became dangerous almost immediately.
- And then there was the middle group – homes where temperatures rose slowly during the simulated blackout, day by day, possibly giving occupants a false sense of security until it was too late.
Texas has already seen conditions like our case study’s – a heat wave paired with a power outage. In 2024, a derecho knocked out power for nearly 900,000 Houston households while the heat index climbed to 100 F (37.8 C). Seven weeks later, Hurricane Beryl cut power to 2.6 million homes, leaving them without power for over three days, with temperatures over 90 F (32.2 C).
What you can do to stay safe
If you can’t get cooling at home, there are steps you can take that can help.
Move to the lowest floor of your home, where it will be coolest. Close the blinds and curtains on sun-facing windows. Drink water constantly to stay hydrated, which is essential for regulating body temperature.
If you’re facing a blackout, be sure to also check on elderly neighbors, especially those living alone. You can also try to find a public cooling center; many cities now open them during heat emergencies.
Longer term, upgrades such as reflective window film, attic insulation and lighter-colored roofing can reduce how much a home heats up. After the 2021 heat dome, British Columbia’s coroner recommended updating building codes to address heat.
Our own findings point in the same direction: We propose that new homes should be required by building codes to maintain conditions in which at least light physical activity remains possible for all occupants for at least 72 hours during a power outage.
As summers get hotter with climate change and blackouts become more frequent, the risks of people suffering heat illnesses will only continue to rise.
Zoltan Nagy, Professor of Building Services, Eindhoven University of Technology
Heat waves can leave homes dangerously hot – even for young, healthy adults
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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(Feature Impact) Relationships and plumbing have something in common: they can both benefit from practicing smarter bathroom habits. Whether you’re sharing a household with your family, a partner or roommates, good etiquette in these frequently shared spaces can save everyone’s sanity – just like rethinking your flushing routines can save your pipes.
From simple annoyances like leaving the toilet seat up to potentially costly mistakes like clogging your plumbing by flushing the wrong items, a new survey from the Responsible Flushing Alliance (RFA) illuminated a variety of bad habits that cause the most tension in American homes.
In addition to shedding light on these problems, the alliance outlined solutions you can implement at home to restore peace in your restroom. Plus, you can gamify the habit changes to make them more entertaining.
“Our goal is to revolutionize public education by keeping it highly engaging, memorable and fun,” RFA President Lara Wyss said. “We are challenging the public to rethink their everyday habits.”
Get started with these seven tips:
Replace the toilet roll properly
Don’t be the reason someone gets stranded with nothing but a cardboard tube in their moment of need. Keep extra rolls nearby, and when you’re down to the last square of toilet paper, make it a race against the clock to replace it.
Use the (flush) force
An unflushed toilet was listed as the biggest bathroom pet peeve by 37% of survey respondents. To make it fun for the family, introduce a new tradition: before you leave the bathroom, pretend there’s an invisible force field pushing you back to make sure you’ve flushed and are good to go.
Hunt for sink and shower hair
Leaving hair in the drain isn’t just a source of potential plumbing clogs – it’s also an irritant for 35% of respondents. After you shower or style your hair, make it a game to see how many stray strands you can capture and deliver to the trash can.
Clean it and close it
You’ve probably heard jokes about people who leave the toilet seat up, so don’t make yourself the punchline. For a completely un-mockable routine, grab the brush to give the bowl a quick swish after you flush, ensure the seat is down and use an anti-bacterial wipe to leave everything sparkling. You’ll notice cleaning wipes bear the Do Not Flush symbol, which means they go in the trash and never the toilet.
Conquer the counter
Toothpaste and water often splatter all over the place, so to be a polite bathroom roommate, wipe up the mess before it’s even had a chance to dry. Keep cleaning wipes or rags within easy reach and give yourself a 10-second deadline to leave surfaces spotless.
Practice good towel etiquette
Wet towels don’t belong on bathroom floors. If they still have a use or two left in them, banish them back to your towel rack. Otherwise, challenge yourself to a game of laundry basketball, aiming for the hamper.
Don’t flush the un-flushable
According to an RFA survey, half of Americans are still flushing things they know they shouldn’t, like paper towels, feminine hygiene products and non-flushable wipes. Since clearing a clog in your home can cost anywhere from $300-$15,000 or more, the only thing you’ll be draining with habits like these is your wallet.
“Always check wet wipes for the Do Not Flushsymbol and disposal instructions, which helps us protect not only the health of our homes and environment but our relationships, too,” Wyss said.
Visit FlushSmart.org to learn more about good bathroom etiquette, take an interactive quiz and put these tips into practice with a seven-day challenge.
