Nifty science

It’s easy to take drinking water for granted. Just turn on a faucet and out it comes. For nearly 800 million people around the world, that’s not the case. They have no access to safe sources of drinking water. That can be true even in places with lots of water, such as Bangladesh. There, tens of millions of people in rural areas depend on well water. Drinking that water, which often isn’t filtered or chemically treated, can expose people to dangerous germs and poisons.

One of those toxic substances is arsenic, a colorless, odorless chemical element. Natural deposits of arsenic taint drinking water wells in many places. Even small amounts of arsenic can increase the risk of cancer. Arsenic also can cause a disease called arsenicosis, notes Thabit Pulak, 18. He’s a senior at Richardson High School in Richardson, Texas.

His grandparents live in Bangladesh. There, between 35 million and 77 million people live in areas where well water contains high levels of dissolved arsenic, according to the World Health Organization. When Thabit went to Asia to visit his relatives two years ago, he learned a family friend had arsenicosis. People can develop this disease from drinking arsenic-rich water, usually for at least 5 years. Its victims often have hard patches of skin on their hands and feet. They also can develop problems with the blood vessels in their legs and feet.

Testing revealed that water from a neighborhood well had arsenic levels of about 500 parts per billion. While that doesn’t sound like much, it is about 10 times the upper limit considered relatively safe for drinking water.

“I saw a problem and I wanted to fix it,” says Thabit. So he developed a simple way to test water for arsenic. Then, he developed a novel filter to remove the toxic contaminant. Both the test and the filter rely on the same simple chemical principle: Dissolved arsenic will glom onto iron oxide — rust.

His ingenuity got noticed. Thabit was named one of 40 finalists at the Intel Science Talent Search, America’s oldest and most prestigious high school science and math competition.

Society for Science & the Public, publisher of Science News for Students, created the contest 73 years ago. The Intel Foundation sponsors the competition — and this year provided $630,000 in prizes.

In recent years, 1,700 students have been signing up for the annual competition. There are almost 20 categories of research from which student researchers can choose. Judges first narrow the field to 300 semifinalists. A few weeks later, judges further winnow the group to 40 finalists. Those fortunate few travel to Washington, D.C., to compete for the top awards. They include a $100,000 grand prize.

Even though the contest ultimately names just a few winners, no one reaches the finals without having first demonstrated substantial success as a student researcher. Here, we highlight the work of five Intel ISEF teen phenoms. From the mysteries of neuroscience to the practicalities of filtering drinking water, their attention-grabbing research is providing new insights.

Water, water, everywhere… but sometimes scary to drink

For his new arsenic test, Thabit soaked bits of paper in a chemical solution that contained iron particles, each just a few billionths of a meter in diameter. Then, he dried the paper. That left him with test strips coated with the iron nanoparticles. When dipped in water contaminated with arsenic, the test strips will collect tiny amounts of the toxic substance.

And that makes the strips conduct electricity more effectively. The more electricity a dipped strip conducts, the more arsenic is in the water. So, it’s easy to estimate arsenic levels in drinking water by using equipment to measure how much the conductivity of a test strip changes after it is dipped into water.

Thabit’s test strips will let people know when arsenic concentrations are more than 50 parts per billion. That’s a safety threshold set by the World Health Organization.

If testing reveals dangerous levels of arsenic, then people can filter it out using the simple device that Thabit also designed. It consists of a pipe made from polyvinyl chloride, or PVC. It’s a type of plastic. A cap closes the pipe’s bottom. Thabit then stands the whole thing on end and fills the pipe almost to the top with gravel and sand. Now he adds powdered rust, which he first dissolves into the fat from melted soap. (The soap helps the iron-bearing particles stick to the sand, so they won’t wash out of the filter.)

When people pour water into the top of this filter, it drains through the sand and gravel. The purified water comes out of a valve near the bottom of the filter. One pass through the pipe will reduce arsenic levels. A second pass will reduce them even more.

Making a filter requires about $7 in materials, says Thabit. “In Bangladesh, they’d be even cheaper,” he adds. And the filters don’t just remove arsenic. They also help eliminate dangerous bacteria. The bacteria trapped in the filter die, and they can be flushed out regularly by stirring the sand and gravel.

Thabit is interested in a career in biomedicine, perhaps in human health and public policy. But that’s far from this tinkerer’s only interests. For instance, he loves cars and “how they hum when they’re running right.”

