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The Best Science Writing Online 2012
Showcasing more than fifty of the most provocative, original, and significant online essays from 2011, The Best Science Writing Online 2012 will change the way...
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It’s a heavy metal. It’s linked to learning problems in school children. And every child is exposed.
Sounds like lead?
It’s cadmium.
Signs are emerging that cadmium – a widespread contaminant that gets little attention from health experts and regulators – could be the new lead.
Children with higher cadmium levels are three times more likely to have learning disabilities and participate in special education, according to a new study led by Harvard University researchers.
Absorbed from the soil, cadmium is found in certain foods, particularly potatoes, grains, sunflower seeds and leafy greens, as well as tobacco. It also has been discovered in some inexpensive children’s jewelry, prompting new voluntary industry standards last fall.
Dr. Robert Wright, the study’s senior author, emphasized that the links to learning disabilities and special education were found at commonplace levels previously thought to be benign.
“One of the important points of the study is that we didn’t study a population of kids who had very high exposures. We studied a population representative of the U.S. That we found any [effect] suggests this is occurring at relatively low levels,” said Wright, an associate professor of pediatrics and environmental health at Harvard.
Scientists said the new findings are a sign that cadmium could have dangerous properties similar to lead that alter the way children’s brains develop. More research is necessary, though, to confirm and refine the potential effects on kids.
“It does certainly point to the fact that we need more attention paid to the neurotoxic effects of cadmium in children," Wright said.
Until now, the nervous system has not received much attention as a target for cadmium. Some studies of adult workers, however, have shown that high exposures can trigger neurological problems, and small, earlier studies of children found links to mental retardation and decreased IQs.
The new study is the largest to look at connections between cadmium in urine and neurological effects, and the only one that has used a national group of children.
“Collectively, the studies are very consistent. They provide fairly substantial support that cadmium is a neurotoxin,” said Dr. Bruce Lanphear, a pediatrician and epidemiologist at Simon Fraser University who was a co-author of the study.
Lanphear, one of the world’s leading experts on the effects of lead in children, added that “the pattern we’re seeing here with cadmium is very consistent with what we see with other toxicants,” including lead and mercury.
The two scientists recommended that government re-examine its standards and guidelines for cadmium in food, soil, workplaces and consumer products to consider the effects on children’s brains.
Current regulations for cadmium are based on threats to adults, and the kidneys have been considered the most sensitive organ to its toxic effects. Classified as a known human carcinogen, it is linked to lung, kidney and prostate cancer in workers.
“We’ve got a large new national study showing a threefold increase [in children’s learning disabilities and special education]. But I wouldn’t go so far to say we definitely need to lower regulatory levels. It deserves to be re-evaluated, though,” said Lanphear.
Of the 2,199 children between the ages of 6 and 15 included in the new study, 12.6 percent had a learning disability and 10.5 percent were enrolled in special education classes, according to the study, published online in Environmental Health Perspectives last month. The children were not tested for disabilities; instead it was reported by their parents on a questionnaire that is part of the National Health and Nutrition Examination Study.
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14 Comments
Add Comment--- They shouldn’t be used unless proven safe,” he said.
Reply | Report Abuse | Link to thisSounds like a near-impossible task. Do we truly know that anything is "safe". Anything and everything in the world around us might be responsible for one thing or another over long-term exposure.
We can only use intelligence and past studies to come up with a list of possible dangers. Cadmium being a heavy metal probably should have already had a warning flashing- but other things.
Do we really know our paper cups that we put our coffee in isn't giving us alzheimers- or the material in our air-filters acting as the trigger that allows prions to move up to our brains?
Prooving something is safe is about as hard as prooving or disprooving a supreme being. You can't possibly run a test on everything that could possibly go wrong.
But Candium just sound so delicious!
Reply | Report Abuse | Link to thisA long long time ago, one of my university assignments was heavy metal contamination is the soils of Western Sydney.
Reply | Report Abuse | Link to thisCadmium was one of the metals I was doing AA spectroscopic analysis for. It has been know for a long time that it was as bad as lead.
prions to move up to our brains?
Reply | Report Abuse | Link to thisBirds....What are you really saying?
Most toxins are well known, Cadmium is one of them.
