Sunscreen Beach

Research Check: should we be worried that the chemicals from sunscreen can get into our blood? The Conversation

A recent study published in the Journal of the American Medical Association (JAMA) has attracted widespread media attention after it found chemicals contained in sunscreen could get into people’s bloodstreams:

A variety of different chemicals in sunscreen are used to absorb or scatter UV light – both long wavelength (UVA) and short wavelength (UVB) – to protect us from the harmful effects of the Sun.

Read more:
Explainer: how does sunscreen work, what is SPF and can I still tan with it

But while small amounts of these chemicals may enter the bloodsteam, there is no evidence they are harmful. Ultimately, using sunscreen reduces your risk of skin cancer, and this study gives us no reason to stop using it.

Why was the study done?

The US Federal Drug Administration (FDA) recently updated its guidelines on sunscreen safety. The guidelines indicate that if long-term users were likely to have a plasma concentration of greater than 0.5 nanograms per millilitre of blood, further safety studies would need to be undertaken.

This level is just a trigger for investigation; it does not indicate whether the chemical has any actual toxic effect.

The JAMA study was done to determine whether commonly used sunscreen compounds exceeded these limits, which would indicate that further safety studies were required under the new guidelines.

So what did the study do?

The study looked at the absorption of some common organic sunscreen ingredients (avobenzone, oxybenzone, octocrylene, and ecamsule), in 24 healthy participants after they applied four commercially available sunscreen formulations.

Each formulation contained three of the four organic sunscreen ingredients listed above. The concentrations of each individual compound were typical of commercial sunscreens and well within the permitted levels. For example, they all contained 3% avobenzone, and the maximum permitted concentration is 5%.

The researchers split the participants into four groups: two groups used a spray, one used cream, and the other used a lotion. The participants applied their assigned product to 75% of their body four times a day, for four days.

The researchers then examined the absorption of these compounds by measuring participants’ blood over seven days using highly sensitive tests.

What did they find?

In all subjects, the blood levels of the sunscreen chemicals rapidly rose above the FDA guidance levels regardless of the sunscreen formulation (spray, lotion or cream).

The levels remained above the FDA guidance levels for at least two days.

But the conditions of the test were extreme. Some 75% of body surface was covered, and the sunscreen was reapplied every two hours and under conditions where the compounds were unlikely to be broken down or removed (for example by swimming or sweating).

Sunscreen comes off in the water | PHOTO: © Xolodan/Shutterstock

This was deliberately a test of a worst-case scenario, as mandated by FDA guidelines to determine whether safety testing was needed.

Of course, going above the FDA guidance levels does not indicate there is a risk; only that evaluation is required.

What about in Australia?

Australia’s FDA-equivalent body uses the European Union’s “non-clinical” guidelines to evaluate sunscreens and ensure they are safe to use.

The EU guidelines are based on several studies which show the components of sunscreens are not poisonous or harmful to human health.

Looking specifically at the chemical avobenzone, the safety studies show no toxic effect or potential harm to human health, aside from a small risk of skin sensitivity.

The level of avobenzone reported in the blood after regularly applying sunscreen, (around 4 nanograms per millilitre) is around 1,000 times lower than the threshold levels for harm to skin cells. And the safety studies report no increased risk for cancer.

European researchers have also investigated whether the chemicals in sunscreens can mimic the effects of the female sex hormone estrogen. They found the levels would have to be 100 times higher than are absorbed during normal sunscreen use to have any effect.

The bottom line

This study found that under a worst case scenario, blood levels of organic sunscreen chemicals exceeded the FDA guidance threshold. Under more realistic use the levels will be even lower.

But even under this worst case scenario, the levels are at least 100 times below the European Union’s safety threshold.

Given the known safety margins and the proven ability of sunscreen to prevent skin cancer, there is no reason to avoid or reduce your sunscreen use. – Ian Musgrave

Blind peer review

The research check is a fair and reasonable summary and interpretation of the JAMA paper on the absorption of active sunscreen ingredients.

It is worth noting that the reference to “extreme” conditions in which the research was conducted is correct, however, in terms of dose, it does align with the recommended level of use of sunscreen. That is, reapply every two hours and use 2mg per 1cm₂. A single “dose” is recommended at 5ml for each arm, leg, front torso, back and head and face, or 7 x 5 = 35ml.

Four such doses suggest each subject would have applied 140ml of sunscreen each day; more than a full 110ml tube, which is a common package size for sunscreen in Australia. This is extremely unlikely to occur. Most people use half or less of the recommended dose per application, and few reapply. Even fewer do so four times in a day. – Terry Slevin

Read more:
There’s insufficient evidence your sunscreen harms cora

Research Checks interrogate newly published studies and how they’re reported in the media. The analysis is undertaken by one or more academics not involved with the study, and reviewed by another, to make sure it’s accurate.

