Yeah, something new to worry about. Man, talk about unintended consequences. So the "greenies" moved to try to ban all sorts of lead products from the environment, and that included electronics and the solder used to fuse those parts together. And look at what has now been unleashed:
https://www.youtube.com/watch?v=SpYibOp4HeQ
The above video repeats after the 5:50 point, btw.
And for some technical papers:
https://nepp.nasa.gov/whisker/refere...r-Failures.pdf
https://nepp.nasa.gov/whisker/refere...ic-Pb-free.pdf
https://nepp.nasa.gov/whisker/refere...app-sensor.pdf