Green Options

Nanotechnology refers to a field whose theme is the control of matter on an atomic and molecular scale.

It involves the manipulation of matter at the nanometer (nm) scale, which is one-billionth of a meter.  The nano scale is so incredibly tiny that a human hair (which is about 50,000 nm thick) is huge by comparison.

Many researchers believe this technology has the potential to create new and unique risks to human health and the environment.

Nanoparticles emitted by common kitchen appliances are more abundant than previously thought, leading for an urgent call for more research on health implications.

In 150 experiments using gas and electric stoves and electric toaster ovens, researchers at the National Institute of Standards and Technology (NIST) are working to determine their impacts on indoor levels of nanoparticles.

Previous studies measured particles with diameters greater than 10 nm, but the technology used in these experiments allowed researchers to measure particles as small as 10 times the size of a large atom, called ultra-fine particles (UFP).

“The results of this test,” said researcher Lance Wallace, “should affect future studies of human exposure to particulates and associated health effects, particularly since personal exposure to these indoor UFP sources can often exceed exposure to the outdoor UFP.”

Other recent research has demonstrated the difficulty of mapping out the health effects of nanoparticles. Even if a certain nanoparticles do not appear to be toxic, the interaction between the nanoparticles and other compounds in the human body can potentially cause serious problems to cell functions.

As I recently discussed, sometimes we need to look to the past for solutions to our current problems. Queensland University professor Zhu Huai Yong has done just that, noting that painting glass windows with gold particles can purify the air.

Zhu came across this realization after studying medieval painted church windows, which were often decorated using glass colored with gold nanoparticles.

Though people likely did not realize it at the time the churches were built, the sun-energized nanoparticles destroy air-borne pollutants, as sunlight creates an electromagnetic field that resonates with the gold particles’ oscillations.

This post is by Cal Baier-Anderson, Ph.D., a Health Scientist at Environmental Defense Fund.

Ah, summer!  It’s a great time to be outdoors, enjoying the warm, sunny weather.  Before you go outside, be sure to grab your sunscreen, that essential product that protects against skin cancer and sun damage.  But which kind of sunscreen is best?  There is a mesmerizing array of sunscreen options, but for our purposes let’s limit the question to one:  Nano or not nano?

We all recall the white noses of the beach lifeguards.  The zinc oxide or titanium dioxide in these nose-protecting potions form a thick, white barrier that blocks damaging ultraviolet (UV) radiation by reflecting and scattering light.  These days, nanoscale titanium dioxide and zinc oxide are increasingly popular sunscreen ingredients, as they provide a UV barrier but are nearly transparent.

As if it wasn’t bad enough that particulate matter from diesel exhaust causes a range of respiratory problems including 15,000 premature deaths each year, new research shows that even short-term exposure to nanoparticles found in diesel fumes can affect brain function.

Nanoparticles can travel to the brain via the olfactory nerve, where they could cause an oxidative stress response in the region of the brain critical to information processing.

Researchers placed subjects in a room with either clean air or diesel fumes (similar to a busy street), and used a electro- encephalograph (EEG) to measure brain response. Subjects breathing the sooty air showed a stress response in the brain’s cortex within 30 minutes, which continued even after they left the room.