| Acute
Toxicity |
"The
evidence that petroleum oils are, indeed, toxic to birds is overwhelming".
(P14.2.w62)
Acute effects of oil
include:
- Physical effects on skin, fur and feathers result in loss of water
repellant properties of feathers (in birds) or pelage
(in mammals) and resultant hypothermia. (B20.13.w10)
- Irritation of the skin and of oral, ocular,
respiratory and gastro-intestinal mucous membranes. (B20.13.w10)
- Irritant effects on the eyes, lungs and other systems may decrease the ability of affected individuals to
oxygenate blood and to capture prey. (B20.13.w10)
- There may be damage to the renal system and to the
hepatic enzyme systems responsible for metabolism of toxins and other
compounds. (B20.13.w10)
- Immune system suppression. (B20.13.w10)
- Haematopoisis disruption or suspension. (B20.13.w10)
Napthalenes cause haemoglobin denaturation and are one
of the compound groups responsible for the development of haemolytic
anaemia in oiled wildlife. (B20.13.w10)
PAH compounds have been shown to be responsible for
toxic effects of petroleum oils observed experimentally on ingestion of
oil by Larus
argentatus - Herring gull chicks. (B20.13.w10)
Physiological disruptions caused by petroleum oils include altered endocrine function, liver and kidney disorders, altered blood chemistry, blood disorders including
anemia,
impaired salt (nasal) gland function resulting in disruption of
osmoregulation.
(B36.42.w42)
Effects of external contamination of birds:
- Oil is rapidly absorbed by feathers, resulting in
loss of the normal waterproof structure, matting of feathers,
exclusion of air and resultant loss of insulation, waterproofing and
buoyancy. (B20.13.w10,
P14.3.w2)
- Plumage disruption compromises the ability of oiled
birds to fly, swim, dive, feed and escape predators. (B20.13.w10)
- There is a direct irritant effect on the skin and eyes. (P24.327.w4)
- Hypothermia due to loss of insulative qualities of feathers. (J40.31.w2,
P24.327.w4,
P14.3.w2)
- Penetration of water to the skin causes considerable
increase in heat loss. Metabolic rate must be increased to compensate for
loss of insulation. (P14.1.w1,
P14.3.w2)
- A 400% increase in metabolic rate was noted in Somateria mollissima - Common eider
experimentally contaminated with oil (externally)
and maintained on cold water. (B20.13.w10,
P14.3.w2)
- In Anas platyrhynchos - Mallard
following experimental oiling and exposure to a range of
environmental temperatures, metabolic rate was found to increase
substantially; below the lower critical temperature, the rate of
energy metabolism appeared to increase linearly with decreasing
ambient temperature. The rate of heat loss increased most
rapidly for low levels of oiling, tending to level off for heavier
oiling. Heavily oiled ducks may have heat losses more than twice
those of unoiled ducks. Oiled ducks with good fat reserves could
survive exposure to low ambient temperatures (-26°C) for longer
than could ducks in poor condition at the same degree of oiling. (J40.31.w2)
- Anas platyrhynchos - Mallard
exposed to oil experimentally by swimming for one hour on water
contaminated with Prudhoe Bay crude oil, then placed in a
respiration chamber, air temperature -15 C, showed a significant
increase in metabolic rate. (J53.29.w1)
- Pygoscelis adelie - Adelie penguins (Spheniscidae - Penguins (Family))
which were oiled, compared to unoiled controls, had reduced heart
rates (90 bpm versus 98 bpm), reduced body temperature (39.6 °C
versus 39.2 °C) and reduced energy expenditure (4.7 W/kg versus
5.2 W/kg). When placed in a swim tank, oiled penguins attempted to
leave the water and showed erratic swimming behaviour. They had a
reduced swimming speed (1.6 m/s versus 1.8 m/s), increased heart
rate while on the water surface (321 bpm versus 252 bpm), a 50%
higher metabolic rate (18.8 W/kg versus 12.7 W/kg) and a much
higher (73%) cost of transport (12. 1 J/kg/m versus 7 J/kg/m). (J313.22.w1)
- A study of Cerorhinca monocerata - Rhinoceros auklets (Alcinae
- Laridae - Skuas, Terns, Gulls, Puffins, Auks (Family))
in
the Southern Japan Sea, found that dead oiled birds had lost one
third of body, muscle and general organ masses, 60% of liver mass,
more than 90% of subcutaneous fat and more than half of all fats
stored in muscles and other organs, including bone marrow, which
was almost entirely replaced with water. It was considered that
these birds died within one to two days, not from the oiling per
se but from "emaciation caused by starvation and
nutritional exhaustion, accelerated by increased energy loss."
(J313.40.w3)
- A study of common eiders (Somateria mollissima - Common eider)
experimentally oiled by exposure to
Statfjord A crude oil (12.5 mL on a 50 L tank of water, i.e. 100
mL oil per m² water surface) showed that their insulation was
reduced to just 22% of the unoiled value. Metabolic heat production increased to about 4.5 times that of unoiled birds and, despite this, body temperature was lower than in nonoiled birds.
