Comment by xxpor | Hacker News Reader

Comment by xxpor | Hacker News Reader

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Looking at the wiki entry for trichloroethylene:

https://en.wikipedia.org/wiki/Trichloroethylene

I guess I'm a little skeptical of the explaination that it could be the source of the explosion of Parkinson's over the past decade. Trichloroethylene has known to be a problem since at least the 50s. For example, its use in bulk in dry cleaning was replaced in the 50s with tetrachloroethylene, and it was used for spot cleaning only up until 2000.

The only seemingly recent increase in uses are:

"The demand for TCE as a degreaser began to decline in the 1950s in favor of the less toxic 1,1,1-trichloroethane. However, 1,1,1-trichloroethane production has been phased out in most of the world under the terms of the Montreal Protocol, and as a result trichloroethylene has experienced some resurgence in use as a degreaser."

I don't think most people are exposed to industrial degreaser in their line of work, let alone in domestic settings.

"TCE is also used in the manufacture of a range of fluorocarbon refrigerants[13] such as 1,1,1,2-tetrafluoroethane more commonly known as HFC 134a"

Now this seems somewhat plausible. R134a started to be used in the early to mid 90s, so the timeline would make sense. However, it says it's only used in the manufacture of it. Perhaps there's some residual left in the final R134a product, and that's how people would be exposed to it? Plenty of ACs and fridges in people's lives.

If your fridge or AC is exposing you to trace amounts of TCE left over from the process of making the R134a it's primarily charged with, it also isn't keeping your food cold.

A common AC charge for a car is around 500g +/- 25g It doesn't take much of that leaking out before it doesn't blow cold air. Even if there was a bunch of residual TCE, you're unlikely to be subject to a long term exposure because you'd notice your AC or fridge not working long before the full charge leaked out to expose you.

In spite of the efforts of the world's accountants, fridges and air conditioners still routinely last a decade or more. That's because the charge of R134a is largely staying put.

It largely is, but on the other hand, there's plenty of ACs out there (especially in cars) that have failed.

There are groundwater plumes of TCE around air force bases because they used to just dump extra TCE into open pits thinking it would evaporate. Maybe those plumes reached enough city wells to cause problems over the last few decades.

Example: https://www.library.pima.gov/blogs/post/trichlorethylene-tce... Hughes is now Raytheon Trichlorethylene (TCE), an industrial solvent, was routinely dumped in areas of South Tucson during the 1950s. The Tucsonans who lived in these areas have had various cancers as a result of this pollution.

The boundary of the area contaminated by TCE is roughly south of 22nd street, north of Los Reales Road, east of Interstate 19 and west of Del Moral Boulevard.

Hughes Aircraft and the city of Tucson were accused of dumping TCE in the water table for 29 years, beginning in 1952. A lawsuit against the city was settled in 1981 for $31 million, and in 1991 a suit against Hughes Aircraft was settled for $84.5 million. In 1981 the Environmental Protection Agency (EPA) tested water wells on the south side of Tucson and found TCE levels were beyond the EPA limits.

In 1983, the EPA set a large southside area of Tucson on its Superfund cleanup list. In March 2000, a $35 million plan was secured for cleanup of the contaminated areas. Other government supervised cleanups started about 20 years ago. The last settlements involving TCE lawsuits occurred in June 2006.

I recall this making headlines in the 90’s in proximity to airbases in Pennsylvania.

Specifically issues around drinking water for residential housing with wells in proximity to the airbases.

My dad is suffering from Lewy Body Dementia which is related to Parkinson's. He was an auto mechanic his entire adult life (from around 1960 - 2010). I wonder if he was exposed to TCE?

I did a 23 and Me test and never unlocked the health results. I'm a little terrified of finding out that dementia is in my future as well.

I bought some brake cleaner not too long ago and saw all the labeling about the new formulation. I just looked up what the old formulations used to look like, check it out.

