Industrial Hygiene in Construction

Many times an IH is called upon to determine the cause of a person’s ailing symptoms. For example, an employee might complain of congestion, irritability, bloody nose, etc. Someone has decided it might be from their exposure at work.

The practice of industrial hygiene is difficult to apply to an individual. What I mean is, this field of study was developed due to serious health concerns over a population of people at work. This is essentially how science works, you take a population, study it, find the differences, then make conclusions.

Trouble occurs when you try this backwards. If the same person (as example above) complains of congestion, irritability, bloody nose- can we assume they must have exposure to lead dust? Not usually. We must obtain other clues.

What industrial hygienists try to do in these instances is rule-out the possible over-exposures. Sometimes we can measure for chemical exposures to see if it might be of concern. But even then, it’s not fool proof. Below are a few issues which make it complicated.

• exposure at work? job? extracurricular activities? home?
• person might have autoimmune disease and gets sick easier
• sampling is not feasible
• sampling is somehow screwed up (by IH, lab, mail carrier)
• exposure is through food, clothing, etc.

Even with these fallacies, there are things an individual can do to narrow down their ailments:

• create a log. time, type of symptoms, pain scale, others experience/smell, food eaten
• change things and see if it improves/makes it worse
• research – but do it right. Look at the items you use, check the SDS

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.

Before you can wear a respirator here’s what has to happen:

If you’re an employer and your employees wear a respirator, they are required to have a medical approval (Appendix C of OSHA respiratory standard). more details here.

The employee fills out the confidential questionnaire and then submits it to the medical provider of the employer’s choice. 95% (I made that # up) of the time, based upon the questionnaire ONLY, they give an approval to wear a respirator.

Occasionally, some employees are requested to come into the medical office to have a spirometry test performed, which tests for lung function. (a video of how it is done, cool accent included) This tests provides more information for the physician/nurse to determine if wearing a respirator will be too difficult for an employee to wear.

The cost for either test is usually pretty close to the same price… spirometry test, or not.

Here’s my suggestion:  Have every employee perform a spirometry test before wearing a respirator. This helps to guarantee they are capable of wearing a respirator. Maybe they forgot to list a risk factor, maybe they have a hidden serious lung problem, or, maybe they lied on the questionnaire so they can wear a respirator and keep their job.?

It is also beneficial for pre-employment screening, claims defense, and for a baseline in health. The specific results are usually NOT view-able by the employer, but they can be subpoenaed.

Many construction companies have a multi gas meter (s). Here is my word of caution: if you have one, know how to use it.

I bet if you’re reading this post, you do know how. However, do your employees?

This type of training is SO critical. Below are some common mistakes I’ve seen from construction companies using these types of equipment:

• Let someone else (a GC, or subcontractor) tell you if it’s ok to enter a confined space (or hazardous one).
  • = do you own monitoring, & use your own equipment!
• Use someone else’s multi gas meter.
  • =do NOT use someone’s meter unless you 1. know the machine and 2. are able to calibrate and see the documentation. Would you send your employees to work in an area you think there might be a deadly hazard? Treat the 4-gas meter like it is your only available tool.
• Not performing a precalibration and bump test before using the gas meter.
  • = ALWAYS perform a bump test (not just zero-out)
• Not knowing which sensors are inside the machine (and what they mean).
  • =train your employees on when/why it alarms. CO is not CO2.
• Blame the machine if it alarms
  • =the machine is alarming for a reason. You either screwed it up, or something is going on. Figure it out. I had a project where the handheld radios were interfering with the multi gas meter. It took us 2 days to figure this out. Luckily no one was so desperate to work they ignored the alarm. On another project, employees were telling me it was ok to work while the alarm was sounding off. Their response was that, “it always goes off for CO, but we aren’t worried”. Yikes! I was.
• Not knowing what the hazards are
  • =you must know what you are measuring for. If you have isocyanates inside the confined space, the multi gas meter is probably not going to give you adequate warning.- if any. Just like wearing the right type of filter cartridge on your respirator, know the hazard you are measuring.

Controlling most of these types of exposures is really simple. If you know the job- and you know it will generate airborne silica = Pre Task Plan!

I wish Superintendents would enforce their project managers, or project engineers, to make a pre-task plan for every concrete/silica producing task. Then, (please don’t stop yet), review the plan once the project starts!

Below are two examples with different outcomes:

1. Cutting concrete block.

The pretask plan called for a garden hose with attachment(s) to wet the cutting area. Everything was perfect until the water was shut off. But, they improvised and found an electric water pump with bucket and recycled the water. It was a great outcome. What if the power went out? They could have used a Hudson sprayer.

2. Grinding plaster off a brick wall.

They built an enclosure and containment. They had a negative air machine with HEPA filters. They had a vacuum with HEPA filters, tyvek, 1/2 face respirator, eye protection, etc. But, as they worked the vacuum couldn’t keep up with the amount of dust generated by the 7 inch Bosch grinder. It was really dusty. They worked like this for days. No one onsite saw them because they were in containment. Unfortunately  the project is almost over and it could have been better. A simple shroud to the grinder, like this one (no endorcement) might have controlled the dust & silica. Sure, it might have been troublesome to find the exact one, and get a vacuum attachment, and have the extra weight, and ….

