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The Bike Helmet Paradox
Recently a good friend told me over a pint in our local pub that he hadn't been able to sleep a wink for two nights. He'd been left traumatised by the sound of a skull cracking and the sight of brains spread over concrete. No, he hadn't just returned from fighting in Afghanistan, he'd witnessed one of the many cycling deaths that occur on the roads every year. We all have stories to tell about the wearing or not wearing of helmets and this is what makes the wearing of helmets such an emotive issue, which can blind us to the facts on both sides of the debate. I was subsequently intrigued to read a viral post on a friend's Facebook wall titled: "Why It Makes Sense To Bike Without A Helmet". The post currently has over 91,000 likes on Facebook, which I thought warranted it some investigation.
The author begins, like any good debater by outlining the very strong case for helmets:
"Let’s first get one thing out of the way: if you get into a serious accident, wearing a helmet will probably save your life. According to a 1989 study in the New England Journal of Medicine, riders with helmets had an 85% reduction in their risk of head injury and an 88% reduction in their risk of brain injury. That’s an overwhelming number that’s backed up study after study. Nearly every study of hospital admission rates, helmeted cyclists are far less likely to receive serious head and brain injuries. These studies confirm what we feel when we’re out for a spin on our bikes: We are exposed. Vulnerable. Needing of some level of protection."
After this good start, the author decides to take a "broader look at the statistics" by zoning in on one study of head injuries in San Diego in 1978. The author points out that only six percent of head injuries were amongst cyclists compared to 53% amongst drivers - seemingly oblivious to the fact that there would have been far more daily drivers than cyclists in San Diego in 1978, making the statistic more than a little misrepresentative. The author provides the pie chart on the left, which is considerably less impressive when placed alongside the pie chart on the right showing the rate at which American commuters actually cycle (the data on the right is from 2005 but the proportion of commuters cycling in the US has remained below 1% since the 70's).
Next the author points out that in the San Diego study and in another French study that was also not weighted for population: "more people were hospitalized after walking down the street than riding on a bicycle", a statistic that can likely be explained by the fact that while more or less everyone walks to some extent, relatively few people regularly cycle and old people tend to hurt themselves falling over a lot.
This is where things begin to get messy. The author cites a 1996 study which looks at injuries per hour travelled and suggests that motor vehicle occupants are actually slightly more likely to suffer head injury than cyclists. On the face of it, this is a shocking statistic, but considering the speed that cars travel, it is should perhaps not actually be surprising that cars may even be more dangerous to their occupants (and to others) than push bikes - and the suggestion that car drivers should wear helmets is certainly a compelling thought to say the least. Whether or not this is relevant information to whether cyclists should be singled out for wearing helmets is certainly an interesting topic for debate. In this respect, it is difficult to argue with the author who writes:
"In other words, if the reason we are supposed to wear helmets while biking is to prevent serious head injury on the off-chance we get into an accident, then why is it socially acceptable for pedestrians and drivers to go about bare-headed? Why has cycling been singled out as an activity in need of head protection?"
Things become yet more interesting when we scratch further beneath the surface. The author of the blog post writes:
"There's an important caveat to the results of that 1989 New England medical study: Bike helmets may reduce the risk of head and brain injury by 85-88%—but only for those who get into accidents.
If we take a closer look at the article we see that both the experiment and the control groups studied are those who have already been hospitalized for bike injuries. If one were to examine the medical and epidemiological literature on bike helmet effectiveness, you'll find the exact same condition over and over: Studies show that helmeted cyclists who are hospitalized are far less likely to have serious head trauma than bare-headed cyclists that have been hospitalized.
But wouldn't this be true, regardless of the activity? Logically, helmeted drivers should also receive significantly fewer head injuries than bare-headed drivers. Similarly, helmeted pedestrians should be less likely to receive serious head trauma than bare-headed ones. But such studies don't exist because there aren't enough helmeted drivers or pedestrians to make a comparison. In other words, one of the reasons we think helmeted cyclists are safer than unhelmeted ones may be due to availability of information more than actual levels of head safety.
Maybe that explains why there's no comparable fear of driving or walking without a helmet."