(J59.16.w1)
Internal effects of oil on birds:
- Birds may ingest oil while attempting to preen it
from their feathers, by drinking from contaminated water or by eating
contaminated food. (B20.13.w10,
P24.327.w4,
P24.335.w11)
- A study on the uptake and clearance of petroleum hydrocarbons in Larus glaucescens -
Glaucous-winged
gulls (Larus
(Genus)) and Anas platyrhynchos - Mallard
found that about 45% of the ingested oil was excreted. Labeling
indicated that the absorbed petroleum hydrocarbons were distributed to
various body tissues, and that these hydrocarbons are removed by
detoxifying mechanisms. In the gulls, levels were highest in fat,
kidney and liver and lower in muscle and plasma; radioactivity leveled
off after 24 hours. In ducks, levels were highest in plasma and
kidney, and lower in liver, muscle and fat; levels returned to
background after 24 hours. It was noted that levels in the liver and
kidney of the gulls were higher than in duck tissues. (J30.58.w1)
- Toxins, particularly PAH, absorbed through the skin,
respiratory tract or gastro-intestinal tract, may affect the
liver, kidneys, nervous system, blood and gonads. (P24.327.w4,
P24.335.w11)
- Reported effects of ingested oil include:
- Anaemia. (B20.13.w10)
- Stressor effects (in which it may be additive
with other stressors such as cold temperatures). (B20.13.w10)
N.B. Petroleum products appear to be highly unpalatable.
Individuals forced to ingest oil may find this an additional stressor. (P24.335.w11)
- Birds may inhale petroleum fumes or vapours. (P24.327.w4)
- Birds may absorb toxins from oil through the skin or mucous
membranes. (P24.327.w4)
- Gastro-intestinal tract:
- General irritation, ulceration, destruction of the GIT
microstructure. (D183.w3)
- Ingested oil causes gastroenteritis (inflammation, ulceration
and haemorrhage of the gastrointestinal tract mucosa), maldigestion and malabsorption
including reduced absorption of sodium and water. (P24.327.w4,
P24.335.w11)
- Clinically, the effects of ingested oil may be seen as diarrhoea,
dysentery and vomiting. (P24.327.w4,
P24.335.w11)
- Bacterial infections may occur secondarily. (P24.327.w4,
P24.335.w11)
- Damage to the GIT contributes to dehydration, anaemia and
protein loss leading to hypoproteinaemia. (P24.327.w4,
P24.335.w11)
- Nutrient absorptive capacity of the intestine may be reduced due
to damage to absorptive cells. (P14.1.w17)
- Larus argentatus - Herring gull
chicks of about four- to five-weeks-old, maintained on unsalted
herring and 50% sea water as drinking water, dosed (by intubation)
with 0.2 ml (about 0.3 ml per kg bodyweight) of South Louisiana
crude (17% aromatics), were found at necropsy (when sacrificed
after eight to nine days) to have histopathological changes of the
GIT: proliferative oedema of the intestine, with considerable
cytoplasmic disruption and numerous lipid droplets in the
epithelial mucosa. Fewer and smaller droplets were found in tissue
sections from one of two chicks which had been given 0.2 ml of
Kuwait crude. (J22.199.w1)
- Respiratory:
- Inhalation of volatile components of oil, or aspiration of oil,
for example while preening, may result in pneumonia. (P24.327.w4,
P24.335.w11)
- Volatile components may cause pulmonary haemorrhage and oedema.
(P24.327.w4,
P24.335.w11)
- Red blood cells:
- Decreases in packed cell volume or blood haemoglobin
concentration have been reported following single or chronic
ingestion of oil by mallards. (P14.2.w6)
- Anaemia often occurs about four to six days after oil
ingestion and is consistent with oxidant chemical damage to
haemoglobin, resulting in haemolysis. (P24.327.w4,
P14.3.w2,
P24.335.w11)
- This is seen more commonly with crude oil and is less
evident with diesel or home heating oils. (P24.327.w4,
P24)
- Feeding of herring gulls with 10 m/kg per day crude oil
caused marked changes in conformation of erythrocytes and
formation of Heinz bodies. (P24.327.w4)
- Destruction of up to 50% of circulating blood cells, with
resultant severe anaemia, has been seen in birds following
experimental ingestion of crude oil. Heinz bodies (visible masses
of oxidised haemoglobin) were seen in 50-100% of
erythrocytes of these birds. Ultrastructural findings and
biochemical indicators were consistent with primary
oxidant damage. (P14.2.w6,
P14.3.w2,
P24.335.w11)
- Metabolic rate must be increased to
compensate for severe anaemia. (P14.2.w6)
- Stress, infection and chronic debilitating
disease may further add to the anaemia by suppressing
erythropoisis. (P24.335.w11)
- In Melanitta fusca - White-winged scoter
held in care following oiling with bunker C fuel oil, sampling
12 days after the birds were caught revealed low red
blood cell count, PCV
(haematocrit) and haemoglobin;
values had increased significantly from these levels by day 26
of treatment. Many polychromatic erythrocytes, indicative of
elevated haematopoisis, were also observed in samples taken on
day 12, and livers of birds which did not survive showed
marked haemosiderin deposits in the liver, and sometimes in
spleen, kidney and even lung. The findings were considered to
suggest haemolytic anaemia in the birds resulting from
ingestion of oil following oiling. (J1.32.w6)
- Other organs:
- Kidney damage may be caused directly by oil toxins or
secondarily due to dehydration. (P24.327.w4)
- Immune system suppression: This may be a toxic effect of
oil or secondary to stress (due to oiling, cleaning, or
rehabilitation). (P24.327.w4,
P24.335.w11)
- Mortality of Eudyptula minor - Little penguins (Spheniscidae - Penguins (Family)) during rehabilitation following oiling was thought to be
