WHAT WE DO...AND WHOM WE SERVE:
Mysteries of the human-ocean relationship
FIRE RETARDANTS: LIFE SAVING, LIFE THREATENING
In 1977, more than a million homes and businesses caught fire in the United States. By 2001 that figure had been cut by almost half, largely through the use of fire-retardant chemicals. Fire retardants are used in upholstered furniture, mattresses, building materials, carpeting, computers, and televisions. In other words, they are all around us.
The major group of fire retardants, called PBDEs (short for polybrominated diphenyl ethers), work by slowing the ignition of fires and the rate of their growth. This gives people more time to extinguish or escape the fire. Of the more than 175 different types of flame retardants, brominated flame retardants have been used the most frequently because of their effectiveness and low cost.
But this fire protection may have come at an environmental cost. Research has shown that these chemicals tend to bioaccumulate in fish, especially—for reasons still largely unknown—in Puget Sound Chinook salmon, which have some of the highest accumulation rates in the world.
Although many of these chemicals are no longer used, they are so resistant to breakdown that they persist for years, leaching into the soil and running off into the water. Animal studies have shown that as these chemicals accumulate, they can become toxic.
In rats, for example, exposures during pregnancy can lead to neurodevelopmental abnormalities in offspring, affecting thyroid function and brain development.
Evan Gallagher
Evan Gallagher, PhD, associate professor of toxicology in our department and principal inves-tigator for a grant through National Oceanic and Atmospheric Administration (NOAA) Oceans and Human Health Initiative, is exploring the link between consumption of PBDE contaminated salmon and potential effects of these fire retardants on human fetal development. Gallagher’s grant examines the effects of exposures to PBDEs in pregnancy.
Although Gallagher’s research project is ultimately geared toward human health, the project begins with experiments aimed at determining the potential for PBDE metabolism in salmon. Fish absorb the chemicals through water and food, and because of suspected slow metabolism and excretion, these chemicals tend to bioaccumulate in body tissues, including the muscle fillets that are consumed by humans.
BRIDGING THE GAP
Research grants rarely combine ecosystem and human health aspects, but Gallagher’s partners are the National Marine Fisheries (NMFS) and Washington Department of Fish and Wildlife. The two natural resource organizations are looking in detail at the levels of the PBDEs in Puget Sound, largely based on concerns for the salmon and the Puget Sound ecosystem.
“One of the side benefits of this project,” Gallagher said, “is that it builds partnerships with local agencies with considerable interest and expertise in the effects of pollutants in the Puget Sound ecosytem.”
Although similar ties with these agencies have existed within other UW units (such as the School of Aquatic and Fishery Sciences), these partnerships are fairly new for our department and are largely a result of Gallagher’s efforts. In particular, NOAA/NMFS scientists are well recognized for their expertise in salmon biology, reproduction and behavior, and for their use of analytical chemistry in the historical characterization of Puget Sound pollution. Our department contributes expertise in toxicology, human health, and genomics.
Before his academic career was underway, Gallagher worked as a field biologist for the US Fish and Wildlife Service. His experiences there gave him an understanding of the need to apply state-of-the-art scientific methodologies to examining and solving real-world environmental problems.
Gallagher’s research will use genomic techniques and biochemical analyses to examine the effects of the most dominant Puget Sound fire retardant compounds in salmon liver cells and to examine the biochemical factors underlying their accumulation. In phase three of his research, he’ll explore which chemicals are of most concern for potential toxicity to sensitive human cells such as liver progenitor cells, which are important for normal blood development.
Gallagher was a postdoctoral fellow at UW from 1991 to 1996. He returned to the faculty as an associate professor in 2004 after eight years at the University of Florida College of Veterinary Medicine, where he worked in human and aquatic biochemical toxicology and directed an aquatic toxicology laboratory. He returned to Seattle because, he said, “The Pacific Northwest has long been a hotbed for biotechnology research, and is now beginning to lead the way in the study of a number of critical marine and coastal toxicological issues.
“The Northwest is the home of a number of energetic researchers who are truly excited about using interdisciplinary approaches to address these environmental problems,” he said. “The Department of Environmental and Occupational Health Sciences has traditionally had one of the strongest groups nationwide in biomedical toxicology. The timing was right for me to build a program drawing on the recent advances in genomics and departmental strengths in public health toxicology to help address the connection between human health and the environment.”
Computer keyboards don't burst into flames, but there is an environmental trade-off to some fire retardants.
FOR FURTHER READING
Birnbaum LS and Staskal DS (2003).
Brominated flame retardants: Cause for concern?
US Environmental Protection Agency http://ehp.niehs.nih.gov/members/2003/6559/6559.html.
Fischer D (2005).
It’s In Us All. Flame retardants contaminate everyone but concentrate especially in children. The Oakland Tribune. 12/11/2005.
http://www.insidebayarea.com/oaklandtribune/localnews/ci_3299744.
Moneypenny CG, Huisden M, Gallagher E.
4-Hydroxynonenal inhibits cell proliferation and alters differentiation pathways in human fetal liver hematopoietic stem cells.
