National Conference to Prevent Hearing Loss in Construction:
P R O C E E D I N G S
Address: Preventing Hearing Loss in the Construction Trades: A Best Practices Conference
DR. MARK STEPHENSON
DR. STEPHENSON: What I would like to say at the outset is that I am going to be talking a lot about education and training programs as they apply to hearing protectors specifically and to hearing conservation programs in general, but do not for a minute think that I do not believe that the best thing in the world would be if we could get rid of the noise.
I want to spend a few minutes reviewing the problem. Then I am going to talk about what we have learned so far. Then I am going to discuss where we are going.
The bottom line is: Occupational hearing loss don't get no respect. We have heard over and over again from all levels, whether it is the greenest apprentice to the most seasoned contractor, that if it does not bleed, we are really not too concerned, and that is really characteristics of occupational hearing loss.
We have already heard this morning that one of the problems we are facing in the construction industry is the plain simple fact that the regulations that OSHA has enacted to provide hearing conservation for the manufacturing sector, by and large, just do not apply to the construction sector.
Another problem that we see is people's perception that occupational hearing loss really is not too much of a concern because we are going to lose our hearing, anyway, as we get older. I suspect that many of you in this room probably believe that to one degree or another, but I have some data that I want to show you that really speaks to this problem, and I want to emphasize it because the fact is if you are not exposed to occupational noise and you are otherwise healthy, you are not going to be hearing impaired by the time you are 60 years old.
Let me show what I mean. These are some audiograms. This is zero decibels. This is the hearing level that you were born with, Lord willing, and then hearing levels decrease as we get older, which you see here by this yellowish-green line which represents the hearing of a 60-year-old, otherwise healthy, non-noise-exposed person, from low frequencies up to the very high frequencies, 4,000 hertz. That is right about where the highest note on a piano is, and that is where typically we see the effect from occupational noise exposure.
What do we have here? Let's take a look at that Association has a way to define somebody whose hearing has changed enough to actually be impaired, and what they do is to take an average of certain frequencies. In fact, they will average the hearing levels at 1,000, 2,000, 3,000, and 4,000 Hertz. So what do we get if we average the hearing levels for this 60-year-old worker? Well, it works out to about 16.75 decibels. What does that mean? If I were to draw a line right across here either at 20 or 25, those lines generally describe the boundary between normal hearing and the beginning of hearing impairment, just the beginning.
So, remember, I just said that this 60-year-old worker's average level of hearing loss is 17 decibels or less. They are not hearing impaired. They still have normal hearing, but what happens to that 60-year-old worker if he or she is exposed to noise? Well, this red line, that is the 60-year-old worker that was not exposed to noise and was otherwise healthy. This is the hearing level that you would expect if you were exposed to time-weighted averages of 90 decibels, just the beginning of hazardous noise according to OSHA. It is pretty simple. No noise exposure, no hearing impairment, even if you are 60 years old. Noise exposure, hearing impairment. In fact, the average level here would be 25 decibels. More noise exposure, more hearing impairment.
Well, what about OSHA? This slide shows the average hearing levels that you would expect for workers who were exposed to 20 years in a job that did not involve significant levels of noise, relatively quiet, 85 or less. In this particular stamping plant, they tried very, very hard to implement all of the OSHA requirements, but the people still got a hearing loss. Why do you think that is? A couple of reasons. First of all, they probably were not wearing their hearing protectors the way they should be. If you are just filling a square with the OSHA requirement to have education and training for the manufacturer sector, that is not going to cut it. That is not really going to teach you how to use hearing protectors to prevent hearing loss, but the other thing that is playing a role here is the fact that these people are in a stamping plant, lots of impulsive noise.
In the construction industry, do we have lost of impulsive noise? You bet we do. So what does that mean for us? That means if we are thinking about developing a program that can actually prevent hearing loss for workers in the construction industry, we need to be more conservative than you would be if you were simply implementing existing OSHA rules and regulations.
PARTICIPANT: [Off mike.]
