Mostly from mining and gas extraction. The source is nuclear decay of natural isotopes. See e.g. https://www.quora.com/What-are-main-sources-of-helium-gas http

Mostly from mining and gas extraction. The source is nuclear decay of natural isotopes. See e.g. https://www.quora.com/What-are-main-sources-of-helium-gas https://www.quora.com/What-are-main-sources-of-helium-gas