May 22, 2013 11:06 am
For the fourth time since 1956, Portland has decided it doesn’t want fluoride in its water. The pro-fluoride side had more money, more support from officials and more diverse backers, but when the votes were tallied, 60 percent of the city voted against adding fluoride to their water.
Fluoride was first added to drinking water in Grand Rapids, Michigan in 1945, just a decade or so after scientists first identified its teeth-saving properties. In 1901, a dentist named Dr. Fredrick McKay moved to Colorado Springs and noticed what the area’s residents called “Colorado brown stain” on patients’ teeth. After years of treating patients, McKay figured that the stain must be coming from the water supply they shared. But he also noticed something interesting. People with the brown stains had less tooth decay.
In 1930, a chemist with the Aluminum Company of American analyzed the well that the spotted-toothed town drank from and found that the water has high concentrations of fluoride—13.7 parts per million, compared to the 1.0 ppm generally found in ground water. Combining McKay’s observations, and the ACA’s findings, dentists started looking into fluoride as a way to protect teeth from decay.
Enter Dr. H. Trendley Dean, who renamed “Colorado brown stain” the more scientific “fluorosis” and did a several year survey to figure out just how much fluorosis there was in the US. What he found was that in 26 states, kids with flourosis also had fewer “dental caries”—a catch-all term for tooth decay. In 1945, Grand Rapids began a study to see whether adding fluoride to the water would have the same effect. In its history of fluoride, the CDC summarizes the preliminary results: “After conducting sequential cross-sectional surveys in these communities over 13-15 years, caries was reduced 50%-70% among children in the communities with fluoridated water.”
These results lead to the United States recommending an optimum water fluoride concentration range of 0.7-1.2ppm, to help people fight tooth decay. The fluoride recommendation came in 1962, and since then about 56 percent of the U.S. population lives in a fluoridated community. About 62 percent of the central water supplies in the country are fluoridated.
But understanding the modern effects of fluoride are a little harder. Several studies have tried to follow up on the effectiveness of fluoride in the water, but since fluoride is now in all sorts of tooth care products it’s hard to separate water fluoride with other sources. Your toothpaste most likely has fluoride in it, and if it doesn’t, your dentist’s toothpaste certainly does. In one literature review, researchers looked at studies on fluoride effectiveness since 1980, and found that the combined effects of fluoride—water delivered or otherwise—prevented about .3 caries per person every year. About on-third of that effect came from fluoride in the water.
A key part of their conclusion was that not only was fluoride effective, but it was important as a public health service for those who don’t have access to regular dental care:
The proportion of the U.S. population comprised of older adults is increasing, most of these persons are likely to be dentate and at risk for dental caries, and many lower-income adults lack access to timely restorative care. Our finding that fluoride is effective among all adults supports the development and implementation of fluoride programs to serve this population.
And in Portland, supporters of fluoride agreed. Not only is Portland the largest U.S. city to reject fluoridation, it’s also a city with one of the highest rates of uninsurance. Their pro-fluoride campaign pointed out that compared to Seattle, a nearby fluoridated community, Portland kids have 40 percent more dental decay.
Anti-flouride Portlanders pointed to a few studies that suggest that fluoride isn’t as safe as the CDC might want you to think. The FDA considers fluoride a contaminant, because it can be toxic at high levels. One oft-cited study found that in China, in places with extremely high fluoride concentrations, the population’s IQ dropped 7 points. The author of that study pointed out that the concentrations of fluoride he looked at in China were three times higher than the amount recommended by the FDA, telling Live Science that his results “do not allow us to make any judgment regarding possible levels of risk at levels of exposure typical for water fluoridation in the U.S.” Another study found a link between fluoride exposure and bone cancer in male children.
Of course, we know now that the anti-fluoride campaign won out, but the debate won’t go away any time soon. This is the fourth time Portland has voted on fluoride, and it certainly won’t be the last.
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May 16, 2013 11:16 am
In the small city of Timmins, Ontario, a town nestled half way between Michigan and Hudson Bay, there is a mine. Actually, there are many mines—it’s a mining town. But this story is about just one, a mile and a half deep, where there is water bubbling up from below that has been cut off from the rest of the world for at least a billion years—maybe as much as 2.6 billion years.
The longer end of that timeline, Ivan Semeniuk points out in the Globe and Mail, is about half the age of the Earth. This water hasn’t been in contact with the rest of the planet since before the rise of multicellular life.
But like the water trapped in frozen lakes below Antarctica’s massive ice sheets, researchers suspect there might be life in these flows.
“What we have here,” says Sherwood Lollar, a microbiologist at the University of Toronto in Canada, “is a plate of jelly donuts.” While she has yet to confirm whether the water is inhabited, she says the conditions are perfect for life.
The scientists don’t know whether there is any life in the ancient, isolated water. But they’re working on it. The water is young enough that it would have been locked away after life arose on Earth. But it’s been trapped for so long that any life that does exist would likely be unique—a relic of an ancient world. The CBC:
Some Canadian members of the team are currently testing the water to see if it contains microbial life — if they exist, those microbes may have been isolated from the sun and the Earth’s surface for billions of years and may reveal how microbes evolve in isolation.
