Research from over 75 years ago set today’s federal standard for nitrates in drinking water.

The baby girl had been born healthy. Eight pounds, eight ounces.

Then came the vomiting and crying. She wasn’t gaining weight. Her parents took her to the hospital, and again a few days later for diarrhea. Each time, the doctors sent her home with a new formula mixture, first substituting skim milk for evaporated milk, then one with soybean powder, suspecting a milk allergy.

Two days later, the parents rushed their daughter back to the hospital once more. The baby was drowsy. And her skin was turning blue.