Methylmercury warning

October 28, 2008

Recent studies hint that exposure to the toxic chemicals, such as methylmercury can cause harm at levels previously considered safe. A new analysis of the epidemiological evidence in the International Journal of Environment and Health, suggests that we should take a precautionary approach to this and similar compounds to protect unborn children from irreversible brain damage.

Philippe Grandjean of the Department of Environmental Health at Harvard School of Public Health, in Boston, and the University of Southern Denmark in Odense, explains that the causes of suboptimal and abnormal mental development are mostly unknown. However, severe exposure to pollutants during the development of the growing fetus can cause problems that become apparent as brain functions develop - and ultimately decline - in later life. Critically, much smaller doses of chemicals, such as the neurotoxic compound methylmercury, can harm the developing brain to a much greater extent than the adult brain.

Methylmercury is a chemical compound formed in the environment from released mercury. Unfortunately, the methylmercury can be transported quickly around the body and may enter the brain. Serious problems will ensue if important developmental processes are blocked as there will be only one chance for the brain to develop.

The researchers point out that until recently research into the effects of pollutants on the brain has been clouded by the lack of information on actual exposure. Moreover, finding a direct link between specific problems with the brain and exposure relies on statistical, or epidemiological, analysis rather than case-by-case understanding. The researchers say that neurodevelopmental disorders of possible environmental origin affect between 5% and 10% of babies born worldwide, leading to dyslexia, mental retardation, attention deficit/hyperactivity disorder, cerebral palsy, and autism.

The toxicity of methylmercury is well known, but the researchers believe that the medical world has underestimated the risk of brain damage associated with exposure to this compound as well as numerous others. Professor Grandjean emphasizes that little research has been carried out into the effects of other neurotoxic chemicals.

"Until there is enough evidence to rule out effects of certain chemicals on the developing nervous system, a cautious approach would involve strict regulation of suspected developmental neurotoxicants and prudent counseling of expectant mothers regarding exposures to untested substances," the researchers conclude.

Source: Inderscience Publishers

Explore further: Brain benefits of aerobic exercise lost to mercury exposure

Related Stories

Brain benefits of aerobic exercise lost to mercury exposure

September 16, 2016
Cognitive function improves with aerobic exercise, but not for people exposed to high levels of mercury before birth, according to research funded by the National Institute of Environmental Health Sciences (NIEHS), part of ...

Measuring mercury: Common test may overestimate exposure from dental amalgam fillings

March 20, 2013
A common test used to determine mercury exposure from dental amalgam fillings may significantly overestimate the amount of the toxic metal released from fillings, according to University of Michigan researchers.

Low-level mercury exposure in pregnant women connected to ADHD risk in children

October 8, 2012
A study of children in the New Bedford, Mass., area suggests that low-level prenatal mercury exposure may be associated with a greater risk of attention-deficit/hyperactivity disorder (ADHD)-related behaviors and that fish ...

Mercury levels in Pacific fish likely to rise in coming decades, study reports

August 25, 2013
University of Michigan researchers and their University of Hawaii colleagues say they've solved the longstanding mystery of how mercury gets into open-ocean fish, and their findings suggest that levels of the toxin in Pacific ...

The influence of the epigenome

March 14, 2016
I first learned about epigenetics in a "fish bowl" meeting room at the University of Pennsylvania in the summer of 2013, when I worked as a research intern in the Ted Abel lab. We were in the middle of a weekly lab meeting, ...

Dental amalgam: Anti-mercury movement pushes for shifts in dentistry

April 4, 2013
Silver tooth fillings have been placed in the mouths of Americans since before the Civil War, an inexpensive, durable and reliable material that helped form the foundation of modern dentistry.

Recommended for you

Hormone therapy in the menopause transition did not increase stroke risk

November 24, 2017
Postmenopausal hormone therapy is not associated with increased risk of stroke, provided that it is started early, according to a report from Karolinska Institutet published in the journal PLOS Medicine.

When traveling on public transport, you may want to cover your ears

November 22, 2017
The noise levels commuters are exposed to while using public transport or while biking, could induce hearing loss if experienced repeatedly and over long periods of time, according to a study published in the open access ...

Different types of alcohol elicit different emotional responses

November 22, 2017
Different types of alcohol elicit different emotional responses, but spirits are most frequently associated with feelings of aggression, suggests research published in the online journal BMJ Open.

Air pollution linked to poorer quality sperm

November 22, 2017
Air pollution, particularly levels of fine particulate matter (PM2.5), is associated with poorer quality sperm, suggests research published online in Occupational & Environmental Medicine.

Sunrise and sunset guide daily activities of city-dwellers

November 21, 2017
Despite artificial lightning and social conventions, the dynamics of daylight still influence the daily activities of people living in modern, urban environments, according to new research published in PLOS Computational ...

Older men need more protein to maintain muscles

November 21, 2017
The amount of protein recommended by international guidelines is not sufficient to maintain muscle size and strength in older men, according to a new study.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.