From eye exams to blood tests and surgery: how doctors use light to diagnose disease
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This is the next article in our ‘Light and health’ series, where we look at how light affects our physical and mental health in sometimes surprising ways. Read other articles in the series.
You’re not feeling well. You’ve had a pounding headache all week, dizzy spells and have vomited up your past few meals.
You visit your GP to get some answers and sit while they shine a light in your eyes, order a blood test and request some medical imaging.
Everything your GP just did relies on light. These are just some of the optical technologies that have had an enormous impact in how we diagnose disease.
1. On-the-spot tests
Point-of-care diagnostics allow doctors to test patients on the spot and get answers in minutes, rather than sending samples to a lab for analysis.
The “flashlight” your GP uses to view the inside of your eye (known as an ophthalmoscope) is a great example. This allows doctors to detect abnormal blood flow in the eye, deformations of the cornea (the outermost clear layer of the eye), or swollen optical discs (a round section at the back of the eye where the nerve link to the brain begins). Swollen discs are a sign of elevated pressure inside your head (or in the worst case, a brain tumour) that could be causing your headaches.
The invention of lasers and LEDs has enabled many other miniaturised technologies to be provided at the bedside or clinic rather than in the lab.
Pulse oximetry is a famous example, where a clip attached to your finger reports how well your blood is oxygenated. It does this by measuring the different responses of oxygenated and de-oxygenated blood to different colours of light.
Pulse oximetry is used at hospitals (and sometimes at home) to monitor your respiratory and heart health. In hospitals, it is also a valuable tool for detecting heart defects in babies.
2. Looking at molecules
Now, back to that blood test. Analysing a small amount of your blood can diagnose many different diseases.
A machine called an automated “full blood count analyser” tests for general markers of your health. This machine directs focused beams of light through blood samples held in small glass tubes. It counts the number of blood cells, determines their specific type, and reports the level of haemoglobin (the protein in red blood cells that distributes oxygen around your body). In minutes, this machine can provide a snapshot of your overall health.
For more specific disease markers, blood serum is separated from the heavier cells by spinning in a rotating instrument called a centrifuge. The serum is then exposed to special chemical stains and enzyme assays that change colour depending on whether specific molecules, which may be the sign of a disease, are present.
These colour changes can’t be detected with the naked eye. However, a light beam from an instrument called a spectrometer can detect tiny amounts of these substances in the blood and determine if the biomarkers for diseases are present, and at what levels.
3. Medical imaging
Let’s re-visit those medical images your GP ordered. The development of fibre-optic technology, made famous for transforming high-speed digital communications (such as the NBN), allows light to get inside the body. The result? High-resolution optical imaging.
A common example is an endoscope, where fibres with a tiny camera on the end are inserted into the body’s natural openings (such as your mouth or anus) to examine your gut or respiratory tracts.
Surgeons can insert the same technology through tiny cuts to view the inside of the body on a video screen during laparoscopic surgery (also known as keyhole surgery) to diagnose and treat disease.
How about the future?
Progress in nanotechnology and a better understanding of the interactions of light with our tissues are leading to new light-based tools to help diagnose disease. These include:
- nanomaterials (materials on an extremely small scale, many thousands of times smaller than the width of a human hair). These are being used in next-generation sensors and new diagnostic tests
- wearable optical biosensors the size of your fingernail can be included in devices such as watches, contact lenses or finger wraps. These devices allow non-invasive measurements of sweat, tears and saliva, in real time
- AI tools to analyse how blood serum scatters infrared light. This has allowed researchers to build a comprehensive database of scatter patterns to detect any cancer
- a type of non-invasive imaging called optical coherence tomography for more detailed imaging of the eye, heart and skin
- fibre optic technology to deliver a tiny microscope into the body on the tip of a needle.
So the next time you’re at the GP and they perform (or order) some tests, chances are that at least one of those tests depend on light to help diagnose disease.
