# "Keys contain lead." ..WTF? **URL:** \ **Category:** Factual Questions\ **Created:** [September 25, 2016, 5:48am UTC](https://boards.straightdope.com/t/keys-contain-lead-wtf/766800 "2016-09-25T05:48:48Z")\ **Posts on this page:** 3\ **Page:** 3
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [December 12, 2023, 7:10pm UTC](https://boards.straightdope.com/t/keys-contain-lead-wtf/766800/41 "2023-12-12T19:10:16Z")
> [@Yllaria](#): > > When Caltrans buys additional land to widen highways, the soil near the highway must first be tested for lead contamination from car exhaust. It’s part of the environmental clearance before the purchase can be completed. I’d bet at least some of the contamination is due to decades of lead wheel-balancing weights falling off of moving cars. Either way, out of curiosity, how often do these tests reveal problematic concentrations of lead in the roadside soil? > [@jz78817](#): > > We phased out leaded gas decades ago. Not completely. Most piston-engined aircraft still burn 100-octane, low-lead (100LL) “avgas”. > **[Avgas](https://en.wikipedia.org/wiki/Avgas#100LL)** > > Avgas (aviation gasoline, also known as aviation spirit in the UK) is an aviation fuel used in aircraft with spark-ignited internal combustion engines. Avgas is distinguished from conventional gasoline (petrol) used in motor vehicles, which is termed mogas (motor gasoline) in an aviation context. Unlike motor gasoline, which has been formulated without lead since the 1970s to allow the use of catalytic converters for pollution reduction, the most commonly used grades of avgas still contain tet... The piston engines on general-aviation aircraft (not the gas-turbine engines used on turboprop or jet aircraft) need high-octane fuel to get the best power-to-weight ratio they possibly can. They need an octane booster to do this, and tetraethyl lead has been the go-to solution for a century. That’s likely to change very soon: [https://www.epa.gov/newsreleases/epa-determines-lead-emissions-aircraft-engines-cause-or-contribute-air-pollution](https://www.epa.gov/newsreleases/epa-determines-lead-emissions-aircraft-engines-cause-or-contribute-air-pollution) ---
**Author:** ![Yllaria](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yllaria/32/3452_2.png) [@Yllaria](https://boards.straightdope.com/u/Yllaria)\ **Post date:** [December 12, 2023, 8:29pm UTC](https://boards.straightdope.com/t/keys-contain-lead-wtf/766800/42 "2023-12-12T20:29:24Z")
> [@Machine\_Elf](#): > > Either way, out of curiosity, how often do these tests reveal problematic concentrations of lead in the roadside soil? I don’t work for Caltrans, so I don’t really know. I only know about the tests because of a joint project where the city did the right of way (ROW) acquisition. Years after the joint work contract was signed, when the ROW parcels were being transferred to Caltrans, they tried to make us do new environmental documents because, among other things, the lead testing had been added. Fortunately the contract specified that we had to meet ROW requirements as documented in 2001, and that was already done. So they did the tests themselves. ---
**Author:** ![MikeF](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@MikeF](https://boards.straightdope.com/u/MikeF)\ **Post date:** [December 12, 2023, 11:08pm UTC](https://boards.straightdope.com/t/keys-contain-lead-wtf/766800/43 "2023-12-12T23:08:00Z")
> [@Tim\_T-Bonham.net](#): > > you probably absorb more lead by breathing in the exhaust fumes from traffic on your commute to & from work. Or eating dark chocolate "CR tested a mix of brands, including smaller ones, such as Alter Eco and Mast, and more familiar ones, like Dove and Ghirardelli. For 23 of the bars, eating just an ounce a day would put an adult over a level that public health authorities and CR’s experts say may be harmful for at least one of those heavy metals. Five of the bars were above those levels for both cadmium and lead. Read more about [how CR tested dark chocolate] "😵([https://article.images.consumerreports.org/image/upload/v1672933163/prod/content/dam/CRO-Images-2022/Special%20Projects/Consumer\_Reports\_Test\_Methodology\_for\_Heavy\_Metals\_in\_Chocolate\_Bars\_-\_January\_2023.pdf](https://article.images.consumerreports.org/image/upload/v1672933163/prod/content/dam/CRO-Images-2022/Special%20Projects/Consumer_Reports_Test_Methodology_for_Heavy_Metals_in_Chocolate_Bars_-_January_2023.pdf)) [Previous page](https://boards.straightdope.com/t/keys-contain-lead-wtf/766800.md?page=2)