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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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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Canadian 2011 Federal Election – where do the parties stand on science-related issues?

April 21, 2011

For a bit of a change of pace from my usual content, today I’m taking a brief look at the major Canadian political parties and the parts of their platforms relating to science and science education. Obviously there’s a lot more to consider before voting than this, but there are plenty of other sources for that information. I’m going to stick to what is actually in the published platforms for the most part. Of course, past history shows us there is also no guarantee any of the parties will actually follow through on what is in their platforms.

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The German Dioxins Scare

January 11, 2011

Just a quick post this week (work is rather busy at the moment). There’s been an incident in the news lately of various agricultural products contaminated with dioxins in Germany (lots of the articles refer to “dioxin”, but it should be “dioxins” since it refers to a group of chemicals that are normally looked at together). The source is apparently contaminated feed for poultry and swine. Is this an immediate health hazard?

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Fluoride and IQ

December 29, 2010
One effect that has been claimed for fluoridation of drinking water that I didn’t really examine in my previous examination of fluoride toxicity is reduced IQ. The major regulatory reviews have previously concluded there is no evidence for any such link at relevant concentrations, but a new study published ahead of print in Environmental Health Perspectives concluded that “higher fluoride exposure may affect intelligence among children.” Does the study really support an effect on intelligence, and if so what are its implications for water fluoridation?

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Fluoride toxicity

December 3, 2010

A bit of a storm arose at Scienceblogs the other day when a blogger normally dealing with climate change allowed his father, James Beck, to do a guest post about a new anti-fluoridation book he had co-authored. Needless to say there were strong reactions on either side of the issue, including a response at Respectful Insolence. Since I’d been planning for a while to post something about fluoridation and just hadn’t got around to it, now seems like a good time.

Some of the arguments against fluoridation involve questions about how effective it is – I’m not going to get into that here (though in general the anti-fluoridation sites I’ve looked at use some pretty questionable analyses when downplaying its effectiveness). I’m also not going to get into the ethical side –  whether it is right for the government to administer fluoride in drinking water when some of the water users may not want it (though to me it’s not that much different than fortifying milk with vitamin D, enriching flour, etc.). I’m going to focus instead on my own area of expertise, specifically whether fluoride is toxic at the concentrations in drinking water.

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San Antonio Statement on Brominated and Chlorinated Flame Retardants

November 24, 2010

A group of nearly 150 scientists has signed a statement about brominated and chlorinated flame retardants (BFRs and CFRs), essentially asking for some serious thought to be given about whether we really need to be using them the way we are.

BFRs and CFRs have been used in a wide range of products due to their fire retardant properties, including furniture, carpets, automobiles, electrical equipment, insulation, adhesives, appliances, construction materials, paints, and more. Unfortunately they are also highly persistent in the environment, and several of them have been found to be highly toxic. Several of these compounds have been banned; however, these have generally been replaced with other BFRs and CFRs.

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