IT IS ESTIMATED that some 60,000 chemicals are discharged into the environment every year. Most of these may be harmless—although only 400 or so have been tested for their toxicity on humans—but some, including many once thought to be harmless, are not.
Take, for example, estrogen. There’s growing concern
about the effects of endocrine-disrupting compounds
(EDCs) like estrogen on the reproductive cycle
of marine life, and perhaps on human reproduction
as well. Most concern has been focused on the by-products of birth control pills passing through municipal wastewater treatment plants. But Paige Novak, associate professor of civil engineering, who is also a Founding Fellow of the Institute on the Environment,
doesn’t think that’s the whole story.
Associate professor of civil engineering Paige Novak is researching the biological transformation
of hazardous substances in sediment, groundwater, and wastewater. Her focus is on how external environmental factors influence the biodegradation of these substances, which is of critical importance in designing and implementing biologically-based remediation systems and using microorganisms to treat wastewater.
“Many people are looking at birth control pills as the primary source of estrogen in the water supply, but they are not looking at plant-based estrogens,” she explains. That oversight led her to study estrogen levels in industrial wastewater systems, especially those located near facilities that process organic material,
like ethanol plants, pulp and paper mills, and food companies that process cereal grains. She has discovered these wastewater streams contain concentrated
forms of natural or phyto-estrogens that pose as great a danger as anything passing through municipal water treatment systems. She is now working on ways to reduce the discharge of phyto-estrogens, research that could affect the design and regulation of new ethanol and biodiesel fuel plants.
“These industrial facilities are often in small towns—ethanol plants, corn processing facilities—and can have a big effect on fish populations,” she said. “We want to find ways to better treat this material,
not just to stir up water.”
Her research also has led her to conduct groundbreaking
studies of an obscure genus of bacteria called Dehalococcoides, a family of organisms that share a peculiar characteristic: they metabolize chlorinated
compounds during respiration. One of the compounds a certain species of the bacteria ingests is PCB, or polychlorinated biphenys, an old industrial chemical once used to produce transformers.
Polychlorinated biphenyls
(PCBs) may be linked to developmental
and nervous system disorders and the induction of some cancers. These containers of microcosms
are set up to study a bacteria called Dehalococcoides, an organism which may lead to ways of accelerating
the degradation of industrial PCB, a chemical once used to produce transformers.
Novak is studying how to stimulate the growth of the PCB-degrading bacteria that contaminate the soil and groundwater around industrial sites. She and her fellow researchers were the first to discover
that members of the Dehalococcoides genus are also native to natural environments where they metabolize
naturally occurring chlorine compounds, such as those produced by dead leaves in the fall. She is now studying whether these organisms will also consume industrial PCBs. If so, it might lead to ways to accelerate the degradation of industrial PCB by introducing multiple forms of Dehalococcoides to a contaminated site.
Similar to her work on phyto-estrogens, her objective
is always the same. “At the end of the day, I’m an engineer, and my goal is always to solve a problem,” she explains. “I get excited by science, but the motivation is always to come up with new techniques
to clean up stuff which shouldn’t be in our water supply.”
