I think your example explains why the article is a potentially gray area of exploitation.
I think it's clear exploitation when you offer someone employment that adversely impacts their rights. So artisan cobalt-mining is exploitative, because of it's health effects, would go against the UN's definition of "the right to work in just and favourable conditions"[1]. However, I'm not sure what, if any, rights are being compromised by the topic in the article. Maybe there's a case that it's unjust because of the asymmetry in the value created and payment. If there are some rights abuses, then it becomes a clearly exploitative endeavor.
I think it's clear exploitation when you offer someone employment that adversely impacts their rights. So artisan cobalt-mining is exploitative, because of it's health effects, would go against the UN's definition of "the right to work in just and favourable conditions"[1]. However, I'm not sure what, if any, rights are being compromised by the topic in the article. Maybe there's a case that it's unjust because of the asymmetry in the value created and payment. If there are some rights abuses, then it becomes a clearly exploitative endeavor.
[1] https://www.un.org/en/global-issues/human-rights