'But the most productive plasma centres are clustered along the southern border, where Mexican citizens cross over to sell plasma in the US. “Our political leaders like Trump don’t want them in the United States but we have been allowing people to cross over to mine their bodies for blood plasma, so what does that say about us?”

https://www.theguardian.com/books/2023/mar/02/blood-money-book-kathleen-mclaughlin