associated with immune system depletion due to oil toxicosis,
as well as due to stress from capture and handling. (J3.130.w5)
- Liver: ingestion of petroleum oil or aromatic fraction of
oil can induce dose-related increased activity of hepatic
mixed-function oxidases (MFO). Increases in liver weight have
commonly been reported following oil ingestion and increased
levels of liver enzymes, indicative of liver damage, have been
reported in some, but not all, studies. (P14.2.w6,
P24.335.w11)
- Rises in liver enzymes may reflect increased
hepatic activity. (P24.335.w11)
- Larus argentatus - Herring gull
chicks of about four- to five-weeks-old, dosed (by intubation)
with 0.2 ml (about 0.3 ml per kg bodyweight) of either Kuwait
crude (22% aromatics) or South Louisiana crude (17%
aromatics), showed significant liver hypertrophy and induction
of hepatic microsomal cytochrome P-450 activity when
euthanased and necropsied eight to nine days after dosing with
the oil. (J22.199.w1)
- In Cepphus columba - Pigeon guillemots (Cepphus (Genus))
in Alaska,
eight years after the Exxon Valdez oil spill in Prince
William Sound, increased levels of AST and lowered levels of
GGT were found in adults from an oiled area, compared to
adults from an area unaffected by the spill. It was noted that
the increased AST suggested liver injury, but that since birds
were sampled opportunistically, the possibility of some
differences being related to breeding season could not be
ruled out. (J313.40.w1)
- Feeding 100 mg or 500 mg of weathered crude oil (weathered
for two weeks) to Larus glaucescens - Glaucous-winged
gulls (Larus (Genus))
for 30 to 134 days, did not significantly affect liver
function, as indicated by metabolism of testosterone. Mean
percentages of testosterone converted to polar metabolites did
not show a significant change in those fed 500 mg oil compared
to those fed 100 mg or no oil. Gulls fed 500 mg oil daily
produced significantly less nonpolar metabolites of
testosterone than did those fed no oil or 100 mg oil daily.
Overall the study indicated that ingestion of weathered oil
did not significantly induce testosterone-metabolising
enzymes. (J30.56.w2)
- When adult Oceanodroma leucorhoa - Leach's storm-petrel
were dosed with 0.1 ml Prudhoe Bay crude oil (2.5 ml per kg
bodyweight), livers collected from sacrificed birds 14-21 days
later did not show significant hypertrophy. (J55.86.w1)
- Osmoregulation: This has been noted to be
affected by oiling; the effect may be due to effects of oil on the
gastrointestinal tract, kidneys or salt glands. (P24.335.w11)
- Larus argentatus - Herring gull
chicks of about four- to five-weeks-old, maintained on
unsalted herring and 50% sea water as drinking water, dosed
(by intubation) with 0.2 ml (about 0.3 ml per kg bodyweight)
of Kuwait crude (22% aromatics) showed slightly elevated
plasma sodium levels compared to controls, while those dosed
with South Louisiana crude (17% aromatics), showed
significantly raised plasma sodium on days six, eight and nine
after dosing, indicating disruption of salt and water balance.
At necropsy following euthanasia after eight to nine days, the
nasal glands showed 30% reductions in specific activity of
sodium-potassium-ATPase, together with hypertrophy of nasal
gland tissue, so that total activity of the glands was reduced
by only 20% in the gulls given South Louisiana crude, and was
not significantly reduced in those given Kuwait
crude. (J22.199.w1)
- In a study on Larus glaucescens - Glaucous-winged
gulls (Larus
(Genus)),
fed 1.0 g of bunker C fuel oil or marine diesel oil followed
three hours later by oral administration of 3% of body weight
of 0.5% sodium chloride (salt water), no effect was found on
the ability of the birds to regulate sodium chloride uptake
from the gut and excretion by the kidney. (J30.56.w1)
- When adult Leach's storm-petrels (Oceanodroma leucorhoa)
were dosed with 0.1 ml Prudhoe Bay crude oil (2.5 ml per kg
bodyweight), nasal glands and adrenals collected from
sacrificed birds 14-21 days later showed significant
hypertrophy. (J55.86.w1)
- Growth:
- Larus argentatus - Herring gull
chicks of about four- to five-weeks-old, maintained on
unsalted herring and 50% sea water as drinking water, dosed
(by intubation) with 0.2 ml (about 0.3 ml per kg bodyweight)
of Kuwait crude (22% aromatics) failed to put on weight in the
eight to nine days following dosing with the oil, compared
with a growth rate of about 3% per day in control non-oiled
birds; this was not due to decreased food intake. Reduced
growth rate had also been seen in immature birds in wild nests
given 0.2 ml of Kuwait crude (about 0.6 ml/kg bodyweight),
compared to non-oiled chicks from the same nest. (J22.199.w1)
- Wild Larus argentatus - Herring gull
chicks of between 10 and 20 days of age (200-500 g
bodyweight), dosed via stomach tube with 0.2 ml or 0.5 ml of
weathered South Louisiana crude oil, showed reduced weight
gain 7-9 days after dosing, compared with control birds given
(non-toxic) corn oil. Weight gain had recovered by 11-13 days
in chicks given 0.2 ml oil, but was still depressed at 11-13
days and through 18-22 days in chicks given 0.5 ml of the
crude oil. Additionally, both groups given petroleum oil
showed significant decreases in culmen growth on days 7-9 and
11-13, compared with controls, although rates of toe growth
were not significantly affected. The birds given the higher
dose of oil also showed a slightly lower survival to 700g/20
days: 41% survival, compared with 62% for control birds and
65% for those given the lower dose of oil. Behaviour of the
chicks was not significantly affected. It was not possible to
