Posts Tagged ‘Miscellaneous Health Scares’
On Depleted Uranium
Last week the local hometown paper ran a nonsensical op-ed about depleted uranium. The person who wrote the op-ed didn’t even seem to have any idea why the military uses DU, which can be found with a single Google search or even in most of the anti-DU literature. Anyway, this is a response I wrote which appeared in the local paper this week as a rebuttal:
There were numerous errors and omissions in Mary Ann Schwenk’s June 9 op-ed, “Federal bill to ban depleted uranium weapons should be revived.”
Schenk claims that “our government has not informed us as to why they decided to use DU weapons,” but the reason why depleted uranium is used both in weapons and in armor plating is hardly any secret — it is about 70 percent denser than lead which gives it extra stopping power when used in armor and additional penetrating power when used in munitions.
During the first Persian Gulf War, for example, an American tank outfitted with DU armor was able to withstand direct hits from three Iraqi T-72 tanks and not only survive but also disable all three enemy tanks.
As a weapon, DU is primarily used to target tanks. Because shells made of DU are able to penetrate armor much easier than other materials, DU munitions allow American forces to engage the enemy at a range of up to 25 percent further than with weapons made of traditional metals.
But isn’t DU radioactive? Yes, in fact, it is about as radioactive as most dirt. Since DU is actually about 40 percent less radioactive than naturally occurring uranium found in almost all rock, soil and water, it poses the same radioactive risk that most dirt does.
When a United Nations Environmental Program team analyzed soil samples from holes where DU rounds had impacted in Kosovo, for example, they found that most samples had radiation levels within normal ranges and just a small number of samples had slightly higher levels of radiation. As UNEP put it in its report, “Surface contamination in the areas we visited is trivial and does not pose any threat to the environment.”
The major long-term danger from DU is the possibility that large amounts of it would enter the water supply. Since DU is a heavy metal, large-scale ingestion of it would pose potential health risks, and UNEP has recommended the monitoring of groundwater where large numbers of DU shells have been expended.
Depleted uranium is also used in a number of civilian applications including x-ray tubes and as a radiation shield (casks used to store spent nuclear wastes, for example, are typically made out of depleted uranium encased in stainless steel).
The claims that DU is some sinister highly radioactive weapon whose use may constitute genocide under international agreements would certainly have made a great X-Files episode, but the facts simply don’t support such flights of fancy.
Tags: Miscellaneous Health Scares
Does Traffic Pollution Lead to Poor Quality Sperm?
Italian researchers published a study in “Human Reproduction” in April suggesting that men exposed to exhaust fumes from traffic had higher sperm motility than men not exposed to exhaust fumes. But the study is a classic example in the pitfalls of confounding factors.
Specifically, their study looked at men who worked at toll booths. Guess what men who work at toll booths do? They sit for up to six hours a day. Guess what one factor that can contribute to reduced sperm count is? That’s right, prolonged sitting.
Now, the researchers claim they took this into account by using a control group that included clerks, students, doctors and drivers who have largely sedentary jobs that involve a lot of sitting. But unless toll booths in Italy include significantly different accommodations than toll booths here in the United States, six hours sitting at a toll both is not quite comparable to six hours of sitting in an office chair.
The study was also very small, involving an experimental group of 85 men and a control group of 85 men. None of which prevented the study from concluding based on their findings that, “Health authorities should be alert to the insidious health effects of environmental pollution.”
A better lesson might be to avoid drawing such unwarranted conclusions from a single small study whose results are as likely explained by confounding factors as by the effects of pollution.
Sources:
Traffic pollution damages men’s sperm. NewScientist.Com, April 30, 2003.
Traffic ‘damages male fertility’. The BBC, April 30, 2003.
Tags: Miscellaneous Health Scares
Florida Group Finds No Risk to Arsenic-Treated Playground Equipment
A six-member panel of physicians in Florida issued a report earlier this month that found no health risks associated with playgrounds and backyard furniture made out of arsenic-treated wood. The arsenic is used as part of a treatment for wood that makes it resist pest damage and other decay.
