United States
Environmental Protection
Agency
Health Effects
Research Laboratory
Research Triangle Park, NC 27711
Research and Development
EPA/600/S1-89/005 July 1989
Project Summary
Interaction Between Water
Pollutants: Quantitative Electron
Microscopy of Hepatic
Morphological Changes
Induced by 1,2-Dichloroethane
(DCE) and 1,1-Dichloroethylene
(VDC)
Robert H. Gray
The full report summarizes
electron micrographic changes in
liver and kidney parenchyma! cell
orgenelles caused by the ingestion of
two halogenated hydrocarbon
pollutants. The conclusions drawn
herein apply to quantitative and
qualitative risk factors derived for
drinting water contaminants,
therefore, have direct programmatic
relevance to the HERL program
mission.
This Project Summary was
developed by EPA's Health Effects
Research Laboratory, Research
Triangle Park, NC, to announce 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).
Results and Discussion
Numerous chemicals that are found as
contaminants in public water supplies
constitute potential public health hazards.
The studies here were designed to
determine the early histopathological
effects of two known water contaminants,
1,2-dichloroethane (DCE) and 1,1-
dichloroethylene (VDC), administered
alone or in mixtures to laboratory rats.
Both agents have been shown to cause
cytotoxic responses in kidney and liver.
Male rats, weighing 170-190g, were used
in all studies. Animals were dosed IP with
DCE (300 and 600 mg/kg body wt) or
VDC (100 and 200 mg/kg body wt) alone
or a mixture (150/50 and 300/100 mg/kg
body wt, DCE/VDC, respectively) of the
two compounds and sacrificed after four
hours. Hepatic tissues were removed and
prepared for quantitative electron
microscopic studies. The following
cellular and subcellular parameters were
evaluated: cell and cytoplasm and
nuclear volumes, the number of
organelles (mitochondria, peroxisomes
and lysosomes) per cell, the mean
volume of the individual organelles and
their absolute and relative fractional
volume/cell. The absolute and fractional
volume/cell of lipid droplets were also
determined. Significant changes were
seen in cell, cytoplasmic and nuclear
volumes, except in the high dose DCE
group (600 mg/kg). Significant increases
in cellular lipid droplets were observed in
all treatment groups except the high dose
mixture group. All treatment groups
exhibited a decreased number of
mitochondria per cell and an increase in
the mean volume of individual
mitochondria. All groups, except the high
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dose DCE group, had increased numbers
of peroxisomes/cell and a concomitant
decrease in mean volume of individual
peroxisomes. lysosomes did not change
significantly in their numbers or their
mean volume.
Comparison of measured parameters
of the single dosed animals with the
mixed dosed exhibited the most sig-
nificant differences in the lipid droplet
compartment. The increases in lipid
droplets in the mixed dosed animals (300
and 100 mg/kg of DCE and VDC,
respectively) were slightly greater than
additive compared to the corresponding
single dosed groups. Similar trends, but
lower in magnitude, were noted for lipid
droplets in the lower mixed dosed
animals (150 and 50 mg/kg of DCE and
VDC, respectively). In the 300 mg/kg
DCE-15O mg/kg VDC mixed dose group,
an additive trend was noted for the
increase in the number of lysosomes per
cell and the peroxisome volume per cell
compared to the single dosed animals.
However, these observed increased
trends were not statistically significant.
Robert H. Gray is with The University of Michigan. Ann Arbor, Ml 48109-2029.
B. Alex Merrick is the EPA Project Officer (see below).
The complete report, entitled "Interaction Between Water Pollutants: Quantitative
Electron Microscopy of Hepatic Morphological Changes Induced by 1,2-
Dichloroethane (DCE) and 1,1-Dichloroethylene (VDC)," (Order No. PB 89-
214 126/AS; Cost: $21.95, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Health Effects Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
EPA/600/S1-89/005
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