state whether the observed growth depression was due to direct
pollutant-induced impairment of nutrient utilisation, and/or a
direct effect on endocrine system function, or whether it was
due to non-specific stress due to the oil. (J50.96.w1)
- A study on fledgling/nestling Rissa tridactyla - Black-legged kittiwake
found that those with internal oiling, detected by the
presence of oil in the gastro-intestinal tract, had lower body
weights and lower liver weights than those without internal
oiling. (J313.19.w1)
- When adult Leach's storm-petrels (Oceanodroma leucorhoa)
were dosed with 0.1 ml Prudhoe Bay crude oil (2.5 ml per kg
bodyweight) while brooding chicks of two- to three-days-old,
chick survival for 21 days was reduced from 100% (in chicks of
control sham-dosed birds) to 70% if one adult was dosed with
oil and to 52% if both parents were dosed; mortality of chicks
occurred within six days of the oil dose. Chicks also showed reduced
weight gain compared to those of un-oiled adults (1.5 +/- 0.2
g/day for controls, 0.7 +/- 0.2 g/day for single oiled adult,
0.5 +/- 0.2 g/day if both adults were oiled, for chicks
surviving three days, P<0.01 for both groups). When adults
were dosed when chicks were 10-15 days old, no chicks died but
weight gain decreased significantly, with no significant
weight gain during the six days after the adults were dosed;
even after 21 days there were still significant differences in
rate of weight gain compared with control chicks. The effects
were considered probably due to the oiled adults having
impaired ability to provide their chicks with food. Giving oil
to the chicks directly (0.05 ml at 10-15 days old) did not
affect their weight gain in the 21 days after dosing. It was
commented that younger chicks were probably less able than
older chicks to survive a period of reduced feeding, and that
in conditions of additional stress such as food shortages,
survival of older chicks may be reduced post-fledging, due to
reduced fat reserves. (J55.86.w1)
- Metabolic rate:
- In an experiment using double-labelled water in adult Oceanodroma
leucorhoa - Leach's storm petrels, birds dosed by
intubation with 0.1 ml of Prudhoe Bay crude oil showed
significantly (P<0.001) higher standard metabolic
rate than did control birds which were not given oil. This
suggested that the metabolic rate of adult birds may be
temporarily increased following ingestion of small amounts of
oil, for example while trying to preen fouled plumage, or by
consuming contaminated food), as well as the known increase in
metabolic rate in response to reduced insulation from oiled
plumage. (J55.88.w1)
Note: Toxicity may be exacerbated in individuals under stress:
in ducks fed a variety of petroleum oils by stomach tube, the oils were
relatively nontoxic in individuals maintained under optimum conditions,
but were much more toxic, with a lower LD50,
in stressed ducks kept outside in temperatures of 0 to 10 °C under
crowded conditions (e.g. for diesel oil, LD50 of 4 mL/kg
under stress conditions, compared with survival when given up to 20 mL/kg
and maintained under optimal conditions). (J40.30.w2)
Effects of oil on mammals:
- "Hypothermia, stress, shock, respiratory compromise
associated with interstitial emphysema, hemorrhage from gastric
erosions, and hepatic necrosis" were thought to
contribute to the deaths of oiled Enhydra lutris
- Sea otters following the Exxon Valdez oil spill. (P14.3.w28)
- Mammals covered with fresh oil are likely to inhale toxins and
may suffer toxic effects on the mucous membranes and respiratory
system. (P14.2.w5)
- Species which rely on their fur for insulation are more vulnerable
than those which rely primarily on blubber for insulation, and are
more likely to show mortality after oiling. This includes otters, newborn Phocidae - Seals
(Family) seal pups, fur seals (Otariidae - Sea lions
(Family)) and polar bears (Ursus maritimus - Ursidae - Bears (Family)).
(B335.15.w15, P14.2.w1,
P14.2.w5)
- In Enhydra lutris
- Sea otters, pelt studies showed a two-
to four-fold increase in thermal conductance when oiled pelts were
immersed in sea water. Mean thermal conductance for unsoiled pelts
was 7.64 +/- 1.30 W/(m².°C). Weathered oil caused less increase
in thermal conductance (mean increase of 4.1 W/(m².°C)
than either fresh crude (mean difference 16.9 W/(m².°C)) or
fresh crude plus a dispersant (mean increase of 12.6 W/(m².°C)).
(J30.66.w2)
- In Enhydra lutris
- Sea otters, in which about 17.5% of
the fur was experimentally oiled with 38 to 60 mL of Prudhoe Bay
crude oil, following oiling and then washing of the fur, the
insulating quality of the fur was significantly reduced, acting as
an energetic liability and requiring an increase in oxygen
consumption: even in water of 15°C average maintenance oxygen
consumption doubled following oiling and washing. At least eight
days were required to return average oxygen consumption to normal.
In one otter left oiled for eight days, by day six the average
metabolic rate had increased by 98% above baseline, to 37.6 mL 02/kg/min.
Otters placed in holding tanks at 16°C after oiling and washing
shivered constantly. Subcutaneous temperatures beneath the oiled
areas of fur decreased, indicating peripheral vasoconstriction
under the oiled areas, although this effect was transitory, with
the subcutaneous temperature rising again by one day after
oiling. The reduction in insulation after oiling appeared to
be due to fur clumping and, due to this, loss of the trapped layer
of air beneath the fur. It was noted that washing would remove the
fur's natural oils and therefore reduce its water repellency.
