Mercury pollution causes immune damage to harbor seals

Oct 21, 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.

Citation: 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)
www.ehjournal.net/

Source: BioMed Central

Explore further: US delays decision on Keystone pipeline project

add to favorites email to friend print save as pdf

Related Stories

How tattoos 'move' with age

Apr 28, 2011

The dyes which are injected into the skin to create tattoos move with time – permanently altering the look of a given design. In this month’s Mathematics Today Dr Ian Eames, a Reader in Fluid Mechanics ...

Recommended for you

US delays decision on Keystone pipeline project

Apr 18, 2014

The United States announced Friday a fresh delay on a final decision regarding a controversial Canada to US oil pipeline, saying more time was needed to carry out a review.

New research on Earth's carbon budget

Apr 18, 2014

(Phys.org) —Results from a research project involving scientists from the Desert Research Institute have generated new findings surrounding some of the unknowns of changes in climate and the degree to which ...

User comments : 0

More news stories

China says massive area of its soil polluted

A huge area of China's soil covering more than twice the size of Spain is estimated to be polluted, the government said Thursday, announcing findings of a survey previously kept secret.

UN weather agency warns of 'El Nino' this year

The UN weather agency Tuesday warned there was a good chance of an "El Nino" climate phenomenon in the Pacific Ocean this year, bringing droughts and heavy rainfall to the rest of the world.

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Ex-Apple chief plans mobile phone for India

Former Apple chief executive John Sculley, whose marketing skills helped bring the personal computer to desktops worldwide, says he plans to launch a mobile phone in India to exploit its still largely untapped ...

Filipino tests negative for Middle East virus

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

Egypt archaeologists find ancient writer's tomb

Egypt's minister of antiquities says a team of Spanish archaeologists has discovered two tombs in the southern part of the country, one of them belonging to a writer and containing a trove of artifacts including reed pens ...