Tuesday, December 21, 2010

AP Style - blood alcohol

AP has now clarified an issue that was a bit muddled by an "Ask the Editor" post of a couple of years ago - the form to use for blood alcohol levels.

With blood alcohol figures, it's probably better to now use "percent" (though the entry does drop it in the example in the last sentence). Also notice the leading zero before the decimal and no hyphen in "blood alcohol":
The concentration of alcohol in blood. It is usually measured as mass per volume. For example, 0.02 percent means 0.02 grams of alcohol per 100 grams of an individual's blood. The legal limit for intoxication in most states is 0.08 percent. The jury found he was driving with a blood alcohol level above Florida's 0.08 limit.

Updated Feb. 7 - Warning: AP probably has that measure (graps per grams) incorrect. See the comments below.

A couple of others:
serviceman, servicewoman: But service member.
Post-it: A reminder that it is a trademark for small pieces of paper with an adhesive strip on the back that can be attached to documents.

Also a reminder that "war" is capped when referring to specific wars, including Korea, Vietnam and Iraq.

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2 Comments:

At 2/7/11, 5:24 AM, Blogger Brian B said...

Hi Doug. I'm a bit late getting to this but better that than never (IMNSHO).

I believe AP, on the blood alcohol question, is dead wrong. Note that it describes the measurement as "mass per volume" but then goes on to describe a mass-per-mass comparison.

In fact blood alcohol is measured in grams per deciliter, not 100 grams. If we were talking about nothing but water, these would be equivalent. But blood is, as they say, thicker than water, and alcohol is considerably thinner. So muddling grams and liters is a bad plan.

And of course, a given mass per a given volume cannot be a percentage.

"Everyone" other than toxicologists uses "percent" anyway, but if AP is tossing aside scientific precision in order to bend to popular usage, it should say so, instead of making muddled, incorrect scientific claims.

Just sayin'.

 
At 2/7/11, 11:09 AM, Blogger Doug Fisher said...

Brian:

Thanks for reminding me - I'd meant to post an update and then had to go out of country, etc.

I challenged Darrell Christian on that exact thing, and his response:

Doug

I'm not an expert in blood alcohol content, thank God, but the definition was presented to me as the standard. There are multiple references on the Internet (I know that doesn't make it right). There also is a reference to millligrams/millimeters.

I think we meant "percent" to be optional, based on the need for clarity.

Darrell

-----Original Message-----
From: fisherdj [mailto:fisherdj@mailbox.sc.edu]
Sent: Wednesday, January 12, 2011 12:12 AM
To: Christian, Darrell
Subject: Stylebook update - questioning units used on blood alcohol

Darrell:
Was reviewing some updates that came out just before the holidays, and I think you all have a minor error in this one:

blood alcohol content
The concentration of alcohol in blood. It is usually measured as mass per volume. For example, 0.02 percent means 0.02 grams of alcohol per 100 grams of an individual's blood. The legal limit for intoxication in most states is 0.08 percent. The jury found he was driving with a blood alcohol level above Florida's 0.08 limit.

The measurement is usually grams/deciliter (100 milliliters) - that would conform to your "mass per volume" wording. But the example you use is grams per grams, which would be mass per mass (there is a mass/mass measurement that uses body mass, but it is not strictly the BAC).

Also, you are unclear as to whether to use "percent" with the figure. An Ask the Editor entry of May 10, 2006, had indicated not to use it. In the example above, you use it in one place (third sentence) but then drop it in the fourth. Clarification?

 

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