Sunday, November 7, 2010

What?? A sippy cup made from PVC!

I really can't believe I missed this, but I just realized recently that the sippy cup I was giving to my toddler to drink water out of... is made of polyvinyl chloride (PVC). Who makes sippy cups out of PVC?! Apparently, Arrow Plastic Manufacturing Company does. How could I have been fooled? The top of the sippy cup is made from polypropylene. OK. The bottom part was clear and hard -- I just assumed it was polystyrene...but if you look closely at the plastic number logo at the bottom, it says "3" which is... PVC. Not OK. The main concern with PVC is the phthalate plasticizers that are used to make PVC more flexible, since it's a brittle polymer in its unmodified form. Phthalates, which are considered to be estrogen mimics, can leach out of PVC products. Bad. According to Arrow, there are no phthalates in the hard PVC plastic used to make the sippy cups, so they are safe. And oh yeah, the sippy cups don't contain BPA either! Of course they don't. BPA isn't used to make PVC... And apparently, lots of other additives are also generally added during PVC processing, like heat stabilizers, UV stabilizers, lubricants, processing aids, impact modifiers, etc.

I'm not sure how reassured I am by that. I did some Googling, and the only thing I could find about PVC sippy cups is this article from Green & Clean MOM who seems to have gone through a similar experience of "Are you kidding me?"

I do wonder about all the PVC water pipes out there though... If those are considered safe to transport drinking water, then technically, these sippy cups should be "safe" too, right?

Friday, November 5, 2010

It gets worse -- BPA in cash register receipts is absorbed through the skin...

Apparently, three recent studies have shown that Bisphenol A -- the chemical that has everyone freaked out about baby bottles, canned foods/drinks, and cash register receipts -- is absorbed through the skin. This doesn't surprise me, since skin absorption is a common pathway for chemicals to enter our bodies. The studies found that cashiers tend to have higher levels of BPA in their bodies, since there are significant amounts of BPA on thermal paper used in cash register receipts.

Two separate studies found that pregnant women who worked as cashiers had the highest levels of BPA in their bodies. In a third study, researchers exposed sections of fresh ear skin from pigs (often used as a model for human skin) to BPA, and found that after three days, 65% of the BPA was absorbed. They repeated the experiment with small samples of excised living human skin, and found that 46% of the BPA was absorbed. These numbers may seem scary, but seriously, they exposed the skin samples to BPA for THREE days. That's not really representative of what happens in the real world.

Sure, BPA is absorbed through the skin, so take precautions when handling thermal paper. It might be a good idea for cashiers to wear gloves when working... or better yet, maybe stores should stop using BPA-containing thermal paper. According to the EPA, Japan phased out the use of BPA in thermal printing applications in 2004. That's six years ago!! There are obviously alternatives out there, so why are we still using BPA-laden receipts?

(To be fair, the EPA did note that the health and environmental effects of BPA alternatives have yet to be assessed. And that is definitely a concern. Sometimes alternatives aren't necessarily better.)

Tuesday, June 15, 2010

Curious about the ingredients in cleaning products?

Have you ever wondered what is really in all the cleaning products you use at home? The Soap and Detergent Association (SDA) and the Canadian Consumer Specialty Products Association (CCSPA) have made it easy for you by creating an Ingredient Communication Initiative to provide consumers with information about the ingredients in various cleaning products.

The SDA Ingredient Central page provides a list of companies and their websites where you can find information on the ingredients used in their products. However, while some of the web links take you directly to the company's ingredient information page, most of them just link to the company website, and you have to do your own exploring to find your way to the ingredients page.

Please, use sunscreen to get cancer...

It seems like chemical sunscreens are a toxic brew of reproductive toxins and cancer causing chemicals...They say, "put on sunscreen to protect against skin cancer," but some new studies are suggesting that perhaps sunscreens are causing cancer.