Matthew Griffith, Associate Professor and ARC Future Fellow and Director, UniSA Microscopy and Microanalysis Facilities, University of South Australia
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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Water-based Lubricant vs Silicon-based Lubricant – Which is Healthier?
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Our Verdict
When comparing water-based lubricant to silicon-based lubricant, we picked the silicon-based.
Why?
First, some real talk about vaginas, because this is something not everyone knows, so let’s briefly cover this before moving onto the differences:
Yes, vaginas are self-lubricating, but a) not always and b) not always sufficiently, especially as we get older. Much like with penile hardness (or lack thereof), there’s a lot of stigma associated with vaginal dryness, and there really needn’t be, because the simple reality is that we don’t live in the fictitious world of porn, and here in the real world, anatomy and physiology can be quite arbitrary at times.
It is this writer’s firm opinion that everyone (or: everyone who is sexual, anyway) should have good quality lube at home—regardless of one’s gender, relationship status, or anything else.
Ok, with that in mind, onwards:
The water-based lube has nine ingredients: water, glycerin, cytopentasioxane, propylene glycol, xantham gum, phenoxyethanol, dimethiconol, triethanolamine, and ethylhexylglycerine.
All of these ingredients are considered body-safe in the doses present, and/but most of them will be absorbed into the skin, especially via the relatively permeable membrane that is the inside of the vagina (or anus—while the microbiome is very different, tissue-wise these are very similar).
While this is not meaningfully toxic, there’s a delicate balance going on in there, and this can upset that balance a little.
Also, because the lube is absorbed into the skin, you’ll then need more, which means either a moment’s inconvenience to add more, or else the risk of chafing, which isn’t fun.
The silicon lube has four ingredients: dimethicone, dimethiconol, cyclomethicone, and tocopheryl acetate.
Note: “tocopheryl acetate” is vitamin E
…which reminds us: just because something is hard to spell, doesn’t mean it’s necessarily bad for us.
What are the other three ingredients, though? They are all silicon compounds, all inert, and all with molecules too big to be absorbed into our skin. Basically they all slide right off, which is entirely the point of lube, after all.
It not being absorbed into our skin is good for our health; it’s also convenient as it means a tiny bit of lube goes a long way.
Any downsides to silicon-based lube?
There are two, and neither are health-related:
- It can damage silicon toys if not cleaned quickly and thoroughly, the silicon of the lube may bond with the silicon of the toy after a while.
- Because it doesn’t just disappear like water-based lube, you might want to put a towel down if you don’t want your bed to be slippy afterwards! The towel can then be put in the laundry as normal.
Want to try it out? Here it is on Amazon
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Air Purifiers & Sleep
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It’s Q&A Day at 10almonds!
Have a question or a request? We love to hear from you!
In cases where we’ve already covered something, we might link to what we wrote before, but will always be happy to revisit any of our topics again in the future too—there’s always more to say!
As ever: if the question/request can be answered briefly, we’ll do it here in our Q&A Thursday edition. If not, we’ll make a main feature of it shortly afterwards!
So, no question/request too big or small
❝I’ve read that air pollution has a negative effect on sleep quality and duration. Since I live next to a busy road, I was wondering whether I should invest in an air purifier. What are 10Almonds’s views?❞
Going straight to the science, there are two questions here:
- Does air pollution negatively affect sleep quality and duration?
- Does the use of an air purify actually improve the air quality in the way(s) necessary to make a difference?
We thought we’d have to tackle these questions separately, but we did find one study that addressed your question directly. It was a small study (n=30 if you believe the abstract; n=29 if you read the paper itself—one person dropped out); the results were modest but clear:
❝The purifier filter was associated with increased total sleep time for an average of 12 min per night, and increased total time in bed for an average of 19 min per night relative to the placebo.
There were several sleep and mood outcomes for which no changes were observed, and time awake after sleep onset was higher for the purifier filter. Air quality was better during the high-efficiency particulate air filter condition.
