Greatest health tool or a hazard? - June 16

X?

A few facts about X quoted below:

X became one of the greatest public health tools of the 20th century.

Overuse harmed its efficacy -- and made it politically unpopular.

Population control advocates blamed X for increasing third world
population. In the 1960s, World Health Organization authorities believed there
was no alternative to the overpopulation problem but to assure that up to 40
percent of the children in poor nations would die of the disease that X
controlled spread of. As an official of the Agency for International Development
stated, "Rather dead than alive and riotously reproducing."

X amongst other things was alleged to have thinned bird egg shells.