Looking through all the sunscreen choices at the store, I've noticed that currently, most formulations contain one or more of the following active ingredients: oxybenzone and avobenzone (bad because they generate free radicals when exposed to UV radiation); cinnamates (often listed as "cinoxate," as if the abbreviation will make it seem less scary); salicylates (often listed as "homosalate" or "octisalate"); titanium dioxide and zinc oxide (physical barrier, but possibly bad because they're often nano-sized). Apparently, one of the non-active ingredients that is commonly added to sunscreens is an anti-oxidant called retinyl palmitate, a derivative of vitamin A, which presumably is supposed to help prevent skin damage from the sun. However, this compound may also be "photocarcinogenic," as it breaks down upon exposure to UV radiation to form compounds that have been shown to accelerate cancer in lab animals. There's no evidence as to what it does in humans, but it might be a good idea to be cautious.

I still haven't found a sunscreen that I like. I don't spend that much time in the sun anyway, but if I know I'll be in the sun long enough to get sunburned, then sure, I'll apply some sunscreen. Otherwise, I'll take my chances and get some vitamin D from a little sun exposure. When needed, I use California Baby's no fragrance sunscreen on my toddler. It's the best I can find so far, but I'm still a little concerned about the whole nanoparticle issue with titanium dioxide and zinc oxide formulations.

The horror! Methyl iodide as an approved pesticide??

I recall hearing a couple of years ago that California was considering using methyl iodide as a replacement for methyl bromide, which has been used extensively as a pesticide for crops, such as strawberries, but has also been wreaking havoc on the ozone layer. So, methyl bromide is being phased out, but what to replace it with? Apparently, Arysta LifeScience has been pushing the use of methyl iodide as a soil fumigant, which should work similarly but not affect the ozone layer. In 2007, the EPA actually approved its use, despite the warnings from many chemists who said they were "astonished" that the EPA was considering "broadcast releases of one of the more toxic chemicals used in manufacturing into the environment."

I personally used methyl iodide in grad school, but I always took great precautions -- gloves, fumehood, syringes to transfer. This is not something you want to get on yourself. It is routinely used to methylate DNA. Can you say, "cancer"? Methyl iodide is 6 times more toxic than methyl bromide. It's still very volatile, so there is a serious inhalation risk. If used on crops, it will contaminate the air and the water, and most likely poison farm workers and people living in the vicinity (especially downwind).

A report from the California Scientific Review Committee in 2009 concluded that there was no good way to use methyl iodide safely and that its use would have a significant adverse impact on public health. Yet, on April 30, 2010, California actually proposed using methyl iodide as a pesticide for use in agriculture. What are these people thinking?? If nothing is done, methyl iodide will become legal for California farmers to use after June 29.

Interesting facts: 47 States have licensed the use of methyl iodide, and 11 states have used it at least once. It has been used mostly on strawberries and sometimes on tomatoes and peppers.

Tuesday, March 16, 2010

'Synthehol' In Development!

If you're a fan of Star Trek, you may be thrilled to find out that researchers at Imperial College London are working on an alcohol substitute, that may have been inspired by the "Synthehol" from Star Trek. Ideally, this alcohol substitute would let the drinker experience the buzz without getting drunk or getting hangovers. Furthermore, it could potentially be "switched off" with a pill, so that drinkers could sober up immediately. The synthetic alcohol will likely be based on benzodiazepines, which are related to the active compound in Valium, diazepam, because these compounds affect the nerves in the brain in a similar way to alcohol, but are much easier to flush out of the body.

Chemtastic Designs: Phat Degree

That hard earned Ph.D. is definitely a Phat Degree.

Friday, March 12, 2010

Chemtastic Designs: The Dalton Chemical Symbol Series

These latest T-shirt designs are inspired by 19th century chemist John Dalton's chemical symbols.

The first one is an interesting-looking symbol for Quicksilver (aka Mercury). The ether and caffeine molecules are drawn using Dalton's chemical symbols.