Grabbing the tiny

Anyone who has ever tried to grab a strand of hair with a pair of tweezers knows it can be difficult and frustrating. Now imagine trying to grab hold of something far, far smaller, like a grain of pollen — or even a virus.

Sometimes, scientists need to pick up or move very small things. For instance, they may need to sort through a large number of blood cells and retrieve only those with a certain defect. Or they may need to measure the force of attraction between one molecule and another, explains Kathy Camenzind. She’s a 17-year-old senior at California High School in San Ramon, Calif.

To perform such delicate tasks, scientists are turning to a clever tool known as an “optical tweezers.” It uses the power of light to trap microscopic objects. The tweezers then holds objects in place without actually touching them.

Kathy first learned about these tools last summer. That’s when she worked in a lab as part of a seven-week summer program at Stony Brook University in New York. “I was baffled by the idea that light could exert a force,” Kathy recalls.

A professionally made optical tweezers can cost more than $20,000. But as she thought about it, Kathy realized she might be able to build a low-cost version. Most of what she needed already existed as spare parts being stored around the university lab. These included a low-power laser and a 50-power microscope. Because much of the equipment that she used had been donated to the lab, she says that it’s not easy to figure out how much it would cost for others to build her version of the device.

Many optical tweezers focus laser light by sending it through an optical fiber. But for her device, Kathy shone the laser upward through the microscope. (This light went in the end of the microscope that’s normally near the tiny object being examined. It came out the top where someone would typically look into the eyepiece.) Kathy then used lenses to focus the light emerging from the eyepiece and to harness the forces it exerted to grab tiny objects. A projection system helped magnify Kathy’s view of the sample and let her see the amazingly tiny objects she was working on. She could better identify one type of blood cell, for example, and separate it from a larger mixed group of cells.

Her invention worked! “I was amazed,” she says, “that you could build your own set of optical tweezers.”

That hands-on approach to science explains in part why Kathy loves physics. “Who doesn’t like blowing things up or watching them fizzle?” she asks.

Microbe-stifling charcoal

Many gardeners fight plant diseases using pesticides and other chemicals. Anne Merrill, a 17-year-old senior at Greenwich High School in Greenwich, Conn., decided to take a greener approach. A big fan of natural gardening, she used biochar to grow healthier and more productive plants.

Biochar is the name growers give to charcoal when it is used in agriculture. It’s a natural substance and doesn’t have added chemicals, so it’s acceptable to organic gardeners, Anne explains. For her Intel ISEF project, she explored biochar’s potential to fight soil-borne diseases that afflict plants (and can sicken people).

Anne started by scattering tiny bits of biochar across her garden plots. But she didn’t mix the charcoal into the soil. She left that to the helpers she recruited: earthworms.

Worms eat soil, and after they digest the organic matter inside they excrete the rest as fertilizer. When Anne’s worms came above ground at night and ate the soil in her garden, they would also consume the tiny bits of biochar she’d scattered. Then, they’d carry the biochar back underground. There, the charcoal provided nutrients to plants.

It also helped fight harmful microbes in the soil, Anne’s tests now suggest.

The teen raised tomato plants for 55 days. Those on plots that included biochar and earthworms grew about 20 percent larger than those raised in the absence of biochar. Plants grown with biochar also did a better job of fighting Fusarium oxysporum. That nasty fungus causes diseases in many types of plants, and Anne had dabbed the it onto her tomatoes. Yet another benefit: The biochar treatment apparently stifled the growth of E. coli. This common bacterium, shed by wildlife (or sick people), can cause food poisoning.

Anne says her results strongly suggest that natural methods of gardening can help boost crop yields. That’s good news, she adds, for people looking for alternatives to pesticides and other garden chemicals. Worm burrows add another benefit: These holes allow air to better penetrate the ground. Those holes also help rainwater more quickly drain down to a plant’s roots.

Anne is a big supporter of organic gardening. She plans to pursue a career in environmental science.

Fruit flies on the brain

Most students fill their shelves with books, posters and stuffed animals. Lisa Michaels, an 18-year-old student at Plano West Senior High School in Plano, Texas, packs her shelves with jars full of fruit flies. The jars cover her desk too.

For her Intel STS project, Lisa used the insects to study possible treatments for Alzheimer’s disease. The incurable brain disorder often causes confusion, mood changes and problems with memory and language. Her grandfather inspired the research. Not long ago, he was diagnosed with a condition that often precedes full-blown Alzheimer’s disease.

