Contaminated Residential Waste from I-131 Patients

["Richard, Mack L" <mrichar@iupui.edu>]

Dear Radsafers:

Most of the municipal and residential waste from the City of Indianapolis is
disposed via a large, municipal incinerator.  A few years ago, radiation
detectors were installed to monitor all trucks entering the incineration
facility.  This was done due to an incident in 1992 when a Cs-137 source
which supposedly came from a stolen moisture/density gauge was discovered in
ash from the incinerator by a metal scrap dealer who would recover metal
from the incinerator ash.

Since the installation of the radiation detectors at the incineration
facility, local hospitals have routinely had waste rejected at the
incineration facility due to the presence of radioactive materials.
Fortunately, most of those situations involved short-lived radionuclides
(most commonly Tc-99m) where the waste was allowed to decay for a day or two
at the incineration facility and then incinerated.

When the NRC revised the regulations regarding the release of
radiopharmaceutical therapy patients, the most common being patients treated
with I-131 for thyroid carcinoma, contaminated residential waste became an
increasing problem at the incineration facility.  A primary difference
between residential waste versus hospital waste is that the incineration
facility cannot determine where the radioactivity came from when the source
is residential waste.  Furthermore, hospital waste is generally collected
and transported in a "roll off" container (i.e., the container can
physically be separated from the truck), while residential waste is
collected and transported in a truck with a permanently mounted container
(i.e., a "trash truck").

Unfortunately for the collectors of the residential waste, the only option
when contaminated, residential waste is rejected at the incinerator is to
empty the contents onto the ground, sort through the waste using a survey
instrument, and place the contaminated portion of the waste in another
container for about 3 months if I-131 is the radionuclide involved.  In
1999, there were 21 instances of I-131 detected in residential waste.

Earlier this week, a meeting was held which included all of the RSOs from
the hospitals in Indianapolis/Marion County, waste collectors, incinerator
representatives, and state regulators to discuss this issue.  Obviously, the
waste collectors would certainly like to avoid sifting through residential
waste (can't blame them for that).  All of the RSOs emphasized that the
hazards associated with the radioactivity are minimal, especially when
compared with the other hazards of sifting through residential waste (the
possibilities of what ends up in residential waste are endless).

A primary problem lies with the operating permit for the municipal
incinerator.  According to the regulators, the permit specifically prohibits
incineration of radioactive materials (we haven't actually seen a copy of
the permit).  Even though the permit is issued by the State of Indiana, we
suspect that EPA guidance is being utilized.  When we (RSOs) suggested that
the permit be modified, the regulators basically told us that such a change
would require a hearing which would bring out the environmentalists.  They
also stated that it would probably require legislative action which would be
a political "hot potato" that no legislator would touch.

The final result of the meeting was that the waste collectors are asking all
local hospitals to provide them the residential address of patients treated
with greater than 33 mCis of I-131 via a faxed form.  Due to confidentiality
issues, a patient will have to provide written permission for hospitals to
release such information.  Upon receipt of the faxed form, the waste
collectors plan to go to the patient's home, survey their waste, and if
radioactivity is detected, pick up the waste from the patient's home in a
separate vehicle.  The waste will then be placed in a container at the
collector's facility and held for decay.  While the actual number of
man-hours involved will probably be greater, the waste collectors feel that
this procedure is preferable to the current procedure of sifting through the
residential waste in search of this material.

I haven't presented this proposal to the nuclear medicine departments at our
facility as yet.  When I do, I plan to remind them not to "shoot the
messenger."  This wasn't my idea.  In fact, I think it's a bad idea, but
then again, I don't have to sift through trash a couple of times a month.

With the increasing use of radiation detectors at waste facilities, there
must be some of you out there that are grappling with this same problem.  We
are open to suggestions.

Regards,

Mack L. Richard, M.S., C.H.P.
Radiation Safety Officer - IUPUI/Indiana Univ. Med. Cntr.
Phone #: (317) 274-0330   Fax #: (317) 274-2332
E-Mail Address:  mrichar@iupui.edu

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