January 30, 2012

As my few regular followers may have noticed, it’s been pretty slow here lately. I haven’t been super-inspired to write new entries, and time has been in short supply between work, family, teaching, and other interests. So I’m going to take a break for a while. I’ll keep the existing posts up, and I’ll try to pop my head in once in a while in case there are any questions. At some point in the future I may return to posting more regularly, but I don’t have a timeline for that right now. Thanks to everyone who has been reading – I hope you’ve learned something.

Anti-vaxxers can’t do math

October 25, 2011

A posting at a “newspaper” (I use the term loosely here) called the Canadian entitled ” America’s Toxic Flu shots: 250 times EPA mercury limit” has been getting a bit of attention (and ridicule) lately. The same article appears to be posted at another site under the name “Flu Shots Contain More than 250 Times the EPA’s Safety Limit for Mercury“, both by someone called Anthony Gucciardi. The article is riddled with factual errors, and actually identifies well-known quack Russel Blaylock as a “leading neurologist”. But without even going into all the factual errors, which have been pointed out elsewhere (such as here), the article has fundamental math errors that  make it even more laughable.

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Human health risks from oil pipeline spills

October 9, 2011

Oil pipelines have been in the news a lot this past year, between the proposed Keystone XL pipeline and various publicized oil spills. Potential human health effects of these spills are one of the concerns frequently raised, so I’m going to take a fairly high-level look at the potential risks here. Environmental effects are a separate topic that I’ll hopefully get to in the future.

First off, to have a human health risk, you have to have a few conditions met. The first is obviously that you have to have a potentially harmful chemical. Since any chemical, whether natural or synthetic, is potentially harmful at some dose, that one is kind of a given. The second condition is that chemical must get to where humans can be exposed. The third is that humans have to be exposed to enough of the chemical to have a potential for adverse health effects.

When oil is inside a pipeline there isn’t really any potential for exposure. So what happens when oil is released during a pipeline rupture?

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Mercury exposure from compact fluorescent lights

September 27, 2011

A commenter on a previous post asked about potential mercury exposure from broken compact fluorescent lights (CFLs). There are also various stories floating around the internet (such as this one) about the dangers of mercury in CFLs. So I thought I’d take the opportunity to look at how much mercury someone could be exposed to from a broken CFL, and whether there were any risks from that level of exposure.

A CFL typically contains about 4 mg of mercury (according to US EPA); a lot of newer CFLs contain 1 mg or less. I’ll look at the worst-case exposure, so let’s go with 4 mg of mercury in a bulb. In reality that mercury isn’t going to all be in the air right away – the evaporation rate of mercury is about 56 micrograms per hour per square centimetre – but figuring out the rate at which it enters the air requires assumptions about the area covered by the spilled mercury, temperature, pressure, etc. To keep things simple and to make sure I’m considering the absolute worst case, I’ll assume that all of that mercury instantly volatilizes.

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Sometimes the good guys win

August 26, 2011

Canadian Blood Services was running a campaign called “What’s Your Type” that included providing all sorts of weird new-agey mumble-jumble about blood types being related to personalities and recommended diet. They also had incorrect information about the origin of the different blood types. After word spread around the blogosphere a lot of people complained (including me), since an agency like that shouldn’t be providing false information, even if they did have a tiny disclaimer at the bottom that it was for “entertainment purposes only”. This has resulted in the nonsense being taken down, and replaced with a page indicating that they’ll determine your blood type for free. So yes, we can make a difference.

In case anyone is wondering, yes, I do plan to get back to talking about actual science in the near future. We get about two months a year of nice weather here, so I’ve been trying to enjoy the outdoors as much as possible before going back into winter hibernation mode. On top of that I’ve recently agreed to take on a new teaching gig on the side (as if I didn’t have enough on my plate already) and am trying to get everything ready before the semester starts in September. I should be able to get to some more substantive posts soon though.

Unfortunately the bad guys sometimes win

August 22, 2011

Epidemiology blogger “EpiRen” has been shut down by an antivaxer called “Mr. X” (reportedly Rhett S. Daniels in real life). EpiRen did not conceal his real identity, so when Mr. X couldn’t win an argument based on reason, he went to EpiRen’s employers (the Department of Public Health) and threatened legal action. Unfortunately EpiRen’s employers caved in and forced EpiRen to stop blogging about public health issues if he wanted to keep his job. More on this story here, here and here.

This is the reason why I and many other science bloggers use a pseudonym. Mr. Daniels reportedly owns Captiva Pharmaceuticals – another company to avoid doing business with for ethical people.


More threats from scam artists

August 17, 2011

The thugs are out again – this time Boiron, an international producer of homeopathic products, is going after an Italian blogger for criticizing one of their products (water marketed as an influenza treatment called Oscillococcinum). The claim is detailed by the original blogger here; there’s also an article at Science-Based Medicine.

Boiron are snake-oil salesmen on a grand scale, with annual sales exceeding half a billion Euros (about $735 million) according to their financial reports. Spread the word, and especially don’t buy anything from them.

Cadmium – the new lead?

July 26, 2011

Health Canada has just proposed a limit on cadmium in children’s jewelry of 130 ppm (0.013%), which is lower than the limit for lead concentrations. This limit was imposed because after a limit was established for lead, manufacturers started using cadmium instead. Several pieces of jewelry tested over the last couple of years have been almost pure cadmium, but in most cases these items remained on the market because there is currently no regulatory mechanism by which Health Canada can force them to be recalled and the sellers refused to voluntarily recall them (and yet there is still a lot of political resistance to proposed regulations that would give Health Canada the power to force a recall…).

So what’s the concern with cadmium, and is it really more toxic than lead? Read on…

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Salt consumption and the media

July 21, 2011

A good post at Science-Based Medicine today about how the media managed to completely misinterpret a meta-analysis of studies on salt effects.

Yes, I’ve been pretty slack about posts lately – summer is pretty short here so I should spend the time outside rather than sitting at my computer.

Cell phones and cancer – revisited

July 4, 2011

ResearchBlogging.orgA few weeks ago the classification of radiofrequency electromagnetic fields (RF-EMF, the radiation from cell phones) as a possible human carcinogen by the International Agency for Research on Cancer (IARC) made headlines. At the time, my position was that it is hard to draw conclusions from a press release, but that given the criteria for classification as a possible human carcinogen, the information in the press release and the data available in the scientific literature I didn’t see a need to panic.

Now more technical information about the IARC evaluation is available, published in the Lancet; while it still isn’t the full IARC technical monograph (which we probably won’t see for several months at least) it does provide a bit more insight into the basis for the IARC classification. At virtually the same time, another analysis of the same data by the International Commission for Non-Ionizing Radiation Protection (ICNIRP) Standing Committee on Epidemiology has been published, which concluded that “the accumulating evidence is increasingly against the hypothesis that mobile phone use can cause brain tumours in adults.” Which of these two apparently conflicting conclusions should we believe? Read the rest of this entry »