Sunscreen Safety and Oxybenzone

Is oxybenzone in sunscreen safe? From Squintmom/Beautiful EntropyI love getting questions about science-related issues from readers. I particularly love it when a question intersects with an issue I myself am curious about, as happened when a reader got in touch with me last week:

I need some advice about sunscreen. I just read some articles on CNN about new FDA guidelines and the Environmental Working Group’s 2012 sunscreen review. Of particular concern is oxybenzone. The FDA claims it’s safe and very effective at protecting against UVA and UVB rays. However, the EWG says that oxybenzone is carcinogenic. Hmm… use sunscreen to prevent skin cancer, but sunscreen causes… skin cancer? That seems like a big time conundrum to me. The other thing I wonder about is who is the EWG? All I really know is they came up with the “Dirty Dozen” foods you should always buy organic. So what’s the deal? Should I toss all of last year’s sunscreen with oxybenzone and buy new? Is the EWG generally a trustworthy, “non-woo” authority?

The oxybenzone molecule

Let’s start with my professional opinions of the Food and Drug Administration (FDA) and of the Environmental Working Group (EWG). The FDA is routinely accused by consumer groups and conspiracy theorists of being “in bed with Big Pharma,” engaging in cover-up operations, putting profit ahead of consumer health, and so forth. I really don’t agree with this take on the organization, as I discuss in this post. The FDA’s history in the US is one of a largely appropriate trajectory. They’re a behemoth organization, and as such, they move slowly. They’re slow to approve new drugs because they insist on rigorous testing; this is one of the things that pisses off consumers who want to see new drugs come to market quickly. They’re relatively quick to warn consumers if there’s evidence that a pharmaceutical or substance is harmful, though they’re not alarmist and rarely respond to the results of an isolated study. The FDA is, to put it simply, stuck performing an impossible balancing act: they’re under public pressure to approve substances quickly, while they’re simultaneously under public pressure to keep anything that could potentially be harmful off the market. These missions are mutually exclusive, and I have to say that for the most part, the FDA handles their task as elegantly as a behemoth government organization can do. Have they made mistakes? Absolutely. But what I appreciate about the FDA is that they correct over time, such that their trajectory is generally appropriate and stable.

The EWG, on the other hand, is far more alarmist than the FDA. They’re not a government organization, but are rather a research and lobbying group made up of citizens and scientists. A survey of toxicologists (unaffiliated with the organizations about which they were questioned) revealed that most felt the EWG overstates risks associated with products. Specifically, toxicologists gave the EWG an accuracy score of 4.2 (1 = significantly understates risks, 3 = accurately states risks, 5 = significantly overstates risks). By comparison, the FDA got a 3 from the toxicologists, indicating that they felt the organization was accurate in assessing and reporting risks. For those who are curious, the U.S. Centers for Disease Control and Prevention (CDC) and the American Medical Association (AMA) also scored near 3, reflecting accurate portrayal of risks, while Greenpeace got a 4.5 — the highest score given — for significant overstating of risks. The Pharmaceutical Research and Manufacturers of America (PhRMA), on the other hand, scored a 2.3 for being the most significant understater of risks. Note that PhRMA is not a government organization, and is not tied to the FDA, the CDC, or other government health regulators.

As far as the EWG goes, I think they have their place. They report on research, but often issue warnings on the basis of single studies or studies with limited applicability. Case in point, they warn consumers against sunscreen containing retinyl palmitate (vitamin A) on the basis of a 2009 study that looked at mice rubbed with the chemical and exposed to light. The vitamin A mice developed more tumors, leading the EWG to report a link between retinyl palmitate in sunscreen and cancer. However, there are significant issues that limit the study’s applicability. Most notably, sunscreen only ever contains a small amount of retinyl palmitate. Dose is very important in toxicology; any substance — even water — is toxic in sufficient quantity. As such, a pure retinyl palmitate rub applied to mice doesn’t provide information about the toxicity of small amounts of the compound in sunscreen. In the end, groups like the EWG help to promote research on issues pertaining to toxicology and public safety, but speaking for myself, I look for corroborating research or concern from more moderate institutions before acting on an EWG warning. In response to the question from the start of this post, I think we can safely say that the EWG is “non-woo,” but they are a little jumpy.

