Biological Monitoring


Honestly, I did not think lead exposure to adults (and even kids in small amounts) was an issue. Mainly because:

  • OSHA has good (protective) rules on lead in construction (updated in 1993) and they mimic the ACGIH TLVs.
  • We all have lead in our blood. (…and I seem to be doing fine)
  • We are doing better as a society. For example: no more* leaded gasoline.

But, one technical session last year at a conference changed my mind. We have a long ways to go.

The point: low levels of lead may have significant health consequences. And, if you have lead (Pb) in your body–it is from a source.

If I haven’t convinced you, the CDC is also considering ANOTHER reduction in childhood blood lead levels. In 2012 they reduced the advisory blood lead levels (in children) to 5 ug/dl. Later this month (Jan 17, 2017) they are meeting to consider reducing this level to 3.5 ug/dl! Whether of not they reduce it, the fact they are considering it should further our attention.

And, if you think this just applies to industries with heavy lead, think again. It has A LOT to do with construction.

“Construction Program researchers and the New Jersey Department of Health and Senior Services (DHSS) conducted a surveillance study in 1993 and 1994 involving the voluntary participation of 46 construction workers’ families. BLL (blood lead level) testing of young children indicated that the workers’ children, particularly those under age six, were at greater risk of having elevated BLLs (≥ 10 µg/dL) than children in the general population”

We (you) must pinpoint the source of your lead exposure. And, it may not be obvious. Since lead exposure can occur from airborne levels and by ingestion, the sources of lead exposure can vary widely.

For example, in Flint, Michigan they changed water sources to a more natural one. But, *spoiler alert*, the water had more salt – which was corrosive – which leached higher levels of lead from the pipes. Other sources can include: kids toys, jewelry, fishing weights, battery recycling, glass manufacturing, etc. (the picture of the above light pole looks like galvanized metal, but actually contained 45% leaded paint!)

What to do…

  • Train and make people aware of the issue (free video that we produced! 1:31)
  • Blame someone. Just kidding. Find the source of your lead exposure.
  • Before starting a project, know where the lead paint is, and the activities you plan on performing.
  • Get your blood tested for lead levels
  • Wear the proper PPE and ESPECIALLY have good hygiene
  • Perform air monitoring (and probably wipe sampling) to verify lead is not escaping from project.

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.

attic

 

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:

audiometer

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.

lead paint

I regret I don’t have the energy to post every question and situation on this site.

However, occasionally there are very unique questions. I won’t say how I answered them, but I will offer some considerations. Here’s are my two favorites from the recent past:

  1. My construction crew is working on a “special TI (tenant improvement)”, alongside an elephant who has Turberculosis (TB). What personal protective equipment (PPE) do my workers need to wear?
    • Is the TB active
    • Does TB transfer from people to animal, and/or vice versa
    • How much contact (distance, time, amount of touching, etc) will the workers have with animal?
    • Will you offer prophylactic shots? (to the employees, of course)
  1. We are going to be excavating the carcasses of dead sheep. What type of PPE will my excavator operators need to wear while performing these tasks?
    • How large of an area (2-3 football fields)
    • How long have the carcasses been in this area
    • Any additives to the soil/area
    • Will workers be in contact with dead animals?
    • Will workers need to enter the excavation?
    • Will you use a multigas meter (4 gas)?

elephant

I’d love to hear your best (or worst) questions.

I am ashamed I have not written on this topic yet. In fact, this issue is so close to me, it bewilders me why I never connected it to occupational exposures. It’s even a carcinogen, and I try to get as much of it as I can when it is around.

To summarize my personal examples:

  • My dad has skin cancer on his ears and annually has these removed.
  • My next door neighbor died in 2009 from skin cancer (metastasized). He was a county construction worker for 35+ years and was in the sun, with his shirt off. A LOT.

More recently:

There are some chemicals and foods, when taken/exposed, actually make you more sensitive to the suns UV exposure (aka: photosentisizer). A list can be found here. Some of them are:

  • foods: carrots, dill, clover, eggs
  • medicine: antibiotics, diuretics, high blood pressure
  • chemicals: coal tar (creosote), benzene, xylene
  • cosmetics

And, if you haven’t noticed, construction workers get a lot of sun exposure, especially in the summer. Don’t forget, welders can have high exposures, and our heavy highway (road paving) crews are exposed to coal tar pitch. We talk about heat stress, but we should talk about the long term effects of skin damage.

There are no specific OSHA regulations on UV exposure. However, there are some guidelines from the ACGIH. There might be an instance where we can work within our “hierarchy of controls” and and eliminate the exposure to the employee. However, with this hazard, rather than working on eliminating the hazard, I would recommend we provide PPE.

Do you provide sunscreen to your employees?

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:

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

If you really have an indoor air quality and mold/fungus issue, it usually stems from moisture. I’ve talked about it before, here. The simplest answer is to find the water. Control the moisture and you inevitable will control the future indoor air quality concerns. Once you have found (and controlled) the water, then it is time to repair the damage and lingering water (which can’t evaporate).

The issue is: where does moisture come from? Well, it ‘can’ come from almost any direction:

EPA moisture control

  • from above (rain, roof vents, skylights)
  • from below (moisture in flooring, concrete)
  • walls (penetrations into the exterior, or windows and flashing)
  • out of thin air (relative humidity)

The EPA has written a new document titled, “Moisture Control Guidance for Building, Design, Construction and Maintenance“. As a contractor, how do you know when the clean up is too much to handle? I’ve written a bit more about it here.

The best time to clean up a moisture issue was yesterday, but the second best time to clean it up is today. Don’t let it sit, it usually doesn’t get any better.

Let me first say that I am still learning about this hazard and why it is so dangerous.

Polyurethane foam is used as an insulating material. More info on it’s uses here. The danger is when you spray it (think: expandable type), or apply it, or cut/remove it after it’s cured. The danger is in the off-gassing.

There are two main considerations:spray foam

  • the process of applying the foam
    • spray type
    • quantity?,
    • ventilation?
  • the type (manufacturer/brand/type) of foam
    • curing rate,
    • type of hazard, etc.

What we know is that there is a hazard. AND, this hazard may not effect everyone, OR, it may not effect you until some time has gone by. But, some of the chemicals in these types of products include:

There is a huge potential for work related asthma when using these types of products. And, even contact with the skin can trigger an allergic response/asthma attack. If you have employees working around this type of product and have ANY respiratory symptoms (or asthma), please have them checked by an occupational medicine doctor.

Control of this hazard should include:

  • PPE for employees (respiratory, eye, & skin protection)
  • ventilation during application
  • ventilation during off-gassing & curing (can be 72 hours)
  • control plan for spills, cutting & demo
  • control plan for employee/occupants with asthma

The EPA has a quick reference card here (hat tip to Tom), and more detail from the EPA on how to control the hazard here. The Spray Polyurethane Foam Alliance has free training here (haven’t checked it out though), and be mindful that anyone can be an instructor (good & bad).

NIOSHNIOSH 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, welding2hardfacing, 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.

 

Next Page »