الفهرس 
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Abstract
Air pollution is the most dangerous form of pollution as it
can expose a person to about 10.000 times more mass of an
environmental pollutant than does food or water.
Gasoline is the primary product of petroleum refining and
it perhaps the most widely used energy source in the world. In
addition to industrial applications, the ready availability of
gasoline to power automotive engines, there are increasing
opportunities for occupational and environment exposure to this
liquid fuel.
With the removal of lead from gasoline and the use of new
technologies, it is very important to conduct studies oftoxic
effects of reformulated gasoline (unleaded gasoline) which will
shed the light on this new formula and either it is more or less
benefit than the old one. The objective of this work was to asses
the health effects of unleaded gasoline refined and used in
Egypt. In this regard, the test substance, unleaded gasoline
vapor, was judged to be representative of the material to which
human are exposed. Thus the data are relevant for the
assessment of potential exposure. Three groups of adult male
albino rats (8 rats each) (I, II & III) were exposed in the present
study to unleaded gasoline vapor (1,2, 4g/m3 for 4 hr daily-e.
5days/week for eight weeks respectively) to investigate changes
in some physiological and histopathological parameters as
compared to a control group (8 rats). The obtained results were
as follow:
(I) Animal observation:
No animal died during the study. Ataxia, hypoactivity and
labored respiration were observed in group III exposed to the
higher level of unleaded gasoline vapor.
(2) Body and organ weights:
Significant decreases in body gain were observed in all
treated groups. The decreases in body gain were higher in group
III (exposed to 4 g/m3 of unleaded gasoline) than those of
groups I (exposed to I g/m3 of unleaded gasoline) & II (exposed
to 2 g/m3 of unleaded gasoline). Organ weights were not
affected significantly with exposure to unleaded gasoline except
testes weight which was significantly increased.
(3) Blood parameters:
Significant declines in Hb contents and RBCs counts were
observed in all treated groups. The decreases were concentration
dependant i.e., the higher the exposure level the higher the
decrease of Hb content. The WBCs counts showed non
significant decreases in treated animal groups compared to the
control one. The differential WBCs count indicated significant
increases in neutrophils of all treated groups compared to
control one, while the lymphocyte number showed significant
reductions in all treated groups. No significant changes in the
number of monocyte, eosinophil and basophil were observed.
(4-]Respiratory functions of blood :
Blood gase and acid-base status parameters indicated the
onset of respiratory alkalosis that represented by the decrease of
PCOz. These respiratory alkalosis may be partially compensated
by metabolic acidosis that indicated by the decrease in pH,
HCO-3
, TCOz and BE. The oxygen equilibrium curves of treated
animals were shifted to the left with decreases in their Pso due to
the decrease in PC02, anemia and hypoactivity of the animals.
The increase in blood oxygen affinity was non significant due to
the compensation occurred by the kidney.
(5) Liver Enzymes (ASTand ALT):
The levels of AST revealed a significant increase in all
treated groups while the increase in the levels of ALT was non
significant.
(6)semm levels of Urea and Creatinine:
The levels of urea decreased in all treated groups except
group II (exposed to 2 g/rrr’) which showed an increase in urea
level. The levels of creatinine also decreased non significantly in
all treated groups.
(7) seurm level of cholinesterase :
Seurm levels of cholinesterase were non significantly high
in all treated groups compared to control one.
(8) serum levels of immunoglobuline G (IgG) :
Immunoglobuline G (IgG) showed a non significant
decline in all treated groups compared to that ofthe control.
(9) semm level of corticosterone:
Serum levels of corticosterone showed marked and
significant increases in all treated groups compared to that of the
control one.
(10) serum levels of thyroid honnones :
The levels of thyroid hormones were affected significantly
with unleaded gasoline vapor inhalation but in a condradict way
i.e., although the levels of thyroxine increase the levels of
triiodothyronine decrease in all treated groups compared to the
control one.
(II) serum levels of testosterone:
Serum levels oftestosterone were decrease significantly in
all treated groups compared to that of the control one.
(121 Hisotpathological examinations:
The results of the present study showed that unleaded
gasoline vapor inhalation induced marked histological
alterations in lung, trachea, brain and testicular tissues. These
alterations were more apparent in group III (high dose); but
were also evident in group II (mid-dose) and were mild in group
I (low-dose).
from this study, it is concluded that, unleaded gasoline
vapor inhalation is very harmful to health and it is very
important to avoid exposure to gasoline and its additives. It is
important to conduct studies about more save additives for
human health.