So, let’s talk to people about silica, talk about solutions, and then check to see if they’re effective.

The new global harmonization system (GHS) is officially adopted by OSHA. Each state run program is rolling out their acceptance of the new changes. Where I live, we have until December 2013 to train employees in this new type of hazard communication.

Honestly, I’m NOT too EXCITED about it. But, I’m trying to have a good attitude. Below are some good things which may occur:

• Raise the level of awareness of hazardous materials & their toxicity
• Train employees (hopefully, retrain) on how to handle chemicals
• More training = less citations. (?) OSHA’s top ten citations include #3 – hazard communication. Maybe people will actually do the training?! (my guess is that there will be more citations)
• Consistent information worldwide.  All UN countries should have the same format. (this might take years)
• Proprietary information will be more visible on the SDS. In the new rules, manufacturers are required to list the % of their proprietary ingredients.
• Pictograms! They’re so cool. My favorite is the exploding person.
• Maybe this is my favorite?!: Manufacturers will have to look again at their products and classify them according to the physical & health criteria. Nowadays with more relevant information from worldwide occupational exposure limits, it might help make employers aware of the hazards.
  • This might help OSHA enforce newer exposure limits (other than the 1978 AGCIH TLVs).

How do you plan on training your employees? If you need help, contact me here.

There are some items you need to do BEFORE you wear a respirator. If you are using it on a voluntary basis, go here.

1. obtain medical approvalfor employees to wear a respirator
   • fill out a questionaiire (just like Appendix C of OSHA)
   • they might have you perform a lung function test (spirometry)
   • you will get a yes/no answer (probably 99% are approved)
   • you might try an online medical evaluation
2. have a fit test performed
   • qualitative fit test unless you wear a full face mask, or a type better than this
   • my favorite choice is irritant smoke, but it could also be saccharine, isoamyl acetate (banana), or Bitrex (R).
3. get trained. Learn how to:
   • clean it
   • store it
   • know what your respirator can’t protect you from
   • choose the right cartridges
   • know when you have break through
   • fit check (different than a fit test -BTW)

Wondering how often you must update the above steps? Go here. There are more steps to having a respiratory program, but you must do these things before you start.

Background: A new client recently had an OSHA health inspection (industrial hygiene). He received citations stemming from overexposures(they found levels above the PELs) to airborne particulates.

The company wondered what to do next. Here were my suggestions:

• Fix the problem. You will need to comply and assure that your employees aren’t overexposed. Even if the inspection made you upset, use your energy to make the situation right. Focus your energy on removing the hazard, not complaining about how you were treated.
  • Engineer the problem out. Remove the hazard. If not,
  • Change your policies so no one is further overexposed. If you can’t fix it by the this, or the above method, then,
  • Provide personal protective equipment to affected employees.
• Request the full inspection package. – this will include the officer’s field notes, interview questions, observations and sampling methodology.
  • look through these documents carefully
  • keep them for your records
•  Informally appeal the citations.
  • at the appeal show them you have complied/changed
  • ask for a reduction in fines (it never hurts to ask)
  • ask to group the citations together – instead of citation 1 item 1a, 1b, item 2, etc. ask to narrow it down to just one
  • bring any additional information which supports your side and/or the changes you’ve made (including training docs, programs, policies, etc.)
• Resample the areas.
  • make significant changes to these areas. Then,
  • hire an industrial hygienist to perform additional sampling in these areas
  • ask them to document the changes you have made to reduce the exposures
  • review this with your safety committee & those affected

You already knew it. There is a lot to do in industrial hygiene. At times this occupation feels like a safety middleman trying to keep people out of trouble. Occasionally I’m rewarded with really helping someone. In the United States, there is still a lot of occupational hygiene issues and concerns. Overseas, particularly in developing countries, there is even more.

It is hard to obtain accurate exposure data, or illness rates, from these underdeveloped countries. (How does a village of 1,000 people in Kenya report that they’ve had lead exposure to battery recycling?) How these exposures are brought to light is by either a massive death (# of people, quickly) or, someone with a camera able to actually photograph the pollution. As we know, what it looks like doesn’t necessarily correlate with hazardous levels of exposure. But, in some cases, it’s pretty obvious.

I ran across this photo story on pollution (The Guardian, UK). They estimate 125 million people are exposed to industrial pollutants (generic term, I know). This makes occupational related exposures a health risk as big as TB and Malaria! The article is based upon a report from the Blacksmith Institute which included this map of the worst pollution with associated disease.

How does this apply to construction? The worst offenders are lead (Pb) (and other metals), and asbestos.

What can you do? Here’s their recommendation, from the report (p50):

Developing countries need the support of the international community
to design and implement clean up efforts, improve pollution control technologies, and provide educational
trainings to industry workers and the surrounding community

Another NPR article about lead poisoning can be found here.

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