EACH DAY, millions of people across the world drink water from faucets and don't think twice about its purity because of a simple chemical process Abel Wolman developed with a classmate in 1918, three years after they graduated from college.
They added small, measured amounts of chlorine, an otherwise toxic substance, to drinking water to kill microorganisms that cause life-threatening diseases.
This celebrated discovery, which dramatically cut disease and improved world health, marked the beginning of an extraordinary career in environmental engineering and public health.
For nearly 75 years, as a sanitary engineer, scientific researcher, Johns Hopkins University professor, consultant and adviser to governments here and abroad, Wolman's work made the world a healthier and more livable place.
The quick disappearance of typhoid as a major killer in Maryland illustrates the magnitude of his early discovery.
Typhoid fever was a common disease in Maryland in 1915 when Wolman joined the Maryland Department of Health as an assistant engineer. By 1930 -- 12 years after Wolman helped perfect the chlorination technique, typhoid cases had dropped 92 percent. This astounding change was replicated throughout the world.
Wolman's accomplishments did not end there. He had the unique ability to devise narrow and broad solutions to problems.
He was one of the first to understand that technical engineering questions had broad public health implications. When Wolman was in his early 30s, he simultaneously edited the Journal of the American Water Works Association and the American Journal of Public Health. As the first chairman of Hopkins' department of sanitary engineering, he received a joint appointment at the School of Public Health and Hygiene.
Wolman had a prodigious intellect and appetite for work. While Maryland's top sanitary engineer during the Depression, he simultaneously chaired the state Planning Commission in charge of capital improvements and served both the Federal Emergency Administration and the Public Works Administration as chief engineer in Delaware and Maryland.
From these posts, he supervised activities as varied as installing kitchen sinks in hospitals, transplanting oysters and overseeing construction of the Gunpowder-Montebello water tunnel, Montebello Filtration Plant, Friendship Airport and Frederick's sewage treatment system.
He also conceived and designed Prettyboy and Liberty reservoirs and the Susquehanna water tunnel.
Until his death in 1989, Wolman served as an unpaid adviser to Baltimore mayors and Maryland governors on public works. He remained a consultant to 50-plus governments overseas.
Long before the nation's environmental movement, Wolman studied the pollution of rivers, lakes and estuaries.
Under his direction, Maryland became a leader in integrating conventional sanitary engineering with wildlife, recreation and public works construction. He brought this same perspective to the national level, heading the Water Resources Committee of the National Resources Board in 1935.
As part of the U.S. delegation that set up the World Health Organization, Wolman made sure environmental health was an important component of WHO's mission. He was one of the first engineers to push the Atomic Energy Commission to focus on the public-health implications of nuclear power.
Perhaps Wolman's most lasting influence was through his teaching. By 1937, when he received his joint appointment at Johns Hopkins and the School of Public Health and Hygiene, Wolman had already influenced one generation of students. By the time he died in 1989, he had instructed thousands of others who spread his wisdom worldwide.
As dedicated as Abel Wolman was to creating pure water, he understood the world was an imperfect place.
"The belief that cleanliness is an absolute rather than a relative concept makes the health officer's lot not a happy one," he said. "Life in a sterile environment -- whether physical, chemical, biological or psychological -- is both improbable and undesirable."