So the evidence remains clear that cyclists who wear helmets who have accidents are less likely to suffer brain injuries than cyclists that don't wear helmets that have accidents - which in my mind is evidence enough to more than justify wearing a helmet. The obvious next question is - are cyclists who wear helmets somehow more likely to get into accidents than cyclists who do not wear helmets - this is a complicated and fascinating debate, which we'll come back to later in this post. But this is not the case the author makes. The author takes the cognitive leap to suggesting that helmets in and of themselves might actually be harmful.
The author cites a New York Times article which reports an increase in bicycle head injuries during a time when helmet use became widespread which coincided with an overall decrease in cycling. There is an obvious correlation ≠ causation issue here which we could talk about all day from a great many different angles, so we'll begin by looking at the author's arguments one by one.
First, the author argues that "wearing a helmet changes how drivers perceive the cyclist" citing a study that suggests drivers pass closer to a cyclist wearing a helmet. The naturalistic study involving only one participant (who was also the experimenter) is interesting, but obviously potentially vulnerable to the same kind of conscious or unconscious bias that might lead a driver to drive closer to a cyclist. On its own it is not compelling evidence for the argument that one should not wear a helmet.
Next the author argues that "the design of the helmets themselves may increase the chance of some types of injuries when incidents do occur" linking to a meta-analysis but conveniently failing to mention what the meta-analysis actually found overall:
"In conclusion, the evidence is clear that bicycle helmets prevent serious injury and even death"
The author also failed to mention that the meta-analysis concluded that the supposed increase in (neck) injuries was found in old data and may not be applicable to the lighter helmets now in use. So that argument is also null and void - and a textbook example of cherry-picked data amongst a sea of data showing the precise opposite.
The author ends their case for the argument that helmets may be harmful with a crucial point which is worth thinking long and hard about if you are a cyclist:
"Finally, wearing a helmet may create a false sense of security and induce risk-taking that cyclists without head protection might not make. Those wearing helmets may take risks that they wouldn't otherwise take without head protection."
Due to the ethical problems that prevent researchers asking cyclists to ride with or without a helmet, this is a difficult hypothesis to test - but it certainly seems likely that wearing a helmet might lead cyclists to overcompensate by taking greater risks. It is worth reminding yourself that a helmet only provides limited protection even though it might lead some people to behave like they are invincible. If helmets really do make cyclists take greater risks then making their use obligatory presents an interesting public health conundrum. Is it possible that helmets could make people safer if they have an accident whilst simultaneously making them behave even more dangerously? It is next to impossible for us to know for sure if this is occurring due to the immense amount of additional uncontrollable variables in the equation.
The author of the blog post makes a number of good points but seems to have overstated the case. These arguments highlight the fact that when it comes to human behaviour, epidemiological data gets incredibly messy and it is can be all too easy to intentionally or not, make whatever argument we want based on what data we look for. We've not even touched on the possibility that the type of casual cyclist who chooses not to wear a helmet may already behave very differently to the type of cyclist who does choose to wear a helmet. As Ben Goldacre explained in an editorial on bike helmets in the British Medical Journal, we are dealing with "confounding variables that are generally unmeasured and perhaps even unmeasurable."
What we are left with is a paradox. On an individual level it is clear that helmets can and do save cyclists from serious head injury and death provided that cyclists and the drivers around them don't overcompensate by taking greater risks. On a societal level, it seems that laws enforcing helmet use have done nothing to make cyclists safer and have driven a great many casual cyclists off the road - which as the author of the post rightly points out, indirectly increases the danger to cyclists in the long run, as cyclists are protected by strength in numbers. Furthermore, in places where helmet requirements have driven cyclists off the road it has been argued that the negative effects on public health outweigh any possible benefits in prevented injuries. In Australia, when a helmet law was introduced at a time when the popularity of cycling was on the rise, a 44% decrease in children cycling was observed, which was five times the size of the increase in children wearing helmets. According to a paper published in the BMJ, it would take "at least 8000 years of average cycling to produce one clinically severe head injury and 22,000 years for one death". It has also been estimated that the health benefits of cycling outweigh the life-years lost by a factor of twenty to one.