Lisa studied three genetically distinct types — or strains — of fruit flies. One type has a genetic defect that causes the same sort of nerve damage seen in Alzheimer’s patients. Those flies typically have shorter life spans too, Lisa says. Another strain has a mutation that causes its cells to make extra amounts of glutathione. This substance is an antioxidant, which protects cells from certain types of damaging chemical reactions. Glutathione is also a possible treatment for Alzheimer’s, notes Lisa. The third fly strain is a hybrid of the first two. Lisa created the hybrid strain for her tests.

The hybrid flies could be important in solving the mystery of Alzheimer’s, Lisa believes. The reason: They include both the gene that causes the fly version of Alzheimer’s and a gene that makes a possible treatment. Because Lisa is the first to create such a hybrid, she has applied for a patent on her “invention.”

Her hybrid fruit flies produced more glutathione in their cells than did normal fruit flies, Lisa found. More importantly, she showed that the antioxidant helped lessen the Alzheimer’s-like nerve damage. So her hybrid flies remained healthier. And they enjoyed much longer lives than the flies lacking the gene to make bonus glutathione. In fact, says Lisa, some hybrid flies lived just as long as normal fruit flies.

The research may lead to better tests for Alzheimer’s, Lisa says. Those tests might look for the toxic substances that harm nerves and brain cells. She hopes that one day this work might lead to better treatments.

The costs of too much screen time

Zarin Rahman, a 17-year-old senior at Brookings High School in Brookings, S.D., found inspiration for her Intel STS project in all of those electronic devices around her. Like most teens, she uses social networking to keep up with her friends. “But,” she says, “I found that whenever I stayed up late at night using my computer and cell phone, I was unable to focus on my teachers’ presentations the next day.” She just was not as mentally alert.

Previous studies had linked teens’ excess use of electronic devices with too little sleep, Zarin says. She wanted to measure the impacts of that.

So she designed a questionnaire that helped her divide volunteers (some of her classmates) into two groups. One included teens who got normal amounts of sleep. Those in the other group were shortchanging their zzzz’s.

Zarin then used a series of tests to assess memory and alertness in her volunteers. She also measured their blood pressure and heart rate during the tests.

Increased screen time leads to poor sleep patterns, her data indicate. Too little slumber, in turn, triggers daytime fatigue and increased stress. And that reduces a teen’s ability to recall information or perform well on other mental tests. Because the developing brain is especially vulnerable to stress, Zarin thinks her research will help show that teens’ excessive use of electronics could pose a threat to public health.

The teen wants to continue her research on the adolescent brain. For now, she’d like to record a radio or TV public-service announcement to make teens more aware of the effects of their lifestyle choices. As for a career choice, “I’d like to stick with science,” Zarin says. “But if I can contribute to public policy in the name of science, that’s awesome.”

What all of these awesome teen researchers have shown is that the route to cool research may be no further than your friends, family or workplace.

Power words

Alzheimer’s disease     An incurable brain disease that can cause confusion, mood changes and problems with memory, language, behavior and problem solving. No cause or cure is known.

antioxidant       Any of many chemicals that can shut down oxidation, power and potentially damaging reactions. Many plant-based foods are good sources of natural antioxidants, including vitamins C and E.

arsenicosis      The poisoning that results from chronic exposure to arsenic, usually through air or drinking water. Arsenic can cause skin disorders, reproductive problems, cancers and diseases of the blood vessels.

arsenic   A highly poisonous metallic element. It occurs in three chemically different forms, which also vary by color (yellow, black and gray). The brittle, crystalline (gray) form is the most common. Some manufacturers tap its toxicity by adding it to insecticides.

biochar   A type of charcoal often used in agriculture to improve soil for plant growth. It can help plants take up nutrients, improve soil drainage, and increase plant yields, tests show.

biomedicine      A field of research relating to the biological underpinnings of medicine, such as how the body works when healthy versus sick.

