Industrial Hygiene in Construction

Sound Level Readings Apps

You’ve probably already seen the sound level apps available on various models of phones and devices. Overall, I’d say they are, “OK“. I would say they’re, “great“, but since I am in a technical field, they actually aren’t that accurate when you figure the amount of error. However, when I consider who might use these: people in the field, I actually think they are, “AWESOME“. It provides an excellent educational tool and a relative-guess as to the noise levels in field conditions. A reading of 95 dBA on your smartphone app, even if it is “inaccurate” isn’t going to be that far off from my certified and calibrated Class II sound level meter. In other words, it will get you close-enough information.

Audiometric Testing Apps

BUT, have you seen the new hearing audiometric testing apps?!  I’m not too sure about these yet. Check out safety awakenings review of these new apps. These are only available on i-devices (ipad, iphone), but their price is worth a look (free & $2.99). The major downside is that these are NOT OSHA approved, so I suppose you would use it as a screening device.  And, in some US states, you must go through specific training to be able to administer the test.

However, there is an “OSHA approved” (I’ve been told, verify yourself please) ipad self-administered audiometric test called, ShoeBox Audiometry, from Canada. They claim their earphones are Class II devices, but you must send these in yearly for recalibration. The portability of this device would be a huge benefit.

Remember to research these on your own before making a decision. Anyone plan on buying audiometric testing equipment for their employees? Or using them now? I’d love to hear your comments.

Old School Portable:

There are pieces of equipment used in construction which are VERY difficult to control their noise generation; open cabs of equipment, drilling machines, impact drivers/drills, and some mechanical devices are the first to come to mind.

Modifying equipment to control the noise is better than handing out ear plugs. But, before you modify the equipment, does your company have a “Buy Quiet” program? NIOSH & CPWR released some info graphics which can help start you down this road to considering noise levels when purchasing new equipment.

Before modifying equipment to control noise consider:

• Does the manufacturer have a “factory approved” modification already available?
• Are there any liability considerations if you make this change?
• Have you discussed the modifications with:
  • The manufacturer? Engineers?
  • Operator?
  • Mechanics?
  • Scope of work?
• How much noise reduction are you hoping to achieve?
  • remember noise is logarithmic, so a reduction of  1 dB is achieving a lot…
  • but not much practical difference in regards to operations
• Measure noise before and after, both static and dynamic

I’m still startled by how many construction companies have not started a hearing conservation program. However, I do know why: we don’t see a lot of worker’s compensation claims from this injury (we still see them, but not in the numbers we think we should).

Recently I was asked this question: My company is strictly a general contractor. We do not have field employees, only Superintendents, Estimators, Project Managers, Project Engineers, etc. Do we need a hearing program?

Here’s why I think you should start a hearing program:

Start one for risk prevention, maybe not for overexposure to noise.
Most hearing loss claims are around $20k, and the cost of a program is about $15/year/employee. And, in some states, if you are the last injurious employer, you have to prove you WEREN’T the cause of the loss. (So, do noise monitoring/dosimetry semi frequently)

Other reasons:
• it set’s a good example for your subs – when your subcontractor is making noise, it’s hard to tell them they need to start a program when you don’t have one at your company.  Call it ‘credibility’.

• you can roll it into your company’s total worker health (TWH) / health promotion/ wellness program – even if you aren’t required to have it. Wouldn’t it be nice if your company took steps to make sure you still have your hearing?

• if you’re checking their hearing; and they have losses, you can intervene – this might be a big one for construction employees. How many construction workers have noisy tasks? Shooting, hunting, motorcycles, concerts, cutting wood, drag racing, mow their lawn? They may have hearing loss outside of work. If you’re monitoring their hearing, you can maybe influence their behavior while doing these activities.

Obviously starting a program can take time to manage, but there are mobile units which can provide most of the work. And, if you have a workforce above 50-70 employees, it might even make sense to purchase your own booth.

Noise has some interesting health effects. Most people assume the worst that can happen is you will lose part of your hearing. However, a recent (March, 2014) study in Injury Prevention by Girard, et.al, concluded that those employees exposed to loud noise (above 100dBA) were admitted to hospitals more frequently, and at risk for other injuries.