These findings offer positive indications that environmental interventions that improve air quality can have benefits for sleep outcomes in healthy populations who are not exhibiting clinical sleep disturbances.❞
In the above-linked paper’s introduction, it does establish the deleterious effect of air pollution on a wide variety of health metrics, including sleep, this latter evidenced per Caddick et al. (2018): A review of the environmental parameters necessary for an optimal sleep environment
Now, you may be wondering: is an extra 12 minutes per night worth it?
That’s your choice to make, but we would argue that it is. We can make many choices in our lives that affect our health slightly for the better or the worse. If we make a stack of choices in a particular direction, the effects will also stack, if not outright compound.
So in the case of sleep, it might be (arbitrary numbers for the sake of illustration):
- Get good exercise earlier in the day (+3%)
- Get good food earlier in the day (+2.5%)
- Practice mindfulness/meditation before bed (+2.5%)
- Have a nice dark room (+5%)
- Have fresh bedding (+2.5%)
- Have an air purifier running (+3%)
Now, those numbers are, as we said, arbitrary*, but remember that percentages don’t add up; they compound. So that “+3%” starts being a lot more meaningful than if it were just by itself.
*Confession: the figure of 3% for the air purifier wasn’t entirely arbitrary; it was based on 100(12/405) = 80/27 ≈ 3, wherein the 405 figure was an approximation of the average total time (in minutes) spent sleeping with placebo, based on a peep at their results graph. There are several ways the average could be reasonably calculated, but 6h45 (i.e., 405 minutes) was an approximate average of those reasonable approximate averages.
So, 12 minutes is a 3% improvement on that.
Don’t have an air purifier and want one?
We don’t sell them, but here’s an example on Amazon, for your convenience
Take care!
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Instant Quiz Results, No Email Needed
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❓ Q&A With 10almonds Subscribers!
Q: I like that the quizzes (I’ve done two so far) give immediate results , with no “give us your email to get your results”. Thanks!
A: You’re welcome! That’s one of the factors that influences what things we include here! Our mission statement is “to make health and productivity crazy simple”, and the unwritten part of that is making sure to save your time and energy wherever we reasonably can!
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Why it’s a bad idea to mix alcohol with some medications
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Anyone who has drunk alcohol will be familiar with how easily it can lower your social inhibitions and let you do things you wouldn’t normally do.
But you may not be aware that mixing certain medicines with alcohol can increase the effects and put you at risk.
When you mix alcohol with medicines, whether prescription or over-the-counter, the medicines can increase the effects of the alcohol or the alcohol can increase the side-effects of the drug. Sometimes it can also result in all new side-effects.
How alcohol and medicines interact
The chemicals in your brain maintain a delicate balance between excitation and inhibition. Too much excitation can lead to convulsions. Too much inhibition and you will experience effects like sedation and depression.
Alcohol works by increasing the amount of inhibition in the brain. You might recognise this as a sense of relaxation and a lowering of social inhibitions when you’ve had a couple of alcoholic drinks.
With even more alcohol, you will notice you can’t coordinate your muscles as well, you might slur your speech, become dizzy, forget things that have happened, and even fall asleep.
Alcohol can affect the way a medicine works.
Jonathan Kemper/UnsplashMedications can interact with alcohol to produce different or increased effects. Alcohol can interfere with the way a medicine works in the body, or it can interfere with the way a medicine is absorbed from the stomach. If your medicine has similar side-effects as being drunk, those effects can be compounded.
Not all the side-effects need to be alcohol-like. Mixing alcohol with the ADHD medicine ritalin, for example, can increase the drug’s effect on the heart, increasing your heart rate and the risk of a heart attack.
Combining alcohol with ibuprofen can lead to a higher risk of stomach upsets and stomach bleeds.
Alcohol can increase the break-down of certain medicines, such as opioids, cannabis, seizures, and even ritalin. This can make the medicine less effective. Alcohol can also alter the pathway of how a medicine is broken down, potentially creating toxic chemicals that can cause serious liver complications. This is a particular problem with paracetamol.