On to sunscreen safety. First and foremost, there’s a major risk-to-benefit analysis that one must conduct when determining whether to use sunscreen and what type to use. This is because the sun emits ultraviolet radiation (UV) that damages cells, leading to development of wrinkles, aging of tissues, and skin cancer. Sunburns are an indication of particularly severe cellular damage — just one or two sunburns before the age of 18 significantly increases risk of skin cancer later in life — but even a so-called “healthy” tan is a sign that damage has occurred. Sunscreen is a part of protecting the skin from sun damage, but it’s not the entire equation. In fact, staying out of the sun during intense radiation hours (midday) and using physical protection such as clothing, sunglasses, and hats provides the best protection from harmful UV radiation. No sunscreen provides complete protection. To this end, one of the new FDA regulations regarding sunscreen labeling is that sunscreens will no longer be allowed to refer to themselves as “sunblock,” on the grounds that this inappropriately overstates protection. While there’s been some muttering by the EWG and other groups about whether sunscreen truly helps to prevent skin cancer, these concerns are largely based upon use of sunscreens that protect from only one type of UV radiation (broad-spectrum sunscreens are best, but not all sunscreens are broad-spectrum) and inappropriate use of or reliance on sunscreen. The general consensus among medical and government organizations, including the CDC and the AMA, is that sunscreen is an important component of safe-sun behavior.

The active ingredients of a barrier sunscreen.

There are two major classes of sunscreens: barrier sunscreens containing minerals (like zinc oxide and titanium dioxide) that reflect light, and chemical sunscreens that absorb the light and prevent it from penetrating cells. There is essentially no risk of absorbing the barrier compounds through the skin, leading even the EWG to note that these sunscreens are likely the safest and most effective. In times past, barrier sunscreens were unpopular because they had a greasy white appearance on the skin (remember Zinka from the 80s?). Newer technology allows for smaller particles (nanoparticles) of barrier compounds, which are less visible on the skin, though some formulations may still be greasy. There’s also some question as to whether these nanoparticle formulations appropriately protect from UVA, one of the types of UV (UVB is the other type). Unfortunately, while the sunlight reaching Earth is made up of mostly UVA, the SPF rating on sunscreen applies to UVB protection only. The new FDA regulations propose a set of standards for reporting UVA protection, as UVA exposure also leads to skin cancer. With regard to barrier sunscreens, then, the most effective UV protection comes from the old-school stuff: greasy, white, and slathered on thick. The next most effective UV protection comes from a nanoparticle formulation combined with a chemical sunscreen containing oxybenzone or similar for enhanced UVA protection. Of course, protection from UV is only part of the equation when it comes to assessing sunscreen safety; the other part is the safety of the sunscreen ingredients themselves.

The active ingredients of a chemical sunscreen.

Oxybenzone is currently raising hackles at the EWG, and is one of the reasons that their Sunscreens 2012 report contains so few “approved” choices. The compound occurs in nature — it’s in flower pigments — and is incredibly common in personal care products. It’s not only a sunscreen, it’s also a fragrance enhancer, preservative, flavor enhancer, and so on. The CDC reports that a recent random sample of Americans revealed oxybenzone in 97% of urine samples (Calafat et al). However, the significance of this information has not yet been determined. The EWG calls oxybenzone a “potential hormone disruptor,” citing the European Commission on Endocrine Disruption (pdf) (ECED), which basically means that the EWG is saying they don’t like oxybenzone on the grounds that the ECED doesn’t like oxybenzone. As to why the ECED takes issue with it, they (like the EWG) are exceedingly cautious. The EWG cites two studies (Ma et al,* Ziolkowska et al) that show the potential for weak endocrine disruption. {Note that the Ma et al reference is incomplete on the EWG website, and I was able to find no evidence of it in the scientific literature}. The extent to which the results of these studies, conducted on cells with pure oxybenzone compound, are relevant to use of the compound in sunscreen are unknown. As the American Cancer Society points out:

Virtually all substances known to cause cancer in humans also cause cancer in lab animals. But the reverse is not always true – not every substance that causes cancer in lab animals causes cancer in people. There are different reasons for this.

