Carbon Nanotubes Pose Health Risks

Carbon nanotubes are a modern and extremely light material that can add desirable properties to many industrial products, but they may be a health hazard. A new doctoral dissertation at Luleå University of Technology in Sweden shows that extremely small fibers such as carbon nanotubes can make their way far into the lungs, which in the worst case can present an increased risk of developing cancer.

“My research substantiates the concerns about health effects and is one reason we should be careful when handling with these materials,” says Sofie Högberg, who now holds a PhD in engineering from the Division of Fluid Mechanics at Luleå University of Technology.

The result of her work indicates that the fibers that are most likely to make their way far into the lungs, perhaps all the way to the alveoli, are those with a diameter of c. 10-100 nanometers (1 nanometer = one billionth of a meter) and a length of 1-10 micrometers. This is a common size for carbon nanotubes.

In her research, she developed equations to describe the movements of a fiber. She then solved these equations numerically for a large number of fibers in a geometry and a flow field that represents the airways, in order to see what proportion of the inhaled fibers might be thought to fasten, depending on parameters like particle size and form.

The field of nanotechnology has been burgeoning in recent years, and today there are more than 1,000 nanoproducts on the market. The technology involves modifying material virtually at the level of the atom. Carbon nanotubes are a popular nanomaterial because of their combination of favorable properties that are desirable in many industrial products. By adding a small amount of carbon nanotubes it’s possible to create materials that are strong yet still light in weight. However, with a diameter on the nanoscale and a highly elongated form, this extremely small particle can constitute a health risk.

“There are concerns, among others, that carbon nanotubes may lead to mesothelioma, a cancer form that previously has been associated only with asbestos,” says Sofie Högberg.

Our knowledge of how spherical and fiber-shaped particles move can be used in other fields, such as production of composites and paper as well as medicines in aerosols. This means that Sofie Högberg’s research has a wide spectrum of applications.

Attached files

  • Sofie Högberg, Phd Luleå University of Technology

  • New doctoral dissertation by Sofie Högberg, LTU

Nanoworld In Color

Microscopically small nanostructured arrays of lenses that can record or project amazingly sharp images in brilliant colors are being demonstrated by Fraunhofer research scientists at the nano tech 2011 trade show in Tokyo from February 16 to 18.

Lights off – projector on. Lecture theaters, conference halls and seminar rooms currently have to be darkened if the speaker wants to project a presentation on screen. Unfortunately, the attention of the listeners goes off with the lights, and tiredness takes over. A new technique promises to remedy this situation. The projectors of the futur will not only be small and easy to use but also shine so brightly that the images appear sharp and clear, even in a sun-filled room.

The image illuminating the wall of the Fraunhofer exhibition stand at nano tech 2011 will be produced by a luminous cube. The prototype of the new projector consists of an optical system just eleven millimeters square and three millimeters thick through which a powerful LED lamp shines. The images are amazingly sharp, the colors brilliant – all thanks to micro and nanotechnology. “The special thing about the new projection technology is that the image is already integrated in the microoptics. The pixels measuring just a hundred nanometers or so are stored in a chromium layer under the lens array. Such a microarray has around 250 microlenses, and under each lens there is a microimage. When all of them are projected onto the wall together, a high-quality complete image is produced from an extremely small projector,” explains Marcel Sieler, physicist at the Fraunhofer Institute for Applied Optics and Precision Engineering IOF in Jena.

This pocket-sized technology has the potential to replace not only overhead and digital projectors but also cameras. “The commercial prospects for ultra-flat microoptical systems are excellent because they open up numerous new applications – like minicameras or miniprojectors” enthuses Dr. Michael Popall from the the Fraunhofer Institute for Silicate Research ISC. He adds: “The leap in manufacturing quality achieved in recent months can be compared to the advance in television from the cathode ray tube to HDTV.” The IOF scientists have also developed a projector that is not much bigger than a box of matches. It can project presentations, video clips and movies from a cell phone or laptop onto any wall – at home, in the office or out and about. Ultra-flat cameras that are ideal for area or production monitoring in exposed locations are another application which will be demonstrated in Tokyo.