At its worst, the consequences of mixing alcohol and medicines can be fatal. Combining a medicine that acts on the brain with alcohol may make driving a car or operating heavy machinery difficult and lead to a serious accident.
Who is at most risk?
The effects of mixing alcohol and medicine are not the same for everyone. Those most at risk of an interaction are older people, women and people with a smaller body size.
Older people do not break down medicines as quickly as younger people, and are often on more than one medication.
Older people also are more sensitive to the effects of medications acting on the brain and will experience more side-effects, such as dizziness and falls.
Smaller and older people are often more affected.
Alfonso Scarpa/UnsplashWomen and people with smaller body size tend to have a higher blood alcohol concentration when they consume the same amount of alcohol as someone larger. This is because there is less water in their bodies that can mix with the alcohol.
What drugs can’t you mix with alcohol?
You’ll know if you can’t take alcohol because there will be a prominent warning on the box. Your pharmacist should also counsel you on your medicine when you pick up your script.
The most common alcohol-interacting prescription medicines are benzodiazepines (for anxiety, insomnia, or seizures), opioids for pain, antidepressants, antipsychotics, and some antibiotics, like metronidazole and tinidazole.
Medicines will carry a warning if you shouldn’t take them with alcohol.
Nial WheateIt’s not just prescription medicines that shouldn’t be mixed with alcohol. Some over-the-counter medicines that you shouldn’t combine with alcohol include medicines for sleeping, travel sickness, cold and flu, allergy, and pain.
Next time you pick up a medicine from your pharmacist or buy one from the local supermarket, check the packaging and ask for advice about whether you can consume alcohol while taking it.
If you do want to drink alcohol while being on medication, discuss it with your doctor or pharmacist first.
Nial Wheate, Associate Professor of the School of Pharmacy, University of Sydney; Jasmine Lee, Pharmacist and PhD Candidate, University of Sydney; Kellie Charles, Associate Professor in Pharmacology, University of Sydney, and Tina Hinton, Associate Professor of Pharmacology, University of Sydney
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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How we treat catchment water to make it safe to drink
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Most of us are fortunate that, when we turn on the tap, clean, safe and high-quality water comes out.
But a senate inquiry into the presence of PFAS or “forever chemicals” is putting the safety of our drinking water back in the spotlight.
Lidia Thorpe, the independent senator leading the inquiry, says Elders in the Aboriginal community of Wreck Bay in New South Wales are “buying bottled water out of their aged care packages” due to concerns about the health impacts of PFAS in their drinking water.
So, how is water deemed safe to drink in Australia? And why does water quality differ in some areas?
Here’s what happens between a water catchment and your tap.
Andriana Syvanych/Shutterstock Human intervention in the water cycle
There is no “new” water on Earth. The water we drink can be up to 4.5 billion years old and is continuously recycled through the hydrological cycle. This transfers water from the ground to the atmosphere through evaporation and back again (for example, through rain).
Humans interfere with this natural cycle by trapping and redirecting water from various sources to use. A lot happens before it reaches your home.
The quality of the water when you turn on the tap depends on a range of factors, including the local geology, what kind of activities happen in catchment areas, and the different treatments used to process it.
Maroondah dam in Healesville, Victoria. doublelee/Shutterstock How do we decide what’s safe?
The Australian Drinking Water Guidelines define what is considered safe, good-quality drinking water.
The guidelines set acceptable water quality values for more than 250 physical, chemical and bacterial contaminants. They take into account any potential health impact of drinking the contaminant over a lifetime as well as aesthetics – the taste and colour of the water.
The guidelines are not mandatory but provide the basis for determining if the quality of water to be supplied to consumers in all parts of Australia is safe to drink. The guidelines undergo rolling revision to ensure they represent the latest scientific evidence.
From water catchment to tap
Australians’ drinking water mainly comes from natural catchments. Sources include surface water, groundwater and seawater (via desalination).