The whole argument reminded me of an anecdote regarding the introduction of helmets for soldiers in WW1 and the supposed consequent increase in recorded head injuries. As the story goes, generals nearly recalled the helmets before it was realised that the rise in head injuries could be explained by injuries that before the introduction of helmets would have been recorded as deaths. I've been unable to track down a bona fide citation for this anecdote amongst the many repetitions of it online (but I've not found any attempts to disconfirm it either). In any case, this has certainly not been true for bike helmets - where deaths still make up a tiny fraction of outcomes from bike accidents, but it is an interesting demonstration of how statistics can mislead - something that seems to be going on left, right and centre in the bike helmet debate.
After looking at the evidence, I'm happy to conclude that I'll choose to wear a helmet, but I'll not be beating the drum that cyclists should be forced to wear helmets - as the health benefits of cycling with or without a helmet are so great, that the risks of riding with or without a helmet pale in comparison. The evidence paradoxically seems to show that while wearing helmets does make cyclists safer, helmet laws don't make cyclists safer and actually harm public health in the long run.
Attewell R.G., Glase K. & McFadden M. Bicycle helmet efficacy: a meta-analysis., Accident; analysis and prevention, PMID: 11235796
Goldacre B. & Spiegelhalter D. (2013). Bicycle helmets and the law., BMJ (Clinical research ed.), PMID: 23760970
Robinson D. (1996). Head injuries and bicycle helmet laws, Accident Analysis & Prevention, 28 (4) 463-475. (PDF)
Walker I. (2006). Drivers overtaking bicyclists: objective data on the effects of riding position, helmet use, vehicle type and apparent gender., Accident; analysis and prevention, PMID: 17064655
Wardlaw M.J. Three lessons for a better cycling future., BMJ (Clinical research ed.), PMID: 11124188
Inventions with revolutionary potential made by a mysterious aerospace engineer for the U.S. Navy come to light.
- U.S. Navy holds patents for enigmatic inventions by aerospace engineer Dr. Salvatore Pais.
- Pais came up with technology that can "engineer" reality, devising an ultrafast craft, a fusion reactor, and more.
- While mostly theoretical at this point, the inventions could transform energy, space, and military sectors.
The U.S. Navy controls patents for some futuristic and outlandish technologies, some of which, dubbed "the UFO patents," came to light recently. Of particular note are inventions by the somewhat mysterious Dr. Salvatore Cezar Pais, whose tech claims to be able to "engineer reality." His slate of highly-ambitious, borderline sci-fi designs meant for use by the U.S. government range from gravitational wave generators and compact fusion reactors to next-gen hybrid aerospace-underwater crafts with revolutionary propulsion systems, and beyond.
Of course, the existence of patents does not mean these technologies have actually been created, but there is evidence that some demonstrations of operability have been successfully carried out. As investigated and reported by The War Zone, a possible reason why some of the patents may have been taken on by the Navy is that the Chinese military may also be developing similar advanced gadgets.
Among Dr. Pais's patents are designs, approved in 2018, for an aerospace-underwater craft of incredible speed and maneuverability. This cone-shaped vehicle can potentially fly just as well anywhere it may be, whether air, water or space, without leaving any heat signatures. It can achieve this by creating a quantum vacuum around itself with a very dense polarized energy field. This vacuum would allow it to repel any molecule the craft comes in contact with, no matter the medium. Manipulating "quantum field fluctuations in the local vacuum energy state," would help reduce the craft's inertia. The polarized vacuum would dramatically decrease any elemental resistance and lead to "extreme speeds," claims the paper.
Not only that, if the vacuum-creating technology can be engineered, we'd also be able to "engineer the fabric of our reality at the most fundamental level," states the patent. This would lead to major advancements in aerospace propulsion and generating power. Not to mention other reality-changing outcomes that come to mind.
