Mercury pollution causes immune damage to harbor seals

October 20, 2008

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.
-end-
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.

BioMed Central

Related Immune System Articles from Brightsurf:

How the immune system remembers viruses
For a person to acquire immunity to a disease, T cells must develop into memory cells after contact with the pathogen.

How does the immune system develop in the first days of life?
Researchers highlight the anti-inflammatory response taking place after birth and designed to shield the newborn from infection.

Memory training for the immune system
The immune system will memorize the pathogen after an infection and can therefore react promptly after reinfection with the same pathogen.

Immune system may have another job -- combatting depression
An inflammatory autoimmune response within the central nervous system similar to one linked to neurodegenerative diseases such as multiple sclerosis (MS) has also been found in the spinal fluid of healthy people, according to a new Yale-led study comparing immune system cells in the spinal fluid of MS patients and healthy subjects.

COVID-19: Immune system derails
Contrary to what has been generally assumed so far, a severe course of COVID-19 does not solely result in a strong immune reaction - rather, the immune response is caught in a continuous loop of activation and inhibition.

Immune cell steroids help tumours suppress the immune system, offering new drug targets
Tumours found to evade the immune system by telling immune cells to produce immunosuppressive steroids.

Immune system -- Knocked off balance
Instead of protecting us, the immune system can sometimes go awry, as in the case of autoimmune diseases and allergies.

Too much salt weakens the immune system
A high-salt diet is not only bad for one's blood pressure, but also for the immune system.

Parkinson's and the immune system
Mutations in the Parkin gene are a common cause of hereditary forms of Parkinson's disease.

How an immune system regulator shifts the balance of immune cells
Researchers have provided new insight on the role of cyclic AMP (cAMP) in regulating the immune response.

Read More: Immune System News and Immune System Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.