We all like to think that the water we're drinking is safe. But how
do we know? In 2000, residents in Walkerton, Canada, learned not to trust
their drinking water supply. E. coli contaminants entered the water system.
It caused six people to die and many more to become seriously ill.
Although no one knows exactly how the water became contaminated, some suspect
that the chlorinator at the water treatment plant wasn't working, and
that perhaps nearby farms were contaminating the groundwater supplies.
Joan Wu is a biosystems engineer at Washington State University. She didn't
work on this particular issue, but she is concerned about water supplies in
general. "Whether it's for agricultural purposes or for domestic use,
I look at water movement," she says.
"It's important that we look at the physical processes of water movement,"
she says. This water is generally found in three areas: beneath the ground
in the aquifer, along the surface in rivers and streams and in the all-important
root zone.
"Crops have roots that stretch beneath the ground about one to two meters
[three to six feet]," Wu says. "I'm interested in every area of water,
but this zone is especially important for agriculture."
Is the groundwater supply clean? Is the aquifer being drained too quickly?
Is agriculture contaminating the water supply? Water is such a valuable resource
that there are many questions that need to be asked and answered.
Of course, studying moving water is often difficult. "It's very challenging
work," she says. While studying groundwater, scientists often have to work
with limited data.
"Because the water is beneath the ground, we have to get access to it,"
she says. "Building monitoring wells is expensive, so we don't have as
many as we'd like. The lack of data is always frustrating."
Nonetheless, Wu perseveres and conducts her experiments on moving water,
and teaches courses in hydrology. "I really enjoy my work," she says. "I'd
encourage any young person to enter this field. It's so important and
it's enjoyable."
Just as important as water is food. When we go to the grocery store, we
assume that the products we buy will be fresh. But if they've been shipped
across the country, how do the perishable and non-perishable items stay fresh
and safe to eat?
There is a whole science behind this industry. Biosystems engineers also
work in food science, and in the complex area of food packaging. "Most people
just think of the package as a non-edible protective layer," says Jung Han,
a professor. He says it's much more complicated.
A package has to protect food against chemical, physical and microbial
damage. "Chemically, the package has to provide a good barrier against oxygen
to stop the growth of bacteria or mold," he says. He also explains that the
package should protect against water damage and water vapors. "It's important
to retain flavors."
It's easy to imagine why food has to have protective packaging. Some
foods are shipped across the country on trains and trucks and are transported
from distribution houses to grocery stores.
Imagine potato chips without their protective packaging. They'd be
piles of yellow dust long before they hit a store's shelves. Other food
simply couldn't be shipped. "Just think: you couldn't ship water
without bottles," says Han.
Microbes can cause food to rot, and can cause serious illness in people.
"Food is sensitive to microbes and so the packaging has to be clean and closed
against the environment," says Han.
Of course, Han also has to consider the information that needs to go on
every package such as brand names, nutritional labels and recipes. All foods
need to be packaged and labeled according to industry standards.
But packaging requirements also trouble engineers. "Thirty percent of the
solid waste going to landfills is packaging," says Han. This is something
he'd like to change. In his efforts to create new packaging, he always
looks for biodegradable alternatives.
Packaging is much more complex than dumping a handful of candies into a
cardboard box. "It's much more difficult than other types of packaging
because you have to specialize in food science, [and] know the physical properties
of the food." For Han, these added requirements only make his job more interesting.