Analysis of authenticated locks clipped from Ludwig von Beethoven’s prodigious head of hair as he lay dying has found astronomically high levels of lead, arsenic and mercury. The poisoning was so severe, it may explain the symptoms that plagued him at the end of his life.

Researchers at the Ira F. Brilliant Center for Beethoven Studies at San Jose State University sampled five locks of hair previously confirmed as Beethoven’s by DNA analysis and subjected them to poison testing. The owner of three of the locks, Australian businessman and Beethoven afficionado Kevin Brown, sent two locks, one collected between 1820 and 1827, the other in April 1826, to a Mayo Clinic lab where they were tested for the presence of heavy metals.

The result, said Paul Jannetto, the lab director, was stunning. One of Beethoven’s locks had 258 micrograms of lead per gram of hair, and the other had 380 micrograms.

A normal level in hair is less than 4 micrograms of lead per gram.

“It definitely shows Beethoven was exposed to high concentrations of lead,” Jannetto said.

“These are the highest values in hair I’ve ever seen,” he added. “We get samples from around the world, and these values are an order of magnitude higher.”

Beethoven’s hair also had arsenic levels 13 times what is normal and mercury levels that were 4 times the normal amount. But the high amounts of lead, in particular, could have caused many of his ailments, Jannetto said.

The composer was famously suffering from hearing loss — he had been functionally deaf since he was 30, 26 years before he died — and he was also afflicted with chronic gastrointestinal problems (painful abdominal cramps, flatulence, diarrhea). High levels of lead damage the human nervous system, which could have caused his deafness, also cause liver and kidney damage. It may also have played a role in some of his other issues, like his notoriously terrible temper, memory lapses, and chronic clumsiness.

This is not an Agatha Christie case. The lead levels were not high enough to be fatal, and there is no reason to believe he was deliberately poisoned, but rather was exposed to the poisons in his daily environment. Lead, arsenic and mercury were in a lot of things people lived with, ate and drank, from food to medicine to wallpaper. He spent decades taking dozens of different types of nostrums in the attempt to cure his deafness and chronic illnesses, and they certainly contained lead, among many other poisons.

One likely source of Beethoven’s high levels of lead was cheap wine. Lead, in the form of lead acetate, also called “lead sugar,” has a sweet taste. In Beethoven’s time it was often added to poor quality wine to make it taste better.

Wine was also fermented in kettles soldered with lead, which would leach out as the wine aged, Nriagu said. And, he added, corks on wine bottles were presoaked in lead salt to improve the seal.

Beethoven drank copious amounts of wine, about a bottle a day, and later in his life even more, believing it was good for his health and also, Meredith said, because he had become addicted to it. In the last few days before his death at age 56 in 1827, his friends gave him wine by the spoonful.

This research fulfills a wish Beethoven expressed in 1802 to his brothers. He asked that after his death, they get his doctor to tell the world about his struggle with progressive hearing loss in the hope that “as far as possible at least the world will be reconciled to me after my death.”