Biochemical Pharmacology 2005; 69(1):105-112.
NEW CENTER STUDIES INTERACTIONS
More than half the world’s population lives in coastal areas. We depend on the oceans for food, transportation, and even medicines. Our ocean environment is intertwined with our lives, our economy, and our health in many ways. Surprisingly, there has been little scientific study about how humans affect the oceans or how the oceans affect human health.
Shellfish harvesting and consumption are important aspects of Northwest culture adn teh costal economy.
Researchers at the Pacific Northwest Center for Human Health and Ocean Studies (H2O Center) aim to uncover some of the mysteries in the human-ocean relationship.
The H2O Center is one of four funded by the National Science Foundation (NSF) and National Institute of Environmental Health Sciences (NIEHS) in 2004. This center initiative is the first time the two agencies have jointly funded research. “This is an exciting development,” said Elaine Faustman, PhD, director of the H2O center. “Public health and ocean sciences researchers rarely talk to each other, despite the obvious interconnections between human and ocean health.” The center is co-directed by E. Virginia Armbrust, PhD, a professor in the School of Oceanography.
The UW H2O Center was awarded $6.4 million over five years to focus on harmful algal blooms. Occasionally, algae grow very fast or “bloom” with potential consequences for health and the environment. One type of harmful algal bloom or “HAB” is caused by the Pseudo-nitzschia pungens algae, which can produce domoic acid.
Key questions addressed by center researchers include:
- What environmental factors lead to development of toxic blooms?
- Why do certain types of shellfish retain toxin?
- What are the biological processes of domoic acid toxicity?
- What populations are at greatest risk?
- How do dietary consumption behaviors contribute to exposure?
Domoic acid can accumulate as it passes through the food web, affecting shellfish, marine mammals, and marine birds. In exposed humans, the toxin can cause a syndrome known as amnesic shellfish poisoning (ASP). Amnesic shellfish poisoning was first identified in 1987, when more than 100 people became ill on Prince Edward Island, in eastern Canada, after eating contaminated mussels. Once researchers identified domoic acid, they realized that a number of other wildlife populations were affected, including sea lions and birds.
Razor clams with detectable levels of domoic acid have been identified from beaches in Oregon, Washington, British Columbia, and Alaska every year since 1991, prompting several shellfish harvest closures.
Ginger Armbrust briefs Elaine Faustman during a training cruise.
The H2O Center has four major research projects underway. One project studies toxic algae genetics and the dynamics of harmful algal blooms to learn what makes them produce toxins. Another project looks at how domoic acid is taken up and retained by shellfish such as razor clams. A third project examines the neurodevelopment effects of domoic acid exposure on humans. The fourth project considers dietary and behavioral aspects of human exposure, especially among vulnerable populations and consumers who eat a lot of shellfish.
The H2O Center fosters collaborative, multi-disciplinary partnerships. “People are interested in collaborating, and it is exciting and challenging to work across traditional boundaries,” said Armbrust.
An example is a pilot project co-led by Kathi Lefebvre, a scientist at the Marine Biotoxins Group of the National Oceanic and Atmospheric Administration’s (NOAA) Northwest Fisheries Science Center (NWFSC) and the University of Washington’s Evan Gallagher (see page 18 for a description of Gallagher’s fire retardant research project). The two researchers are studying how domoic acid affects both fish and humans. “In this project we’re looking for sublethal or subacute affects.” Lefebvre said. “We’re investigating what might be happening at the level of chronic exposure, for example.”
In addition to its research mission, the center is committed to training new scientists and translating research for a variety of audiences. It supports undergraduate education through an NSF Research Experiences for Undergraduates program and co-sponsors (with NWFSC) a bimonthly seminar series. The H2O Center plans to use research on domoic acid as a starting point for developing novel methods and collaborations that can be applied to a wide variety of public health concerns.
Center researchers aboard the research vessel Thomas G. Thompson in November 2004.
FOR FURTHER READING
H2O Center website http://www.pnwh2o.washington.edu.
Committee on the Ocean’s Role in Human Health (1999).
Monsoons to Microbes. National Research Council
http://www.nap.edu/books/0309065690/html.
Northwest Fisheries Science Center Domoic Acid Poisoning.
http://www.nwfsc.noaa.gov/hab/habs_toxins/marine_biotoxins/da/index.html.
Judd NL, Drew CH, Acharya C, Mitchell TA, Donatuto JL, Burns GW, Burbacher TM, Faustman EM. Framing scientific analyses for risk management of environmental hazards by communities: Case studies with seafood safety issues. Environ Health Perspect 2005; 113(11):1502–1508.
Judd NL, Griffith WC, Faustman EM. Consideration of cultural and lifestyle factors in defining susceptible populations for environmental disease. Toxicology 2005; 198(1-3):121–133.
Ocean Studies Board of the National Research Council
http://dels.nas.edu/osb/.
Washington State Department of Health press releases
regarding domoic acid closures:
http://www.doh.wa.gov/Publicat/2005_news/05-134.htm.
http://www.doh.wa.gov/Publicat/2005_news/05-118.htm.