> Chlorinated brake cleaners (often sold as non-flammable) use organochlorides like tetrachloroethylene and Dichloromethane.

https://en.wikipedia.org/wiki/Brake_cleaner#Composition

Compared to the new formulation

https://www.crcindustries.com/products/brakleen-174-pro-seri...

so called 50 state compliant. https://www.crcindustries.com/products/brakleen-174-pro-seri...

Well shit, I always preferred the old fully chlorinated stuff because it works better. When you say "chlorinated" I assume that means it contains chlorine, which isn't great, but is more an issue for chemical burns than anything, so you wear gloves and eye pro and don't worry about it. I never looked into it. I've probably inadvertently exposed myself to a /ton/ of TCE working on cars and other mechanical things. I buy brake cleaner by the case...

Yah I chloro is used to communicate that a chlorine atom is somewhere present in the molecular structure of the compound. https://www.etymonline.com/word/chloro-

Degreaser is a common part of a car mechanics life. Especially so 30+ years ago where it was more common to clean and replace parts than now when it's more usual to just replace any removed part.

This is counter-intuitive but I guess there are cases where throwing away the part and replacing with a new one is MORE environmentally friendly that reusing the part—when it involves not-so-nice solvents. I hadn't considered this before.

Maybe. Depends on how environmentally friendly manufacturing, packaging and transporting the new part is. I suspect it’s a win in chemical terms most of the time, but it may not be an overall blowout win.

I did a 23 and Me test and never unlocked the health results. I'm a little terrified of finding out that dementia is in my future as well.

I was in almost the identical boat but I pulled the trigger on looking at the test results, ended up fine. Better to know and try to manage it I think.

Intellectually, I know you're right.

There's also the angle that if I want to buy life insurance I may be better off not knowing.

After seeing how it's affecting my dad, I know how I'd "manage" it. It really is awful and decades of mental decline coupled with terrifying hallucinations is not something I'm willing to endure.

> buy life insurance I may be better off not knowing.

I think it’s moot because life insurance will check your genes as part of underwriting.

In the US genes can’t be used to discriminate for employment or healthcare [0], but can for everything else.

I got a quote for term insurance in 2008 and they tested for lots of genetic conditions.

You can probably get by if you have unique, rare mutations that aren’t commonly studied. But anything basic enough to be found in a 23andme profile is likely to be checked by your insurance.

[0] https://en.wikipedia.org/wiki/Genetic_discrimination

The life insurance angle is real, but the solution isn’t to wait, it’s to get into the plan before you find out. You can always stop the plan if you think your risks aren’t as high later when you know more!

If he used a lot of brake cleaner or carburator cleaner then likely yes. Either TCE or a similar chlorinated solvents.

Both Parkinson's and Dementia with Lewy Bodies mostly occur without family history, so the test may not say much anyway.

In my mom's case I wonder about a viral infection she had in her eye. It was quite severe.

> mostly occur without family history

Does that suggest it's environmental rather than genetic?

Even genetic diseases sometimes need environmental influences to develop.

For example, some people are prone to alcoholism in a hereditary way. But if they live in a society that has zero alcohol, they won't ever become alcoholic. Upon moving to a society where alcohol is sold freely and frequently, they may sink into alcoholism without having any obviously alcoholic ancestor.

I don't know really.

I think the cutting edge opinion is that it isn't known why they occur.

Not necessarily. A homozygous recessive disorder often occurs without prior family history.

Two carriers have a child together, the child has the disorder, this is how they learn they are carriers.

I'm sorry to hear that.

TCE is a degreaser which is used to clean car parts so most likely.

There is also the interesting process of chemical Oxidation, which occurs naturally, and with environmental clean up. ( Various treatment processes: ozonation, peroxide injection, etc.) The break down by products of complex chemicals, are often more toxic (long term hazard to organisms, including humans.) For example, Tetra fluoroethylene, may easily breakdown down to Tri fluoroethylene. There are even more toxic by products, further down the break down chain. Soil chemistry is very complicated, and interesting. EPA has very good articles following these processes across hundreds of superfund sites, across the USA.

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