Among Pais's other patents are inventions that stem from similar thinking, outlining pieces of technology necessary to make his creations come to fruition. His paper presented in 2019, titled "Room Temperature Superconducting System for Use on a Hybrid Aerospace Undersea Craft," proposes a system that can achieve superconductivity at room temperatures. This would become "a highly disruptive technology, capable of a total paradigm change in Science and Technology," conveys Pais.
High frequency gravitational wave generator.
Credit: Dr. Salvatore Pais
Another invention devised by Pais is an electromagnetic field generator that could generate "an impenetrable defensive shield to sea and land as well as space-based military and civilian assets." This shield could protect from threats like anti-ship ballistic missiles, cruise missiles that evade radar, coronal mass ejections, military satellites, and even asteroids.
Dr. Pais's ideas center around the phenomenon he dubbed "The Pais Effect". He referred to it in his writings as the "controlled motion of electrically charged matter (from solid to plasma) via accelerated spin and/or accelerated vibration under rapid (yet smooth) acceleration-deceleration-acceleration transients." In less jargon-heavy terms, Pais claims to have figured out how to spin electromagnetic fields in order to contain a fusion reaction – an accomplishment that would lead to a tremendous change in power consumption and an abundance of energy.
According to his bio in a recently published paper on a new Plasma Compression Fusion Device, which could transform energy production, Dr. Pais is a mechanical and aerospace engineer working at the Naval Air Warfare Center Aircraft Division (NAWCAD), which is headquartered in Patuxent River, Maryland. Holding a Ph.D. from Case Western Reserve University in Cleveland, Ohio, Pais was a NASA Research Fellow and worked with Northrop Grumman Aerospace Systems. His current Department of Defense work involves his "advanced knowledge of theory, analysis, and modern experimental and computational methods in aerodynamics, along with an understanding of air-vehicle and missile design, especially in the domain of hypersonic power plant and vehicle design." He also has expert knowledge of electrooptics, emerging quantum technologies (laser power generation in particular), high-energy electromagnetic field generation, and the "breakthrough field of room temperature superconductivity, as related to advanced field propulsion."
Suffice it to say, with such a list of research credentials that would make Nikola Tesla proud, Dr. Pais seems well-positioned to carry out groundbreaking work.
A craft using an inertial mass reduction device.
Credit: Salvatore Pais
The patents won't necessarily lead to these technologies ever seeing the light of day. The research has its share of detractors and nonbelievers among other scientists, who think the amount of energy required for the fields described by Pais and his ideas on electromagnetic propulsions are well beyond the scope of current tech and are nearly impossible. Yet investigators at The War Zone found comments from Navy officials that indicate the inventions are being looked at seriously enough, and some tests are taking place.
If you'd like to read through Pais's patents yourself, check them out here.
Laser Augmented Turbojet Propulsion System
Credit: Dr. Salvatore Pais
A new study suggests that reports of the impending infertility of the human male are greatly exaggerated.
- A new review of a famous study on declining sperm counts finds several flaws.
- The old report makes unfounded assumptions, has faulty data, and tends toward panic.
- The new report does not rule out that sperm counts are going down, only that this could be quite normal.
Several years ago, a meta-analysis of studies on human fertility came out warning us about the declining sperm counts of Western men. It was widely shared, and its findings were featured on the covers of popular magazines. Indeed, its findings were alarming: a nearly 60 percent decline in sperm per milliliter since 1973 with no end in sight. It was only a matter of time, the authors argued, until men were firing blanks, literally.
Well… never mind.
It turns out that the impending demise of humanity was greatly exaggerated. As the predicted infertility wave crashed upon us, there was neither a great rush of men to fertility clinics nor a sudden dearth of new babies. The only discussions about population decline focus on urbanization and the fact that people choose not to have kids rather than not being able to have them.
Now, a new analysis of the 2017 study says that lower sperm counts is nothing to be surprised by. Published in Human Fertility, its authors point to flaws in the original paper's data and interpretation. They suggest a better and smarter reanalysis.
Counting tiny things is difficult
The original 2017 report analyzed 185 studies on 43,000 men and their reproductive health. Its findings were clear: "a significant decline in sperm counts… between 1973 and 2011, driven by a 50-60 percent decline among men unselected by fertility from North America, Europe, Australia and New Zealand."
