Hominins suffered lead poisoning starting at least 2 million years ago

New research reveals that our early hominid ancestors were not just struggling against the harsh realities of the Pleistocene era but were also contending with the dangers of lead poisoning. While many might associate lead exposure with modern times, particularly with the practices of ancient civilizations like the Romans, this study suggests that the issue extends back nearly two million years. A team led by paleoanthropologist Renaud Joannes-Boyau from Southern Cross University in Australia discovered significant evidence of lead exposure in the teeth of ancient apes and hominins. This exposure, they argue, may have played a role in shaping the evolutionary path of our genus, Homo. The researchers analyzed samples of enamel and dentin from the teeth of 51 fossils, uncovering alarming traces of lead. Their findings indicate that these early beings frequently encountered dangerous levels of lead during their formative years. Tooth enamel, which develops in layers similar to tree rings, holds a record of an individual's health during childhood. The presence of lead-tainted enamel suggests considerable lead exposure during the years when those layers were formed. In fact, in 71 percent of the sampled hominin teeth, researchers found noticeable dark bands indicative of episodic lead exposure during critical childhood stages. This included specimens from our own species, Homo sapiens, dating back 100,000 years in China, as well as Neanderthal remains from France that are around 250,000 years old. Additionally, earlier hominins from South Africa, including members of our genus and relatives like Australopithecus africanus and Paranthropus robustus, also exhibited these signs of lead exposure, illustrating that the problem is indeed ancient and pervasive.