It’s so much worse than the headline. IIRC, mercury and lead (among others like just straight ass white paint) were used as whitening agents, and the milk was specifically marketed towards immigrants as an affordable and nutritious infant food. It caused a huge scandal at the time and (shooting from the hip here, double checking encouraged) prompted NY to implement some of the first food health laws in the US. I can’t help but think that this is the kind of market innovation we’ll get as republicans ‘deregulate’.