Public access to these areas is typically limited to preserve optimal water quality.
Filtration and purification of water occurs naturally in catchments as it passes through soil, sediments, rocks and vegetation.
But catchment water is subject to further treatment via standard processes that typically focus on:
- removing particulates (for example, soil and sediment)
- filtration (to remove particles and their contaminants)
- disinfection (for example, using chlorine and chloramine to kill bacteria and viruses)
- adding fluoride to prevent tooth decay
- adjusting pH to balance the chemistry of the water and to aid filtration.
This water is delivered to our taps via a reticulated system – a network of underground reservoirs, pipes, pumps and fittings.
In areas where there is no reticulated system, drinking water can also be sourced from rainwater tanks. This means the quality of drinking water can vary.
Sources of contamination can come from roof catchments feeding rainwater tanks as well from the tap due to lead in plumbing fittings and materials.
So, does all water meet these standards?
Some rural and remote areas, especially First Nations communities, rely on poor-quality surface water and groundwater for their drinking water.
Rural and regional water can exceed recommended guidelines for salt, microbial contaminants and trace elements, such as lead, manganese and arsenic.
The federal government and other agencies are trying to address this.
There are many impacts of poor regional water quality. These include its implication in elevated rates of tooth decay in First Nations people. This occurs when access to chilled, sugary drinks is cheaper and easier than access to good quality water.
What about PFAS?
There is also renewed concern about the presence of PFAS or “forever” chemicals in drinking water.
Recent research examining the toxicity of PFAS chemicals along with their presence in some drinking water catchments in Australia and overseas has prompted a recent assessment of water source contamination.
A review by the National Health and Medical Research Council (NHMRC) proposed lowering the limits for four PFAS chemicals in drinking water: PFOA, PFOS, PFHxS and PFBS.
The review used publicly available data and found most drinking water supplies are currently below the proposed new guideline values for PFAS.
However, “hotspots” of PFAS remain where drinking water catchments or other sources (for example, groundwater) have been impacted by activities where PFAS has been used in industrial applications. And some communities have voiced concerns about an association between elevated PFAS levels in their communities and cancer clusters.
While some PFAS has been identified as carcinogenic, it’s not certain that PFAS causes cancer. The link is still being debated.
Importantly, assessment of exposure levels from all sources in the population shows PFAS levels are falling meaning any exposure risk has also reduced over time.
How about removing PFAS from water?
Most sources of drinking water are not associated with industrial contaminants like PFAS. So water sources are generally not subject to expensive treatment processes, like reverse osmosis, that can remove most waterborne pollutants, including PFAS. These treatments are energy-intensive and expensive and based on recent water quality assessments by the NHMRC will not be needed.
While contaminants are everywhere, it is the dose that makes the poison. Ultra-low concentrations of chemicals including PFAS, while not desirable, may not be harmful and total removal is not warranted.
Mark Patrick Taylor, Chief Environmental Scientist, EPA Victoria; Honorary Professor, School of Natural Sciences, Macquarie University; Antti Mikkonen, Principal Health Risk Advisor – Chemicals, EPA Victoria, and PhD graduate, School of Pharmacy and Medical Sciences, University of South Australia, and Minna Saaristo, Research Affiliate in the School of Biological Sciences, Monash University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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Bushfire smoke affects children differently. Here’s how to protect them
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Bushfires are currently burning in Australian states including Victoria, Tasmania, Western Australia and South Australia. In some areas, fire authorities have warned residents about the presence of smoke.
Bushfire smoke is harmful to our health. Tiny particles of ash can lodge deep in the lungs.
Exposure to this type of smoke may worsen existing conditions such as asthma, and induce a range of health effects from irritation of the eyes, nose and throat to changes in the cardiovascular system.
Public health recommendations during smoke events tend to provide general advice, and don’t often include advice specifically geared at children. But children are not just little adults. They are uniquely vulnerable to environmental hazards such as bushfire smoke for a number of reasons.