Some other known health effects include (from Medscape & WHO):

• fatigue
• impaired concentration
• behavioral changes
• irritation
• impaired academic performance
• interrupted sleep (during sleep times)
• changes in endocrine & autonomic nervous systems
• increase in heart rate, blood pressure, vasoconstriction
• sexual impotence
• neurosis
• hysteria

Noise is a simple subject, but there are many factors which influence noise exposure to individuals. Some include:

• The individual: age, prior exposure
• The noise: loudness (dB), type of noise (Hz), distance from noise
• Time: exposure vs. non-exposure time per day

More information on how to control this hazard in construction can be found here.

And, as a bonus, the Journal of the Acoustical Society of America has published a review of the top Smartphone Sound Measurement Apps..  The winner (most accurate) was SPLnFFT, at only $3.99. A close runner up was SoundMeter by Faber. Another summary review is here, and here.

Let’s clarify: You are a working adult. You are feeling symptoms (of some sort). And, you think it’s from something your exposed to while at work (in construction). This could include, but will not, the flu-bug. Below is a list of the most common construction illnesses.

Most Common Construction Illnesses:

1. Upper respiratory
   • could be from silica, drywall, dust, asbestos, nuisance dust, chemicals (I won’t even try to list all of them)
2. Skin (dermal, dermatitis) damage –
   • From: concrete, abrasion, chemicals
3. Eyes
   • mostly from things that get into the eye.
4. Cumulative trauma (ergonomics) or inflammation
   • repetitive motion, over a day hurts, imagine this for years
5. Burn (heat or chemicals)
   • Usually around hot work like welding, but this can occur when using certian chemicals
6. Hearing loss
   • cumulative trama to the ears when exposure is above about 85 decibels for any extended period of time.
7. Poisoning– General or systemic
   • From: poison ivy, stinging needles, dog bites, bees, etc.

This list may vary depending on many things including what type of construction you are in; GC, heavy, civil, specialty, etc.  I put this list together to get a picture of where we see illnesses. However, as previously mentioned, and, everyone knows, the FOCUS FOUR is really where most injuries occur in construction.

We have seen the most prevention of illness due to one single device:

the back support.   ha. just kidding, of course.

It’s sad to say, but many construction companies have not yet started a formal hearing conservation program. Their solution is to purchase the best earplugs, for the lowest cost, and give them away like candy.

As I’ve mentioned before: Sometimes OSHA’s rules are protective (meaning: you will be safe) and other times they are really not on par with the health research. Hearing loss and OSHA’s method of measuring noise are NOT protective to employee health (your hearing). For the best method of measuring noise, look to the recommended guidelines of the ACGIH. In order to get the exact parameters, you must purchase their Guide to Occupational Exposure Values (TLVs) booklet. It hasn’t changed (at least for noise) for a few years, but it is still the most up to date on health for your hearing. Here’s a summary of some differences:

• Exchange rate (how noise doubles and is averaged over time)
  • OSHA uses 5, ACGIH uses 3 >>which means noise doubles every 5, or 3 dB increase
  • this makes a BIG difference in your accumulated average noise level (TWA).
• Exposure Limit, or Criterion Level
  • OSHA says 90 dBA, ACGIH says 85 dBA
  • Doesn’t seem too different (-5), but remember noise is logarithmic and it’s measured different by OSHA & the ACGIH

NIOSH also has some guidelines, which are very similar to the ACGIH.

There are some strong benefits to having a hearing conservation program. Here are some examples and suggestions for bettering your own program.

• You can be recognized
• Win an award. 
• Have less (or even better: none) hearing loss claims
• What about just hearing soft noises? kids? hunting? sports? the TV?

If you have worked in construction for any period of time, you know how loud it can be, and how much exposure is out there. Don’t assume working in this industry that hearing loss will to happen to you. Do something about it. Here’s a presentation from CDC/NIOSH a few years back on how to start.

Hair growth for your ears! This type of hair growth is different than the hairs which grow longer as you get older… 

The problem with most types of hearing aids, cochlear implants, and other types of enhancements is that they only amplify the body’s ability to hear. I talked about a type of pill we someday might be able to take that helps, here.

Research has found a way to regrow the hairs in your ear…well, at this point, only in mice. But, in theory, you could put these hair growth cells in the part of your ear where you have the most damage…and, well, it might help!

The summary article is here. The original article is here. And, to nerd-out, here is the research paper.

If you operate a ready-mix plant and have concrete trucks, you are aware of this process. Once a year (hopefully, only once) a person must climb into the drum of the ready-mix truck and chip off excess concrete. What happen during regular use, is that some concrete hardens, which usually sets-up over and around the blades. Access into the drum is by either the 3×4 hole in the side, or down the chute.

Yes, it is a confined space (def’n: 1. large enough to enter, 2. not designed for occupancy, and 3. limited entry/egress).

