Mourners gathered at a cemetery in what’s now western China around 2,500 years ago to inhale fumes of burning cannabis plants that wafted from small wooden containers. High levels of the psychoactive compound THC in those ignited plants, also known as marijuana, would have induced altered states of consciousness.
Evidence of this practice comes from Jirzankal Cemetery in Central Asia’s Pamir Mountains, says a team led by archaeologist Yimin Yang of the University of Chinese Academy of Sciences in Beijing. Chemical residues on wooden burners unearthed in tombs there provide some of the oldest evidence to date of smoking or inhaling cannabis fumes, the researchers report online June 12 in Science Advances. Rituals aimed at communicating with the dead or a spirit world likely included cannabis smoking, the team speculates.
Cannabis remains of comparable age have been found in several other Central Asian tombs, including a site in Russia’s Altai Mountains located about 3,000 kilometers northwest of the Pamir Mountains. But the discoveries at Jirzankal Cemetery offer an unprecedented look at how cannabis was initially used as a mind-altering substance, the researchers say. East Asians grew cannabis starting at least 6,000 years ago, but only to consume the plants’ oily seeds and make clothing and rope out of cannabis fibers. Early cultivated cannabis varieties in East Asia and elsewhere, like most wild forms of the plant, contained low levels of THC and other mind-altering compounds.
Some of the earliest evidence for people smoking marijuana comes from the Greek historian Herodotus, who wrote of cannabis smoking roughly 2,500 years ago on the Central Asian steppes, about 2,000 kilometers west of the Pamir Mountains. But a determination of exactly when and where high-THC cannabis plants first developed and which people first smoked cannabis has long eluded scientists.