Photo courtesy of Shutterstock (throwing away non-flushable wipe)
SOURCE:
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Lifestyle
Social media before bedtime wreaks havoc on our sleep − a sleep researcher explains why screens alone aren’t the main culprit
Social Media Before Bedtime? A sleep researcher explains why late-night social media disrupts sleep less because of screens and blue light, and more because of emotional engagement—doomscrolling, social comparison, habitual checking and FOMO—that keeps the brain aroused and delays rest.
Brian N. Chin, Trinity College
“Avoid screens before bed” is one of the most common pieces of sleep advice. But what if the real problem isn’t screen time − it’s the way we use social media at night?
Sleep deprivation is one of the most widespread yet overlooked public health issues, especially among young adults and adolescents.
Despite needing eight to 10 hours of sleep, most adolescents fall short, while nearly two-thirds of young adults regularly get less than the recommended seven to nine hours.
Poor sleep isn’t just about feeling tired − it’s linked to worsened mental health, emotion regulation, memory, academic performance and even increased risk for chronic illness and early mortality.
At the same time, social media is nearly universal among young adults, with 84% using at least one platform daily. While research has long focused on screen time as the culprit for poor sleep, growing evidence suggests that how often people check social media − and how emotionally engaged they are − matters even more than how long they spend online.
As a social psychologist and sleep researcher, I study how social behaviors, including social media habits, affect sleep and well-being. Sleep isn’t just an individual behavior; it’s shaped by our social environments and relationships.
And one of the most common yet underestimated factors shaping modern sleep? How we engage with social media before bed.
Emotional investment in social media
Beyond simply measuring time spent on social media, researchers have started looking at how emotionally connected people feel to their social media use.
Some studies suggest that the way people emotionally engage with social media may have a greater impact on sleep quality than the total time they spend online.
In a 2024 study of 830 young adults, my colleagues and I examined how different types of social media engagement predicted sleep problems. We found that frequent social media visits and emotional investment were stronger predictors of poor sleep than total screen time. Additionally, presleep cognitive arousal and social comparison played a key role in linking social media engagement to sleep disruption, suggesting that social media’s effects on sleep extend beyond simple screen exposure.
I believe these findings suggest that cutting screen time alone may not be enough − reducing how often people check social media and how emotionally connected they feel to it may be more effective in promoting healthier sleep habits.
How social media disrupts sleep
If you’ve ever struggled to fall asleep after scrolling through social media, it’s not just the screen keeping you awake. While blue light can delay melatonin production, my team’s research and that of others suggests that the way people interact with social media may play an even bigger role in sleep disruption.
Here are some of the biggest ways social media interferes with your sleep:
- Presleep arousal: Doomscrolling and emotionally charged content on social media keeps your brain in a state of heightened alertness, making it harder to relax and fall asleep. Whether it’s political debates, distressing news or even exciting personal updates, emotionally stimulating content can trigger increased cognitive and physiological arousal that delays sleep onset.
- Social comparison: Viewing idealized social media posts before bed can lead to upward social comparison, increasing stress and making it harder to sleep. People tend to compare themselves to highly curated versions of others’ lives − vacations, fitness progress, career milestones − which can lead to feelings of inadequacy and anxiety that disrupt sleep.
- Habitual checking: Social media use after lights out is a strong predictor of poor sleep, as checking notifications and scrolling before bed can quickly become an automatic habit. Studies have shown that nighttime-specific social media use, especially after lights are out, is linked to shorter sleep duration, later bedtimes and lower sleep quality. This pattern reflects bedtime procrastination, where people delay sleep despite knowing it would be better for their health and well-being.
- Fear of missing out, or FOMO: The urge to stay connected also keeps many people scrolling long past their intended bedtime, making sleep feel secondary to staying updated. Research shows that higher FOMO levels are linked to more frequent nighttime social media use and poorer sleep quality. The anticipation of new messages, posts or updates can create a sense of social pressure to stay online and reinforce the habit of delaying sleep.
Taken together, these factors make social media more than just a passive distraction − it becomes an active barrier to restful sleep. In other words, that late-night scroll isn’t harmless − it’s quietly rewiring your sleep and well-being.
How to use social media without sleep disruption
You don’t need to quit social media, but restructuring how you engage with it at night could help. Research suggests that small behavioral changes to your bedtime routine can make a significant difference in sleep quality. I suggest trying these practical, evidence-backed strategies for improving your sleep:
- Give your brain time to wind down: Avoid emotionally charged content 30 to 60 minutes before bed to help your mind relax and prepare for sleep.
- Create separation between social media and sleep: Set your phone to “Do Not Disturb” or leave it outside the bedroom to avoid the temptation of late-night checking.
- Reduce mindless scrolling: If you catch yourself endlessly refreshing, take a small, mindful pause and ask yourself: “Do I actually want to be on this app right now?”
A brief moment of awareness can help break the habit loop.
Brian N. Chin, Assistant Professor of Psychology, Trinity College
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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