That may be far too grandiose and speculative, but there was no doubting that there was so much more lead in the modern world, and it seemed to have appeared only recently. But why? And how?
In a Eureka moment, Patterson realized that the time frame of atmospheric lead's rise he was seeing in his samples seemed to correlate perfectly with the advent of the automobile, and, more specifically, with the advent of leaded gasoline.
Leaded gas became a thing in the 1920s. Previously, car engines were plagued by a loud knocking sound made when pockets of air and fuel prematurely exploded inside an internal combustion engine. The effect also dramatically reduced the engine's efficiency. Automobile companies, seeking to get rid of the noise, discovered that by adding tetraethyl lead to gasoline, they could stop the knocking sound, and so-called Ethyl gasoline was born. "Fill her up with Ethyl," people used to say when pulling up to the pump.
. . .
When Patterson published his findings in 1963, he was met with both applause and derision. The billion-dollar oil and gas industry fought his ideas vigorously, trying to impugn his methods and his character. They even tried to pay him off to study something else. But it soon became apparent that Patterson was right. Patterson and other health officials realized that If nothing was done, the result could be a global health crisis that could end up causing millions of human deaths. Perhaps the decline of civilization itself.
Patterson was called before Congress to testify on his findings, and while his arguments made little traction, they caught the attention of the nascent environmental movement in America, which had largely come into being as a result of Rachel Carson's explosive 1962 book Silent Spring, which documented the decline in bird and other wildlife as a result of the spraying of DDT for mosquito control. People were now alert to poisons in the environment, and they'd come to realize that some of the industrial giants that were the foundation of our economy were also having serious impacts on the planet's health.

Smog in Los Angeles in 1970. (Courtesy of UCLA Library Special Collections - Los Angeles Times Photographic Archive)
Downtown Los Angeles today. (Erik Olsen)