Draped over a chair in Mary Davis' office
at the University of Maine is a pair of bright orange nylon coveralls
bearing the insignia of the Maine Marine Patrol.
A nearby duffel bag holds an orange neoprene
cold-water survival suit, also the property of the water-based law
enforcement wing. Both are standard-issue equipment in Davis' most
recent line of work, which involves gathering safety-compliance data
aboard Maine commercial fishing boats.
On a bookshelf sits a well-used air monitor that
allowed her not long ago to measure the particle pollution drifting
from the cigarettes she reluctantly puffed on a car trip from Bangor
to Bar Harbor while researching the costly effects of secondhand smoke
Not exactly the tools of the typical economists'
trade, perhaps, but Davis doesn't think of herself as a typical
"I would say it's rare to do this type of active
sampling in economics," says Davis, an assistant professor in the
School of Economics. "Most economists would rely on data that already
As an environmental health economist, drawing on
the natural and the social sciences, Davis looks at the impact of the
environment on the development of human diseases. She believes that in
order to understand the economic cost of exposure to airborne
pollutants or the policies that address such public health concerns,
she has to learn firsthand the nature of that exposure and whether it
"I start with improving the underlying scientific
knowledge regarding the health effects of disease," she says, "before
I try to make policy recommendations or cost assessments from an
Being able to access large collections of data can
be a valuable tool in economic research. But the issues Davis tackles
in Maine don't necessarily offer an abundance of preexisting data.
Sometimes, as in the case of her ongoing study of safety practices in
Maine's dangerous commercial fishing industry, there are no statewide
data sets available. The only way to get the data she needs is to go
out and collect it herself.
"My work is looking at what's actually being done
by fishermen to mitigate risks on an individual level," she says, "so
that we can more efficiently determine the best course of action to
prevent accidents and deaths among commercial fishermen in the state."
After getting a bachelor's degree in economics and
international studies in 1998 at the University of Miami, Davis worked
as a U.S. Customs inspector at the city's busy airport.
"I was a drug interdiction officer, which meant I
was constantly arresting people and putting my life in danger over
drugs," she recalls. "I was also their data person, collecting and
cataloguing information. It was a life-altering experience, I'd have
to say, but it wasn't for me."
Davis eventually shifted her economics focus from
international to environmental, and got her doctorate in economics in
2003 from the University of Florida. For her dissertation, she
examined the economic factors that influence state environmental
policymaking, and developed a model to predict those decisions. She
determined, among other things, that a state is more likely to adopt
stricter environmental standards when compliance does not come at
great economic expense.
In 2003, Davis began studying at Harvard for a
second master's degree, this one in biostatistics, but changed her
plans when she got a chance to do postdoctoral research for a project
in environmental health at the university's School of Public Health.
The project, which she is involved with still, is a comprehensive
examination of the connection between elevated lung cancer rates and
exposure to diesel exhaust fumes among some 55,000 unionized truck
With an epidemiologist, a physician and an
occupational hygienist, Davis helped to collect and analyze 5,000 air
samples from 36 trucking terminals nationwide. She is now working to
create an exposure model to predict the risk of lung cancer for
employees in various aspects of the trucking industry, including
drivers, diesel forklift operators and loading dock workers.
Davis says the information is relevant not only to truckers, but to
the public that lives, commutes or works near diesel-fueled traffic or
"It's definitely an ongoing project," says Davis,
who came to UMaine in 2006 and maintains a visiting scientist
appointment with Harvard. "Diesel exhaust is now considered to be a
probable carcinogen. But no one has ever done so large and
comprehensive a study as this. Our hope is that we can refine the risk
estimates and move diesel from a probable to a known carcinogen.
Increasing the level of certainty allows people who make policy to be
better informed in their decisions."
Last summer and fall, Davis did a study that put an eye-opening
number on the economic impact of secondhand smoke on children in
Maine. The idea for the research came from Bangor pediatric dentist
Jonathan Shenkin, who led a successful effort to get the Bangor City
Council to prohibit smoking in vehicles carrying passengers 18 and
younger, and then pushed to have a similar ban enacted statewide.