First, most lab studies of potential carcinogens (cancer-causing substances) expose animals to doses that are much higher than common human exposures. This is so that cancer risk can be detected in relatively small groups of animals. But doses are very important when talking about toxicity. For example, taking a couple of aspirin may help with your headache, but taking a whole bottle could put you in serious trouble. It’s not always clear that the effects seen with very high doses of a substance would also be seen with much lower doses.

Second, there may be other differences between the way substances are tested in the lab and the way they would be used, such as the route of exposure. For example, applying a substance to the skin is likely to result in much less absorption of the substance into the body than would be seen if the same substance is swallowed, inhaled, or injected into the blood. The duration and dose of the exposure also help determine the degree of risk.

While the above refers to cancer risk, the same is true of other toxic effects of compounds that are revealed through laboratory and animal studies. With specific regard to cancer and oxybenzone, even the cautious EWG notes that there’s no evidence that oxybenzone is carcinogenic — or, more accurately, THERE IS evidence that oxybenzone IS NOT carcinogenic (non-mutagenic in 4 of 4 studies: CTFA, 1980; DHEW, 1978; Hill Top Research Labs, 1979; Litton Bioneics, 1979).

Taking all the information together and conducting a risk-to-benefit analysis, I think it’s fair to say that because of the limited data available and the availability of alternatives to oxybenzone, it may be worth avoiding it in sunscreen, but there’s no reason to get particularly excited about previous use or occasional future use. Given that it’s present in almost all chemical (non-barrier) sunscreens, this essentially leaves the barrier sunscreens containing zinc oxide and titanium dioxide. If one chooses to use the nanoparticle formulations with somewhat reduced UVA protection, one must then decide whether to use a chemical sunscreen for additional protection — but this once again leads to oxybenzone exposure.

One last thing: with regard to old sunscreen, if in doubt, throw it out. The CDC recommends that sunscreen be no more than three years old if there’s no expiration date on the bottle. If the bottle has an expiration date, abide by it. The protective chemicals in sunscreen break down over time, meaning that protection wanes.

Science Bottom Line:* Given that there is no sunscreen that provides complete protection, the evidence suggests that the safest choice (particularly for children) is the use of zinc oxide or titanium dioxide sunscreen (I prefer nanoparticle formulations for convenience and aesthetics), without a chemical sunscreen backup. This should be augmented through the judicious use of shade, clothing, sunglasses, and hats, particularly during the most intense periods of sunlight.


How do you protect your family’s skin outdoors?



Calafat et al. Concentrations of the sunscreen agent benzophenone-3 in residents of the United States: National Health and Nutrition Examination Survey 2003–2004. Environ Health Perspect. 2008 Jul;116(7):893-7.

Ziolkowska et al. Endocrine disruptors and rat adrenocortical function: studies on freshly dispersed and cultured cells. Int J Mol Med. 2006 Dec;18(6):1165-8.


The No-Measure, No-Sew, No-Sweat Tutu

No-measure, no-sew EASY tutu tutorial (tututorial!!) by Beautiful Entropy

I’ve been obsessed with Pinterest all week (it’s kept me sane while I’ve held the couch down post-surgery), and it’s had me DYING to do some crafts. Today I saw my orthopedic surgeon, who gave me the go-ahead to use my arm a little bit (and he was careful to qualify that statement so thoroughly that he nearly retracted it entirely). I decided to make a tutu for W, who has been so sweet and understanding of me during my convalescence that I wanted to give her a present. However, I didn’t want to:

  1. Drag my sewing machine out of its current hibernating place, to which it retreats when I have guests staying in the guestroom.
  2. Measure anything (hey, feeling crafty doesn’t necessarily mean I’m not feeling lazy).
  3. Make anything I could possibly screw up.

There were a few “no-sew” tutu tutorials I found online, but most of them were *mostly* no-sew (which is to say, I would have had to sew the waistband. Didn’t want to.) In the end, I drew inspiration from these tutorials, but went it alone where it came to the waistband. I also took some chances that worked out well in terms of doing the whole thing without the assistance of a tape measure. The other cool thing about the way I made the tutu is that it has about 3″ of potential for letting-out in the waist, which means it will fit for a longer period of time. I’m so happy with the way the tutu turned out that I wanted to share the project. I figure if I can make this thing with one-and-a-half arms while I’m hopped up on pain pills, anyone working with a full deck and two hands should be able to whip it out in no time! More

Easy DIY Toys — “Tickle Monster” Sensory Ball

tickle featured

“Tickle monster” soft sensory balls are deceptively easy and fast to make, and kids love them. They’re squeezable, lovable, throwable, catchable, and just generally fun. Best thing about them is that they’re easy to do even if you’re just learning to knit or crochet. Because they’re felted, dropped stitches don’t matter, you can be as lazy as you like, you can take shortcuts galore…and they basically come out looking perfect no matter what! Don’t knit? It’s really easy to learn, and there are tons on instructive online videos and websites (that’s how I learned!).