The Florida Physicians Arsenic Workgroup, set up by the state of Florida to investigate the matter, found that any exposure to arsenic that children might conceivably get from treated wood “is not significant compared to natural sources and will not result in detectable arsenic intake.”
They physicians group also noted that the arsenic-treated wood had been in use since the 1960s and there is no evidence linking it to any health problems.
The federal Environmental Protection Agency is also conducting a review of arsenic-treated lumber which his expected to be released sometime in 2003.
Both it and the Florida study are largely irrelevant at this point, because the EPA reached an agreement with manufacturers to end the sale of arsenic-treated lumber by the end of 2003. Nothing like working to rid the world of something and then later deciding whether or not it really poses a threat.
Source:
Doctors: Amount of arsenic in playground wood not harmful. Associated Press, August 8, 2002.
Tags: Miscellaneous Health Scares
The Horrors of For-Profit Hospitals
The BBC recently published an unintentionally hilarious article on a study published in the Canadian Medical Association Journal. The headlined blared, ‘More die in private hospitals’ - researchers.
After supposedly studying the medical records of nearly 40 million people over a 13-year period, the researchers concluded that more people die in private hospitals than in public ones. The BBC continued,
The researchers have suggested the higher mortality rate may be because hospitals run for profit in the US have to pay dividends so shareholders and tax, and have less money to spend on patients.
They say their findings should discourage Canada from privatising its healthcare system.
In fact this was a meta-analysis of 15 different studies and the best it could do was find a whopping two percent difference in adjusted mortality rates. That low of a difference is statistically irrelevant. A better way to summarize the findings would have been, “Study find no difference in mortality rates between profit and non-profit hospitals.”
In fact, Canadian Medical Association Journal implicitly recognized this by wondering if the true effect wasn’t hidden by the methodology of the study,
Although studies that analyzed hospitals that changed ownership status were excluded from the meta-analysis, the admissions to hospital that were studied took place at a time when hospitals were characterized by a variety of forms of ownership. Some were long-term not-for-profit hospitals, some long-term for-profit hospitals, some were about to convert, some had just converted, and so on. This information is not characterized or controlled for in the studies included in the meta-analysis. The dilution of the “true effect” of ownership type is likely to bias findings of relative mortality comparing not-for-profit and for-profit hospitals toward no difference. Thus, the mortality difference found is likely to be a conservative estimate.
That is the smell of desperation.
Source:
‘More die in private hospitals’ - researchers. The BBC, May 28, 2002.
A systematic review and meta-analysis of studies comparing mortality rates of private for-profit and private not-for-profit hospitals. P.J. Devereaux, et al. Canadian Medical Association Journal, May 28, 2002; 166(11).
What price for-profit hospitals? Donald H. Taylor, Jr, Canadian Medical Assocation Journal, May 28, 2002; 166(11).
Tags: Miscellaneous Health Scares
Is Hydration Advice All Wet?
An interesting conversation recently took place between CNN MEdical Correspondent Elizabeth Cohen and CNN anchor Paula Zann about a pressing issue — just how much water should people drink?
Of course we have all been told that we need to drink at least 64 ounces of water each day, but according to Cohen that is simply an urban legend that inexplicably found its way into widespread circulation.
According to Cohen,
This eight eight-ounce glasses a day it turns out, after talking to the USDA, the National Academy of Sciences, the National Institutes of Health, people at various universities, they say, you know what, this appears to be kind of a myth. We can’t find a single study that says that that’s what people out to do.
. . .
Let’s look at the water content of some other food and beverages here. For example, milk — 84 percent water. You could get your water there. Watermelon, 85 percent water — you could get your water there. other fruits also have lots of water. Diet Coke, 99 percent water — you could get your water there.
Now I can hear you thinking, well, gee, you know Diet Coke, that has caffeine in it, that can’t be good. We’ve all heard that caffeine is dehydrating. However, we’ve talked to a couple of experts who point to studies that say, you know what, when we look at it, people gut just as hydrated from caffeinated beverages as they do from decaffeinated beverages.
Cohen reports that The National Academy of Sciences is currently looking into just how much water human beings require, and should report their results sometime in 2003. Until then, drink up.
Source:
How much water do we really need? CNN, transcript, May 24, 2002.