By analyzing numerous national and state studies
on a variety of respiratory conditions in young people, Davis assigned
a relative risk estimate for childhood illnesses linked to secondhand
smoke in cars, homes and other environments. The annual price tag for
the increased doctor visits, hospitalization, medication and work time
lost to parents who care for sick children, Davis calculated, is more
than $8 million.
Davis says she prefers not to legislate personal
responsibility, and doesn't usually feel comfortable in an advocate
role. But she is willing to make an exception when it comes to a
statewide ban on smoking in cars with children present. For Davis, the
numbers simply do not lie.
"I was able to identify a clear risk regarding
secondhand smoke and children," she says. "Nonsmoking adults have a
choice to not be around secondhand smoke. Children don't have that
choice, not if their parents smoke at home or in the car, and the car
is certainly a peak setting for exposure."
To further drive home that point, Davis strapped
the real-time air particle pollution monitor to the back seat of her
car, roughly where a child's head would be, and took a ride from
Bangor to Bar Harbor. Davis rolled down the window a bit and lit up in
the name of science. As she smoked, the monitor registered 10 times
the allowable level of particle pollution. When the cigarette was out,
the particles from the smoke dropped to negligible levels after a few
Although her work examined the effects of
secondhand smoke on children in general, and was not specific to cars,
Davis says she did the driving experiment to emphasize the dangerously
high particle levels that can build up in small spaces where children
are so often confined.
Her Harvard connection also led Davis to her most recent field
study, and the reason for all that bright orange seagoing gear in her
office. Funded by a $200,000, two-year Maine Sea Grant, Davis has
teamed up with Ann Backus, director of outreach for the Harvard School
of Public Health, and the Maine Marine Patrol on a first-ever
assessment of the rate of safety compliance among Maine commercial
Although fishing is one of the most dangerous
occupations, Davis says there is currently no way of knowing how many
Maine fishermen are actually complying — and to what degree — with the
regulations intended to keep them safe. Her research will be used to
create an economic model of the cost of compliance, which can then
help industry regulators better understand the impact of imposing new
federal safety laws in the future.
Davis, the project's lead investigator, and Greg
Blackler, a Damariscotta lobsterman who is pursuing his master's
degree in economics at UMaine, began boarding vessels last November to
gather data from the fishermen themselves. Their goal for 2008 is to
board 300 vessels working in a variety of fisheries along the Maine
coast. The initial response from fishermen was encouraging; the
researchers were welcomed aboard each of the first 30 lobster boats
they encountered about 10 miles off Rockland.
Davis, Blackler and Backus, who is a member of the
Maine Commercial Fishing Safety Council, always begin by assuring
fishermen that the survey will not lead to citations, even if safety
violations are found. All information is anonymous, Davis says, and
neither the fishermen's names nor the identities of the boats are ever
The survey is brief — less than 10 minutes — but
thorough. There are general questions concerning the fishermen's lives
and work history, as well as the lengthy list of safety equipment
they're required to carry, at their own expense, by the Commercial
Fishing Industry Vessel Safety Act of 1988. To avoid a fraudulent and
thereby worthless collection of data, the fishermen are asked not only
if they have, say, the correct number of life preservers or fire
extinguishers aboard, but if they might be kind enough to show them to
"Truckers and lobstermen are similar in some
ways," says Davis. "They both tend to be rough-and-ready, independent
people. There's a wide variety of types among fishermen. Some of them
are all about getting help regarding safety issues, and there are
those out there by themselves on rickety boats who worry that we're
going to catch them doing something wrong. But we assure them that
we're not out there to mess with them."
The Maine Marine Patrol, which transports the
researchers to the sampling sites, are grateful for the data, Davis
"They're sincerely interested in safety, and would
like to know what things are really like on the water," she says.
"This has never been done before, in any state, and by the end we'll
have a broad, one-of-a-kind understanding of safety compliance. Maybe
we could use this information to develop safety-education programs.
And finding out which fishery or area of the coast is least compliant
can help the Marine Patrol to best use their resources."
Davis, a member of a National Academy of Sciences
panel studying air pollution issues, plans to focus her considerable
number-crunching skills — and that handy air particle monitor — on
wood smoke in Maine at some point.
"I really like getting out there and collecting my
own data whenever possible," she says. "It's exciting for me, and more
the kind of thing you'd see in the natural sciences."
by Tom Weber
for more stories from the current issue of UMaine Today Magazine.