  • 1 skein of cheap wool, any brand (yes, it MUST be wool; otherwise, it won’t felt). It should be medium weight (worsted) for best results. You can use any color; I used black to really allow the colors of the textured yarn to pop.
  • 1 skein textured yarn. Craft stores like Joann have lots of options, as do online stores like Yarn Market. The texture you use will determine the look and feel of the tickle monster.
  • Large knitting needles (maybe a 10) or a big crochet hook (maybe an M). It doesn’t really matter what size you use, but working with the textured yarn (especially popcorn) will be much easier with a larger set of needles or hook. One great thing about the tickle monsters is you can just eyeball everything; no measuring, no stitch counting, no patterns. The smaller your needles/hook and the tighter your work, the less your fabric will shrink when you felt it, though, so keep that in mind. More

Essential Baby And Toddler Products

I’m recovering from last week’s shoulder surgery, which basically means I’ve been spending a lot of time holding the couch down and exploring the Interwebs. I’ve become addicted to Pinterest (want to follow me?), and have been madly collecting craft, DIY, and repurposing ideas for when I have the use of both hands again. Browsing through the baby- and kid-related boards on Pinterest got me thinking about baby products — both the ones I purchased pre-baby and the ones I actually use. The intersection of these sets is approximately zero, which is Geek for the things I bought originally are not the things I ended up using. If I could go back in time and give my pregnant self a shopping list, this is what would be on it:


How does one small person take up so much bed!?

A King Bed

Pregnant me picked out a beautiful crib, which my husband and my dad set up in the future nursery. My mother lovingly rubbed a fresh coat of wood conditioner on the cradle my grandmother had hand-carved for my mom when she was pregnant with me, and we put it in our bedroom near our bed. The plan was that Lil’ Bit (our gender-neutral name for the baby whose sex we’d decided to leave a surprise) would sleep in the cradle during the early weeks, and then we’d transition to her crib. Ha. W had different ideas, and within days, I (who had never even considered the idea of co-sleeping) found myself curled into a protective “C” shape around my daughter, who spent her nights blissfully alternating between sleeping and nursing. As W grew — and more to the point, as she became capable of some maneuvering – my husband and I increasingly found ourselves clinging to the edges of our queen-sized bed as W’s preferred sleeping position became increasingly sprawling. We finally gave up, sold the crib, sold our queen mattress, and bought a king. Should have saved myself the trouble and done it from the start; it’s SO much more comfortable. These days, my husband and I each get a good 18 inches or so of mattress, and W sleeps right in the middle, doing a fair impression of a starfish.


Comfortable Rocker/Recliner

Not only is it useful for nursing and rocking, it’s also comfortable enough for me to sleep in. This comes in handy when W is sick (especially if it’s respiratory), because she can lie tummy-to-tummy with me, which keeps her propped up and eases her breathing. We’ve spent many nights in this chair.



Ok, technically, I purchased gDiapers — a hybrid cloth diaper — before W was born. However, when she was about 7 months old, I got it into my head that there were better cloth diapers out there, sold all the g’s, and tried a bunch of other brands. To each her own, but I ended up exactly where I started, and am now convinced that g’s are the easiest and most convenient cloth out there. I love that I don’t have to wash the entire diaper after each change (for pee diapers, I just replace the absorbent pad), the colors and patterns are adorable, and gDiapers sells flushable, compostable, sustainably-sourced absorbent inserts as an alternative to cloth inserts. This flexibility is perfect for us; we use cloth inserts at home, and disposable inserts when we travel. Because the inserts are 100% compostable, we can actually bury them cat-hole style when we’re out camping, and don’t have to carry out a bunch of heavy, soiled diapers.



