United States
Environmental Protection
Agency
Health Effects Research
Laboratory
Cincinnati OH 45268
Research and Development
EPA-600/S1-81-023 Apr. 1981
Project Summary
Epidemiological Study of
Klebsiella pneumoniae Among
Pulp and Paper Mill Workers
Marty S. Kanarek and Nijole R Caplenas
In a one-year study fecal coliform
and Klebsiella bacteria densities were
measured in several of Wisconsin's
pulp and paper mill processing wash
waters, treated waters, and waters
receiving pulp and paper mill effluent
discharge. The isolation of fecal coli-
form bacteria ranged from as low as a
minimum detectable level of less than
10 organisms/100 ml water sample
to as high as an estimated 5 x 106
organisms/100 ml water sample.
Water data were obtained from an
effluent survey of twenty plants and a
within-plant survey of three mills.
These findings support previous
investigations concerning the selec-
tive growth of coliform bacteria in
pulp and paper mills utilizing pro-
cessed water recycle loops.
Biochemical testing revealed that
over 50 percent (range from 4 to 97
percent) of the fecal coliform bacteria
associated with pulp and paper mill
processing were identified as bacteria
of the genus Klebsiella. of which K.
pneumoniae was found to be the most
prevalent species.
Sampling of paper mill workers re-
sulted in Klebsiella isolation from the
upper respiratory tract. Klebsiella bio-
typing revealed that the Klebsiella
isolation from a pulp mill worker
matched the Klebsiella biotype found
in the plant's processing waters. An
additional relationship was observed
between Klebsiella biotypes isolated
from plant sanitary sewers and the
mill's processing waters.
There is a strong suggestion that
upper respiratory tract colonization,
with potential health hazards, can
occur in pulp and paper mill workers
occupationally exposed to Klebsiella
bacteria. K. pneumoniae has been
identified as the predominant coliform
bacterium from such an industrial
waste source and is responsible for 2
percent of the bacterial pneumonia
cases in the susceptible population of
the United States and 60 to 70
percent of the deaths attributed to this
disease. Recycling or reuse of water
within the pulp and paper industry has
been shown to enhance proliferation
of K. pneumoniae densities. Until
further research to assess the health
risks of populations exposed to water
contaminated with Klebsiella is
carried out, the U.S. Environmental
Protection Agency should not
encourage recycling within the pulp
and paper industries as a means of
reducing waste discharges.
This Project Summary was develop-
ed by EPA's Health Effects Research
Laboratory, Cincinnati. OH, to an-
nounce key findings of the research
project that is fully documented in a
separate report of the same title (see
Project Report ordering information at
back).
Introduction
Industrial organic wastes from pulp
and paper mill effluents and their treat-
ment facilities have been known from
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previous studies to generate high
numbers of coliform bacteria. Klebsiella
pneumonias has been isolated and
identified as the predominant coliform
bacteria from such an industrial waste
source K pneumoniae is responsible
for 2 percent of thebactenal pneumonia
cases in the susceptible population of
the United States with 60-70 percent of
the deaths attributed to this disease.
Recycling or reuse of water within the
pulp and paper industry has been evalu-
ated with respect to coliform densities
in various mill systems and has been
shown to be selective for bacterial pro-
liferation especially with regard to K.
pneumoniae densities
It was the purpose of this study to
determine first, the fecal coliform and
Klebsiella bacteria distribution m
Wisconsin's pulp and paper mills, and
second, because of the potential health
risk, to determine if workers employed
in pulp and paper mills have signifi-
cantly greater colonization of Klebsiella
than workers employed in nonpulp and
paper industries.
Discussion
In general, the results showed that
the level of fecal coliform bacteria pre-
sent in influent waters supplying paper
mills, as measuredbythestandardfecal
coliform indicator test, was significantly
lower than the fecal coliform counts
being discharged from plant effluents.
In two out of the three mills sampled,
the influent water source had minimum
detectable levels of fecal coliform
bacteria (i e , less than 10 organisms
per 100 ml) whereas effluent water dis-
charged had high levels of fecal coliform
bacteria, ranging from 270,000 to an
estimated 2 x 1 O6 organisms per 100 ml
Since Klebsiella was the predominant
coliform bacteria identified as giving
positive fecal coliform response, it may
be postulated that Klebsiella prolifer-
ating early in the pulp processing stages
may be responsible for the elevated
fecal coliform levels discharged from
plants in the final effluent. The study
observations give supporting evidence
for Klebsiella maintaining a possible
wood or bark reservoir since influent
water supplying the three sampled mills
had no detectable Klebsiella levels.
However, once raw wood combined
with distilled phosphate buffer was
sampled from each plant, Klebsiella was
consistently isolated.
Thus, once Klebsiella proliferated
from the early pulping stages, the reuse
of water within the plants aided in
maintaining elevated bacterial levels
through each plant's treatment stages.
Wastewater treatment could not signifi-
cantly reduce the Klebsiella nor total
fecal coliform levels
The goal of a fecal coliform indicator
implicitly refers to a restricted group of
microorganisms specifically and exclu-
sively associated with fecal wastes.
However, the study findings indicate
that such is not the case because of the
significant proportion of Klebsiella
bacteria isolated from pulp and paper
mill processing waters having no
apparent fecal source The fecal
coliform test selects for bacteria primar-
ily of the genus Escherichia but because
of the test's lack of specificity, other
bacteria including Klebsiella, Citro-
bacter, and Enterobacter give positive
reactions as well. Because of Klebsi-
ella's tremendous "regrowth" potential
m waters contaminated with pulp and
paper mill waters, there is an increasing
need for reevaluatmg the validity of the
fecal coliform test as an indicator in
these types of industrial wastewaters.
Since Klebsiella is not exclusively or
specifically associated with fecal waste,
the study findings recommend that
highly specific indicators of fecal waste
contamination, such as E. coli, be used
as indicators of fecal contamination,
thereby eliminating the interfering
response of Klebsiella bacteria from a
nonfecal source.
Further study is needed intheevalua-
tion of the health effects in workers
exposed to high levels of Klebsiella in
the workplace The study findings indi-
cated that paper industry processes
selectively allowed Klebsiella to grow
and in levels exceedings the only water
contact standard promulgated - i.e.,
fecal coliform levels cannot exceed 200
organism per 100 ml. Klebsiella and
fecal coliform bacteria were present in
levels as high as an estimated 2 x 106
organisms per 100 ml where exposure
to any worker involved in the mill pro-
cessing could occur. Although no sig-
nificant relationship was found for
Klebsiella colonization in paper
workers, there is a strong suggestion
that upper respiratory tract colonization
can occur. Larger sample size evalua-
tion with subsequent infection follow-
up may answer the question of potential
health hazards to pulp and paper mill
workers occupationally exposed to
Klebsiella Until these studies are
carried out, it would be prudent that the
U.S Environmental Protection Agency
not encourage recycling in the pulp and
paper industry as a means of reducing
waste discharges.
Marty S. Kanarek and Nijole R. Caplenas are with the University of Wisconsin.
Madison, Wl 53706.
Herbert R. Pahren is the EPA Project Officer (see below)
The complete report, entitled "Epidemiologial Study of Klebsiella pneumoniae
Among Pulp and Paper Mill Workers," (Order No. PB 81-172 298; Cost: $9.50,
subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650 , , y
The EPA Project Officer can be contacted at: 5 • - - •
Health Effects Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
> US GOVERNMENT PRINTING OFFICE 1981 -757-012/7091
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