We have a good idea about what's toxic and NOT.
And can easily limit the known ones!
But, some people resist change.
Why?
Dear Marla Cone, keeping young children from ingesting heavy metals, in the form of objects, is part of good parenting. Renee Gardner said, "Iron helps prevent absorption of cadmium, so parents worried about exposure should ensure their kids have adequate iron in their foods." Good information to be sure; however, where iron is concerned many food products marketed for kids have iron added!
Reply | Report Abuse | Link to thisMy larger concern regarding iron & kids is poisoning of children by self-ingestion of moms iron pills! That is a heavy metal problem that IS a leading killer (in the poisoning area) of small children, and, by the way, primarily a parenting problem!
Richard Carlson
Use my brain? Well, my brain remembers recent recalls of children's jewelry and toys due to lead content. Corporations certainly knew that was not a good thing! I see no reason to place faith in a "free market system" when it comes to our well-being vs. their profits.
Reply | Report Abuse | Link to this"It interferes with the development of synopses, or connections between neurons, that allow a child to learn"
Reply | Report Abuse | Link to thisYou mean SYNAPSES, synopsis is something completely different.
In Europe the RoHS directive banned cadmium since 2002
Reply | Report Abuse | Link to thiswhy does the EU banned Cadmium from Europe since 2002 with the RoHS directive? Maybe they demonstrated Cadmium is neurotoxic 10 years ago.
Reply | Report Abuse | Link to thisMy husband's body was full of Cadmium when he was diagnosed with Lou Gehrig's Disease (ALS), which is a neurological disease that kills you within 3 years + and there is NO cure. He was an aircraft mechanic for most of his working life. I met another woman whose husband who died of ALS body was very high in Cadmium and was an aircraft mechanic. Additionally, there is a much higher incidence of veteran's that were in the air force to have ALS. So much so, ALS has been categorized as a disease that is connected to armed services. So I think a litte due diligence on our part in exposing ourselves to chemicals, being aware is on step in the right direction.
Reply | Report Abuse | Link to thisYour readers should be aware of the greatest danger of contamination of Cd is from CdTe Photovoltaic power projects that are built around the world. Just one company, First Solar has delivered 5GW of CdTe PV modules around the world, covering about 100 million square meter of the earth's surface with these panels, containing over 200,000 kg of Cd.
Reply | Report Abuse | Link to thisIt now has been established that this CdTe is water soluble in any kind of rain water, anything that is not distilled water. How can the US EPA tolerate this?
The irony of the industry is that if one believes in the importance and benefits of solar energy, as I do, one can use several other, either thin film of crystalline Silicon materials, at no higher costs to install PV electricity.
To top this, our premier scientific corporation, GE, has also selected CdTe as their material of choice to enter the PV industry with a $1 billion investment.
At the same time our primary competitor country in PV, China, does not even allow the installation of Cd containing PV materials.
I hope after your article calling our attention to the dangers of Cd to our children and grandchildren, our government will review the issue of CdTe
containing PV, covering the water tables of millions of Americans.
Are you serious??? Do you even understand what a true free market system is? It's one in which there are no regulations to protect the consumers. Everything is geared towards making money anyway a businessman under such system can dream of. Quality control??? Forget it. Poison in your food and drinking water? You better believe it. Punishment for the crooks? Maybe...if the consumer of such inferior products has the personal means to go after the cheats. I hate to break it to you; there is no such thing as a true free market system...not even our own (U.S market).
Reply | Report Abuse | Link to thisSince it's a low incident problem. Why all the fuss? Iron added is not the same as Iron digestible. Added usually means it goes in and goes out. Misses the stations, so to speak.
Reply | Report Abuse | Link to thisIron is easy to get, use iron cookware. I don't know how much of an iron pan is bio soluble, but it tastes good. And if it keeps out the cadmium form my greens, cool.
We are omnivores, eating many things protects us from the many things we eat.
We'll let SA sort it all out, we will be too busy eating the many things.
In a solar panel, the CdTe is sandwiched between other layers (metal and glass among others), and would not be in contact with any rain (thankfully for both us and the solar panel). But with this information on cadmium, proper disposal, at the end life, of the solar panel most certainly needs to be done.
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