6th Grade Science Chat: Edited Transcript
December 10, 2001, 9:30 a.m.

Miss Nelson's Class: how many plants have you helped?
Dr. Newman: Well, I don't really help the plants; the plants help me to clean up toxic chemicals in the environment. I have worked now with about 12 different plants, and we are constantly working with more.

Miss Nelson's Class: How does this job have to do with your everyday life?
Dr. Newman: Well, I am more aware of chemicals that we put into the environment without thinking about it - if someone changes their oil and doesn't have protection, it gets into the water. Whenever we use pesticides, if we don't use them right, they also get into the water.

Miss Nelson's Class: how Long did it take to be a actual scientist?
Dr. Newman: Well, it took me a while - I wanted to be able to run my own laboratory, so I needed to get a Ph.D. That took about 10 years of college. But there are people who work with me who have gone to college for only 4 years, and contribute a lot to the research.

Miss Nelson's Class: In what ways are you going to make sure that illegal chemical dumpings will not take place in the poplar trees area?
Dr. Newman: That is actually a very big problem, as many of our sites were originally "midnight dump" sites; meaning that people were sneaking onto the sites and dumping chemicals to avoid paying for proper disposal. Thus we often have to lock up the sites. However, one of the ways that we have found that works really well is having the community in the area aware of what we are doing, and asking the people who live there to keep an eye on the sites for us.

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Miss Nelson's Class: You said that when some chemicals stay in the ground, it can cause problems in the environment. Can you give an example of a problem from the dangerous chemicals?
Dr. Newman: Well, there were two movies recently about chemicals in groundwater - one was about a solvent, trichloroethylene, which got into drinking water and was causing leukemia in the children who were drinking it and breathing in the vapor when they showered. The other was about chromium, a metal, that was in the water and causing cancer and all sorts of health problems.

Miss Nelson's Class: why does it take a few years for the scientists to find out if the trees work?
Dr. Newman: The reason it takes a few years to see if it works is because we need to allow time for the trees to grow. If we plant a tree, we have to water it and care for it until it gets to be big enough for the tree roots to reach the chemical. Sometimes, to shorten the time, we will irrigate the trees with the contaminated water. That way, we are cleaning up the site before the trees get big enough to do the job on their own.

Miss Nelson's Class: Are there other plants that could be used beside poplar trees?
Dr. Newman: There is a whole big world of trees and plants out there, and we are just starting to look at them. There has been work done with willows to take up solvents, eucalyptus to take up gasoline additives, and pine trees to take up tritium. Poplars were first worked with because they took up lots of water (and certain chemicals!) and we had lots of experience growing them. But they won't work for every site, so we have to spend more time looking at all those other plants to see what they can do.

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Miss Nelson's Class: Why are poplar trees the only trees that work in this case? Have you tried other fast growing trees?
Dr. Newman: Poplars are not the only ones that work. Willows and eucalyptus take up the solvents just as well. We are still working with them to see how well they break down the chemicals. As I said, poplars were the first ones we worked with, so we have the most knowledge about them, but there are lots of others out there, some that might even work better than the poplars.

Miss Nelson's Class: how do the chemicals survive in the environment?
Dr. Newman: Well, a lot of the chemicals are very resistant to breakdown. Some of the pesticides were choosen specifically because they DIDN'T breakdown, and the farmer didn't have to apply them as often. But in general, in order for the chemicals to be broken down, there have to be very specific conditions there - the right amount of oxygen, the right amount of food for the bacteria, and sometimes, the right chemical to 'turn on' the proteins that do the breakdown. Very hard to get all the conditions right just by chance! With some chemicals, they could last for hundreds of years if the conditions were right for them.

Miss Nelson's Class: Do poplar trees grow well here in the North West?
Dr. Newman: Poplar trees grow VERY well in the the North West. We work with one type of poplar that, if grown under good conditions (and my sites rarely have those!), the trees can grow 12-15 feet per year.

Miss Nelson's Class: What do you think will happen if the experiment works?
Dr. Newman: If the experiment works, the trees take up the chemicals, and break it down inside the plant to non-toxic chemicals, like water and carbon dioxide. The trees can be left in place, or the area used as a park. There is actually some work going on in Wyoming where they are using the site as a park WHILE the trees and plants are cleaning up the site.

Miss Nelson's Class: why do some chemicals hurt us but not the trees?
Dr. Newman: A lot of the chemicals cause problems only after years of exposure. Now, if the concentration was high enough, it would kill the plants pretty fast. But many sites use annual plants, which are harvested every year and replanted. With our poplars, we will probably go in and replant every 15-20 years, as the trees get too old to work properly. We simply don't know yet what long term exposure will do the the trees, and the only way we have to find out is to plant them and see what happens.

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Miss Nelson's Class: what is your favorite part about being a scientist?
Dr. Newman: What I like about being a scientist, and working in this area, is that I am constantly learning. There is always someone with a new idea to test, some new technique or skill that needs to be learned to make the work go better, some new idea that my students and I come up with that we want to test. It is NEVER boring! As far as the work I do now, it allows me to work in the lab, learning what the plants are doing with the chemicals. I get to work in the field, and test all the theories we come up with. And finally, when things do work out, I get to go out on some really contaminated sites and work at cleaning them up for the future.

Miss Nelson's Class: If the trees suck it up the poison would get stuck in the tree and will it stunt its growth?
Dr. Newman: Sometimes, especially with metals, they do get stuck in the plants. And yes, they can stunt the plant, or even kill it. With the solvents and groundwater chemicals that I work with, they can stunt the growth of the trees, and affect other things about how they react in their environment. But fortunately, the chemicals I have worked with all seem to be changed in the plant to non-toxic chemicals, so the bad chemicals don't stick around.

Miss Nelson's Class: we enjoyed chatting with you and thank you for paying so much attention to the environment! Good luck on your research!

Dr. Newman: Thank you. If anyone has any other questions, you can email them to me and I will try to answer them for you.