However, the new analysis points out flaws in the data. As many as a third of the men in the studies were of unknown age, an important factor in reproductive health. In 45 percent of cases, the year of the sample collection was unknown- a big detail to miss in a study measuring change over time. The quality controls and conditions for sample collection and analysis vary widely from study to study, which likely influenced the measured sperm counts in the samples.
Another study from 2013 also points out that the methods for determining sperm count were only standardized in the 1980s, which occurred after some of the data points were collected for the original study. It is entirely possible that the early studies gave inaccurately high sperm counts.
This is not to say that the 2017 paper is entirely useless; it had a much more rigorous methodology than previous studies on the subject, which also claimed to identify a decline in sperm counts. However, the original study had more problems.
Garbage in, garbage out
Predictable as always, the media went crazy. Discussions of the decline of masculinity took off, both in mainstream and less-than-reputable forums; concerns about the imagined feminizing traits of soy products continued to increase; and the authors of the original study were called upon to discuss the findings themselves in a number of articles.
However, as this new review points out, some of the findings of that meta-analysis are debatable at best. For example, the 2017 report suggests that "declining mean [sperm count] implies that an increasing proportion of men have sperm counts below any given threshold for sub-fertility or infertility," despite little empirical evidence that this is the case.
The WHO offers a large range for what it considers to be a healthy sperm count, from 15 to 250 million sperm per milliliter. The benefits to fertility above a count of 40 million are seen as minimal, and the original study found a mean sperm concentration of 47 million sperm per milliliter.
Healthy sperm, healthy man?
The claim that sperm count is evidence of larger health problems is also scrutinized in this new article. While it is true that many major health problems can impact reproductive health, there is little evidence that it is the "canary in the coal mine" for overall well-being. A number of studies suggest that any relation between lifestyle choices and this part of reproductive health is limited at best.
Lastly, ideas that environmental factors could be at play have been debunked since 2017. While the original paper considered the idea that pollutants, especially from plastics, could be at fault, it is now known that this kind of pollution is worse in the parts of the world that the original paper observed higher sperm counts in (i.e., non-Western nations).
There never was a male fertility crisis
The authors of the new review do not deny that some measurements are showing lower sperm counts, but they do question the claim that this is catastrophic or part of a larger pathological issue. They propose a new interpretation of the data. Dubbed the "Sperm Count Biovariability hypothesis," it is summarized as:
"Sperm count varies within a wide range, much of which can be considered non-pathological and species-typical. Above a critical threshold, more is not necessarily an indicator of better health or higher probability of fertility relative to less. Sperm count varies across bodies, ecologies, and time periods. Knowledge about the relationship between individual and population sperm count and life-historical and ecological factors is critical to interpreting trends in average sperm counts and their relationships to human health and fertility."
Still, the authors note that lower sperm counts "could decline due to negative environmental exposures, or that this may carry implications for men's health and fertility."
However, they disagree that the decline in absolute sperm count is necessarily a bad sign for men's health and fertility. We aren't at civilization ending catastrophe just yet.
A year of disruptions to work has contributed to mass burnout.
- Junior members of the workforce, including Generation Z, are facing digital burnout.
- 41 percent of workers globally are thinking about handing in their notice, according to a new Microsoft survey.
- A hybrid blend of in-person and remote work could help maintain a sense of balance – but bosses need to do more.
More than half of 18 to 25 year-olds in the workforce are considering quitting their job. And they're not the only ones.
In a report called The Next Great Disruption Is Hybrid Work – Are We Ready?, Microsoft found that as well as 54% of Generation Z workers, 41% of the entire global workforce could be considering handing in their resignation.
Similarly, a UK and Ireland survey found that 38% of employees were planning to leave their jobs in the next six months to a year, while a US survey reported that 42% of employees would quit if their company didn't offer remote working options long term.