Here are a list of the possible hazards:

• silica dust (from chipping concrete)
• noise exposure
• hazardous atmosphere (curing concrete uses up oxygen, which we DO need BTW)
• slipping hazard (drum is round inside)
• heat stress (if you’re trying to do this activity in the summer)
• eye hazard (chipping)
• electrical hazard (if you’re using water & have an electric hammer)
• lock out / tag out (if the truck drives away, or if the barrel starts turning)

There are many resources available (see below). Some things to keep in mind; ventilation (fans, etc) to control the airborne silica dust are usually not effective (too much dust versus exhaust). Water controls are best, but you must limit the amount of water and the direction of the sprayer. I suggest looking at what others have done.

Keep in mind, if you perform this activity you will need (as a company):

• respiratory program (medical, fit test, written plan)
• confined space program (multi gas meter, written program, attendant?)
• lock out /tag out policy or procedures
• training (for each of the above, and for this specific activity)

At this point I know what my contractor-friends are thinking…I will subcontract this out!   ha. If you do, please make sure your sub is doing it right.

Resources:

Georgia Tech – good presentation & guidance

Georgia Tech/OSHA – Safe Work Practices (in Spanish too!)

Teamsters H&S hazards & controls

Illinois DCEO – Consultation on ready mix cleaning

Yes. If you are in construction, I recommend it. Here’s why:

First, the rules. OSHA does NOT have a specific construction standard for hearing conservation. Why does this matter? Well, the current OSHA rules state that if you have 1 day (that’s only one day) of average noise level above an average of 85 decibels A-weighted (dBA), called the Action Limit, you are required to start a program. Obviously noise levels vary on construction jobsites. I’d guess that most projects have at least one day of levels above 85dBA’s.

And, these particular OSHA rules are terrible. Well, they are terrible if you care about your hearing. (see my earlier post). The rules are simply not protective enough. If you are exposed to noise for 8-hours a day at 90 dBA (the OSHA average exposure limit) you WILL have hearing loss (this is without hearing protection). Does that seem like a very protective rule?  I’ve heard talk about them changing it, but…I doubt it will ever happen.

Second, let’s consider cost vs. reward. To start a hearing conservation program you must measure your employees hearing , called audiometric testing (and do a few other things). It costs approximately $20/employee to do this per year. Compare this with the average claim (of hearing loss) cost of around $20,000. So, if you have 20 employees, and it costs you $400/year…it takes about 50 years to pay yourself back for NOT starting a program. ($20,000/400= 50 years)

Third, consider your employees. Having their hearing checked may seem like a hassle and a worthless exercise, but, some will appreciate it. I’ve found that employees like to know how they are hearing. It’s good if your employer cares how well you hear. It’s also a yearly reminder in hazard awareness to noise.

Because in construction, we know there’s noise!

If you’re dead-set on NOT having a program, you’ll need documented noise dosimetry for each employee, job task, and possible overexposure above 85 dBAs. It is possible  for a construction company to avoid having a program, but you have the burden to prove there isn’t noise. Call your favorite industrial hygienist for help.

As I have said in an earlier post, some OSHA, EPA, and MSHA rules are a good fit. They blend well with health research, scientific technology, good practices, and a low-cost-of-compliance for employers. Other rules are just bad. They are  totally out of date, not protective enough, or just not feasible/practical. Here’s my plug for a good safety manager/industrial hygienist – A good one will know which rules/guidelines to follow.

The New York Times (July 19, 2012, Cara Buckley) recently wrote an article on the US noise standards which are not protective enough for employees. In construction we also have three additional problems.

1. hearing loss is expected (or at least assumed in certain fields – carpenters, sheetmetal, ironworkers, etc.) and,
2. work shifts are usually over 8-hours. Noise exposure is usually calculated on an 8-hour time weighted average. During the busy months, an 8-hour work day is rare. It’s at least 10, maybe 12-14 hours. This doesn’t allow your ears to “rest” between shifts. For more information on extended work shifts go here.
3. extracurricular activities contribute to overall hearing loss – my point is that most construction workers don’t sit at home at the end of their shift. Almost everyone I know in construction is involved in one of these activities: hunting, shooting, motorcycles, water sports, yard work, cars, wood working/cutting, concerts, music, etc. Each of these activities contribute to their overall hearing loss, and again, doesn’t allow your ears to “rest”.

…which reminds me that I need to keep a set of ear plugs in my motorcycle jacket.