DR. STEPHENSON: That is a good question. The question is how do we deal with this, then. Does this actually complicate matters?
Well, it does complicate matters, but if we change from a permissible exposure limit of 90 to a permissible exposure limit of 85 and then if we use a time intensity trading ratio of 3 decibels instead of 5 decibels, then those factors will build in enough of a safety factor to be sufficiently protective to the average construction worker's hearing.
What I want to make absolutely certain, this is not OSHA-bashing. There is no conspiracy to prevent the worker from having effective hearing loss prevention programs. One reality is that until fairly recently, there were a number of legitimate barriers that inhibited the fielding of effective hearing loss prevention programs, but that is not the case today.
We have better measurement systems now that are more capable of assessing the types of noise exposures that we see in the construction site. We have more sophisticated computer-based information management systems that can allow us to track our data and to record and manage audiometric measurements. We know more about hearing loss prevention. We are just in a better position now, and now there is no reason why we cannot provide effective hearing loss prevention programs for construction workers.
What I want to do briefly is provide an overview of some of the work that NIOSH has been doing in the last few years that has been focussed on developing hearing loss prevention programs for construction workers.
One of the first things that we needed to do was to get a handle on the types of noise exposures that our target population was receiving. It is real simple. I do not need to go into a lot of detail here.
This is just a summary of some noise measurements that we made. The take-home message from this slide is if you plug it in and you turn it on, it is hazardous. You do not have to be an industrial hygienist. You do not have to be an acoustical engineer. You do not have to be an audiologist to know if the noise exposures that you are getting are hazardous. If you plug it in and turn it on, not only is it hazardous to you, but the power tools would be hazardous to somebody in the vicinity.
There a good rules of thumb that you could use, and you have probably heard these before, but, by and large, if you are on any construction site or around any type of loud noise, if you have to raise your voice to be heard 3 feet away, it is hazardous.
The next thing that we did in trying to understand risk of the target population, which in this case was carpenters, was to get some audiometric data. Randy Tubbs and his group at one of our other divisions at NIOSH went to a couple locations in the United States and were able to take hearing threshold measures of about 700 to 800 carpenters, and from those data, we were able to do some very interesting analyses.
Let's take a look at these two red lines. This red line shows the hearing threshold levels of the average 25-year-old carpenter. This next red line shows the average hearing threshold levels of a carpenter who is 55 years old.
What do they show us? Well, let's look at this bottom line first. The average 55-year-old carpenter has hearing threshold levels that would be equal to those of a worker who had worked for 40 years, 8 hours a day, 5 days a week, in continuous noise that was 100 decibels, time-weighted average of 11 decibels.
We know that the average carpenter, if you were to put a dosimeter on that person, would probably show time-weighted averages on the order of 90 to 95 dB or thereabouts. So this is just another very solid example illustrating that the typical construction worker, carpenters in this case, noise exposures are more hazardous than you might otherwise realize.
Let's take a look at this other line up here, the 25-year-old carpenter. That is not too bad. In fact, here is a very conservative estimate, 20 decibels. Some people would use 25 decibels as the dividing line between normal hearing and where hearing becomes to be impaired. We can say why should we be worried. Gosh, they have got pretty good hearing. That 25-year-old carpenter has normal hearing.
Well, that is true, but that is just part of the picture.
Look at this other blue line that is winding around. What that blue line is, is the hearing threshold level for a 50-year-old otherwise healthy non-noise-exposed worker, and what does this mean? This means that the average 25-year-old carpenter has 50-year-old ears. That is very significant.
I am 50 years old, and in fact, I have hearing that mirrors this almost exactly. So I do not have a hearing impairment, but I can tell you I do not hear the way I did when I was 20. It is noticeable, and this is significant regardless of whether it falls above or below this 20-dB line.
What about money? We heard some stories this morning about the economic impact. I did a study for the United Brotherhood of Carpenters that had requested the health hazard evaluation from NIOSH, and it turns out that to provide two pairs of hearing aids to the members of their union who would need them would cost them a billion dollars. This does not include batteries, and by the way, while we laugh, that is not a trivial consideration. I think people could easily spend a couple hundred dollars a year on batteries.
