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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IH standard baggage

While at work today, I stopped to talk to one of the workers, to explain what was going on regarding a project before the team arrived. I noticed rather quickly that his work station was particularly loud.  I asked if he was required to use hearing protection.  He said no, but then qualified his statement by pointing out he had only been on the job for 2 months.  Stunning me with his initiative, he walked to the next work station and asked his group leader.  No, no noise PPE required.

Not being convinced this assessment was correct, and being chronically curious, I went to the safety office to get a noise meter.  I returned, only to discover that the 2nd work station was no longer running.  Ah, well.  Loud, but not the same.

He asked me about what I was doing. I of course answered him,
explained there is a limit for how much noise you can have,
showed him the meter was measuring noise,
explained the meter read-out, and
explained how that number relates to the company's exposure limit.
He was satisfied and thanked me for my time.  Just what every IH wants, eh?

If only I hadn't needed to spend 10 minutes finding a noise meter!

I often find myself wishing I had a standard bag-of-tricks to carry around.  Sure, there's always the things I might personally really need, like a spare pair of non-prescription safety glasses that I know fit over my prescription glasses or ear plugs.  (I do always carry a spare set of ear plugs in my pocket - even if I'm already wearing mine.  I've given them away 2 times in the past 3 days.) With the advent of smaller and smaller electronics, I would definitely add a noise meter to the bag.  The one I used a couple years ago for my internship was pretty compact.  It wouldn't need to be fancy; only functional.  A Dräger hand pump (the simplistic kinds) with a set of tubes for VOCs and CO.  A particle meter. ... hmmm...  a professional shopping list.

questions for noise monitoring

As I progressed with this project, I realized that I should ask more questions. Sure, these are patently obvious, and are probably mentioned in any text on the topic. But, hey, this is why the first time doing something is educational. And of course, some of these I realized ought to have been asked after getting data I didn't want. Do you move to other tasks in the day? If so, find out which ones & how long they are at each station. How long do you stay at this work station? If the answer is less than a full shift, find out where else they are (& what they're doing). Is this a normal day for you? Do you normally run this (gizmo) more? less? Is production running faster or slower? Are you doing more tasks than usual? How long have you been doing this task, i.e., years, months, weeks You should establish how much experience the worker has with this task, which might be different than their seniority/time-in-grade might indicate. 30 years with the company might mean she's been doing this task for 6 months. Are you working overtime today? Often? Will you need to set the measuring instruments to accommodate a longer measurement? When you do calculations, you'll need to know what their normal exposure is, if today is different. Who else does this task or works at this station? Do you have someone who just helps out occasionally? This might be different than the answer you get from the supervisor. You're more interested in finding the perhaps unofficial or unknown "helpers", to make sure the helpers get included in your surveillance program. Is this task done every day? If this isn't a routine task, find out how often it is done. You might manage to catch someone doing a quarterly or annual task. And, if you miss the infrequent/irregular jobs, find out when they happen so that you can catch it next time.* As with anything else, have a pre-printed sheet with all of these questions. If you expect to have standard answers, put the standard answer with the question, so that you can easily circle it, rather than write it. E.g.: How long have you been doing this task? less than 6 months 1 year 5 years more than 10 years How long are you at this work station? 8 hours 4 hours 2 hours other ________ The easier it is for you to gather information, the more relaxed the employees will be. If it's quick and painless, it won't interrupt their work (as much). * Especially with irregular jobs, I find it much better to be able to approach the Supervisor and ask for a very specific thing: "Please contact me the next time you shut down Machine 5 for cleaning?" If you already know what you want (because you got the information from the worker), the manager will be either a) impressed that you know what you want and hopefully b) more likely to do it, because she knows what you want. This will also benefit your relationship with the worker: Asking them for information indicates your respect for their professional competence.

Too Helpful Employees

I've discovered that one must anticipate the bizarre things employees might do, presented with the opportunity. No, I don't mean the zillion truly stupid things like standing on top of 30' ladders, plugging toasters into an area where flammable vapors accumulate, using a forklift to raise another forklift ... No, I mean the things they'll do in a sincere effort to help you. Or a sincere lack of understanding about what you're trying to accomplish. While performing personal noise exposure monitoring, I have discovered the instructions to the employee when applying the dosimeter must include:

1. Don't share. The employee understood that my primary concern was Machine A. She took the meter off, and gave it to the other worker when switching jobs. She wanted to make sure I found out how loud the machine was by keeping the meter with the worker at the machine.
2. It doesn't record things. Despite the fact that the meter does indeed "record" things, it doesn't actually record what you say. My boss advised this as part of the instructions. I would never have thought of it, but apparently others have.
3. "All day" means "until you leave". A couple employees seemed to either not care or not realize what data are recorded. I down-loaded the data & reviewed the dB v. time. I immediately noticed the last hour of data is 0 (i.e., uniformly less than the threshold). I also immediately realized the employee was not accurate in reporting it had been off for "20 minutes".
4. Have a reason for explaining why you picked on her/him. This week's measurements included a worker in an area already identified as in a hearing conservation program. 3 dB exchange rate or not, there's no way it was going to be less than the previously measured 92 dB. Standing next to a bright blue punch press that is at least 10 times larger than the '53 Plymouth I once owned, and was probably built in the same year, the operator asked rather plaintively, "why did you pick me?" My answer: "because I like blue". That wasn't my real rationale. But, it could have been. The reason was actually because he was the only one operating one of the giant beastie