Industrial Hygiene in Construction

Unfortunately this website has taken a backseat to actual work. My apologies for not updating the information, and especially to trusted subscribers of this site.

In the coming months, I plan to publish more posts with the same type of information. Thanks for hanging on. – Alden

As a preview: Did you notice that the State of Michigan OSHA (MIOSH) has updated (lowered) their lead (Pb) blood level mandates? Sadly, it took a lot of people being overexposed to lead (remember Flint, MI?) in order to make this simple change. I hope other states follow.

I live in a moderate climate, but we had some 102 degree weather and it reminded me of how important it is to have a heat stress program and educate our workers.

Here are some tips and suggestions for keeping this hazard under control:

• Mandatory rest/water breaks (time between work & break dependent on heat) in shade
• Monitor/measure water consumption (& urine, if extreme)
• Educate employees on symptoms and factors which might contribute (medications, were you drinking last night?= deydration)
• Always work with a partner
• Flexible work schedule (start early, leave when conditions get unbearable)
• Increase ventilation
• Consider the space (attics can be worse than conditions outside)
• Provide easy access to emergency services
• One of the coolest (pun intended) ways is a “smart” vest with a downloadable app – workers wear this safety vest and it will alert people when symptoms/conditions get bad (heart rate, temperature, etc). Developed in Australia by RMIT University in Melbourne.

If you are in the United States, you have probably been hearing issues with lead (Pb) exposures. The main focus lately has been in Flint, Michigan and their (new) source of water, which contains high levels of the metal. Wiki here.

So, who is to blame?

The NY Times suggests we should blame HUD for the millions of pounds of lead in paint. However, I’m not so sure we can cast all of the blame on them, the legislators, or manufactures. But, we are going to be dealing with lead exposures in the future.

I do not know the depth and extent to which lead poisoning is occurring throughout the US. I’m not sure anyone really does. But, there are MANY sources of lead exposure. For example: leaded gasoline (tetraethyl lead) was used in the past, aviation fuel (av gas low lead) still is, lead in paint, lead in copper pipe solder, lead in fishing weights, lead in ammo, lead in sheet rock, lead in Chineese toys…I could go on.

Bottom line though, if you (or your kids) have elevated lead levels,…there is a source. So, What To Do? Here’s my takeaways:

• Test you & your kids for their blood lead levels.
  • It is a very established method, but isn’t an exact science. Don’t freak out if they are above “background” levels. Just do what you can.
  • The CDC recently lowered their recommended blood lead threshold to 5 ug/dl of blood.
  • Don’t do chelation therapy, unless the blood lead level is REALLY high. How high? I’m not a doctor.
  • DO eat lots of vegetables and fruit. These have found to lower lead levels the best (but maybe not the fastest).
• Find the source.
  • Keep looking, there might be more than one. School, work, hobbies, nearby businesses, daily activities.
  • Measure: dirt, water, paint, your workplace.
  • Consider how small an amount is dangerous. 5 micrograms in 1 deciliter of blood. 5 micrograms is 5 millionth of a gram. A fruit fly weighs about 200 micrograms. So, cut a fruit fly into 200 pieces, take 5 of them…you get the idea.
• Tell others.
  • Recommend that others investigate for themselves.

“Do I need a bloodborne pathogens (BBP) program for my construction company?”

Of course, the answer depends, . But, OSHA does have a letter of interpretation.

The basics are: do your employees have DAILY exposure (anticipated exposure) to blood, or blood containing substances? Further defined as; “today we are going to pick up these bloody needles. Or, “this afternoon we are going into this live sewer, which is coming from the treatment plant”.

Here is OSHA Bloodborne construction letter of interp, but interpret the letter of interpretation yourself. 🙂

“…while the bloodborne pathogens standard does not apply to construction work, as defined in 29 CFR 1910.12(b), it does apply to employees performing maintenance activities who experience occupational exposure to blood or other potentially infectious materials. OSHA expects the construction employer performing maintenance activities to take the following precautions as required by the following referenced standards: Section 29 CFR 1926.21(b)(2) requires that the employer instruct each employee in the recognition and avoidance of unsafe condition…”

In summary, most construction firms do NOT need a full blown bloodborne pathogen program. However, you should still train your employees on the hazards they might incur. This might include the hazards of bloodborne pathogens. There may be a time and project where they wished they had the training.