PARTICIPANT: [Off mike.] Ms. Margaret Roberts provided input regarding the amount of money spent on hearing aid batteries by the British Columbia Board of Workers’ Compensation.
DR. STEPHENSON: And that is for the 30,000 people that have hearing aids?
PARTICIPANT: [Off mike.]
DR. STEPHENSON: British Columbia spends $100,000 a year on batteries.
This is very conservative because these cost estimates are for two hearing aids, i.e., one pair, and the average 55-year-old person is going to go through a lot more than two pairs of hearing aids in his or her life. So these are conservative data.
Let's take a look at the next slide. What kind of money are we talking about to provide a hearing conservation program? We got some data from one of our partners, James Anderson & Associates, and the bottom line, to provide a hearing conservation program for these workers would cost almost exactly the same amount of money.
Now, that is not a small amount of money. We are talking a billion dollars, but on the one hand, you are paying a billion dollars for hearing aids, and you still have a hearing loss and you have not paid for batteries. On the other hand, you are paying a billion dollars and you have got good hearing. It seems like a no-brainer to me, and we are not even talking about the effect of workers' compensation.
In some States, perhaps many States, that is negligible. On the other hand, in other States such as Washington or particularly in Illinois, where workers' compensation allowances may be as much as $126,000 per individual claim, then we are talking some big bucks. So I think the case can easily be made that hearing loss prevention programs can pay for themselves.
What do we need to do? We really need to market hearing loss prevention programs. I suspect that there is not a person in this room who not only does not recognize every one of these symbols, but who has not purchased something from these manufacturers.
But these manufacturers do not just put their wares out on a shelf and figure the world will beat a path to their door. They market. They market their products. In the same way, we cannot just pass our earmuffs or hearing protectors and expect people to use them. We need to market hearing conservation programs.
There are a couple of problems with just putting hearing protectors out and expecting people to use them in addition to the lack of marketing. Even if we were able to get people to use them, the reality is any hearing protector that can be worn wrong will be worn wrong. I have yet to talk to a single hearing conservationist who has not been conducting a hearing protector fit clinic and found people that would wear hearing protectors backwards or sideways, any which way. You can take this to the bank.
The other issue is even if you do get people to wear them, without training, they will only achieve a small fraction of the protection that you can get with training. I will not go into detail for time reasons here, but this shows the amount of protection in decibels that are possible under ideal conditions, and these show the amount of protection that is likely to be obtained in the real world. This is without training. A bit gap, and this is why you cannot just put hearing protectors in a box and have people put them on and use them. They are very much like respirators.
How many of you would put respirators in a box in a corner and tell your people to go pick up the respirator and put them on? You would not even do that with a pair of shoes or a hard hat. You would try to shoes on and make sure that they fit and make sure that they work for >you. The same thing needs to be done with hearing protectors. They need to be tried on and properly fit.
PARTICIPANT: [Off mike.]
DR. STEPHENSON: I wish I could, and what we are doing now is actually looking at the effect. We are developing a project to do what is called a smart-subject fit. We know that if we do a subject fit where we just put a person in a laboratory and measure the attenuation that you will get maybe a little bit more than this because you are in a laboratory environment and you do not have sweat and a lot of other things, but we do not know the effect of training right now and we are studying that.
The other thing that you need to consider when you are making hearing protections available in your hearing conservation program is the barriers that prevent people from wearing hearing protectors. If you do not make a conscious effort to address barriers, you simply will be ineffective at getting people to wear hearing protectors.
What if you do remove the barriers? What if you say, "All right. I have got a hearing protector device that is cost effective, that I can make available and get out to the worker"? What happens if you do not train the worker to wear that hearing protector, when and how they should wear it?