A special material composition has been developed by researchers at ISC for the manufacture of the microlens arrays used in all these applications. Organic carbon-hydrogen and oxygen compounds are enveloped in an inorganic matrix of silicon oxide or titanium oxide. This prevents the embedded plastics from changing chemically over the course of time. Such ORMOCER®s are insensitive to mechanical and thermal loadings. Incidentally, the formula for stabilizing sensitive compounds is very old: The ancient Mayas mixed their natural indigo dye, which normally bleaches quickly in the sun, with a clay mineral to render it fast. As a result, the blue dye they used to decorate the walls of their houses and temples lasted for more than a thousand years.

The method employed by the Mayas was very effective but rather crude compared with modern techniques. “Today we can control the chemical bonding of the inorganic and organic substances with nanometer precision,” states Popall. “Development of the material, however, is only one part of the puzzle. The shaping process and the technology needed to control it play a crucial role in lens manufacture. It was only through close cooperation between chemists and physicists at Fraunhofer that we succeeded in producing the arrays, substrates and components needed for extremely flat, high-quality optics.” The resolution attainable is now almost as high as that of high-quality glass optics – but using significantly less material and space. What’s more, the new material can be mass produced, which keeps the costs much lower.

Small is beautiful is the principle for the new optical world. The days of suitcase-sized projectors will be therefore numbered.

Top 10 Mistakes In Behavior Change

Playing the “Is It Healthy?” Game, like any other game has values, attitudes and practices that result in “wins”. Games are just an agreement we have about something being more important than something else – ball in basket, puck in net or first over the finish line.  Knowing the rules of the game is the first step in mastery.

Understanding the Top 10 Mistakes In Behavior Change can mean the difference of playing in the minor leagues and going pro. Thanks to Derek Franklin of for sharing.

American Style Biscotti

American Style Biscotti

Total time: About 1 hour, plus cooling times
Servings: Makes about 2 1/2 dozen cookies

Note: Adapted from “The King Arthur Flour Cookie Companion”


6 tablespoons unsalted butter at room temperature

2/3 cup sugar

pinch of salt

1 teaspoon vanilla

1 1/2 teaspoons baking powder

2 large eggs

2 cups (8 1/2 ounces) unbleached all-purpose flour

1. Heat the oven to 350 degrees. Line a baking sheet with parchment paper.

2. In the bowl of a stand mixer, or in a large bowl using a hand mixer, beat together the butter, sugar, salt, vanilla and baking powder until smooth and creamy. Beat in the eggs, one at a time (the batter may look slightly curdled). Over low speed, beat in the flour, mixing until smooth. The dough will be soft and sticky.

3. If you would like to add finely chopped nuts, chocolate chips, seeds or dried fruit, you can do it after mixing in the flour. (For example, I added one-fourth cup of poppy seeds and 1 cup of chopped pecans.)

4. Shape the dough into a rough log about 14 inches long, 2 1/2 inches wide and about three-fourths of an inch thick. Place the log on the cookie sheet and bake for 25 minutes.

5. Remove from the oven and lower the temperature to 325 degrees. Cool the log on the cookie sheet for 20 minutes.

6. Cut the biscotti into straight one-half inch slices. Arrange them so they stand upright on the cookie sheet, keeping a little space between the slices.

7. Bake for another 20 minutes.

8. Cool completely before storing in an airtight container or in the freezer.

Each cookie: 72 calories; 1 gram protein; 11 grams carbohydrates; 0 fiber; 3 grams fat; 2 grams saturated fat; 20 mg. cholesterol; 5 grams sugar; 34 mg. sodium.

Copyright © 2011, Los Angeles Times

Who Could Possibly Resist Lynn Tilton?

I love reading stories about how business builders overcome obstacles and create profit in their companies. I particularly love to read about women who refuse to be constrained.

Last year, private-equity chief Lynn Tilton flew to Detroit to try to improve sales at one of her auto-parts companies. She got a cool reception from Ford Motor Co.’s purchasing chief, Tony Brown, who asked if she was like other private-equity chiefs that “strip and flip” their companies.

“You must be mistaken,” she shot back. “It’s only men that I strip and flip. My companies I hold long and close to my heart.”  Read more about Lynn Tilton in the Wall Street Journal.  I’d guess Lynn made their top ten list of stories that day. Male readers (and probably females too) were probably either wishing to date her or do some business.

This is a woman to know. Underestimate  her at your peril. I’d  love to have a nanny cam to see the faces of the men getting a quick attitude adjustment after an encounter with her! A Lynn Tilton for President movement can’t be too far away, can it? Love the shoes.