NIOSH has just recommended a new exposure limit (REL) for hexavalent chromium. The new limit is 0.2 ug/m3 as an 8-hour TWA. If you remember, the OSHA PEL is 2.5 ug/m3 (8-hour TWA). SO, if you’re good at math, you can see this is A LOT lower.

The reasoning for this level is they have found a lung cancer risk (get this) EVEN AT 0.2 ug/m3. They recommend bringing airborne levels below this limit for lung exposures.

As I’ve described before, exposures are not limited to just inhalation. Dermal contact is a big concern.

If you have any hexavalent chromium at your facility, or stainless steel (welding, welding2, hardfacing, etc.) you need to do more than just air sampling. You need a comprehensive program including wipe samples, medical monitoring, etc. This may not be a specific OSHA rule for your facility.  However, these exposures are something you must manage.

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.

Looking back at my lead in construction posts, I realized I did an inadequate job of summarizing why construction activities are dangerous when working with lead.

If you work in construction, here’s are the quick points as to why you should be concerned about lead.

• There has been A LOT of lead added to paint over the years. (it can vary 0.01% to upwards of 20%, and there’s no way to tell by looking)
• The activities we do in construction disturb this paint (some worse than others)
• You can be exposed to paint by inhaling it (if it is airborne), and if you happen to get it on your hands and you eat it (by transfer).
• The real concern is kids. (your kids, the kids who might be there after you’re gone, AND, the kids unborn (lead exposure can go from mom to baby)

The solution is simple (and, of course, more complicated as you dig in):

• test the paint to see if there’s lead in it
• if you disturb it, follow the rules (OSHA, EPA, HUD, City, etc.)
• train your employees (and measure the lead in their blood)
• prevent the dust from going everywhere (containment)
• measure the air to see if you are really screwing it up, or doing a good job.
• finally clean up. (the area, you, your hands, the perimeter) and dispose properly

The answer is Yes.

If you are working with lead (in any amount) and you are performing any of the “trigger tasks” in construction = you must follow OSHA rules. Trigger tasks are demolition, removal, encapsulation, new construction, installation, cleanup, abrasive blasting, welding, cutting, torch burning, transporting, storing, heat gun work, sanding, scraping, spray painting, burning, welding, etc. What about the EPA rules (RRP)? Look here.

The only exceptions to not measuring employees blood lead are:

When clients ask me to assist in choosing a product, I try to recommend a product with the least dangerous chemicals in it. I understand this isn’t always possible. However, I try to emphasize the worst case health scenarios and leave it up to the company to decide how to proceed. There are reasons to use a hazardous (to your health) product.

However, here are some considerations when choosing a hazardous product:

• more hazard vs less cost
• more hazard vs less time actually using product
• more hazard vs cost of PPE
• more hazard vs what the spec says
• more hazard vs different hazard
• more hazard vs terrible health effect/potential
• more hazard vs perception by others on the project (by the GC/public/subcontractors, media, neighbors)

Another issue with chemicals is the names and nomenclature. There are so many different names, common names, chemical names, and sub names of products – it gets confusing.

One solution called, ChemHat.org, offers a unique way of considering other chemicals. Plug in the CAS# (Chemical Abstract Number) or the name, and it gives you some ideas.

Another alternative in choosing the best product is to ask.

• Ask your industrial hygienist if this product is safe and/or are there concerns?
• Ask the GC if this is the only product that can be used
• Ask the architect if there are alternatives that are equally effective
• Ask the manufacturer if they have comparable products without the XXX hazard

When taking blood lead levels, the occupational health clinic will typically measure both the lead in the blood, and the zinc protoporphyrin (ZPP). The reason for this is the blood lead level measures just that, only the lead in the blood – which can come from previous exposures and whatever amount has been stored in your bones (soft tissues). It really only gives one piece of information. An early indicator of  lead exposure is the ZPP level.

The ZPP level indicates lead absorption. If your ZPP levels are elevated, this may mean that lead is being absorbed into your body (affecting the heme synthesis pathway). However, an elevated ZPP can be caused by other things, including iron deficiency anemia, etc.

If you have elevated ZPPs, you need to find out what is causing it. If you’re working with lead, you may have overexposure. If this is the case, your blood lead levels will most likely elevate in 2-6 weeks.

Ask your occupational health clinic for ranges of acceptable blood lead levels and ZPP levels.