Wednesday, January 22, 2014

MCHM is probably not a "deadly poison"

Huffington Post is doing its absolute best to troll on the West Virginia/Freedom Industries disaster with this headline:


From the text of the article (italics from the article): "Among the other no-brainer regulations that Tomblin would finally install for the purpose of public safety, this legislation would require businesses like Freedom Industries -- the company that owns the recently liberated contaminants -- to tell regulators where their tanks of deadly poisons are actually located. It's a start, I guess!"

I think my frustrations with the media are small beer considering the absolute mess that this leak of 4-methylcyclohexane methanol into the Elk River has wreaked on the Charleston, West Virginia metropolitan area. But really, there's not much evidence that MCHM is a "deadly poison." It's probably toxic and if you eat enough of it (like 100 grams), it will probably kill you.

But it's a chemical and like all chemicals, the dose makes the poison. 

10 comments:

  1. While I find the mischaracterization annoying, it does bring up a good point: there's lots of compounds that we don't know all that much about. It also draws attention to the Chemical Safety Improvement Act (S. 1009) https://www.govtrack.us/congress/bills/113/s1009. As chemists we should make sure we're heard on this subject. As enjoyable as it is to laugh at chemphobia we should also get out and engage people on this as much as possible.

    ReplyDelete
  2. As common as pharmaceuticals are in every day life in America, I'm constantly surprised by the general public lack of understanding of dose dependency/exposure limits when dealing with chemicals. Your previous post about the class action lawsuit and videos such as this:

    http://www.youtube.com/watch?v=2ugqjGgWNAY&noredirect=1

    really hits home how little the public understands chemistry.

    ReplyDelete
  3. I'm actually concerned that this compound might be an endocrine disruptor. It looks difficult to metabolize, and it looks like it is likely to bioaccumulate. It's probably not so toxic in an accute exposure, but it could do a lot of damage over time. It would probably be wise for Charleston to install piping to move its water intake upstream of the spill.

    I think activated carbon filters would absorb a lot of this substance. Residents might be safer if they filter their water. Alternatively, the plant could install some sort of charcoal filter.

    ReplyDelete
    Replies
    1. See, this is where I gotta figure things out, because I'd think it would be relatively easy to metabolize, but maybe I'm wrong. I definitely see that it would bioaccumulate.

      Delete
    2. When I look at the compound, it is small enough that a good estimate for its maximum affinity for a given target (endocrine target or other) is ~ 3 mM. You would a *lot* of compound to achieve systemic exposures at that level. And as for bioaccumulation -- I would put this compound in the category of "CYP food". Lots of places for oxidation. It can also be conjugated on the alcohol as well as oxidized through to the acid for rapid clearance. I would estimate a very low probability for bioaccumulation (although this is an estimation -- not based on actual PK data). My biggest concern as far as potential fox effects would be if the steady state concentrations of the corresponding aldehyde get too high. Aldehydes can be a problem from a pure reactivity standpoint.

      Delete
  4. Chemists weren't very helpful during this spill since most of us were saying it's not too toxic but we don't know much about but by the way don't drink the water. No wonder people are confused and scared.

    ReplyDelete
    Replies
    1. The article mentions the Chemical Safety Improvement Act which is supposed to update the Toxic Substances Control Act. I think we need more info on a lot of the chemicals we use industrially. No most of them aren't going to be lethal or even particularly toxic but there's too much "No Data Available" out there. The difficult question is how to decide what should be better characterized. With thousands of chemicals in use should the expectation be that all of them are thoroughly characterized in terms of safety? If so how should it be paid for? If not how do we prioritize? The bill for the Chemical Safety Improvement Act (s. 1009) establishes a two tier system where the EPA only tests high priority compounds. I need to read the whole bill to see what makes a compound high-priority.

      Delete
    2. Here's a hearing about the bill:http://energycommerce.house.gov/hearing/s-1009-chemical-safety-improvement-act and the text of the bill: http://beta.congress.gov/bill/113th/senate-bill/1009

      Delete
  5. It is the huffington post....no explanation needed, they are not exactly a bastion of journalistic integrity.

    ReplyDelete
  6. I'm a 30+ year industrial chemist, stuck with this water supply. All the tox data is for acute exposure, there is NO DATA for chronic. I offer "hexane" as a simple molecule with vastly different toxicities. 2 weeks after the spill - CDC, governor, water company, and "spiller" have all changed stories several times - and many spots in the distribution system still have > 100 ppb and stinky water! The National Guard (reporting to the governor) is sitting on all the analytical data. There is no evidence that any analyses followed EPA protocols.

    ReplyDelete