Whole body heat conductance increased considerably following
oiling and following oiling-and-washing, even with only about 20%
of the pelt oiled. It was noted that should the animals be
oiled all over the body and then remain in the normal water
temperatures of their environment, it would be unlikely that they
could maintain metabolism sufficiently high to offset the
increased heat loss for the extended period that oil would remain
soiling the fur. (J30.60.w1)
- When Enhydra lutris
- Sea otters were experimentally oiled with a "sour
crude" oil containing highly volatile sulphur, applied in a
band across the chest using a brush, to cover 20% of the body
surface area, and placed in water at 13 °C, thermal conductance
of the otters increased 1.8 times; the otters increased average
metabolic rate 1.9 times, by shivering and voluntary activity in
order to maintain core body temperature. Time spent grooming and
swimming was increased 1.7 times, with resting time reduced
(grooming time increased from 35% to 61%, swimming from 10% to
17%, while resting in water decreased from 45% to 12%). The fur
was then cleaned using detergent (Dawn; Proctor and Gamble),
followed by rinsing; this obviously removed the natural oils (squalene)
from the fur, and three to six days, plus grooming activity by the
otters, were required to return core body temperature, baseline
metabolic rate and thermal conductance to base-line (pre-oiling)
levels. In cleaned otters 49% of time was spent grooming and time
spent shivering was increased, particularly in animals which did
not groom well. It was noted that in order to double the average
metabolic rate, as would be required following oiling, an otter in
the wild would have to increase daily food intake to 40-50% of
body weight per day, requiring 40-100% of its time to be spent in
foraging (depending on location and season); since capturing and
digesting this about of food each day may not be possible, the
otter would go into negative energy balance, metabolise body
protein, rapidly lose weight, have increased susceptibility to
disease, and die. It was recommended that, following cleaning, at
least one to two weeks should be allowed for the animals to
restore fur insulation and recover from the stresses of oiling and
cleaning. With severe oiling, even in captivity with food
provided, it may be necessary to maintain oiled sea otters in warm
water (e.g. 25°C, rather than normal water temperatures (e.g. 13°C), in order to ensure that energy balance is maintained. (J30.66.w1)
- When muskrats Ondatra zibethica (Muridae - Rats, mice, voles, gerbils etc. (Family))
were oiled experimentally
with varying quantities of crude oil, by swimming in water
contaminated with oil, the muskrats showed attempts to escape from
the tank, preening and shivering. Subsequently the muskrats showed
an increase in heat production above that of control individuals
from 20% in lightly oiled to 119% in heavily oiled muskrats,
reducing on subsequent days, although still about 20% above
control values on day three in heavily oiled muskrats. There was a
seven-fold difference between metabolic rates of unoiled and
heavily oiled musk rats held at 5°C on the day of oiling.
Thermal conductance increased by up to 122%. Food intake of oiled
animals increased markedly, with the greatest increase recorded in
animals with the greatest oiling. Heavily oiled individuals
preened more than did lightly oiled individuals, resulting in loss
of considerable quantities of underfur and making the guard hairs
stay erect. Heavily oiled animals also stayed out of water for up
to ten days. It was considered that, for these animals which
depend on water for feeding and refuge, even moderately oiled
animals would have been unable to meet their high energy
requirements in the wild. (J30.52.w1)
- Instability of body temperature has been noted in oiled Enhydra lutris
- Sea otters. (B20.13.w10)
- In all mammals coming into contact with spilled petroleum oils,
irritation of the skin and eyes may occur, also interference with
normal swimming of aquatic mammals. (P14.2.w1)
- Corneal ulceration has been recorded in heavily oiled harbour seals
(Phoca vitulina - Common seal).
(P14.2.w5)
Internal effects:
- Large quantities of ingested oil may cause renal failure and blood
disorders and be lethal to polar bears Ursinus maritimus (Ursidae - Bears (Family)). (P14.2.w1)
- Ingestion of oil may cause gastrointestinal haemorrhage in Lutra lutra - European otter.
(P14.2.w1)
- Both oil toxicity and stress are believed to have
contributed to gastrointestinal haemorrhage (resulting in melaena) and
chronic gastric erosion in oiled Enhydra lutris
- Sea otters. (B20.13.w10)
- Seals and cetaceans are able to metabolise petroleum oils and show
rapid renal clearance, which minimises the toxic effects of ingested
oil on these species. (P14.2.w1)
- Weight loss has been recorded, probably due to increased metabolic
demand, hypoglycaemia, lethargy and anorexia. (B20.13.w10)
- Levels of various liver enzymes such as AST and ALT
may be increased. (B20.13.w10)
- Liver lipidosis and centrilobular necrosis may occur due to
hypoglycaemia and shock secondary to hypothermia resultant from
oiling. (B20.13.w10)
- Severe leucopaenia and a left shift seen in oiled Enhydra lutris
- Sea otters, indicating a severe inflammatory response, may be partly due
to severe stress and use of corticosteroids. (B20.13.w10)
- Inhalation of volatile hydrocarbons may result in
mucous membrane inflammation, pulmonary oedema, pulmonary haemorrhage
and pneumonia. (P24.327.w4)
- Dyspnoea in Enhydra lutris
- Sea otters, with associated interstitial pulmonary emphysema. (B20.13.w10)
- Volatile hydrocarbons may be distributed systemically resulting in
anaemia, and may accumulate in the brain or liver. (P24.327.w4)
- In domestic cattle calves experimentally dosed with oil (high-sulphur
sour crude, low-sulphur sweet crude or kerosene), the most serious
consequence appeared to be aspiration pneumonia; bloat was also seen.
It was considered that aspiration occurred more readily, and caused a
more fulminating pneumonia, in calves given oil containing large
amounts of light hydrocarbon fractions (kerosene, naphtha or
gasoline), and that with more volatile oils than kerosene, bloat could
be an important cause of death. (J4.162.w1)
- Ingestion of oil may cause hepatic toxicity and blood disorders in Mus domesticus - Laboratory mouse
and blood disorders in laboratory rats (Rattus norvegicus - Brown rat).
