Mercury linked to immune changes and autoimmune diseases

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Mercury linked to immune changes seen in autoimmune disease.

<http://www.environmentalhealthnews.org/ehs/newscience/mercury-linked-to-immune-\

changes-in-gold-miners/ >

Apr 13, 2010

Gardner, RM, JF Nyland, IA Silva, AM Ventura, JM deSouza and EK

Silbergeld. 2010. Mercury exposure, serum antinuclear/ antinucleolar

antibodies, and serum cytokine levels in mining populations in Amazonian Brazil:

A cross-sectional study. Environmental Research

<http://dx.doi.org/10.1016/j.envres.2010.02.001>

Synopsis by F. Nyland

Mercury increases the risk of developing autoimmune symptoms - similar

to those seen with arthritis - in miners from Amazonian Brazil who work

with the metal.

A study in people adds to the growing evidence and concern that mercury

can alter the immune system in ways that may promote autoimmune diseases such as

arthritis and lupus. The researchers report that mercury

increased levels of key signaling and antibody markers measured in the

blood of Brazilian gold miners who use the metal to extract the gold

from river sediments.

This is the first time mercury has been shown to affect in people the

immune signaling proteins that are responsible for inducing

inflammation. The results support recent animal studies that find

similar changes to rodent immune systems after mercury exposure. The

study adds to the few other human studies on the subject, which are less

consistent in their conclusions.

Mercury is a well known toxicant. Exposure to even small amounts can

damage the brain and nervous system in ways that reduce motor, verbal

and attention abilities. This is especially true for developing fetuses

and children.

Its effects on the immune system are still being teased apart.

In the United States, most people are exposed to mercury - by eating

certain species of fish - most notably large predators such as tuna,

swordfish and tilefish. Federal fish advisories warn against eating too

much of certain species or too much fish caught from contaminated

waterways so as to limit exposure to the metal.

The researchers studied five separate populations: a gold mining camp

where mercury is used to extract the gold and two diamond and two

emerald mining camps where mercury is not used. Mercury exposure was

determined through questionnaires, urine samples and hair samples.

Overall, mercury levels and the ranges were higher than what is reported for

people who live in the United States.

When blood from gold miners was compared to diamond and emerald miners,

changes were found. Levels of certain antibodies and proteins called

cytokines were increased only in the gold miners. These increased

protein levels are often used to help diagnose some autoimmune diseases

like lupus or rheumatoid arthritis.

Even though the miners were exposed through their work to periodic and

relatively high levels of mercury, the findings apply to others since

mercury exposure from multiple sources is a global problem. Importantly, these

changes were not related to whether the miners had malaria,

giving the findings a broader application worldwide. Malaria is a

common parasitic infection in many parts of the world, but not in the

United States or Europe, and it too can cause changes in the immune

system. Since the immune changes observed in this study were unrelated

to whether or not the miners were infected, the authors can conclude

that the effects are most likely from mercury exposure.