Tuesday, March 2, 2010

The top 15 chemical additives in food

According to Coupon Sherpa, the top 15 chemicals that are added to food to make it look better and last longer are:
  1. 1-Methylcyclopropene: also known as "SmartFresh," this gas is used to keep fruit from producing ethylene, which causes ripening. Apparently, it preserves apples for a year and bananas for a month.
  2. Artificial coloring: many of the artificial colors developed since the early 1900s have been banned by the FDA as proven carcinogens. The artificial colors currently allowed in foods are: Blue #1, Blue #2, Green #3, Red #3, Red #40, Yellow #5, and Yellow #6. However, many are banned in other countries and still have potential health risks. The following have been restricted or banned: Greens #1 and #2, Reds #1, #2, #3, and #4, and Violet #1. As a safer alternative, look for natural food dyes, such as: caramel coloring, annatto, cochineal, betanin, turmeric, saffron, and paprika.
  3. Artificial flavoring: apparently these have been linked to behavioral changes...
  4. Aspartame: also known as Equal or NutraSweet, should be avoided by people suffering from phenylketonuria, who can't metabolize the amino acid phenylalanine. The safety of aspartame is still debatable as it breaks down into methanol, phenylalanine, and aspartic acid, and then further into formaldehyde, formic acid, and diketopiperazine.
  5. Astaxanthin: is apparently added to the diet of farm-raised salmon so that their flesh acquires that pink color found in wild salmon. This is because farm-raised salmon don't get to eat crustaceans which contain a natural astaxanthin.
  6. Sodium benzoate: is a preservative that is often added to soft drinks, cereals, meats. It has been linked to digestive problems, headaches, asthma attacks, and hyperactivity.
  7. Antioxidants: such as BHA and BHT, are added to oil-containing processed foods, like crackers, cereals, and sausages, as a preservative to keep them from getting rancid. Both butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) are possible human carcinogens.
  8. Canthaxanthin: is apparently used to make egg yolks look golden yellow. Large amounts of canthaxanthin can cause retinal damage.
  9. Emulsifiers: such as agar, albumin, alginate, casein, egg yolk, glycerol monostearate, xanthan gum, Irish moss, lecithin, and soaps. These help to improve the shelf life of bread products and help oil and water to mix homogeneously. Reduced-fat and low-calorie products tend to contain emulsifiers.
  10. High fructose corn syrup: is used as a sweetener and also helps to maintain moisture while preserving freshness. It is highly used in processed foods. In addition to causing obesity, its consumption has also been linked to diabetes, heart disease, as well as kidney and liver disease.
  11. Monosodium glutamate (MSG): is the sodium salt of glutamic acid, an amino acid. MSG is used as a flavor enhancer in processed foods, such as chips, condiments, and seasonings. Some people have reported tightening in the chest, headaches and a burning sensation in the neck and forearms after consuming food containing MSG.
  12. Olestra: also known as "Olean," is a fat substitute that doesn't get digested by the human body, and is often used in foods such as fat-free chips. Aside from the well-publicized "anal leakage" problem, consumption of large amounts of Olestra can also prevent our bodies from absorbing fat-soluble vitamins.
  13. Partially hydrogenated oils: are a cheaper alternative to butter and are found in many processed foods. The process of hydrogenating oil can lead to the production of trans fats as a side product. Trans fats have been linked to heart disease.
  14. Potassium bromate: is an oxidizing agent and is used to improve flour, so that bread dough rises higher. Most of the bromate breaks down during the breadmaking process, but traces of it can be a cancer risk.
  15. Sodium nitrite and sodium nitrate: are commonly used to preserve meat and is found in cold cuts, hot dogs, and sausages. When heated to high temperatures (like frying), sodium nitrite in meat can form nitrosamines, which are carcinogenic.
I'm not sure I can rid my diet of all of these additives, but it definitely makes sense to limit our consumption of processed foods (so hard!) Check out the ingredient list of foods that you commonly buy and see if you're horrified.

Saturday, February 27, 2010

A Handy Resource: The Skin Deep Cosmetic Safety Database

I recently came across this handy website called the Skin Deep Cosmetic Safety Database, which was created by the Environmental Working Group. The site is useful because it allows you to search for cosmetics and personal care products by product name, ingredient, or company/brand, and it shows you their safety rating, which is based on the potential health hazards (e.g., cancer, developmental/reproductive toxicity, allergies, etc.) linked to the individual ingredients in the product. You can also browse categories of products, such as makeup, skin care, hair care, etc., and try to find safer products to use.

