Toxins remain in your clothes

 

In a new thesis 60 garments from Swedish and international clothing chains have been tested. An initial analysis found thousands of chemicals in the clothes and around a hundred chemicals were preliminary identified. Credit: Image courtesy of Stockholm University Thousands of chemicals are used in clothes manufacturing. Researchers at Stockholm University have examined if there are chemicals in the clothes we buy as well. Several substances related to health risks were identified and not even organic cotton was a guarantee for non-toxic textiles. In a new thesis 60 garments from Swedish and international clothing chains have been tested. An initial analysis found thousands of chemicals in the clothes and around a hundred chemicals were preliminary identified. Several of the substances were not on the producers' lists and are suspected to be by-products, residues or chemicals added during transport. "Exposure to these chemicals increases the risk of allergic dermatitis, but more severe health effect for humans as well as the environment could possibly be related to these chemicals. Some of them are suspected or proved carcinogens and some have aquatic toxicity," says Giovanna Luongo, PhD in Analytical Chemistry at Stockholm University. Depending on occurrence, quantity, toxicity and how easily they may penetrate the skin, four groups of substances were chosen for further analysis. The highest concentrations of two of these, quinolines and aromatic amines, were found in polyester. Cotton contained high concentrations of benzothiazoles, even clothes made from organic cotton. The researchers washed the clothes and then measured the levels of chemicals. Some of the substances were washed off, with a risk of ending up in aquatic environments. Others remained to a high degree in the clothes, becoming a potential source of long-term dermal exposure. It is difficult to know if the levels of these harmful substances are hazardous, and what effects chemicals in our clothes can have in the long run. "We have only scratched the surface, this is something that has to be dealt with. Clothes are worn day and night during our entire life. We must find out if textile chemicals go into our skin and what it means to our health. It is very difficult to assess and requires considerably more research," says Conny Östman, Professor in Analytical Chemistry. The thesis can be found online at: http://www.diva-portal.org/smash/get/diva2:850089/FULLTEXT02.pdf Story Source: The above post is reprinted from materials provided by Stockholm University.Note: Materials may be edited for content and length.   http://www.sciencedaily.com/releases/2015/10/151023084508.htm