WRITTEN BY: Ian Musgrave, Senior lecturer in Pharmacology, University of Adelaide

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The Conversation

Wine Cheers

Health check: is moderate drinking good for me?

Hassan Vally, La Trobe University

For the past three decades or so, the conventional wisdom has been that drinking alcohol at moderate levels is good for us.

The evidence for this has come from many studies that have suggested the death rate for moderate drinkers is lower than that for non-drinkers. In other words, we thought moderate drinkers lived longer than those who didn’t drink at all.

This phenomenon has been communicated with great impact by the J-shaped curve that shows death rates fall as you move from non-drinking to moderate drinking, before rising again as drinking levels increase.



Most of us embraced these studies with enthusiasm. But the findings were probably too good to be true. The problem has always been the potential mixing of many other variables – called confounding factors – with drinking.

The concern was that non-drinkers as a group in many of these previous studies were different to moderate drinkers in many ways in addition to their drinking. Non-drinkers may have been unhealthier to begin with (hence not taking up drinking in the first place) or they may have included recovering alcoholics with poor health.

These confounding factors may have made moderate drinkers look healthier than they actually were (relative to non-drinkers) and thus have led us to associate moderate drinking with better health.

More recent studies have been able to address this challenge of separating out the effect of drinking on health, independent of other confounding factors. And these newer studies tell us moderate drinking is probably not good for us at all.

Instead of the J-shaped curve described previously, the most recent evidence is showing a curve that continues on an upward trajectory.


As you increase your level of drinking beyond not drinking at all, for all levels of drinking, your health outcomes worsen. The curve starts off relatively flat, before rising dramatically, indicating much higher rates of early death as drinking levels increase.

So what is the health cost of moderate drinking?

If we look at a recent Lancet study that addressed this issue, we can start to make sense of this cost. This suggests that if you drink one alcoholic drink per day you have a 0.5% higher risk of developing one of 23 alcohol-related health conditions.

But risk expressed in this way is difficult to interpret. It’s only when we convert this to an absolute risk that we can begin to understand the actual magnitude of this risk to our health. It translates to four more deaths per 100,000 people due to alcohol, which is actually a pretty small risk (but an increased risk nonetheless).

This risk estimation assumes several things, including that you drink alcohol every single day, so you would expect the risk to be smaller for those who drink every other day or only occasionally.

The latest evidence suggests the health cost of light to moderate drinking, if there is one, is quite small. What was previously thought to be a marginal benefit of moderate alcohol drinking is now considered a marginal cost to health.

So for you as an individual, what does this new evidence mean?

Maybe it means having to lose the contentedness you have felt as you drink your evening glass of wine, believing it was also improving your health.

Or maybe this new evidence will give you the motivation to reduce your drinking, even if you are only a moderate drinker.

Of course, if you get pleasure from drinking responsibly, and you have no intention of changing your drinking habits, then you will have to consider and accept this potential cost to your health.

But remember, the evidence is still incontrovertible that drinking high levels
of alcohol is very bad for you. It will shorten the length of your life and affect the quality of your life and those around you.The Conversation

Hassan Vally, Senior Lecturer in Epidemiology, La Trobe University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

BACK TO SCHOOL: Here’s how to keep kids free of head lice

A new school year, and another battle between bloodsucking parasites and the kids they love to live on.

But the real casualties are the stressed-out parents and carers trying to keep their kids free of lice.

Here are some tips for delaying the inevitably tricky task of lice treatment for as long as possible.

Remind me, what are head lice?

Head lice (Pediculus capitis) are insects found almost exclusively in the hair on human heads. These parasites aren’t found anywhere else on the planet.

They’re perfectly designed to scuttle up and down strands of hair, feeding on blood from the scalp of those infested. They typically feed about three times a day, spending up to 15 minutes on each occasion.

While their bites may cause some mild irritation, lice don’t spread bugs that make us sick.

Head lice don’t live long – not much more than a month. The adults lay eggs (commonly known as nits), which typically hatch in around a week or so. This life cycle is simple, but crucial for identifying and eradicating infestations.

PHOTO: © Blamb /

You want to remove the adult lice, then treat again two weeks later to get rid of the newly hatched lice before they have a chance to lay more eggs.

The eggs are immovably cemented to shafts of hair. These eggs, even when the lice have hatched, will remain and grow out with the hair strands.

This means that spotting nits more than a centimetre or so from the scalp may not require treatment at all.

Instead, look for the live lice moving about. This is the most reliable way to confirm an infestation. Use a special lice comb from the local pharmacy to make the search easier.

How do children become infested?

Head lice don’t jump or fly or swim. They move from head to head through direct contact as the strands of hair from two people make contact, creating a bridge for adventurous lice to a new world.

But lice can be fussy, with one study showing hairs need to be specifically aligned to allow the parasites to skip from one strand to another.

