Industrial Hygiene in Construction

Another MSHA site where they are actually not crushing rock or selling it. This location only screens the rock/dirt and loads it. It’s transported to another location where they screen it again (wet, this time) and sell it. They had two loaders and an excavator working this pit. We would have normally performed air and noise monitoring at the at the crusher location. However, the crusher was actually not crushing rock and was only screening the rock wet. At this location they were at least screening dry. We figured this would be the best chance of finding any dust. However, we found hardly anything.

There was nothing too exciting or unique, other than a strong wind in the afternoon and a pesky pheasant that remained out of site, but kept cackling.

The big scare in commercial construction is a new Senate House Bill 596 which makes certain insulation with the polybrominated diphenyl ethers (PBDE) illegal to install if you’re in Oregon. I think this bill caught everyone off guard.

PBDEs are used in fireproofing as a flame-retardant. However, they are in LOTs of other things including; foam products, plastics, couches, etc.

The issue is that this chemical(s) is a bioaccumulator. And this description is telling. It accumulates in your body. Health studies are inconclusive, and forthcoming, but it could be linked to brain development, memory, learning, and lowering thyroid hormone levels.  Most all symptoms are long term, but as mentioned before, it accumulates.

For more information about PBDE you can start at the Agency for Toxic Substances & Disease Registry. The Oregon Health Authority is enforcing the rule. The Fact Sheet is here dated January 28, 2011.

I am cautious about saying if this is a real-public health issue, or just a passing scare. Honestly I don’t know. I haven’t seen a lot of information about the health effects from unbiased sources (please point me in if you have).  Regardless, this is in some brands of commercial insulation, and if you’re in Oregon, you should not install it.

Another week – another rock crusher. ”Tiz the season for the crushing to begin.

This particular rock crusher happened to be located a few miles up the mountain. Which had a great view, but the elevation difference can significantly change your flow rate if you precalibrated the pumps at sea level (which we did). The difference between our pre and post calibration (post calibration was done onsite) had a difference of 1.4%. Not too much, you say, but multiply that times 10 hours of sampling and… that might be significant.

The quick solution is to calibrate onsite. Pre and post. There is a formula you can use to calculate the difference in pressure (due to altitude) but it makes me dizzy just thinking about how to post it on this site.