E. coli (short for Escherischia coli) A bacterium that researchers often use to study genetics. Some types of this microbe cause disease, although many other forms of it do not.

electronics    Devices that are powered by electricity but whose properties are controlled by the semiconductors or other circuitry that channel or gate the movement of electric charges.

filter    (in chemistry and environmental science) A device which allows some materials to pass through but not others, based on their size or some other feature.

environmental science The study of ecosystems to help identify environmental problems and possible solutions. Environmental science can bring together many fields including physics, chemistry, biology and oceanography to understand how ecosystems function and how humans can coexist with them in harmony.

force    Some outside influence that can change the motion of a body or produce motion or stress in a stationary body.

fungus    (plural: fungi) Any of a group of unicellular or multicellular, spore-producing organisms that feed on organic matter, both living and decaying. Molds, yeast and mushrooms are all types of fungi.

gene  A segment of DNA that codes, or holds instructions, for producing a protein. Offspring inherit genes from their parents. Genes influence how an organism looks and behaves.

germ    Any one-celled microorganism, such as a bacterium, fungal species or virus particle. Some germs cause disease. Others can promote the health of higher-order organisms, including birds and mammals. The health effects of most germs, however, remain unknown.

hybrid     An organism produced by interbreeding of two animals or plants of different species or of genetically distinct populations within a species. Such offspring often possess genes passed on by each parent, yielding a combination of traits not known in previous generations.

laser  A device that generates an intense beam of coherent light of a single color. Lasers are used in drilling and cutting, alignment and guidance, and in surgery.

mentor  An individual who lends his or her experience to advise someone starting out in a field. In science, teachers or researchers often mentor students, helping them refine their research questions. Mentors can also offer feedback on how young investigators prepare to conduct research. 

mineral  The crystal-forming substances, such as quartz, apatite, or various carbonates, that make up rock. Most rocks contain several different minerals mish-mashed together. A mineral usually is solid and stable at room temperatures and has a specific formula, or recipe (with atoms occurring in certain proportions) and a specific crystalline structure (meaning that its atoms are organized in certain regular three-dimensional patterns).

molecule  An electrically neutral group of atoms that represents the smallest possible amount of a chemical compound. Molecules can be made of single types of atoms or of different types. For example, the oxygen in the air is made of two oxygen atoms (O₂), but water is made of two hydrogen atoms and one oxygen atom (H₂O).

mutation  Some change that occurs to a gene in an organism’s DNA. Some mutations occur naturally. Others can be triggered by outside factors, such as pollution, radiation, medicines or something in the diet. A gene with this change is referred to as a mutant.

nerves      Long, delicate fibers that communicate across the body of an animal. An animal’s backbone contains many nerves, some of which control the movement of its legs or fins, and some of which convey sensations such as hot, cold, pain.

nanoparticle     A small particle with dimensions measured in billionths of a meter.

organic  (in agriculture) Farm products grown without the use of non-natural and potentially toxic chemicals, such as pesticides.

parts per (million, billion or trillion)  A measurement of extremely small concentrations of one chemical dissolved in another. For example, a solution of 300 parts per billion of sodium in water would mean that there are 300 sodium atoms for every billion water molecules.

patent  A legal document that gives inventors control over how their inventions — including devices, machines, materials, processes and substances — are made, used and sold for a set period of time. Currently, this is 20 years from the date you first file for the patent. The U.S. government only grants patents to inventions shown to be unique.

pesticide  A chemical or mix of compounds used to kill insects, rodents or other organisms harmful to cultivated plants, pet or livestock, or unwanted organisms that infest homes, offices, farm buildings and other protected structures.

polyvinyl chloride    Also known as PVC, this is a plastic formed by using heat to turn a liquid resin into a solid. The plastic can be soft and flexible or rigid and hard. The raw ingredients consist primarily of chlorine and carbon.

questionnaire      A list of identical questions administered to a group of people to collect related information on each of them. The questions may be delivered by voice, online or in writing. Questionnaires may elicit opinions, health information (like sleep times, weight or items in the last day’s meals), descriptions of daily habits (how much exercise you get or how much TV do you watch) and demographic data (such as age, ethnic background, income and political affiliation).

social network     Communities of people that are interrelated owing to the way they relate to each other, such as sharing details of their life and interests on Twitter or Facebook, or perhaps belonging to the same sports team, religious group or school.

stress    (in biology) A factor, such as unusual temperatures, moisture or pollution, that affects the health of a species or ecosystem.

toxic   Poisonous or able to harm or kill cells, tissues or whole organisms.

World Health Organization     An agency of the United Nations, established in 1948, to promote health and to control communicable diseases. It is based in Geneva, Switzerland. The United Nations relies on the WHO for providing international leadership on global health matters. This organization also helps shape the research agenda for health issues and sets standards for pollutants and other things that could pose a risk to health. WHO also regularly reviews data to set policies for maintaining health and a healthy environment.