This is why transmission of lice from one person to another doesn’t happen as readily as urban myths suggest.

Sharing hats, towels, or pillows won’t dramatically increase the chance of picking up head lice. They’re not going to crawl across the classroom floor either.

Direct head-to-head contact is the best way to share an infestation, so keep an eye out for kids crowded around smartphones and tablets.

Lice don’t necessarily have a particular predilection for clean or dirty hair. Short hair isn’t immune from infestation, but long hair means the chances of picking up lice are greater.

Ensuring hair is neatly pulled back will dramatically reduce the risk of picking up head lice.

Are head lice really a problem in Australia?

Head lice are a problem the world over. But they are more of a nuisance than a health risk in most instances.

Research suggests around one-third of Australian primary school-aged children could currently have head lice. With more than 2.1 million primary school students in Australia, that’s about 700,000 potentially infested children.

The thought of head lice may be actually worse than the itchiness resulting from an actual infestation. The Australian Academy of Science provides an entertaining breakdown of why this maligned parasites cause so much stress.

It’s more difficult to control head lice than in the past. International studies indicate lice are becoming resistant to commonly used insecticide treatments. This is also likely to be a problem in Australia but more research is needed to better understand the situation here.

Alternatives to traditional insecticides, such as botanical extracts, may be more useful in the future.

Most health authorities in Australia recommend avoiding insecticides, and instead suggest wetting the hair (or using conditioner) and then combing the lice out.

Essential to eradicating head lice infestations is two treatments, each about a week apart. This ensures adult lice are killed, then any eggs remaining are allowed to hatch but those newly hatched lice are killed by the second treatment before they have an opportunity to lay more eggs.

I’m itchy already!

Perhaps the biggest health issue associated with head lice is the stress and anxiety for parents and carers of infested children.

Even before a single louse is even spotted, finding a note from the school warning of a “lice outbreak” could be enough to trigger frantic head scratching! There is even a term for this: psychosomatic itching.

Unfortunately, there are no quick fixes for getting rid of lice. And no matter what social media claims, using mayonnaise, hair straighteners or household cleaning products) is a bad idea.

The most important thing to remember is lice aren’t going to cause health problems, nor are they indicators of poor household hygiene or quality of care.

Cameron Webb, Clinical Lecturer and Principal Hospital Scientist, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

How to opt out of My Health Record

If you don’t want a record created for you the deadline to opt out is fast approaching.

After midnight tonight, a My Health Record will be created for every Australian.

To complete the online opt-out process for either yourself or your dependents under 18 (listed on your Medicare card) as a minimum, you will need your Medicare card and driver licence (or other identification).

If you need to opt-out of a My Health Record for someone over 18 who is dependent on you, additional documentation is required and you may need to contact the My Health Record Helpline on 1800 723 471.

The following video steps through the process;

Once you have completed the opt-out process, you cannot cancel your request however if you change your mind down the track, and would like to create a My Health Record you can re-register any time.

For more information visit the My Health Record website or phone the 24/7 helpline on 1800 723 471.


Here’s to presence rather than presents

While most people appear to be whizzing around trying to make a dent in their Christmas shopping list, I’ve been reading about the psychology of Christmas.

Start digging and you’ll find lots of studies showing that lower emotional wellbeing is common at Christmas.

When did society declare that Christmas should become so stressful?

Considering it’s meant to be ‘the most wonderful time of the year’, it certainly has its trying moments, doesn’t it?

Perhaps this is a good time to remember that presence is more important than presents. By that I mean, choosing to spend time with those you cherish and really being mindful to be in the room.
Not thinking about how much you have to do, or which presents you haven’t bought yet but really enjoying moments of quality time.

This is so much more important than dragging yourself to every single social outing just because you feel you should or spending far too much on gifts you can’t really afford.

If you switch on the TV, ads will pretend that everyone else is playing happy families and filling the fridge with enough food to feed 5000. It’s all so over the top and unrealistic.

In reality, it’s a tough time of year for many.

It’s a time when feelings of nostalgia and isolation can be overwhelming. Many feel lonely at Christmas and it’s important to remember that not everyone will spend it surrounded by family they love. There are alienated parents right across the country (and the world) that will be carrying a heavy sense of loss at this time of year especially.

So, this is a really important time of year for self-care.

Setting boundaries is crucial and saying ‘no’ is essential.

It is perfectly wise to make time for yourself rather than cramming your diary full just for the sake of it.

Take time to do things you genuinely enjoy and make the time to feel grateful for what you do have.

Also, you don’t have to completely abandon your health because it’s Christmas, it’s perfectly acceptable to take care of yourself. Eating well and getting plenty of sleep will ensure you come out into the New Year without feeling like a shadow of your former self.

Importantly, don’t fall for the hype and don’t get overwhelmed – keep this Christmas in perspective!