When Enrique Romero Jr. finishes his shift fulfilling online orders at a Fred Meyer grocery store in Bellingham, Wash., he often walks to a nearby plasma donation center. There, he has his blood drained, and a hydrating solution is pumped into his veins, a process that leaves him tired and cold.Mr. Romero, 30, said selling his plasma made him feel “like cattle.” But the income he earns from it — roughly $500 a month — is more reliable than his wages at Fred Meyer, which is owned by the grocery giant Kroger. His part-time hours often fluctuate, and he struggles to find enough money to cover his rent, his groceries and the regular repairs required to keep his 2007 …
