What happened to NPR's critical thinking? They are repeating the information from Karen Dannemiller, an associate professor of environmental health science at The Ohio State University. And neither this professor nor NPR seems to have looked at the list of chemicals and products in those 40 cars that were involved in this accident? Let's just look at 5 hopper cars that carried solid materials that burned:
2 cars full of vinyl chloride plastic,
2 cars full of polyethylene plastic, and
1 car full of polypropylene.
It wasn't just vinyl chloride monomer, cars full of vinyl chloride plastic with all their additives went up in smoke. The emissions from incomplete combustion of burning plastic is going to involve hundreds or even thousands of chemicals. And the composition of the emissions varies with the temperature and the access to oxygen of that burn. And you can't know what those chemicals are by some damn theory, you need to sample the air and analyze.
So let's look at what the NPR expert says here:
The EPA human health risk assessment is ongoing and unfolds in four steps.
1. Hazard Identification - First, the EPA has to identify what chemicals were onboard the train and released into the area, and determine which pose a risk to the community and the environment.
The chemicals on board that were "released," i.e. spilled in the area are minor compared to what burned. But if we look at just one that spilled, ethyl hexyl acrylate, it has a MAK of 5 ppm, no US standard, and essentially no chronic data. You can't evaluate the hazards of chemicals that are untested for hazards.
Some propylene glycol was both spilled and burned. This chemical has just always been assumed to be safe, but there is no chronic data on it either. And when it burns, I know it gives off a flock of chemicals, formaldehyde and other aldehydes, and a bunch of other toxic intermediates. How do I know? The studies of its use in vaping and theatrical fog since this is one of the most common chemicals used in both.
Theatrical fog machines that use heat to vaporized propylene glycol (or any other glycol) are prohibited in entertainment industries since any temperature higher than 700 Fo produces adverse respiratory effects in those exposed. We also learned that the propylene glycol emissions change greatly depending on temperature and EPA doesn't even know how hot this fire got.
We learned this stuff about heating propylene glycol the hard way -- by exposing people and dealing with effects and complaints. Sounds like the railroads and EPA are about to learn this the same way with propylene glycol. And this is just ONE of the dozen or so chemicals that burned.
And those chemicals were spilling and vaporizing and some were burning. The black smoke indicates the presence of carbon so the combustion of this mixture was incomplete. There is no data base for this kind of combustion. The only way to know what chemicals were released was to have done a lot of capture of air samples and analysis at the time. And that wasn't done.
There were about a dozen different chemicals that spilled and/or burned either in an uncontrolled or a controlled fashion. But all burning was incomplete producing soot. What about the PAHs on the soot? You going to monitor for them? Dioxins? Dibenzofurans?
Again, the only way to know what was released to the air was to capture samples and analyze during both the initial burn and the controlled burns.
2. Dose-Response Assessment - The EPA looks at what the effects of each hazardous chemical are at each level of exposure in the area.
This is a very small town that was exposed. So you'd have to set up sampling in a number of places throughout this area and collect enough air for analysis of the hundreds or thousands of chemicals released in the initial fire and the controlled burns. Many of these incomplete combustion chemicals are going to be ones for which there is absolutely no dose response data or any other data.
3. Exposure Assessment - Once the above steps are done, the agency will examine what is known about exposures — frequency, timing and the various levels of contact that occur.
Garbage in, garbage out.
4. Risk Characterization - Here, the EPA essentially pieces together the whole picture. They compare the estimated exposure level for the chemicals with data on the expected effects for people in the community and the environment. They also describe the risks, which shape the safety guidelines.
Not going to be possible. The time to collect data has passed without obtaining the necessary samples. The human subjects have been exposed. The data from this uncontrolled experiment now will, sadly, be empirically developed over the years as health effects are documented.
Monona
-----Original Message-----
From: Ralph Stuart <ralph**At_Symbol_Here**RSTUARTCIH.ORG>
To: DCHAS-L**At_Symbol_Here**Princeton.EDU
Sent: Mon, Feb 27, 2023 10:50 am
Subject: Re: [DCHAS-L] Article focus on monitoring + testing of Ohio train derailment incident