It took me a lot of trial and error (and a lot of bought and re-sold carriers) to find the perfect one. I love, love, LOVE my ERGObaby. I purchased a Baby Bjorn before W was born, but returned it when I read that some health practitioners and groups (including the International Hip Dysplasia Institute) worry about baby carriers that allow the legs to dangle. When she was about a month old, I bought an Ergo and started carrying W in it while I did chores around the house or walked for fitness. I’ll admit that the infant insert (mandatory for babies under about 15 pounds) isn’t completely awesome, but once a baby is big enough to ride insert-free in the Ergo, it can’t be beat. I also love that the weight goes on my hips rather than my shoulders. I don’t know how we would have survived the early months of W’s nighttime sobbing without the Ergo and an iPod full of Paul Simon and Tom Petty (her favorites in those days); I’d sway and sing to her, and she’d eventually fall asleep against my chest. These days, we don’t use the Ergo much, but it’s still great for craft fairs and so forth where there’s a lot of walking to be done. Also, if she’s sick or very fussy and wants to be carried all day, it gives me a comfortable, hands-free option.



Chariot CX

The Chariot CX is, quite simply, the Worlds. Best. Running. Stroller. I did a complete review of it for Trail and Ultra Running, but in short, it’s easy to use and comfortable for W. It also converts into a bike trailer, regular stroller, and — believe it or not — trailer for cross-country skiing! We use it every day.




A High-Quality Humidifier

Upper respiratory infections are hard on babies and their parents. When W is stuffed up and coughing, she doesn’t sleep — and therefore, neither do I. Sitting with her in the rocker/recliner helps, as does holding her in a steaming shower. Running a humidifier with some eucalyptus and thyme essential oil in it (or this vapor oil from Northern Essence) really helps, though. The essential oils seem to help open the airways, and the mist decreases swelling of the respiratory membranes and loosens secretions. I prefer cool mist to hot, simply because it reduces the risk of an accidental burn.


Aveeno Baby Eczema Therapy

Newborn W had real trouble with eczema. The first pediatrician we took her to told us not to use lotion on her. The doctor’s “logic,” if you want to call it that, was that lotion-free skin would begin to produce its own moisture. Well, we live in Arizona, and the humidity here often runs in the low single-digit percents. The dry skin coupled with some early antibiotics she had to take produced a wicked case of eczema (antibiotics kill helpful bacteria as well as the bad ones, which can sometimes cause eczema in sensitive individual). I eventually found Aveeno Baby Eczema Therapy, which works wonders as long as we use it regularly.


Northern Essence Diaper Rash Salve

Because we use cloth diapers, we have to be careful about diaper creams. Most contain zinc oxide and a petroleum base. The zinc oxide stains cloth diapers, and the petroleum base can coat the cloth and make it repel moisture, which leads to leaks. Northern Essence makes an awesome, developed-for-cloth diaper salve. It’s gentle on W’s skin and doesn’t damage her diapers at all. Despite having somewhat rash-prone skin, she’s never once had a diaper rash, which is as good a product recommendation as any! Northern Essence also makes awesome gentle baby wash and detangler, and the coolest thing about them is that you can pick from hundreds of scents (many of which are essential oils). I love the Sleepytime essential oil (lavender and vanilla), and W loves “Monkey Farts,” which is sort of tropical.


Nose Frida

I tried a couple different nasal aspirator bulbs in the early days of motherhood, but gave up on them quickly. They never seemed to work, and they terrified W. A few months ago when she had a really bad cold, a friend told me about the Nose Frida, which is basically a mom-powered nose-sucker. It’s smaller and less intimidating to W than an aspirator bulb was, and I love that I control the power and duration of the suction. She doesn’t seem to mind it, either. Squeamish moms, rest assured: the tube is long enough that you will NEVER get snot in your mouth, and there’s a sponge filter that prevents any material from entering the tubing. Another benefit of the Nose Frida over a nasal bulb is that it comes apart for easy cleaning.


**This is a completely unpaid post. None of these brands sent me a stroller, diapers, a baby carrier, or anything like that, and I wrote all this good stuff about the products because I just love them so freakin’ much. But if you’re from Chariot (or Ergo, or gDiapers, etc)  and you’re reading this and are super impressed and grateful and want to send me money? Let’s talk!


What were/are your “can’t live without them” items?


My Surgery Is Tomorrow, and I’m Scared!