(P14.2.w1)
- In addition to acute physical and toxic effects of oil, oiling of
mammals may lead to abnormal reproductive behaviour, increased
embryonic death, lowered survival rates of young and increased
abandonment of young. (D183.w3)
- Oil on unweaned seal pups may disguise the smell of the pup and thus
interfere with maternal recognition of the pup; this may result in
abandonment. (P24.327.w4)
Effects of oil on reptiles:
- Reptiles have been killed by oil, such as a spill of bunker C oil. (P14.2.w1)
- Inhalation of volatile hydrocarbons may result in
mucous membrane inflammation, pulmonary oedema, pulmonary haemorrhage
and pneumonia. (P24.327.w4)
- Sea turtles may ingest oil and tar balls; these have been found in
the mouth, oesophagus and stomach. (D183.w3,
D228.4.w4)
- Oil may have adverse effects on respiration, blood chemistry, energy
metabolism, diving patterns and salt gland function. (D183.w3)
- Effects of tarballs in the gut of turtles may include starvation due
to blockage of the gut, local necrosis or ulceration at the site of
blockage, interference with fat metabolism, and, due to build up of
fermentation gases, buoyancy problems, preventing feeding and
increasing vulnerability to predation and boats. (D228.4.w4)
- Since oil remains in the intestinal tract of turtles for several
days there is considerable time for absorption of toxins. (D228.4.w4)
- Caretta caretta - Loggerhead
turtles experimentally exposed
to oil showed gross and histological skin lesions consistent with a
contact/irritant dermatitis. Dysplastic change was sometimes marked.
Most changes had resolved by 10 days after cessation of exposure to
the oil. It was noted that the nature of the inflammatory response
could break the integumentary barrier and allow entry of pathogenic
organisms, resulting in localised bacterial infection and even septicaemia. (P14.3.w29)
- Haematocrits of oil-exposed turtles decreased by nearly 50%. (D228.4.w4)
- In sea turtles, which do not seem to avoid contact with oil slicks,
"physical contact with, and ingestion of, oil has been described
as causing dermatological damage, detrimental respiratory changes, a
decrease in digestive efficiency, hematological damage that elicits a
profound immune reaction, and a decrease in the efficiency of the salt
gland, which maintains osmotic and ionic balances." (B369.w6)
Effect of oil on amphibians:
- Amphibians have been killed by oil, such as a spill of bunker
C oil in the St. Lawrence River. (P14.2.w1)
- Amphibian larvae show sensitivity to fuel oils and crude oils
similar to that seen in fish larvae. (P14.2.w1)
- Rana catesbeiana - bullfrog (Rana (Genus))
tadpoles exposed to No. 6
fuel oil, in amounts similar to those expected to be found in shallow
waters after an oil spill, were adversely affected. All tadpoles
showed abnormal behaviour; mortality was highest in tadpoles in the
late stages of development. (P14.2.w1)
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| Reproductive
effects |
Toxic effects of oil may include decreased egg production
and sperm production, reduced fertility and reduced hatchability. (B36.42.w42)
Effects of oil contamination on avian eggs and embryos:
Contamination of eggs may cause failure of hatching or damage to
embryos.
- Field observations and experimental trials have demonstrated that
oil transferred to eggs from the feathers of incubating oils can cause
mortality of embryos. (P14.2.w6)
- A female Larus marinus - Great black backed gull
oiled on the breast and underparts was observed incubating her
eggs, which failed to hatch; the eggs were later found to contain
partially-developed embryos. It was not possible to determine
whether the oil sealed the pores and suffocated the eggs, or
whether the effect on the embryos was an effect of oil penetrating
the eggs. (J41.66.w1)
- Eggs of various shore birds failed to hatch after the incubating
adults became contaminated by stranded oil. (B378.6.w6)s
- Embryos of most birds species appear to have similar
susceptibility to the embryotoxic effects of oil. (P14.2.w6)
- Avian embryos are most susceptible to the toxic
effects of oil during the first half of incubation. (P14.2.w6)
- Days 6-10 of incubation appears to be the most
sensitive time. (P14.3.w16)
- In chicken eggs, it was noted that embryos at day
nine of incubation were sensitive to the toxic effects of oil, but
less sensitive than younger embryos (even those only a day
younger). (P14.3.w16)
- Eggs which are covered completely or almost completely in oil may
fail due to gaseous exchange being prevented. (P14.1.w7)
- However, the toxic effects of crude oil are not accounted for by
reduced gas exchange. (P14.3.w16)
- Toxic effects of smaller quantities of oil deposited on the shells
of eggs will vary with the type of oil. Significant reductions in
hatchability can result from very small quantities (1 - 20 microlitres)
of very toxic oils. Either the aromatic hydrocarbon or the
non-hydrocarbon fractions of the oil may be responsible for such
toxicity. (P14.1.w7).
