Getting to the root of water quality

Getting to the root of water quality

March 1, 2006
Long road trips with the family can be much more enjoyable if you have an activity to occupy yourself with along the way—such as collecting water samples from the various cities you visit! That’s how 16-year-old Nashila Addetia chose to pass the time when her family drove from their home in St. John’s, Newfoundland, to Boston, Massachusetts.

By the end of the two-week trip, the car was packed with tap-water samples from more than two dozen cities, stored in airtight, leak-proof containers. As a growing amount of trunk space was sacrificed to the collection, Nashila’s father began to wonder what was going to become of all this water. What he might not have guessed was that Nashila planned to throw a buttercrunch lettuce seed into each of the samples, then watch what happened.

“It was actually a fun experiment,” she says. “Lettuce seeds are a good indicator of the quality of water. If there are any pollutants in the water, the roots will be smaller.”

This experiment became the basis for Nashila’s entry into the 2005 Canada-Wide Science Fair competition, held in Vancouver last spring. There, she took honourable mention in the Earth and Environmental Science category, and won the Canadian Stockholm Junior Water Prize.

Her project presented the lettuce seed growth as an effective bioassay. It supported the hypothesis that water from cities near highly industrialized areas showed deficient root growth, indicating higher levels of local pollution. Without detecting or measuring any specific pollutants, the work provided a relative comparison of the samples.

She used tap water from her own home as the control by which to measure the others, and the lettuce seeds thrived better in that sample than they did in any other. In fact, the five samples she took from other parts of her province also did well. “All of the Newfoundland ones showed a good root length growth,” she says. “They were all among the top 10 of my samples.”

Among the samples that did not do as well, she notes, were those in areas around the Great Lakes and points directly east of them. Nashila’s subsequent research indicated that these places lie in a path of air pollution carried by winds blowing from southern Ontario into Nova Scotia. Interestingly, she found the second best root growth in a sample from Buffalo, New York, leading her to explore the possibility that some cities go to greater lengths than others to clean up their drinking water.

“After I finished the experiment, I researched the possibility that some cities have better water filtration systems,” she says. Although she was unable to pin down technical differences in the way different cities treat their water, she did find a significant amount of phosphate in her worst root growth sample, and none in her best sample.

The lettuce-growing project was just the latest of many that Nashila, who graduates from high school this year, has entered in science fairs since she was in Grade 8. And as her family vacation cum scientific field excursion taught her, a simple approach to research is generally best.

“Most people over-think things,” she says. “They turn it into something that they can’t do, or they can’t get it done on time.”

Her outlook is encapsulated by the buttercrunch lettuce seed, a simple organism that has demonstrated its potential for bioassay work all over the world. After reading about some of the seed’s applications, Nashila realized that the seeds would be good indicators of water quality for her own project.

“It wasn’t very difficult to understand what I was doing,” she explains. “It was something that a high school student could do without having help from a mentor or their parents in order to build something.”

As she looks ahead to university, Nashila has a similarly straightforward plan: “I want to know as many languages as I can fit in my head.” She already speaks English and some French, and she has studied German and Spanish in school. Eventually, she would like to take her knowledge of science across linguistic boundaries.

“I want to do something that is new, something that people have not done before,” she says, citing the importance of language in helping to address many of today’s most pressing scientific issues. “If people can talk with each other, then they can solve so many problems.”

Visit Environment Canada's water web page.