This will be me around noon tomorrow. Photo from Wikimedia Commons.

My shoulder surgery is tomorrow. I have been pretty calm all week. In fact, I’ve been looking forward to the surgery, for two reasons. First, because it’ll finally fix my shoulder, which aches all the time, and that will be nice. Second, because while I’ll be in more pain for a few weeks post-surgery than I’m in now, I’ll be on drugs, so I’ll probably be more comfortable than I am now. Yes, I’ve been calm all week. But as of this morning, I am Freaking. Out.

I woke up feeling very energetic, but I realized pretty quickly that I wasn’t myself when, before I’d even finished my first cup of coffee, I started dusting the whole house. That turned into cleaning the bathrooms, which turned into cleaning the floors. My house hasn’t been this clean since the week before I went into labor. The cleaning hurts my shoulder, but I didn’t notice it while I was running around in a frenzied manner. Now that I’m forced to sit still (W is napping, and I am keeping her company), my mind is racing and my shoulder aches. I’m face to face with the fact that no, it’s not just that I wanted a really clean house to come home to — it’s that I’m scared shitless.

Where’s your damn science now, the snarky part of my brain asks in a taunting way. You know you aren’t going to DIE in there, you idiot. The snarky part of my brain can be really mean. But it’s right. My odds of dying under general anesthesia are hard to calculate, because most of the statistics out there include those who are ill before surgery, in general poor health, undergoing emergent procedures (which are riskier) or elderly. Still, for all surgical procedures, the risk of death as a result of anesthesia is between 0.01 and 0.016% (Arbous et al, Lienhart et al), with the risk for healthy individuals having non-emergent procedures closer to 0.0004%. For the sake of comparison, I am almost 40 times more likely to die in a car accident (odds of 1 in 6700, or 0.015%) than on the surgical table. I know this intellectually, and yet I am still scared. This is at least partly because humans are absolutely terrible at assessing risk accurately.

It occurred to me the other day that I am not actually scared of dying on the table. How do I know this? Because if W were the one going for surgery (heaven forbid), I would feel sorry for her, and I would wish to be in her place…but I would not be afraid she was going to die. By extension, the logical part of my brain explains to me, you are not actually scared you’re going to DIE. You’re scared of being out of control. You’re a control freak. A neurotic, obsessive control freak. Ok, that last bit might have been the snarky part, rather than the logical part. Still, I think there’s something to this. I am not scared I won’t wake up. I’m scared of feeling myself going under.

The Adequate Mother, who is an anesthesiologist, wrote a very helpful post about what to expect when you’re anesthetized (thank you!). Between that and watching videos of the procedure I’m going to have (or part of the procedure, anyway; these videos cover the Bankart repair, and I am also having a capsular repair), I am intellectually prepared for what will happen tomorrow.

In the quiet spaces in my brain, though, the fear continues to churn. I am afraid of being in pain. Not because of the pain itself, but because I’m scared it’ll make me cranky and less responsive to W. I am scared for W, that she’ll be afraid of what’s going on. I’ve talked to her about it a lot (I even made a little book for her about what is going to happen and what Mommy will be like when she comes home), but I know it’ll still be difficult for her. I’m scared that she’ll be nervous, or worried, or frightened that I can’t hold her with both arms. That I can’t sleep beside her. That I won’t be giving her nighttime bath. That I won’t be able to cuddle her as she falls asleep, or nurse her when she wakes in the middle of the night with her teeth aching. I’m scared she won’t feel as connected to me. I’m scared of losing some of our attachment. That’s probably silly — I’m the mama, after all, and nothing is changing that — but I’m scared all the same. I’m scared that as a reasonable and appropriate medical precaution, I had to write a living will and medical power of attorney for the first time in my life. I had to specify which organs I wanted to donate and for what purpose, under what conditions I wanted medical care to cease, what I wanted done with my remains.

I’m a logical person. So logical that sometimes, I think, I seem cold. I know that. But logic, science, statistics, facts and figures…they have nothing to offer me now. Tomorrow I will have to lay back, let go, trust someone else completely — and science won’t be there to comfort me. If I want comfort tomorrow, I will need something even more profound. Some people call it god, some say faith. Me? I call it peace. And I hope the universe has some to spare for me tomorrow.


Any words of wisdom? Advice? Experiences to share?