You'd think that with the FDA's "strict" regulation of cosmetics and personal care products, all the products that you buy should be safe. Well, before these products can be sold to the public, the U.S. Food, Drug, and Cosmetic Act (FD&C Act) requires that companies show that the products and their ingredients are safe and that they don't contain banned ingredients. But really, how do you prove that a certain chemical is "safe" before you try to market a product? A lot of these chemicals may not show any significant health effects until years down the road, and what company is willing to wait that long before marketing a product? You get the idea.

The Skin Deep Cosmetic Safety Database is neat in that it lists all the relevant information in an easy-to-use layout. The safety ratings are color coded -- green for "low hazard", yellow for "moderate hazard", and red for "high hazard" --so you can get an idea for how safe a product is at a glance. Of course, when I first discovered the site, I immediately started looking up all the products I use on a daily basis, and I was a little horrified at the results. There were a couple of things that I use that were in the high moderate to high hazard category. Yikes! As a result, I looked up some safer alternatives. You'll notice that a lot of the safest products will likely be hard to find in your average store, and that was something that annoyed me. I decided to look for products that you can find in the store with a decently safe rating instead.

HOWEVER -- this is a big HOWEVER... Just because the rating says a product is safe, it doesn't mean it actually is. What? You say. Well, it's important to look at the actual ingredient list. For example, a lot of the sunscreens that are rated the safest contain zinc oxide or titanium dioxide nanoparticles, and recent studies have shown that these particles can be absorbed through the skin. The Australian government has been looking into this and has published a review of the scientific literature on the safety of titanium dioxide or zinc oxide nanoparticles in sunscreens. A while ago, I had bought some California Baby Sunscreen thinking that it would be safer than other kids' sunscreens. Skin Deep rates it at "1" or "low hazard," but guess what. It uses titanium dioxide nanoparticles. So, is it really safer? Not sure...

Another ingredient that has been listed as hazardous is polyethylene, which I find rather puzzling. It is listed as a cancer risk (based on a study from 1955!) Huh? Polyethylene is one of the cleanest and safest plastics out there. So, for example, Maybelline's Lash Discovery mascara is dinged pretty heavily (score: 7, high hazard) partly because it contains polyethylene... Hmm. Well, my point is, look at the ingredient list carefully. Skin Deep is a useful tool, but don't take the ratings at face value.

Thursday, February 11, 2010

Blood sugar sensing tattoos for diabetics

The thought of having to draw blood (even if it's just a tiny pin prick) to check for blood sugar levels several times a day is rather unpleasant... Perhaps here is some good news for diabetics. Researchers at Draper Laboratory in Cambridge, MA have developed a tiny color-changing sensor tattoo that can detect blood sugar levels. The tattoo ink consists of nanospheres containing a fluorescent dye and a molecule that can attract and bind glucose to produce a color change. The nanospheres are injected into the outermost layer of skin. [Apparently, when blood glucose levels increase, they also increase everywhere else in the body, including the outermost layer of skin.] The nanospheres turn purple when glucose is present -- otherwise, they're yellow. Of course, there will be a range of colors depending on how much glucose is present. With a healthy blood sugar level, the tattoo is an orangish color.

The tattoo has been successfully tested in healthy mice, and the next step will be to test it in diabetic mice. The tattoo may be ready for testing in people within the next 5 years.

Pregnant women beware -- Folic acid plus vitamin B12 increase cancer risk?

A recent study of patients with heart disease in Norway found that they had an increased risk of cancer and death if they were treated with folic acid and vitamin B12. Previous studies have typically shown that folic acid deficiency can promote the development of cancer, while high doses of folic acid can enhance cancer cell growth. Apparently this particular study showed that there was an increased incidence of lung cancer among patients who received both folic acid and vitamin B12. Food in Norway isn't fortified with folic acid like it is in North America. Since 1998, folic acid has been added to flour and grain products in order to reduce the risk of neural-tube birth defects, which can result in spina bifida or anencephaly in developing fetuses. Pregnant women are also encouraged to take prenatal vitamins which contain even more folic acid and vitamin B12. What does this mean for the general population and especially pregnant women? Pending further studies, the authors recommend that the safety of widespread folic acid consumption be monitored. Wonderful...