Technological advances in medicine are treasured, but they have their place and in the field of biochemistry it can be disastrous to cross the line. Just ask the women who developed breast cancer from taking hormone replacement therapy. CNN reports that drug recalls surged 309% in 2009 and physicians continue to prescribe antidepressants to children in spite of the fact they drive some to suicidal thoughts. The point is: you have to look out for yourself and your loved ones. It’s a smart move to inform yourself about nanotechnology and its use in zinc oxide and other sunscreens. This article provides an overview and all the links you need to find out more
FDA approved sunscreen ingredients
As the drug recall rate proves, just because the FDA gives a stamp of approval to an ingredient doesn’t mean it’s safe. An earlier post demonstrated that of the 17 FDA approved ingredients, only zinc oxide stands the test of time for safety and efficacy. Below you’ll see a chart distributed by the Environmental Protection Agency (EPA) comparing the degree of UV protection each approved ingredient provides. Note that only zinc oxide provides full protection from both UVA and UVB radiation.
Oddly, the FDA only requires sunscreen manufacturers to protect you against UVB sunlight. While UVB is considered more cancer-promoting, UVA radiation is far more abundant and accounts for 95% of the sunlight that reaches earth (Gruijl 2002). Further, UVA light is responsible for the classic signs of photoaged skin including wrinkling, dryness, and loss of elasticity (Lowe 1995 and Lavker 1995). Finally, a very recent study comparing the effects of both types of sunlight on DNA damage reports that UVA is far more carcinogenic than previously thought (Tewari 2012).
The chart shows that only zinc oxide (last item on the list) provides full UVA and UVB protection. Unfortunately, zinc oxide’s safety is called into question as a nanoparticle. The problem with zinc oxide and any other topically applied nanoparticle ingredient is the size itself. Size can transform a beneficial substance into a cancerous one.
How big is a nanoparticle?
Nanoparticles are measured in atomic-sized fractions of a meter called nanometers. Many of our readers use the non-metric measuring system, so you may be confused.
- One meter is a little over a yard long – exactly 39.38 inches. Just think three inches more than a yard.
- A nanometer is one billionth of a meter. The measurement was established to give scientists a way to measure atomic sized particles. One nanometer is about 3-5 atoms wide.
- The International Standards Organization (ISO) is well – an organization that aims to set standards everyone will use. According to the ISO, a nanoparticle is between 1 and 100 nanometers (nm) or between 3 and 500 atoms wide.
Putting nanoparticle size into perspective
One millimeter is one thousandth of a meter. The head of a pin is about 2 millimeters long. In the image below, the head of a pin with a human hair lying across is magnified 10 times. Note the tiny dot on the head of the pin at the tip of the green arrow.
Now look at the image below magnified 30 times. The dot pointed out by the green arrow is a dust mite. What’s the tiny dot pointed out by the pink arrow?
Magnified 100 times, the unidentified dot appears as a speck of ragweed pollen. The scale shows 200 micrometers. A micrometer, also known as a micron, is one millionth of a meter — its symbol is μ, or mu.
One micrometer (μ or mu) = 1000 nanometer (nm)
Magnified 30,000 times, the dust mite and ragweed pollen are relatively speaking, thousands of miles away. The green tubes below represent E. coli and the yellow balls are staphylococcus bacteria. The huge red blob in the upper right hand corner represents a red blood cell. The lavender squiggle is an ebola virus. Note the tiny specs pointed out by the blue arrow.
Jumping ahead 100,000 times, the tiny specs appear. They represent the common cold virus (rhinovirus). Note the scale of 200 nanometers.
Finally, we’ll magnify one million times. Note the cold virus measures greater than 20 nanometers. This is very relevant because researchers found that a range of 20 to 80 nanometers is the size most often used in zinc oxide nanoparticle cosmetic and sunscreen formulas (Cross 2007). From this perspective, it’s easy to see why scientists are worried about slathering human skin in particles smaller than the rhinovirus with the intent of going out into the sun.
Studies demonstrating nanoparticles and skincare formulations don’t mix
Researchers reporting in Toxicological Letters (Sharma 2009) are apprehensive about the fact over 20 countries worldwide manufacture and market cosmetics using nanoparticles. Specifically, they’re concerned that their extremely small size is allowing them to interact directly with DNA. So they performed experiments to test where or not zinc oxide nanoparticles are toxic to human skin cells and genes. They report their small size caused damage to DNA, killed skin cells, and induced oxidative stress by depleting crucial antioxidants. Glutathione and superoxide dismutase are the two most important antioxidants the body synthesizes. Nanoparticles of zinc oxide reduced their levels by 59% and 75% respectively. Consider the fact that the researchers were testing under normal conditions: that is, without the additional stressor of ultraviolet exposure. The worries escalate at the idea of applying nanoparticle oxidants to skin and spending the day at the beach. The researchers are so concerned that they cautioned against worker exposure in the factory as well as against nanoparticle use in cosmetics.
A separate group of researchers decided to find out what happens when people apply nanoparticle sunscreen ingredients and do spend the day at the beach (Kocbek 2010). Titanium dioxide and zinc oxide nanoparticles are often combined in commercial sunscreens. In addition, they’re often combined in makeup formulas to provide “a built-in” sunscreen effect. The authors studied the nanoparticles’ effects on the skin of people who went out into the sun for recreational activities five days in a row. They studied the intracellular formation of free radicals, alterations in cell structure and the impact on cell reproduction. Their analysis showed that cell death increased in proportion to higher concentrations of the oxides and with longer term exposure. Furthermore, they report that zinc oxide nanoparticles are more dangerous than titanium dioxide nanoparticles. The findings confirm an earlier study reporting that zinc oxide nanoparticles are more effective at killing cells than titanium dioxide nanoparticles (Lia 2008). The researchers warn that long-term exposure to these nanoparticles “indicates” a health risk.
Nanotechnologies used in consumer goods
Nanotechnologies manipulate matter at the atomic scale to create new nanomaterials. Their tiny size imparts new properties as compared to the “bulk” material. A typical example is carbon, which in its bulk form is used extensively in pencils. When engineered into a carbon nanotube, it becomes 100 times stronger than steel while being one-sixth of its weight.
The Project on Emerging Nanotechnologies is a partnership between the Woodrow Wilson International Centre for Scholars and the Pew Charitable Trusts. One of its aims is to ensure that as nanotechnologies advance, possible risks are minimized. The Project also seeks to secure strong public and consumer engagement. Toward this end it provides an online inventory of nanotechnology consumer products including details on manufacturers. The inventory grew 521% since its launch in March 2006 with publication of 212 products. By March 2011, the total inventory contained 1317 products. The lion’s share of all products listed fall under the category of “cosmetics and personal care.”
Copyright © 2014 Felecia Rose Labs 😎