Arbous et al. Mortality associated with anaesthesia: a qualitative analysis to identify risk factors. Anaesthesia. 2001 Dec;56(12):1141-53.

Lienhart et al. Survey of anesthesia-related mortality in France. Anesthesiology. 2006 Dec;105(6):1087-97.

Organic Versus Conventional Milk: Health Issues And Environmental Perspectives (Guest Post at Science of Mom)

I’m guest-posting today! Alice at Science of Mom has recently featured two articles about conventional versus organic milk; the first claimed that milk from rBST-treated cows was the same as (or even preferable to) milk from non-rBST-treated cows, while the second claimed that conventional milk was just as good as organic. As a chemist with a special interest in environmental and social issues, I have a different take. Here are the major points/conclusions:

  • Small, idyllic-sounding conventional family dairy farms (like the one described in in this recent guest post on Science of Mom) sound lovely. If everyone raised dairy cattle like she does, there’d be little reason to consider organic milk. However, farms like this one are the exception in the U.S. dairy industry, and are rare exceptions at that.  The vast majority of U.S. dairy cows are housed in animal feeding operations (AFOs), and specifically in concentrated animal feeding operations (CAFOs). By EPA definition, then, both AFOs and CAFOs are crowded, and CAFOs are major sources of environmental pollution.
  • Milk from dairy cows, regardless of how they’re raised, is free from antibiotics. However, antibiotic overuse — meaning use of antibiotics in a prophylactic sense and as necessary for treatment of diseases spread through unnecessary husbandry practices — is promoting the development of antibiotic-resistant bacteria. Because conventional operations including CAFOs promote the development of antibiotic-resistant bacteria (thorough antibiotic overuse) that then proliferate in the environment, it’s not necessary to have contact with or consume a conventionally-raised animal or product to be negatively impacted by these practices.
  • CAFOs produce tremendous amounts of concentrated environmental waste. There’s far too much of it for the land to absorb, so it runs off into the surface water (lakes and rivers) and leeches into the groundwater (aquifers that feed municipal supplies and wells). Excess nitrogen in the water is associated with acid rain, fish-kills, blue-baby syndrome (methemoglobinemia), and global warming.
  • Conventional farming practices result in dairy cattle consuming large amounts of chicken feces and chicken feed, which contains cattle meat. This cannibalization of cattle by cattle increases risk of spreading BSE (mad cow disease) in the U.S.
  • Conventional farms that use rBST increase the likelihood that their cows will suffer mastitis (an animal welfare issue.
  • Conventional dairy cattle have less access to pasture, which results in a different (and less healthy) fatty acid profile in the milk. Organic milk is higher in heart-healthy omega-3 fatty acids, while conventional milk is higher in pro-inflammatory omega-6 fatty acid.
  • In the end, organic milk is healthier for everyone: your family, the cows producing the milk, humanity as a whole, and the planet.

Read the full article at Science of Mom.


Should A Toddler Wear A Helmet On A Tricycle?

A sweet trike and helmet for a sweet girl!

My husband and I are both avid cyclists, recreationally and for commuting purposes. We both owe our lives, several times over, to helmets. Some of our crashes have been due to, shall we say, “operator error,” while others have been the result of collisions with vehicles. Aside from those crashes that were severe enough to have been potentially life-threatening, we’ve also both been in a number of crashes that would have likely caused traumatic brain injury (commonly called concussion) had we not been wearing helmets. It’s easy to dismiss the importance of wearing a helmet on a bicycle, scooter, or similar non-motorized vehicle, particularly if one doesn’t believe the risk of death is significant in the event of a crash (e.g., I’m just riding a cruiser down the sidewalk; I won’t die if I crash). Nevertheless, any time a person is thrown or falls from a moving bike or similar, there’s the significant risk of head injury. Further, there’s a growing body of research that links even mild traumatic brain injury to depression, cognitive impairment, and early-onset dementia (see, for instance, Guskiewicz et al [2005 and 2007], Kiraly et al). Even people who don’t ride a non-motorized vehicle in a way that makes death a significant risk in the event of a crash are at risk for traumatic brain injury, and its associated complications.

