[Enesta Jones] 
Hello, and welcome to EPA's 
Green Scene, an environmental
podcast you can
take with you.
I'm Enesta Jones from the 
Office of Public Affairs.
This month marks the 23rd 
anniversary of the worst
nuclear accident 
in history.
The scene was Chernobyl in 
the former Soviet Union.
In April 1986, a nuclear power 
plant in the eastern Soviet Union
accidentally released large 
amounts of radioactive
material into the environment.
The White House designated EPA 
as the lead federal agency to
respond to the emergency.
Elizabeth Cotsworth, Director 
of EPA's Office of Radiation
and Indoor Air, is here today 
to talk about EPA's monitoring
system called RADNET.
RADNET tracked the radioactive 
cloud as it moved across the
United States.
Welcome to the show, 
Elizabeth.
[Elizabeth Cotsworth] 
Thank you, Enesta.
Glad to be here.
[Enesta Jones] 
So, Elizabeth, what is RADNET, 
and how does it help to protect
people and the
environment?
[Elizabeth Cotsworth] 
RADNET is the national monitoring 
system that EPA operates.
It is a tool that we use to 
develop information that we
can use to protect the public 
and the environment from
unnecessary, potentially harmful 
levels of radiation in
the environment.
We measure radioactive 
contamination that might
exist in the air as well as in our 
water supplies around the country
and in precipitation and 
also in milk supplies.
For example, we collect the 
filters from about 120 monitoring
stations around the country and 
measure the airborne radiation
on those filters.
We also collect information 
from those same monitors almost
continuously, electronically.
We collect samples of water from 
our water supplies at about
80 different locations around the 
country, four times a year,
and we also sample precipitation 
in the form of rain and snow,
and to a smaller extent, milk, 
to determine radiation levels.
[Enesta Jones] 
How long has EPA been 
using RADNET?
[Elizabeth Cotsworth] 
RADNET and it's predecessor 
monitoring systems have been
in place for well 
over 50 years.
Even prior to the formation of 
EPA, there were networks for
monitoring radiation 
in the ambient media.
Since the EPA was established in 
the 1970's, we have consolidated
those monitoring systems 
into a program called
the Environmental Radiation 
Ambient Monitoring System,
or ERAMS, as 
it was known.
Then, just a few years ago when 
we upgraded and enhanced the air
monitoring part of the program, 
we changed its name to RADNET,
which we think is more informative 
as to what it does.
[Enesta Jones] 
And what makes it so useful?
[Elizabeth Cotsworth] 
RADNET monitors and measures 
the background radiation that
we all experience, and background 
radiation is composed of radiation
that comes from natural sources 
as well as man-made sources,
and it can vary quite considerably 
from place to place across
the country.
It can depend on
your elevation.
It can depend on the materials 
in your buildings.
It can depend on the rocks and 
the soil and what the contents
of that is, as well as, again, 
man-made releases of radiation
into the environment.
And its power comes from the 
fact that we can detect these
very low levels of background 
radiation and any changes in
those levels that could be of 
concern to the American public.
Fortunately, the good news is 
that with very few instances,
the background radiation levels 
in the United States have
remained very low and very 
constant and very little change.
[Enesta Jones] 
Back to Chernobyl, what did 
EPA's monitoring show as far
as radioactivity?
[Elizabeth Cotsworth] 
Well, the most important thing 
that the monitoring system
showed was that the additional 
levels of radiation were not
significant enough to warrant 
alarm and were not significant
enough to necessitate any 
protective actions to be
taken for the public and 
protection of the environment.
That was the
best thing.
[Enesta Jones] 
And as I understand it, some 
states right next door to
each other had different 
levels.
Why did this occur?
[Elizabeth Cotsworth] 
What we found during our 
monitoring of the Chernobyl
incident was that the levels of 
radiation that were monitored
and measured were very 
significantly affected
by the weather patterns, 
particularly the amount
of rainfall that a particular part 
of the country experienced.
We were able to see the levels 
of radiation and see that they
very closely correlated to the 
areas of rainfall or dryness
in the United States.
But again, the wonderful thing was 
that in no cases were any changes
in the levels enough to warrant 
concern or alarm or to be the
basis for the need for 
protective actions.
[Enesta Jones] 
And what are some other 
highlights of EPA's tracking
of radioactivity?
[Elizabeth Cotsworth] 
Historically, one of the good 
things of the monitoring system
is that we were able to see that 
background radiation levels
actually decreased a little bit 
when the nuclear weapons testing
programs ended in the 1960s.
We were also able to see the 
effects of international
accidents and releases into 
the environment during some
additional weapons testing in 
other countries in the 1970s.
But again, those levels were 
not enough to warrant concern
and protective actions.
[Enesta Jones] 
Since the terrorist attack 
September 11, 2001,
how has RADNET been enhanced?
[Elizabeth Cotsworth] 
It has changed in two ways.
For instance, our air monitoring 
network at our fixed locations
around the country, those have 
been substantially upgraded
and enhanced.
They can report on an almost 
near real time basis.
They also have continuous 
communication capability,
and they can provide much 
better detail regarding 
the radionuclides that they 
can detect on the filters.
We've also instituted a deployable 
monitoring aspect of RADNET.
These are portable monitors.
We have 40 of them, and they can 
be sent to a location where there
is an imminent threat or concern 
about a possible radiation
release, such as a dirty bomb, 
and can provide information
back to EPA regarding the levels 
of radiation that are being seen 
in the environment.
[Enesta Jones] 
Speaking of dirty bomb, say we 
had a terrorist attack today.
How would RADNET 
be useful to us?
[Elizabeth Cotsworth] 
Well, first of all, the 
deployable monitors that
I mentioned would be sent to 
the location, and they would
be able to provide information to 
decision makers regarding the
extent, the nature and the levels 
of radiation that are being seen
in the area around the dirty bomb 
location, but beyond the local
area, the fixed monitors elsewhere 
in the country, they would be
working and be able to give us 
information relative to, again,
the background levels and any 
changes to those that are being
experienced across the country 
at a great distance from the
location of the 
dirty bomb.
And our greatest hope is that 
they will show that there are
no discernible changes in the 
background levels that the
majority of the population, 
those who are removed from
the area around the dirty bomb 
site, are experiencing.
[Enesta Jones] 
It's EPA's mission to protect 
people in the environment.
Does the public have access 
to this information?
[Elizabeth Cotsworth] 
Yes, it does.
Through our Web site we can 
provide all the historical
RADNET data to the public, and 
we provide some tools such as
a graphing tool which allows 
the public to provide --
to do some analysis of the data 
and to compare information and
data from the various 
monitoring locations.
[Enesta Jones] 
Elizabeth, thank you for being 
here today and providing such
useful information
on RADNET.
[Elizabeth Cotsworth] 
Thank you, Enesta.
It was wonderful.
[Enesta Jones] 
And for more information on 
radiation and the environment,
go to 
www.epa.gov/enviro/html/erams.
See you next time 
on Green Scene.