Let's just take a look at what happens. Let's say that you provide a hearing protector that can reduce the noise by 30 decibels. So it has got a noise reduction rating of 30 decibels. Let's say you train that worker and you fit that worker so that they are properly fit, and they actually can get 30 decibels of protection from that plug and you turn them loose on a construction site. They take their hearing protector off, a minute here, a minute there, a few more minutes here, a few more minutes there. Let's just say over the course of an 8-hour day that this one person takes their hearing protector off a total of 30 minutes. That has effectively reduced the attenuation of that device by more than half.
So the take-home message is you have to train the worker to wear the hearing protector not only how they should, but when they should because intermittent use, if it is sufficiently intermittent, if that person does not wear their hearing protector for 2 hours out of their 8-hour day, they might think, "Hey, I am wearing my hearing protector most of the time."
What do you think would happen if a welder wore their welding goggles most of the time? It would not be good, would it? Well, it is the same thing with hearing protectors. The damage just takes longer. If that person did not wear their hearing protector of 2 hours out of an 8-hour day, then they would be getting effectively no hearing protection.
I cannot emphasize enough how important it is to use a message that is targeted to your audience. Do not just fill a square. Do not just go out and buy an education and training tape or use something that Joe Blow used down the line in his widget factory.
Let me give you an example of what I mean. NIOSH was working with some coal miners trying to develop a hearing loss prevention program for them. One of the things that we did first off was to conduct focus groups because we wanted to gather information from our target audience to try to really focus in on their needs. We found that without exception, every person that we talked to was concerned about roof talk.
I spent 20 years in the Air Force before I joined NIOSH. I can assure the Air Force did not put me in many coal mines. I asked these miners. I said, "What do you mean 'roof talk'?" They said, "'Roof talk' is the noise that a mine makes," and some of them call it "roof working." It is the noise that it makes right before it collapses. Do you think they wanted to hear that? You bet. They all had the perception that if they wore hearing protectors, they would not be able to hear this.
It turns out that that is not a correct perception. Absolutely, I guarantee you, you can wear any hearing protector made in the world, and it will not prevent you form hearing roof talk. So we addressed this in our training materials and in fact developed a demonstration that was able to convincingly demonstrate that they would be able to hear roof talk.
So the take-home message here is that you have to focus your message.
What is the effect? I will just show you one other slide. If you do meet your user's needs, all you need to do is look at these red lines here. This represents hearing protection that was worn in a powerplant by workers who knew that they had a hearing loss.
Thirty-three percent of them were wearing hearing protectors when they should, only 33 percent. We said, "Why are you not wearing your hearing protectors?" They said, "Because they are inconvenient or uncomfortable. Our hands get dirty, and we have to roll down these yellow foam plugs, and it is just not convenient." I said, "What if we made something that was on a stem so you did not have to touch it, and what if we put it on a cord so you could take it in and out when you were going in and out of noisy areas? What if it was custom-molded so that it was comfortable?" They said, "Yeah, that would address our concerns."
Did it? You bet. Without any additional training, without doing anything else but addressing those specific barriers, we almost doubled the use of hearing protectors, from 33 percent to 63 percent. So the take-home message is focussing your education and training materials not only is necessary, but it also works.
MODERATOR: Wow. Thank you, Mark. That was very interesting. I think one of the things I learned was that the training and education component of a hearing conservation program really underpins the rest of the program. If people are not trained in how to properly use hearing protection, it does not matter that you have chosen the right kind of personal protective equipment or that you have it available even if people are not aware of how to use it.
The other thing that I think was very interesting is how our training needs not just to be one way. It cannot be I am going to tell you what you need to do, but it also needs to include a component of getting
some feedback from the people who are having the training to assess what kind of barriers might stand in the way of effectively implementing that hearing conservation program. So I really, really appreciate that, Mark.
Our next speaker is Margaret Roberts. You heard her already this morning. So I am not going to spend a lot of time on her introduction. She is going to talk about some innovative things that the British Columbia Workers' Compensation Board have done to address this issue of effectively implementing hearing protection programs in the construction industry.