Monday, August 10, 2015

A little medical/chemical mystery

John Spevacek has a good one on acroosteolysis, a disease that would afflict those chemical operators who were assigned the manual cleaning of vessels used to make PVC:
The disease was observed for the first time in mid-1963 in Belgium (Jemeppe) in a chemical plant operated by Solvay, and affected two workers whose job was the manual cleaning of vessels used for the polymerization of vinyl chloride; similar cases occurred in almost all PVC production plants all over the world, but not in the plants where the main activity was the production of vinyl chloride monomer (VCM). 
Little more than one hundred cases are described in the scientific literature, and this number increases by a few dozen if we consider known but unpublished cases. These figures confirm the rarity of the disease, which peaked at the end of the 1960's and disappeared during the 1970's, probably due to the complete elimination of manual reactor cleaning. Observation of the disease lasted no more than fifteen years and the disease was not replicated in experimental conditions on animals.
I think the "horses not zebras" explanation would be one of the additives used in PVC production. But I sure would like to know what level PPE those operators were using, and what gas-phase compounds they were exposed to...

1 comment:

  1. One important factor to consider is the actual solvent used to manually scrub the reactor. If it was something chlorinated, it soaked through rubber gloves and took with it the leftover goo. This would set up inflammation and the result would be osteolysis in inflamed digits.

    By the way, the exceptionally nasty toxicity of dimethylnitrosamine was only fully realized after it was introduced as a "low toxicity" dipolar aprotic solvent that is excellent for manual scrubbing the reactors in 50s. (It was very cheap while it was produced in huge volumes as an intermediate for N,N-dimethylhydrazine rocket fuel for ICBMs.) The poor little wretches climbing into reactors and scrubbing them with the stuff from inside suddenly started turning bright yellow due to a fulminant liver injury...