First glimpse of a chemical bond being born

February 12, 2015 SLAC National Accelerator Laboratory Scientists have gotten the first glimpse of the transition state where two atoms begin to form a weak bond on the way to becoming a molecule. This fundamental advance, long thought impossible, will have a profound impact on the understanding of how chemical reactions take place and on efforts to design reactions that generate energy, create new products and fertilize crops more efficiently. This illustration shows atoms forming a tentative bond, a moment captured for the first time in experiments with an X-ray laser at SLAC National Accelerator Laboratory. The reactants are a carbon monoxide molecule, left, made of a carbon atom (black) and an oxygen atom (red), and a single atom of oxygen, just to the right of it. They are attached to the surface of a ruthenium catalyst, which holds them close to each other so they can react more easily. When hit with an optical laser pulse, the reactants vibrate and bump into each other, and the carbon atom forms a transitional bond with the lone oxygen, center. The resulting carbon dioxide molecule detaches and floats away, upper right. The Linac Coherent Light Source (LCLS) X-ray laser probed the reaction as it proceeded and allowed the movie to be created. Scientists have used an X-ray laser at the Department of Energy's SLAC National Accelerator Laboratory to get the first glimpse of the transition state where two atoms begin to form a weak bond on the way to becoming a molecule. This fundamental advance, reported Feb. 12 in Science Express and long thought impossible, will have a profound impact on the understanding of how chemical reactions take place and on efforts to design reactions that generate energy, create new products and fertilize crops more efficiently. "This is the very core of all chemistry. It's what we consider a Holy Grail, because it controls chemical reactivity," said Anders Nilsson, a professor at the SLAC/Stanford SUNCAT Center for Interface Science and Catalysis and at Stockholm University who led the research. "But because so few molecules inhabit this transition state at any given moment, no one thought we'd ever be able to see it." Bright, Fast Laser Pulses Achieve the Impossible The experiments took place at SLAC's Linac Coherent Light Source (LCLS), a DOE Office of Science User Facility. Its brilliant, strobe-like X-ray laser pulses are short enough to illuminate atoms and molecules and fast enough to watch chemical reactions unfold in a way never possible before. Researchers used LCLS to study the same reaction that neutralizes carbon monoxide (CO) from car exhaust in a catalytic converter. The reaction takes place on the surface of a catalyst, which grabs CO and oxygen atoms and holds them next to each other so they pair up more easily to form carbon dioxide. In the SLAC experiments, researchers attached CO and oxygen atoms to the surface of a ruthenium catalyst and got reactions going with a pulse from an optical laser. The pulse heated the catalyst to 2,000 kelvins -- more than 3,000 degrees Fahrenheit -- and set the attached chemicals vibrating, greatly increasing the chance that they would knock into each other and connect. The team was able to observe this process with X-ray laser pulses from LCLS, which detected changes in the arrangement of the atoms' electrons -- subtle signs of bond formation -- that occurred in mere femtoseconds, or quadrillionths of a second. "First the oxygen atoms get activated, and a little later the carbon monoxide gets activated," Nilsson said. "They start to vibrate, move around a little bit. Then, after about a trillionth of a second, they start to collide and form these transition states." 'Rolling Marbles Uphill' The researchers were surprised to see so many of the reactants enter the transition state -- and equally surprised to discover that only a small fraction of them go on to form stable carbon dioxide. The rest break apart again. "It's as if you are rolling marbles up a hill, and most of the marbles that make it to the top roll back down again," Nilsson said. "What we are seeing is that many attempts are made, but very few reactions continue to the final product. We have a lot to do to understand in detail what we have seen here." Theory played a key role in the experiments, allowing the team to predict what would happen and get a good idea of what to look for. "This is a super-interesting avenue for theoretical chemists. It's going to open up a completely new field," said report co-author Frank Abild-Pedersen of SLAC and SUNCAT. A team led by Associate Professor Henrik Öström at Stockholm University did initial studies of how to trigger the reactions with the optical laser. Theoretical spectra were computed under the leadership of Stockholm Professor Lars G.M. Pettersson, a longtime collaborator with Nilsson. Preliminary experiments at SLAC's Stanford Synchrotron Radiation Lightsource (SSRL), another DOE Office of Science User Facility, also proved crucial. Led by SSRL's Hirohito Ogasawara and SUNCAT's Jerry LaRue, they measured the characteristics of the chemical reactants with an intense X-ray beam so researchers would be sure to identify everything correctly at the LCLS, where beam time is much more scarce. "Without SSRL this would not have worked," Nilsson said. The team is already starting to measure transition states in other catalytic reactions that generate chemicals important to industry. "This is extremely important, as it provides insight into the scientific basis for rules that allow us to design new catalysts," said SUNCAT Director and co-author Jens Nørskov. Story Source: The above story is based on materials provided by SLAC National Accelerator Laboratory. Note: Materials may be edited for content and length. Journal Reference: H. Öström, H. Öberg, H. Xin, J. LaRue, M. Beye, M. Dell’Angela, J. Gladh, M. L. Ng, J. A. Sellberg, S. Kaya, G. Mercurio, D. Nordlund, M. Hantschmann, F. Hieke, D. Kühn, W. F. Schlotter, G. L. Dakovski, J. J. Turner, M. P. Minitti, A. Mitra, S. P. Moeller, A. Föhlisch, M. Wolf, W. Wurth, M. Persson, J. K. Nørskov, F. Abild-Pedersen, H. Ogasawara, L. G. M Pettersson, and A. Nilsson. Probing the transition state region in catalytic CO oxidation on Ru. Science, 12 February 2015 DOI: 10.1126/science.1261747

Inspired by a music box, Stanford bioengineer creates $5 chemistry set

 

Home » About » News & Updates » Inspired by a music box, Stanford bioengineer creates $5 chemistry set

Manu Prakash won a contest to develop the 21st-century chemistry set. His version, based on a toy music box, is small, robust, programmable and costs $5. It can inspire young scientists and also address developing-world problems such as water quality and health.

When Manu Prakash was young he had a thing about flames. He's not encouraging all kids to follow his fiery lead – he did burn one hand pretty badly – but he thinks kids should explore more when it comes to learning about science. That's the idea behind his programmable, toy-like device that won a competition to "reimagine the chemistry set for the 21st century."

The Science Play and Research Kit Competition (SPARK) was jointly sponsored by the Gordon and Betty Moore Foundation and the Society for Science & the Public. Prakash, an assistant professor of bioengineering at Stanford, will receive a $50,000 award toward further developing his prototype into a low-cost product, which he thinks can have widespread use both in the developing world and as a creative toy for kids.

"In one part of our lab we've been focusing on frugal science and democratizing scientific tools to get them out to people around the world who will use them," Prakash said. "I'd started thinking about this connection between science education and global health. The things that you make for kids to explore science are also exactly the kind of things that you need in the field because they need to be robust and they need to be highly versatile."

