Download Organochlorines in California sea lions

OrganOchlOrines in califOrnia sea liOns - TempOral Trends
and assOciaTiOn wiTh cancer and infecTiOus disease
Nistara Randhawa , Frances Gulland , Gina Ylitalo , Robert deLong , and Jonna Mazet
1
1
2
3
3
1
University of California, Davis; The Marine Mammal Center, Sausalito; NOAA, Seattle
2
3
Because:
We found:
Legacy organochlorines (OCs) such as polychlorinated
biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DTT)
are ubiquitous in the global ecosphere.
Biological association - Stranded adult male sea lions had
the highest levels of summed PCBs and DDTs compared to
stranded adult females and juveniles.
PCBs and DDTs
enter the food chain
Table 1. Mean (±SD) summed DDTs and PCBs (μg/g, lipid weight) in the
They biomagnify up the food chain - marine mammals like
California sea lions accumulate lipophilic OCs in their lipid
rich blubber layer.
3
blubber of stranded California sea lions in the study (n = 306)
n
PCBs
DDTs
523 a ± 878
Adult males
43
126 a ± 219
162 b ± 342
Adult females
121
50.2 b ± 121
105 a b ± 104
Subadults
25
26.3 b ± 29.9
369 a b ± 525
Pups
11
75.4 a b ± 113
They are associated with adverse effects like
immunosuppression, carcinogenicity, endocrine disorders
and reproductive impairment in humans and animals (1-6).
ab
Can California sea lions act as sentinels for marine
environment health?
Means with different letters are significantly different with Tukey’s HSD (honestly significant difference), p<0.05
Temporal association - A decrease in PCBs and DDTs
was observed in stranded sea lions through time.
4
Accumulate in lipid rich blubber layer
6
5
Females transfer
OCs to offspring
Males continue to
accumulate OCs
1
We conducted:
Figure 1. Mean (±SE) log summed blubber PCBs and DDTs (μg/g, lipid weight) in stranded sea lions through
the time periods 1992-95 (13 males:13 females) 1996-99 (11:27), 2000-03 (10:60), and 2004-07 (9:21).
A retrospective cross-sectional study on California sea lions
between 1992 and 2007.
Association with health - PCBs and DDTs were significantly
associated with cancer and infectious diseases in stranded
California sea lions. Healthy sea lions had lower contaminant
levels than their sick counterparts.
Lipid- normalized contaminant data were provided by the
NOAA Fisheries’ Northwest Fisheries Science Center:
OC (μg/g) = Observed OC value/lipid percent
7
Table 2. Logistic regression analysis of cancer/infectious diseases and log
transformed blubber OC levels of stranded sea lions presenting to TMMC
California sea lions in the study:
Stranded California sea lions brought to
The Marine Mammal Center (TMMC);
n = 200
Cancer
PCBs
DDTs
Odds ratio
2.0
1.9
Infectious
disease
PCBs
DDTs
1.4
1.4
95 % CI
1.55 - 2.62
1.51 - 2.47
p-value
<0.001
<0.001
1.03 - 1.82
1.07 - 1.86
0.030
0.015
Cancer
High contaminant loads
significantly
associated
with
A sea lion with 1000
μg/g blubber OCs was 5
times more likely to have
cancer than a sea lion
with 100 μg/g.
Infectious
disease
A sea lion with 1000 μg/g
blubber OCs was twice as
likely to have an infectious
disease than a sea lion with
100 μg/g.
Figure 2. Mean (±SE) log summed blubber
PCBs and DDTs (μg/g, lipid weight) of adult
Healhty Puget Sound males; n = 60
stranded sea lions presenting to TMMC
between 2000 and 2003 (10 males:60
females), healthy males from Puget Sound
Healthy San Miguel Island females;
n = 46
(n = 60), and healthy females from San
Miguel Island (n = 46).
2
References:
Acknowledgements:
1. DeLong RL, Gilmartin WG, Simpson JG. Premature births in California sea lions: association with high organochlorine pollutant residue
levels. Science (New York, NY). 1973;181(4105):1168-70.
2. Ylitalo GM, Stein JE, Hom T, Johnson LL, Tilbury KL, Hall AJ, Rowles T, Greig D, Lowenstine LJ, Gulland F. The role of organochlorines
in cancer-associated mortality in California sea lions. Marine Pollution Bulletin. 2005;50(1):30-9.
3. Shaw S, Brenner D, Hong C-S, Bush B, Shopp G. Low-level exposure to PCBs is associated with immune and endocrine disruption in
neonatal harbor seals (Phoca vitulina) from the California coast. Organohalogen Compounds. 1999;42:11-4.
4. Mos L, Morsey B, Jeffries SJ, Yunker MB, Raverty S, Guise SD, et al. Chemical and biological pollution contribute to the immunological
The authors are grateful for the support provided by NOAA’s Oceans and Human Health Initiative. We would like to
thank Drs. Mary Christopher, Heejung Bang, Robert Poppenga, and Christine Kreuder Johnson for their assistance
in this project; as well as Alexandria Glover, Eline Britz and Jannette Ramirez. We appreciate the chemical analyses
provided by Bernadita Anulacion, Daryle Boyd, Jennie Bolton, Richard Boyer, Ronald Pearce, Catherine Sloan, and their
colleagues at the Northwest Fisheries Science Center and the support and funding provided by Teri Rowles from the
Marine Mammal Health and Stranding Response Program of NOAA Fisheries.
OC contamination has significant
health implications for California sea
lions.
California sea lions can act as sentinels to monitor
future OC trends in the marine environment, as well
as provide information on effects of exposure.
5. Jepson PD, Bennett PM, Deaville R, Allchin CR, Baker JR, Law RJ. Relationships between polychlorinated biphenyls and health status in
harbor porpoises (Phocoena phocoena) stranded in the United Kingdom. Environmental Toxicology and Chemistry. 2005;24(1):238-48.
8
Photo credits:
9. Jivedanson on Flickr
9