There was a small series of these ads in the 1950s. This was before a big public awareness campaign about the dangers of asphyxiation from thin plastic, especially to small children. While the material technically dates to the early 1900s, it was still new to the public in the 1950s, who had not yet come to appreciate its dangers.

In 1959, New York City Health Commissioner Leona Baumgartner, herself a physician, staged a famous and viscerally disturbing photo of her own face wrapped in a thin plastic bag, to vividly illustrate the risk. I'll link it here, but not inline it.

Also in the 1950s, the risks to wildlife from improperly disposed plastics was not widely understood, a critical problem that persists to this day for both ocean and land animals.