Department of Biological Sciences (Environmental Toxicology)
Joined SFU in September 2014
The growing threat to ecosystems posed by pollution and climate change highlights the importance of environmental monitoring activities and informed action by governments. Endocrine disruption in wildlife exposed to environmental contaminants is of concern worldwide. Through lab work and field studies, she is developing new biomarkers as early onset indicators of exposure to environmental contaminants that can be used in risk assessment and monitoring activities, which will benefit both local and global communities.
What early experiences influenced you to pursue a career in science?
I didn’t come from an academic family, but I had amazing high school teachers who were very encouraging. In fact, I did my B.Sc. in Animal Physiology with a minor in Environmental Toxicology here at SFU. My first exposure to the topic of environmental toxicology was in third-year biology. I had been thinking about going into medicine, but learning about environmental and pollution issues made me realize that the environment needed me more.
What is the most satisfying part of the research you do? What is most frustrating?
The most satisfying part is trying to advance environmental toxicology and the testing of environmental contaminants to ensure we have the best data set to assess the risk of various chemicals and pollutants on the planet.
Research is a very slow process – that is probably my main frustration. It takes an incredible amount of time, effort, and planning to execute an experiment that will produce high quality data. And working with live organisms can be very unpredictable.
Considering pollution, which activities/exposures concern you the most?
Some of the biggest pollution problems in Canada stem from the use of pesticides in agriculture, which is an issue for wildlife habitat. We use large quantities of pesticides for food production. Upwards of 15 different pesticides can be detected in water bodies surrounding agricultural areas. Pesticides are designed to kill; typically, they target invertebrates, but they often have detrimental effects on non-target organisms, aquatic wildlife in particular. Some pesticides end up in the surface water – that’s our sink for environmental pollutants.
We know that pesticides have an effect on ecosystems, but the extent of that effect, and which chemicals are the offenders – this is something we are still trying to discern in the field. And to complicate matters, multiple pesticides in a single body of water make it difficult to establish cause-and-effect. Thus, it is challenging for our government regulators to identify which pesticides are the worst offenders.
Other pollutants that are an ongoing problem include sewage and various components of municipal effluents. Sewage discharged from wastewater treatment plants contains mixtures of personal care products and pharmaceuticals that treatment systems are not designed to degrade, therefore many of these pollute our surface waters. Pharmaceuticals are bioactive in vertebrate species; there is some conservation of biological receptors in wildlife and humans, so biologically active compounds discharged into waterways can certainly have an impact on the biology of other vertebrates, such as fish and amphibians. For example, the birth control agent ethinyl estradiol is an extremely potent estrogen and it acts as an estrogen in fish as it does in humans.
Is effective action being taken?
In Canada progress is slow – most of our regulations lag behind those in Europe, the US, and Japan. Canada is really in the late stage of the game when it comes to regulatory guidelines for endocrine disruptors. With respect to sewage effluent, the BC Ministry of Environment has a water quality guideline for ethinyl estradiol. Typically, however, pharmaceuticals and personal care products are not monitored so there's little incentive to implement changes in our municipal wastewater treatment practices. These are societal problems that weren’t being questioned years ago; we recognize them as problems now, but it takes millions of dollars to upgrade treatment plants to degrade these compounds.
Another endocrine disruptor, bisphenol A (BPA), is present in many plastic bottles and food can linings. Health Canada banned it in baby bottles because it behaves as an estrogen, and infants and small children are more susceptible to the effects of these hormone mimics. However, BPA is present in most Canadian adults, including pregnant women. And until we get rid of BPA in pregnant mothers, their babies will be exposed to it at critical stages of development. Too much estrogen at certain stages promotes a more female gender even in a genetic male embryo. Canada’s ban of BPA in baby bottles is a good first step, but in utero exposure remains a disturbing problem.
How do you see your program developing over the next 5-10 years?
My general research plan is to continue to unravel the molecular signaling pathways and physiological processes that modulate and integrate the endocrine system, i.e., the reproductive, thyroid, and stress endocrine axes in non-mammalian vertebrate models, and apply this knowledge to advance the field of endocrinology and environmental toxicity testing regimes relevant to North American ecosystems.
One of my interests is to understand the interactions or ‘cross-talk’ of hormones such as estrogen, androgen, thyroid, and stress hormones, especially at sensitive stages of a life cycle. One of the models I use, an early-life stage rainbow trout, can be exposed to several hormones individually and in combination, thereby allowing us to examine the effects of the hormones on gene and protein expression in the whole animal and in particular tissues, as well as on hormone levels in the animal and on its phenotype. This work will reveal molecular level signaling cascades involved in controlling major physiological processes such as growth, development, and reproduction. This same model can be used to determine the extent to which environmental contaminants impact the endocrine system at the molecular and organismal level.
How is the research you now do similar or dissimilar to your earlier research experiences?
My research skills and expertise have expanded due to my work experience in academic, governmental, and industrial settings. For the fields of environmental toxicology and biology, the quality control and quality assurance that I incorporate into experiments is very robust and results in an approach that is perhaps a little different than that used by other academic labs. This stringency is a great asset, especially if you're studying environmental toxicology and you want to be employed in that field afterward. Understanding the quality assurance and control issues that must be adhered to in a commercial or a government setting is very important. That was a big eye-opener for me, going from the university setting to a postdoc position in a commercial lab.