In recent years the ability of chemical scientists to create new molecules and transform existing ones has greatly contributed to preserving our environment. Since the 1960s chemists have engineered new pesticides that break down more rapidly instead of accumulating in soil and water. Two chemists, Marinus Los (1933– ) of American Cyanamid and John E. Franz (1929– ) of Monsanto, devised new herbicides—necessary for ensuring an abundant food supply for a growing world population—that do not harm the environment.
Los discovered another class of herbicidal compounds that are not toxic to humans and animals—imidazolinones. He was born in the Netherlands but emigrated as a boy with his family to Great Britain, where he received most of his education, including bachelor's and doctoral degrees in chemistry from the University of Edinburgh. After a postdoctoral fellowship in Canada he joined the agricultural division of American Cyanamid, where he worked for his entire career, except for a brief return to the University of Edinburgh as a research professor. In the early 1970s, while screening thousands of existing American Cyanamid chemicals for substances that would regulate plant growth, Los noted that one seemed to have herbicidal potential, so he made modifications in its molecular structure to enhance this capability. The first imidazolinone was actually created later when Los was trying to reproduce a substance that had crystallized out of a solution of the original herbicidal agent prepared for testing on crops. The new herbicides, introduced in 1985, need only be applied in ounces per acre, a property that has drastically reduced the amount of herbicide used. These highly selective and effective compounds allow farmers to increase yields while helping to preserve our land, water, and wildlife.