Throughout the 1920s a scientist named Morris Kharasch filed a blizzard of applications with the U.S. Patent Office.
In 1924: "The present invention relates to the production of water soluble organo-metallic compounds ... including mercury. ... This invention is of particular importance in connection with the organic compounds having germicidal or therapeutic value."
In 1926: "This invention relates to the treatment of infections of soil, and more particularly to the use of mercury and other compounds in conjunction with a fertilizer and its application to the infected soil."
Kharasch, who died in 1957, is widely known for work reflected in that 1924 patent: the creation of thimerosal, the ethyl-mercury-based preservative used in a wide range of medical products including vaccines. It allowed for multidose vials and mass vaccination.
Less recognized is his invention of similar ethyl-mercury applications for fungicides, reflected in that 1926 patent for "the treatment of infections of soil."
Until now, a possible link between ethyl mercury and autism has focused on vaccines. But what about fungicides? In the last column we outlined a new theory by Mark Blaxill, research chair of the advocacy group SafeMinds.
Blaxill's theory is simple: The possibility of fungicide exposure connects some of the first 11 cases diagnosed by child psychiatrist Leo Kanner. The most striking: Case 2, the son of a plant pathologist, and Case 3, the son of a forestry professor at a southern university.
Case 1, Donald T., grew up in a small Mississippi town surrounded by land that was being heavily planted with tree seedlings by the Civilian Conservation Corps.
The idea that ethyl mercury -- in vaccines or anything else -- causes autism is hotly debated. The notion has been firmly rejected by the Centers for Disease Control and Prevention and the Institute of Medicine, part of the National Academies of Science. (In 1999 manufacturers were asked to phase out thimerosal in routine childhood vaccines; fungicides no longer use mercury.)
No one doubts, however, that ethyl mercury is a potent neurotoxin especially dangerous to the developing brains of infants. The question: Did "domesticating" it inadvertently trigger the age of autism?
"What's fascinating is if you look at the natural history of autism and ethyl mercury, there's a pretty interesting coincidence in time and place," said SafeMinds' Blaxill.
-- A trademark for "Merthiolate," the brand name for thimerosal, was filed in 1928. Kharasch was the inventor. Innovations included water solubility, compound stability and effectiveness.
-- A trademark for "Ceresan," an ethyl-mercury-based fungicide, was filed in 1929. Kharasch and Max Engelmann were the inventors. Innovations included organic mercury usage, methods of delivery and compound stability.
-- The oldest child diagnosed with autism was Virginia S., born in 1931. That is the first year records refer to thimerosal in vaccines.
-- In Europe, the first child that pediatrician Hans Asperger diagnosed with a similar disorder was Fritz V., born in 1933. His mother talked of trips to her "beloved mountains."
-- A German company manufactured a brand of ethyl-mercury fungicide.
Blaxill notes that Kharasch's work had enormous impact. He was a founder of the Journal of Organic Chemistry and a member of the National Academy of Sciences.
"Kharasch came to Chicago from the Ukraine at the age of 13, and spent most of his professional career at the University of Chicago," according to the Web site of the University of Michigan Chemistry Department. "Kharasch brought free radicals, previously considered esoteric species, into the mainstream of organic chemistry.
"Kharasch made pioneering studies on organomercurials important in agriculture (as seed disinfectants) and medicine (the antiseptic merthiolate)."
We asked Boyd Haley, a professor and former chair of the chemistry department at the University of Kentucky, to look at the early ethyl mercury fungicide and thimerosal patents.
"You're on to something," said Haley, who is controversial for his belief that mercury is behind a range of neurological disorders including autism.
"The whole problem -- and if you read these patents, it just jumps out at you -- is that ethyl mercury was not water-soluble. You had no delivery. All Kharasch did was really very simple straightforward chemistry. He coupled ethyl mercury to an organic acid to make it water-soluble."
Haley speculated that if ethyl-mercury-based fungicides caused some of the early cases, it might have been because the fathers got it on their clothes, sprayed it on their gardens or used it in their labs to control fungus.
"If they ever took any home or got it on their hands, they could end up with big problems," Haley said.
Next, we'll look at other countries' use of fungicides for more possible dots to connect.
This ongoing series on the roots and rise of autism welcomes reader comment. E-mail: firstname.lastname@example.org