Public Release:  Mercury pollution causes immune damage to harbor seals

BioMed Central

Methylmercury (MeHg), the predominant form of mercury found in the blood of marine mammals and fish-eating communities, could be more damaging to seals than has previously been thought. Research published in BioMed Central's open access journal Environmental Health shows that MeHg harms T-lymphocytes, key cells in a seal's immune system. Similar results were also found for human lymphocytes.

Mercury exposure is known to occur as a result of man-made pollution and natural events such as volcanic eruptions. According to the lead author of this study, Krishna Das of the Université de Liège, Belgium, "Mercury is known to bioaccumulate and to magnify in marine mammals, which is a cause of great concern in terms of their general health. In particular, the immune system is known to be susceptible to long-term mercury exposure". In order to determine the scale of this problem, the authors carried out analysis of the blood mercury levels of harbour seals caught in the North Sea and tested the effects of MeHg in lab experiments.

By applying increasing doses of MeHg to lymphocytes, a type of white blood cell, the authors determined that the amount of mercury found in the blood of the seals studied was enough to cause damage to the important immune system cells. They said, "Although the in vitro approach utilised in this investigation represents an extreme reductionism relative to the complex situation in the intact organism, it provides an insight into the specific effects of mercury pollution."

Immune system damage may already have taken a toll on the population of harbour seals. The 1998 and 2002 outbreaks of phocine distemper virus, known to have killed thousands of seals, were linked to the deleterious effects of pollution on the seals' ability to fight the infection.

###

Notes to Editors

1. Mercury immune toxicity in harbour seals: links to in vitro toxicity
Krishna Das, Ursula Siebert, Audrey Gillet, Aurélie Dupont, Carole Di-Poi, Sonja Fonfara, Gabriel Mazzucchelli, Edwin De Pauw and Marie-Claire De Pauw-Gillet
Environmental Health (in press)

During embargo, article available here: http://www.ehjournal.net/imedia/1711193095161354_article.pdf?random=542245

After the embargo, article available at journal website: http://www.ehjournal.net/

Please name the journal in any story you write. If you are writing for the web, please link to the article. All articles are available free of charge, according to BioMed Central's open access policy.

Article citation and URL available on request at press@biomedcentral.com on the day of publication

2. Environmental Health is an Open Access, peer-reviewed, online journal that considers manuscripts on all aspects of environmental and occupational medicine, and related studies in toxicology and epidemiology. Environmental Health is aimed at scientists and practitioners in all areas of environmental science where human health and well-being are involved, either directly or indirectly. Environmental Health is a public health journal serving the public health community and scientists working on matters of public health interest and importance pertaining to the environment.

3. BioMed Central (www.biomedcentral.com) is an STM (Science, Technology and Medicine) publisher which has pioneered the open access publishing model. All peer-reviewed research articles published by BioMed Central are made immediately and freely accessible online, and are licensed to allow redistribution and reuse. BioMed Central is part of Springer Science+Business Media, a leading global publisher in the STM sector.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.