Different physiology, different behaviour
Children’s lungs are still developing and maturing.
Airways are smaller in children, especially young children, which is associated with greater rates of particle deposition – when particles settle on the surfaces of the airways.
Children also breathe more air per kilogram of body weight compared with adults, and therefore inhale more polluted air relative to their size.
Further, children’s detoxification systems are still developing, so environmental toxins take longer to effectively clear from their bodies.
Meanwhile, children’s behaviour and habits may expose them to more environmental toxins than adults. For example, they tend to do more physical activity and spend more time outdoors. Higher levels of physical activity lead to more air inhaled per kilogram of body weight.
Also, a normal and important part of children’s early play is exploring their environment, including by putting things in their mouth. This can result in kids ingesting soil, dust and dirt, which often contain environmental contaminants.
For these reasons, it’s important to consider the specific needs of children when providing advice on what to do when there’s smoke in the air.
Keeping our environments healthy
The Australian government offers recommendations for minimising the health risks from exposure to bushfire smoke. The main advice includes staying indoors and keeping doors and windows closed.
This is great advice when the smoke is thick outside, but air pollutants may still accumulate inside the home. So it’s important to air your home once the smoke outside starts to clear. Take advantage of wind changes to open up and get air moving out of the house with a cross breeze.
Kids are natural scientists, so get them involved. For example, you and your child can “rate” the air each hour by looking at a landmark outside your home and rating how clearly you can see it. When you notice the haze is reducing, open up the house and clear the air.
Because air pollutants settle onto surfaces in our home and into household dust, an easy way to protect kids during smoky periods is to do a daily dust with a wet cloth and vacuum regularly. This will remove pollutants and reduce ingestion by children as they play. Frequent hand washing helps too.
Healthy bodies and minds
Research exploring the effects of bushfire smoke exposure on children’s health is sparse. However, during smoke events, we do see an increase in hospital visits for asthma, as well as children reporting irritation to their eyes, nose and throat.
If your child has asthma or another medical condition, ensure they take any prescribed medications on a regular schedule to keep their condition well controlled. This will minimise the risk of a sudden worsening of their symptoms with bushfire smoke exposure.
Make sure any action plans for symptom flare-ups are up to date, and ensure you have an adequate supply of in-date medication somewhere easy to locate and access.
Children may be anxious during a bushfire.
Media_Photos/ShutterstockKids can get worried during bushfires, and fire emergencies have been linked with a reduction in children’s mental health. Stories such as the Birdie’s Tree books can help children understand these events do pass and people help one another in times of difficulty.
Learning more about air pollution can help too. Our group has a children’s story explaining how air pollution affects our bodies and what can help.
It’s also important for parents and caregivers not to get too stressed, as children cope better when their parents manage their own anxiety and help their children do the same. Try to strike a balance between being vigilant and staying calm.
What about masks?
N95 masks can protect the wearer from fine particles in bushfire smoke, but their use is a bit complicated when it comes to kids. Most young children won’t be able to fit properly into an N95 mask, or won’t tolerate the tight fit for long periods. Also, their smaller airways make it harder for young children to breathe through a mask.
If you choose to use an N95 mask for your children, it’s best to save them for instances when high-level outdoor exposure is unavoidable, such as if you’re going outside when the smoke is very thick.
N95 masks should be replaced after around four hours or when they become damp.
If your child has an existing heart or lung condition, consult their doctor before having them wear an N95 mask.
Our team is currently recruiting for a study exploring the effects of bushfire smoke in children. If you live in south east Queensland and are interested in participating in the event of a bushfire or hazard reduction burn near your home, please express your interest here.
Dwan Vilcins, Group leader, Environmental Epidemiology, Children’s Health Environment Program, The University of Queensland; Nicholas Osborne, Associate Professor, School of Public Health, The University of Queensland, and Paul D. Robinson, Conjoint Professor in Respiratory and Sleep Medicine, Child Health Research Centre, The University of Queensland
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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