New work trends
Based on surveys with over 30,000 workers in 31 countries, the Microsoft report – which is the latest in the company's annual Work Trend Index series – pulled in data from applications including Teams, Outlook and Office 365, to gauge productivity and activity levels. It highlighted seven major trends, which show the world of work has been profoundly reshaped by the pandemic:
- Flexible work is here to stay
- Leaders are out of touch with employees and need a wake-up call
- High productivity is masking an exhausted workforce
- Gen Z is at risk and will need to be re-energized
- Shrinking networks are endangering innovation
- Authenticity will spur productivity and wellbeing
- Talent is everywhere in a hybrid world
"Over the past year, no area has undergone more rapid transformation than the way we work," Microsoft CEO Satya Nadella says in the report. "Employee expectations are changing, and we will need to define productivity much more broadly – inclusive of collaboration, learning and wellbeing to drive career advancement for every worker, including frontline and knowledge workers, as well as for new graduates and those who are in the workforce today. All this needs to be done with flexibility in, when, where and how people work."
Organizations have become more siloed
While the report highlights the opportunities created by increased flexible and remote working patterns, it warns that some people are experiencing digital exhaustion and that remote working could foster siloed thinking. With the shift to remote working, much of the spontaneous sharing of ideas that can take place within a workplace was lost. In its place are scheduled calls, regular catch-ups and virtual hangouts. The loss of in-person interaction means individual team members are more likely to only interact with their closest coworkers.
"At the onset of the pandemic, our analysis shows interactions with our close networks at work increased while interactions with our distant network diminished," the report says. "This suggests that as we shifted into lockdown, we clung to our immediate teams for support and let our broader network fall to the wayside. Simply put, companies became more siloed than they were pre-pandemic."
Burnout or drop out
One of the other consequences of the shift to remote and the reliance on tech-based communications has been the phenomenon of digital burnout. And for those who have most recently joined the workforce, this has been a significant challenge.
The excitement of joining a new employer, maybe even securing a job for the first time, usually comes with meeting lots of new people, becoming familiar with a new environment and adapting to new situations. But for many, the pandemic turned that into a daily routine of working from home while isolated from co-workers.
"Our findings have shown that for Gen Z and people just starting in their careers, this has been a very disruptive time," says LinkedIn Senior Editor-at-Large, George Anders, quoted in the report. "It's very hard to find their footing since they're not experiencing the in-person onboarding, networking and training that they would have expected in a normal year."
But it is perhaps the data around quitting that is one of the starkest indications that change is now the new normal. Being able to work remotely has opened up new possibilities for many workers, the report found. If you no longer need to be physically present in an office, your employer could, theoretically, be located anywhere. Perhaps that's why the research found that "41% of employees are considering leaving their current employer this year".
In addition to that, 46% of the people surveyed for the Microsoft report said they might relocate their home because of the flexibility of remote working.
A hybrid future
In looking for ways to navigate their way through all this change, employers should hold fast to one word, the report says – hybrid. An inflexible, location-centred approach to work is likely to encourage those 41% of people to leave and find somewhere more to their tastes. Those who are thinking of going to live somewhere else, while maintaining their current job, might also find themselves thinking of quitting if their plans are scuppered.
But remote working is not a panacea for all workforce ills. "We can no longer rely solely on offices to collaborate, connect, and build social capital. But physical space will still be important," the report says. "We're social animals and we want to get together, bounce ideas off one another, and experience the energy of in-person events. Moving forward, office space needs to bridge the physical and digital worlds to meet the unique needs of every team – and even specific roles."
Bosses must meet challenges head on
Although the majority of business leaders have indicated they will incorporate elements of the hybrid working model, the report also found many are out of touch with workforce concerns more widely.
For, while many workers say they are struggling (Gen Z – 60%; new starters – 64%), and 54% of the general workforce feels overworked, business leaders are having a much better experience. Some 61% said they were 'thriving', which is in stark contrast to employees who are further down the chain of command.
Jared Spataro, corporate vice president at Microsoft 365, writes in the report: "Those impromptu encounters at the office help keep leaders honest. With remote work, there are fewer chances to ask employees, 'Hey, how are you?' and then pick up on important cues as they respond. But the data is clear: our people are struggling. And we need to find new ways to help them."
Buildings don't have to be permanent — modular construction can make them modifiable and relocatable.