- Oil may be transferred to eggs from contaminated plumage during
incubation. Oil in the environment may contaminate nesting sites
and thereby contaminate eggs. (P24.327.w4)
- Both crude and refined oils may have teratogenic
effects on bird embryos resulting in growth retardation, bill
deformation, incomplete skull ossification, skeletal deformities and
other deformities. (P14.1.w7)
- PAH compounds have been shown to be responsible for
toxic effects of petroleum oils observed causing mortality of avian
embryos. (B20.13.w10)
- Different petroleum products may cause different
levels of embryo mortality and reduced hatchability. (P14.2.w6)
- High levels of bird embryo mortality may be seen
following application of very small quantities of oil to the egg
shell. The quantities required for such effects would easily be
transferred from the plumage of adults during incubation. (B20.13.w10,
P14.2.w6)
- Avian embryos dying after the egg is oiled sometimes,
but not always, show developmental defects. (P14.2.w6)
- Pathological findings in embryos from oil-exposed
eggs have included generalised oedema, liver necrosis, kidney
degeneration, kidney necrosis and mineralisation and enlargement of the heart, liver and spleen. (P14.2.w6,
P14.3.w16)
- Paraffin (a petroleum product composed of large
alkanes) applied to eggs did not affect hatchability or embryo
survival, nor did propylene glycol. (P14.2.w6)
- 50 µL propylene glycol applied to mallard (Anas
platyrhynchos) eggs at eight days of incubation did not cause
reduced hatchability. This amount of propylene glycol would cover
about 13% of the egg surface. (J40.42.w1)
- 50 µL paraffin applied to mallard (Anas platyrhynchos)
eggs at eight days of incubation did not cause reduced
hatchability. (J40.42.w1)
- Various petroleum oils (South Louisiana crude, Kuwait crude, No. 2
fuel oil) all caused significant reductions in hatchability when
applied to Anas platyrhynchos - Mallard
eggs at eight days of incubation. Application of
even 1 µL of these oils reduced survivability of embryos to 70-82 %
by 96 hours after application and hatching success was reduced to
62-72%. Greater volumes of oil resulted in higher 96-hour mortality
and in lower hatching success; with 20 µL embryo survival at 96 hours
was reduced to 6%, 20% and 2% respectively and hatching success to 0,
6 and 0%. With application of 50 µL of South Louisiana crude, no
embryos survived even 96 hours. It was noted that the reduced survival
could not be accounted for by reduced air exchange. It was noted that
most mortality occurred within 96 hours of the application of oil, and
that the toxicity was probably due to the aromatic rather than the
aliphatic oil components. Hatched (i.e., surviving) ducklings did not
show any gross abnormalities, nor did they have lower hatching weights
than controls. (J40.42.w1)
- Weathering was shown to decrease toxicity of oils (Prudhoe Bay crude
oil, No. 2 fuel oil) to mallard eggs, with significant reduction in
toxicity by two to three weeks of weathering, although some toxicity
still remained following weathering, as indicated by reduced
survivability of embryos from treated eggs, compared to controls. Oil
killed rapidly: more than 80% of embryos dying after application of
oil died within six days of the application. Surviving ducklings
showed normal hatching weights. (J40.44.w1)
- A single application of medicinal mineral oil at 2.0 to 35.9 mg per Anas platyrhynchos - Mallard
egg, wiped thinly over the shell
after six days of incubation, was sufficient to kill about 50% of
embryos within two days; only five of 24 treated eggs hatched and all
but one of these had been treated with less than 12 mg of oil. (J40.29.w2)
- Application of four to five ml of medicinal mineral oil to the
breast feathers of mallard ducks after eight days of incubation was
sufficient that none of the eggs being incubated by the ducks hatched.
(J40.29.w2)
- A single dose of No. 2 fuel oil (10, 20, 50 or 100 µL) was applied
to the eggs of gulls (Larus marinus and Larus argentatus)
during natural incubation. Survival of embryos was inversely
proportional to the quantity of oil applied to the egg, and was
affected by the age of the eggs at the time of treatment: significant
reductions were seen with eggs treated with 10 or 20 µL of oil at
four to eight days after laying, while eggs which were more than half
way through the 28 day incubation period at the time of oil
application did not show reduced hatchability even with 100 µL oil.
Outdoor weathering of the oil for several weeks prior to application
to the eggs did not reduce toxicity to the embryos. It was considered
that oiling of eggs from pollution of adults was only likely to have a
significant impact on populations of these species if severe oiling occurred
early in incubation. However, it was noted that larger
population effects might occur with species with lower reproductive
potential and higher postfledging mortality, or greater sensitivity to
oil, or subject to other stresses. (J50.101.w1)
- Chicks surviving oiling initially may still show
increased mortality during hatching. (P14.2.w6,
P14.3.w16)
- The precise toxic effect which causes hatching
failure despite survival of the embryo following oiling, is unknown. (P14.3.w16)
Effects of oil on reproductive cycles and activity of
adult birds:
- Oil may have
long-term effects on reproduction. (B334.w3)
- Reproductive tract damage may occur. (B20.13.w10)
- Ingested oil has been shown to result in decreased
egg laying, decreased fertility and decreased hatching rates. (B20.13.w10)
- Oestrogen cycles may be disrupted leading to
reduced laying and fertilisation. (B20.13.w10,
P24.335.w11)
- Prolactin cycles may be disrupted leading to
failure to incubate properly. (B20.13.w10,
P24.335.w11)
- Abnormal yolk structure has been reported,
associated with reduced hatchability. (B20.13.w10)
- A single oral dose of 500 mg No. 2 fuel oil to
quail Coturnix coturnix japonica (Coturnix japonica - Coturnix - (Genus))
caused cessation of egg
production for six to eight days; the same dose of bunker C
oil caused cessation of egg production for the whole two
week trial period. 200 mg bunker C oil, but not 100 mg, caused a
reduction in egg production. Neither safflower oil at 500 mg nor
mineral oil at 500 mg had any effect on egg production.
