Vuvuzela

Okay, so I've been procrastinating about writing due to the World Cup. I feel positively European, since I can tell you which 8 games went on this week and who's advancing and when the next games are. One of the big to-dos about the games in South Africa is the use of the Vuvuzela, a traditional horn used there for soccer games.

At one of the U.S. games (I think it was England, if not it was Algeria), I saw two men in the American fan section wearing ear plugs. I was so amused (pleasantly). You could see the little yellow ear plugs, which means they probably weren't inserted exactly the right way. But, given the fact that these traditional horns can produce up to 120 dB(A) at 1 meter @ 1 kHz, I finally agree that any amount of noise reduction is a good thing. What I really want to know is who these two fellows are and why they thought that was a good idea. Do they already have occupational exposure to noise? Are they industrial hygienists or safety professionals or occupational medicine nurses/doctors? Or did they just decide 'hey, this is going to be really really loud, let's bring ear plugs!"

There are countless studies published on noise induced hearing loss (NIHL) and many involving sports-related exposure. Two months ago, immediately prior to the World Cup in South Africa, several articles have been published about the vuvuzula in particular, as well as - of course! - a Wikipedia page on health effects.

So, in summary, they're really really really loud.

original cited research (if the article is on-line, I included a link):

Swanepoel D, Hall JW III, Koekemoer D. Vuvuzela – good for your team, bad for your ears.
S Afr Med J (2010) 100, 4, 99-100.
with a follow up report from the authors explaining their noise measurement method & providing a table of results:  122 dB(A) at 1000 Hz and 2000 Hz at the bell opening.

Swanepoel D, Hall JW III. Football match spectator sound exposure and effect on hearing: A pretest-post-test study.
S Afr Med J (2010) 100, 4, 239-242

Berglund B, Lindvall T, Schwela DH, Goh KT, eds. Guidelines for Community Noise. Technical Report. Geneva: World Health Organization, 1999.

According to South African media Sports24, 1.5 million of these things have been sold in Europe since October.  If they were all being manufactured in South Africa, I would be more likely to believe the ever-present claims of sports proponents about how wonderful things like this are for the local economy.

One manufacturer has designed a vuvuzula which reportedly produces 20 fewer decibels.  While 100 dB dropped down to 80 dB will get you by in the workplace, it still ignores the fact that Soccer City in Johannesburg will hold up to 84,490 people for the World Cup this year.  Noise exposure is additive.  The end result of 20,000 (or more) people blowing is going to be far above 80 dB even with the new gadgets.

Picture of warning symbol on vuvuzula

One of these things turned up at the Riverview last week during the US : Slovenia game.  With the theater at almost capacity (I'd guess 90% of 700 person capacity), the vuvuzula was surprisingly loud.  Everyone turned around at the first blast and immediately knew what it was without seeing it.  One of them was a nice, if loud, addition to the game since it was only blown about a dozen times in short blasts.  In a really large movie theater, one was enough for me sitting at least 20 yards away.  I think it was at the back of the theater and I was sitting almost down front.

Last Sunday at the Germany : England game, someone brought a small (18") version to a restaurant.  It was an unholy racket.  Luckily he only blew it about 3-4 times before the game started.  The restaurant, needless to say, was much smaller than a movie theater.
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Sports and Risk Perception

This is an astonishing example of public risk perception.  The public health advice is also shocking.

Soer, who was present when the study was done and is knowledgeable of the findings, gave some simple advice on how to avoid any danger.

"Wear earplugs to the games," she said. "Either buy them at a pharmacy or make them yourselves and take it with you to the soccer games.

make them yourself... ? And this comes from a medical doctor?
I don't know what Communication Pathology is.  I infer from their limited website it is infectious diseases.  One of study foci was transmission of disease by sharing horns, so I understand a pathologist being involved.  But she obviously isn't familiar with how ear plugs work.  Does she think a wad of cotton is going to help?  Or is there some common item South Africans use for this purpose?

With poor risk communication from professionals, it is unsurprising that individuals are not making optimum choices.

"I am not worried," said Matthew M'Crystal, a 24-year-old law student. "Anyway, it won't kill us."

The chronic excuse:  'it won't kill me'.  Well, one of these days, being a lawyer, he's going to decide to sue someone over his noise-induced hearing loss by claiming "But I didn't know it was bad for me!"


"I could have died in Mexico," said Ricardo Avila, a 56-year-old soccer fan visiting South Africa for the tournament. "So no, it does not bother me."

Here is a different problem with individual risk perception.  Even when you give a perfectly clear explanation of the risks of exposure, and the employee really does understand it ... her risk comparison may be standardized against something other than yours.

"You have a 1:100 probability of losing your hearing"
"Yes, but I live in the area of town with the highest crime rate, gang activity and there was a drive-by shooting on my block last night.  Losing my hearing isn't so bad."

There will be a few more posts about noise and the World Cup.

I think I might borrow a noise meter from the U's IH lab to see how loud it gets on Saturday during the Germany-Argentina game over at the Glockenspiel in StPl.  I'm considering playing hookey with my spouse on Friday to watch the Brazil-Netherlands game.  Maybe I can compare the two?  Get a publication?  lol
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BP & OSHA citations & data presentation

Following the ecological disaster in the Gulf, British Petroleum is in the news about all of the myriad failures to comply with regulations.  Of course, the regulators are also in the news about failing to do the regulating.  I'm wondering if OSHA is going to come under fire?  Or if anyone will notice OSHA's inspection frequency compared to MSHA.

Flowing Data is a great site with interesting examples of data presentation.  The OSHA citation frequency for BP is notable due to its calculation based upon production in barrels of oil, rather than dollars of profit/cost.  The worker hazard exposure is the same regardless of whether crude is $50 or $200/barrel.

I like the presentation even more because the author cites the data and provides links to it.  The presentation of prostitution in San Francisco as a 3-D topographic over a map of the city is not so data-dense, but certainly visually impressive.

With the post on BP's citations, I am really amused by the posts discussing different ways to normalize or present the data.  Something any scientist should be trained to do.

Back in the saddle again?

The 3 sentences I want to hear:

You should start writing.

You should stop writing.

Congratulations, you passed.

one down, two to go.