There’s some concern among physicians that the use of the term “concussion” confuses parents and downplays the seriousness of this injury (DeMatteo et al). It should be noted that a concussion is a traumatic brain injury, is associated with alterations in brain blood flow in children (Maugans et al), and can cause developmental delays and functional losses that persist months to years post-injury (Rivara et al). Traumatic brain injury is one of the leading causes of disability and death in children (Keenan et al.)

Last week, we decided W was old enough for her first tricycle. I found a really cool company called Wishbone that makes a 3-in-1; it converts from a low-rider trike for the toddler set to a low-rider bike, and finally to a taller bike for older children. Best of all, it has no pedals; it’s a so-called “run bike,” which allows little ones to work on refining balance and steering before having to coordinate pedaling action. And I love the company’s ethics and commitment to sustainability. Anyway, with the bike on order, we went and bought W a helmet. For a toddler. Riding a trike. With no pedals. No joke. There were a few reasons for this. First, while it might seem suspect that a toddler could fall off a trike and do any significant damage, there are actually many reports of serious trike injuries (see, for instance, Powell et al [1997 and 2000], Sacks et al, Sosin et al). Toddlers and preschoolers who fall off tricycles sustain head, face, and mouth injuries with great frequency, and researchers strongly recommend helmets for this group. Secondly, among toddlers, it’s not just accidents while riding that account for tricycle injuries; these not-yet-stable walkers can fall and sustain a head injury while attempting to mount or dismount a tricycle. The final reason we bought W a helmet was simply to get her in the habit early on, which has been quite successful even over the course of just a few days; if she wants to ride her trike, she points to her helmet. I’m happy to be getting her into this habit early, because the kid will be wearing a helmet every time she gets on a trike, bike or similar, rides a skateboard, or skis. Every time. And her parents will too, both because it sets a good example, because we know from experience, and because, as an article published in the Journal of the American Medical Association (Sacks et al) put it:

From 1984 through 1988, bicycling accounted for 2985 head injury deaths (62% of all bicycling deaths) and 905,752 head injuries (32% of persons with bicycling injuries treated at an emergency department). Forty-one percent of head injury deaths and 76% of head injuries occurred among children less than 15 years of age. Universal use of helmets by all bicyclists could have prevented as many as 2500 deaths and 757,000 head injuries, ie, one death every day and one head injury every 4 minutes.


Science Bottom Line:* Use a brain bucket. Wear a skid lid. Invest in some skull insurance. Don’t crack your melon.


Do you wear a helmet when you ride a bike? Do you make your kids wear one?



DeMatteo et al. “My child doesn’t have a brain injury, he only has a concussion”. Pediatrics. 2010 Feb;125(2):327-34. Epub 2010 Jan 18.

Guskiewicz et al. Association between recurrent concussion and late-life cognitive impairment in retired professional football players. Neurosurgery. 2005 Oct;57(4):719-26; discussion 719-26.

Guskiewicz et al. Recurrent concussion and risk of depression in retired professional football players. Med Sci Sports Exerc. 2007 Jun;39(6):903-9.

Keenan et al. Epidemiology and outcomes of pediatric traumatic brain injury. Dev Neurosci. 2006;28(4-5):256-63.

Kiraly et al. Traumatic brain injury and delayed sequelae: a review–traumatic brain injury and mild traumatic brain injury (concussion) are precursors to later-onset brain disorders, including early-onset dementia. Scientific World Journal. 2007 Nov 12;7:1768-76.

Maugans et al. Pediatric sports-related concussion produces cerebral blood flow alterations. Pediatrics. 2012 Jan;129(1):28-37. Epub 2011 Nov 30.

Powell et al. Bicycle-related injuries among preschool children. Ann Emerg Med. 1997 Sep;30(3):260-5.

Powell et al. Cycling injuries treated in emergency departments: need for bicycle helmets among preschoolers. Arch Pediatr Adolesc Med. 2000 Nov;154(11):1096-100.

Rivara et al. Disability 3, 12, and 24 months after traumatic brain injury among children and adolescents. Pediatrics. 2011 Nov;128(5):e1129-38. Epub 2011 Oct 24.

Sacks et al. Bicycle-associated head injuries and deaths in the United States from 1984 through 1988. How many are preventable? JAMA. 1991 Dec 4;266(21):3016-8.

Sosin et al. Pediatric head injuries and deaths from bicycling in the United States. Pediatrics. 1996 Nov;98(5):868-70.