One can’t help but be reminded of the Balrog: “Moria! Moria! Wonder of the Northern world. Too deep we delved there, and woke the nameless fear.”
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May 13, 2013 12:08 pm
Having a baby can mean thinking a lot about pee. You pee on a stick to see if you’re ovulating. You pee on a stick to check if you’re pregnant. And soon, you might be able to pee to check your baby’s health. Using urine samples collected from pregnant women, researchers have developed a test that found signs of serious medical issues in the still unborn baby, including Down syndrome, premature birth, brain damage and pre-eclampsia (a disorder that can cause a mother to have seizures).
The new research, conducted by a team of Portuguese researchers lead by Sílvia Diaz, is still in the early stages. But, if the technique bears out it could mean that checking for serious complications will be as easy as peeing in a cup—an alternative to the invasive techniques, like biopsies or umbilical cord blood tests, used today.
The researchers collected urine samples from 300 women who were in the second trimester of their pregnancies. They froze the samples and waited until the baby was born. Then, they combed through the urine with a sensitive analytical technique called nuclear magnetic resonance spectroscopy looking for chemicals that were related with the conditions of the babies. According to the researchers, they found chemicals that could be related to “central nervous system malformations, trisomy 21, preterm delivery, gestational diabetes, intrauterine growth restriction and preeclampsia.”
According to Chemical and Engineering News, the next step is to do bigger and better tests, looking at more mothers from a larger geographic area.
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April 26, 2013 4:04 pm
In a letter to Congress, writes the Guardian, the White House stated that officials believe, with “varying amounts of confidence,” that the chemical weapon sarin was used in the ongoing conflict in Syria and that the use of this type of weapon “would very likely have originated with” supporters of Bashar al-Assad and the Syrian government. The link between the use of sarin and al-Assad is not completely firm, though, and the U.S. Intelligence community is looking for more proof of what’s really going on.
Sarin, wrote Smart News previously, is a nerve agent first developed in 1938 Germany. “A colourless, odourless gas with a lethal dose of just 0.5 mg for an adult human,” sarin, “can be spread as a gaseous vapor, or used to contaminate food. The CDC says that symptoms can arise within seconds, and can include, like VX, convulsions, loss of consciousness, paralysis, and death.” And according to a 2002 article from the New York Times, sarin “dissipates to nondeadly levels after a few hours.”
How exactly are investigators supposed to figure out what’s going on in Syria? According to the Guardian, the United Nations will carry out analyses of soil samples collected in Syria to try to figure out if sarin gas was used. But, says Wired‘s Danger Room, there is another way to check for sarin.
The U.S. military tests for evidence of nerve gas exposure by looking for the presence of the enzyme cholinesterase in red blood cells and in plasma. (Sarin messes with the enzyme, which in turn allows a key neurotransmitter to build up in the body, causing rather awful muscle spasms.) The less cholinesterase they find, they more likely there was a nerve gas hit.
The problem is, some pesticides will also depress cholinesterase. So the military employs a second test. When sarin binds to cholinesterase it loses a fluoride. The pesticides don’t do this. This other test exposes a blood sample to fluoride ions, which reconstitutes sarin if it’s there, in which case it can be detected with mass spectrometry.
Blood samples are drawn from a pricked finger tip into a 10 milliliter tube. They can be kept fresh for about a week before they have to be used in the blood analyzer, a gizmo about the size of a scientific calculator that produces varying shades of yellow depending on the cholinesterase level.
There is still a lot of uncertainty around this news, both about what happened and what, if anything, to do about it. At least there are relatively specific tests that can be done to sort out the first question.
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April 22, 2013 1:45 pm
The ocean is full of uranium. Well, not really “full.” The concentration of dissolved uranium in seawater is around three parts per billion: for every billion molecules of water, salt, dead fish bits and whatever else makes up a scoop of sea water, three of those atoms will be uranium. But the absolutely massive size of the ocean means that there is still a lot of uranium floating around out there, most often tied up with a pair of oxygen atoms to form the dissolved compound uranyl.
Scientists have long wanted to extract this uranium for use in nuclear power plants. “The world’s oceans hold nearly 1,000 times more uranium than all known land-based sources,” says Chemical and Engineering News. “The total, an estimated 4 billion metric tons, could supply the nuclear power industry’s fuel needs for centuries, even if the industry grows rapidly.”
Plucking uranium out of the sea would likely be much better for the environment than mining it from the ground. But, as you can imagine, getting a few lonely atoms from a pool of billions is a difficult and expensive task.
According to C&EN, scientists working with metal-organic frameworks have developed a new type of material that can latch on to uranium floating in sea water. These frameworks are a relatively new class of compounds that have captivated chemists in recent years for their ability to selectively attract and bind on to very specific target chemicals. The new compound is around four times better than the previous best bet for trapping dissolved uranium.
And aside from putting the new metal-organic framework to work sifting the ocean waters for uranium, tweaks to the compound could theoretically also offer a way to help clean-up efforts during radioactive leaks or other situations where super-selective chemical nets would be useful.
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