That’s the point- DDT was *never* about harm to humans, but harm to birds. But so many posters here say ‘well it didn’t hurt me’-well, no. you or I can practically drink the stuff. Other animals in the ecosystem, such as birds, not so much
Actually the birds in the study were given a diet low in calcium, known to produce thin shelled eggs. The thin shelled eggs were then blamed on DDT. see:
https://www.acsh.org/news/2016/02/11/how-poisonous-is-ddt
https://www.wsj.com/articles/SB116727843118861313