 

From music to chemistry

The idea for this device started not with flames or even chemistry, but with a music box that Prakash's wife brought home from a gift exchange at work one Christmas. It used a tiny hand crank to pull a paper ribbon through a set of pins on concentric disks. When one of the pins hit a hole in the paper, the disk and pin rotated, causing another pin to pluck a metal strip to make a sound. One of the tapes in his lab has holes set up to play the song "Happy Birthday."

Stanford graduate student George Korir holds a programmable microfluidics kit built on music box parts. (Kurt Hickman / Stanford News Service)

In his toy-filled office, Prakash played with this music box and got the idea that the rotating pins could also be used to pump fluids through tiny channels or to control valves and droplet generators in a programmable fashion. "Punch-card paper tapes like this have been used to program computers and fabric looms, so why not chemistry?" he said.

After talking with graduate student George Korir, Prakash started working with him on a way of pairing the hand-cranked toy with a small silicon chip containing tiny channels for manipulating fluids. These chips, called microfluidics chips, are increasingly common in research labs, but require expensive equipment and electricity to run. The expense and equipment required is a bottleneck in adapting the technology for science education and global health, Prakash said.

What Prakash and Korir invented is inexpensive, hand-powered, self-contained and programmable. "It's important to bring open-ended tools for discovery to a broad spectrum of users without dumbing down the tools," Prakash said.

 

Programmable and portable

Like the music box, the prototype includes a hand-cranked wheel and paper tape with periodic holes punched by the user. When a pin encounters a hole in the tape it flips and activates a pump that releases a single drop from a channel. In the simplest design, 15 independent pumps, valves and droplet generators can all be controlled simultaneously.

Prakash and Korir didn't set out to make a kit for kids. Their idea was that a portable, programmable chemistry kit could be used around the world to test water quality, provide affordable medical diagnostic tests, assess soil chemistry for agriculture or serve as a snake bite venom test kit. It could even be used in modern labs to carry out experiments on a very small scale.

Although the original prototype was made from music box parts, Prakash and Korir have many versions in which the crank and pins (they call this part the actuator) were printed on a 3-D printer. They say the actuator, the paper tape and the silicon chip can all be modified to meet different uses, and can be made from inexpensive, durable materials costing less than $5.

For example, if someone wants to test water quality he might create a chip with channels that combine the water with chemicals that detect contaminants, pH, or the presence of microorganisms. Another kit might force droplets through a twisting pattern to mix chemicals within the drops. Holes in the paper tape can be punched to release drops from different channels in a set sequence or to open and close valves that combine chemicals or keep them separate. Prakash said each chip can be rinsed out and reused with a new batch of chemicals.

A kit for kids might come with several chips containing different types of channels and with a few pre-punched tapes. The chemicals never leave the chip and thus are never exposed. Prakash said he envisions youngsters eventually punching their own holes to program new experiments.

 

Sparking inspiration

This kind of open-ended creativity is what the competition sponsors intended. They cite a concern about classic chemistry sets that inspired a generation of scientists being reduced to rote toys that don't spark the same excitement and wonder.

Prakash said inspiring kids to be interested in science is directly tied to solving developing-world problems. "Science education in developing countries doesn't exist and that's probably one of the reasons why we don't have enough doctors and scientists," he said. "It's not just about resources. It's about people not realizing that this is something they want to invest their life in."

Korir was born and raised in Kenya. "If we were curious and wanted to explore, for example to find out what was out there in the muddy water, or to find out why some water tastes different than other water, we had no way to do that," he said. "Having something that you could use to ask these questions would open up the space to kids but also to other people all over the world. It really democratizes chemistry."

Prakash is affiliated with both Stanford Bio-X, which encourages interdisciplinary research between biological sciences and engineering, and the Stanford Woods Institute for the Environment. This project and other "frugal science" from his lab marry those two affiliations by creating low-cost engineering tools that can be used for health care or environmental applications. He recently announced development of a 50-cent microscope called Foldscope that can be folded like origami out of paper.

With the prize money, Prakash and Korir hope to continue working toward a product that other groups, including researchers and citizen scientists, can then modify and program for a wide range of uses, both educational and scientific. "When you go out in the field you feel like, 'If I'm not making a product, then I'm not getting out to people in even the smallest possible way,'" Prakash said.

For more Stanford experts on bioengineering and other topics, visit Stanford Experts.