Greenland’s human history spans multiple cultures, from Paleo-Inuit groups around 2500 BCE to Norse settlers and later Danish arrivals. These populations left behind middens, or ancient refuse heaps containing animal bones, waste, shells and artifacts that offer valuable archaeological insights.
Microbiologists are now examining these sites to identify historic diseases, track livestock presence and assess potential risks from thawing permafrost as the Arctic warms rapidly. A recent study concluded that the chance of ancient pathogens escaping from Greenland’s middens remains low at present.
Instead, the frozen deposits function as long-term natural records. Bacterial traces linked to humans and animals, including some carrying antibiotic resistance genes, persist centuries later, reflecting past activities such as Norse farming.
In 2020 and 2021, researchers sampled several permafrost-preserved middens across West and South Greenland spanning 4,500 years. They also gathered soil from former livestock areas at Norse sites. DNA sequencing identified 1,207 bacterial species, many previously unknown. Middens showed richer microbial communities than nearby undisturbed soils, preserving clear signs of human and animal presence.
Bacterial makeup varied with waste type. Some contained bacteria associated with seal remains or animal carcasses, while others held species linked to human waste. Diverse antimicrobial resistance genes were detected, yet these microbes appear unlikely to spread widely from thawing sites.
Overall, local environmental bacteria quickly replace ancient ones once released, suggesting limited immediate public health concerns.
