17 research outputs found
Pyrethroid bioaccumulation in Mediterranen dolphins
Pyrethroids are organic
pollutants with high hydrophobicity used as insecticides. Concern exists
about aquatic organisms¿ exposure to their toxicity. They were believed
to be converted to non-toxic metabolites in mammals, but our group has
detected them in human breast milk and has proved their
bioaccumulation in marine mammals and river fish. The present study
investigates the occurrence of pyrethroid compounds in liver samples
from striped dolphins (Stenella coeruleoalba)and common dolphins
(Delphinus delphis) from southern Spain, as the first attempt to
determine the occurrence and bioaccumulation and distribution of
pyrethroids in marine mammal tissues from the Mediterranean Sea.
Samples of dolphin tissue were collected from the Abloran Sea (south of
Spain) between 2003 and 2010, including 37 liver samples from striped
dolphin and different tissues¿blubber, muscle, liver, brain and
kidneys¿from 11 common dolphins. The analytical method monitored 10
pyrethroids, including cypermethrin and detamethrin. For the sample
preparation?lyophilized sample was spiked with internal standards,
extracted by sonication and underwent a clean-up with alumina and C18
SPE cartridges. Extracts were analysed by GC-NCI-MS/MS. Method
recoveries for the pyrethroids ranged 53-116?% and method LODs and
LOQs were 0.02-0.46?ng/g and 0.08-1.54?ng/g, respectively.
Pyrethroids were detected in 87?% of the striped dolphins and 100?% of
the common dolphins, with total concentrations of nd-5,210?ng/g?lw
and 69-2,036?ng/g?lw, respectively. These levels were higher than those
reported found in dolphins from Brazil (7.0-68?ng/g?lw). Permethrin
and tetramethrin were the main contributors to the pyrethroid profiles
for all tissues. The samples of striped dolphins where used to observe
that bioaccumulation of pyrethroids was unlike that of persistent organic
pollutants (POPs), as pyrethroid levels were not correlated to the age of
the specimens. Levels slightly increase from calves to juveniles, whereas
juveniles present similar levels to adults. Metabolization of pyrethroids
after achieving sexual maturity might account for this pattern. Because
of the pyrethroids lipophilic behaviour, blubber was the most
contaminated tissue and brain showed the lowest levels. Normalizing the
data to the lipid content, the highest value was for muscle by far,
suggesting a preference for that tissue.
SETA