Hatchability of eggs was markedly reduced for eggs laid on the
first or second days after 200 mg bunker C oil. Yolk deposition in
eggs laid after dosing with 200 mg bunker C oil was uneven and
distinctly abnormal; lesser abnormalities were noted with a dose
of 100 mg bunker C oil. In chickens 500 mg oil resulted in
structural abnormalities in egg yolks and 3g caused egg production
to cease. In Canada geese dosed with 2.0, 3.0 or 5.0 g of bunker C
oil yolk abnormalities were noted. (J22.195.w1)
- Laying mallards fed crude oil showed alterations in oestrus
cycles.
(P14.2.w6)
- Plasma prolactin levels in breeding female ducks have
been shown to be disrupted by oil. (P14.2.w6)
- Failure of normal incubation behaviour has been
demonstrated in breeding female ducks fed oil. (P14.2.w6)
- Ingestion of oil may cause temporary abandonment of
chicks, which may be lethal to recently-hatched chicks. (P14.2.w6)
- Anas platyrhynchos - Mallard
fed a diet contaminated with oil showed reductions in
oviposition rates, egg fertilisation and hatchability. With 1 ml
Kuwait crude oil per 100 g dry food no effect was observed. With 3 ml
per 100 g dry food, oviposition was abolished; subsequent reduction to
1 ml/100g food restored a normal rate of oviposition, but reduced
fertilisation was noted and none of the fertilised eggs produced
viable ducklings. Egg shell thickness was not affected. With South
Louisiana crude oil, ducks fed 3 ml per 100 g dry food showed
significant declines in oviposition with fertilisation under 25% and
hatchability of fertilised eggs only 40%; 1 ml per 100 g dry food did
not affect oviposition rate but none of the eggs were fertilised.
Additionally, a 33% decrease in egg shell thickness was noted with 3
ml of this oil per 100 g dry food. (J206.54.w1)
- Ducks (Anas platyrhynchos - Mallard
and Pekin (Anas platyrhynchus domesticus - Domestic Duck)) in lay, fed 2 g lubricating oil by stomach
tube, ceased laying immediately and did not resume for two weeks;
reproductive behaviour was also reduced. This amount would be ingested
in the first three days after contamination of the plumage with about
6 g of oil. (J40.29.w2)
- Cassin's auklets (Ptychoramphus aleuticus) were dosed with
300, 600 or 1,000 mg bunker C fuel oil, or 1,000 Prudhoe Bay crude
oil, in gelatin capsules. The proportion of birds laying eggs
significantly decreased in birds fed 1,000 mg of either oil, and, of
eggs laid, significantly lower percentages hatched in those birds
given 600 mg or 1,000 mg of bunker C oil. Hatching success was not
affected in the birds given 1,000 mg of Prudhoe Bay crude oil.
Post-hatching development of the chicks was not affected. Decreased
egg laying occurred in the period nine to 13 days after dosing; given
eight days of rapid formation of yolk and 4-5 days from the end of
yolk formation to laying, this indicated that the oil was affecting
yolk deposition in these birds. (J313.12.w1)
- When female Coturnix coturnix japonensis - Japanese quail (Coturnix
japonensis - Japanese quail (Coturnix - (Genus))
in lay were dosed with various petroleum oils, obvious changes in
laying, egg yolk development and hatchability of eggs were noted.
Dosing with 500 mg of No. 2 fuel oil halted production of eggs for six
to eight days while 500 mg of bunker C oil halted egg production for
at least 14 days. With 200 mg bunker C oil egg production was
decreased on days one and two (P<0.001) and hatchability of eggs
laid on these days was also markedly reduced (P<0.001) but
hatchability had returned to normal by day four, while with 100 mg
there was no apparent effect on the number of eggs produced.
Structural abnormalities were noted in eggs laid after oil dosing
(bunker C, 40% aromatic No. 2 fuel oil, Kuwait crude or south
Louisiana crude); yolk deposition was uneven in the first few hours
after dosing with petroleum oil. Thin, easily-cracked shells sometimes
occurred in eggs from the birds fed oil. Similar effects were noted in
chickens (Gallus gallus - Red junglefowl)
fed oil: those fed 3 g bunker C oil ceased egg production; those fed
500 mg bunker C oil showed structural alterations in the yolk of eggs.
Structural alterations in the yolk were also seen in eggs from Branta canadensis - Canada goose
fed 2-5 g bunker C oil. (J22.195.w1)
- A study of Spheniscus magellanicus - Magellanic penguin in
Argentina noted a scarcity of oiled penguins at a nesting colony,
compared to the number at non-breeding sites where the penguins were
found. It was suggested that the discrepancy indicated that oiled
penguins, even if they could survive while oiled, are not fit to
breed. (J313.14.w1)
On mammals:
- Mammals ingesting low levels of petroleum products could show
reduced reproductive success. ((P9.1.w5))
- In female Mustela vison - American mink
experimentally exposed to oil, while individuals exposed acutely (by
being placed in a slick of the oil on sea water) to either Prudhoe Bay
crude oil or bunker C fuel oil showed no reproductive effects, females
given either of the oils in feed at 500 ppm (a low contamination
level) from sixty days prior to breeding until weaning, showed
reductions in percentage whelping (76.2% of those given Prudhoe Bay
crude oil and 25.0% of those given Bunker C fuel oil) and reduced
number of liveborn kits per female bred (2.4 and 0.7 kits/female,
respectively). No behavioural changes (eating, grooming or breeding)
were seen with this level of oil ingestion. (P9.1.w5)
On reptiles:
- Exposure of turtle eggs to oil-contaminated
sand has been shown to result in death or abnormal development of
turtle embryos. (P14.2.w1)
- Fresh oil was more harmful than weathered oil. (P14.2.w1)
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