Exposure to a large-scale disaster affects people’s health even more than a decade later, according to a new study by a multidisciplinary team of researchers from the United States and Indonesia. The research was published in the journal Proceedings of the National Academy of Sciences.

The research studied women living along the coast of Aceh province in Indonesia when it was hit by the waves of the 2004 tsunami.

They found that 14 years later they had lower cortisol levels than women living in other nearby coastal communities, which were not immediately affected.

Cortisol is a stress hormone produced by the adrenal glands. Cortisol levels rise in response to stress caused by the fight or flight response. However, constant increased stress can lead to dysfunction of the hypothalamus-pituitary-adrenal axis (HPA axis), one of the most important functional systems of the body, which is responsible for ensuring the balance of the body. This particular study links stress from tsunami exposure to the “burnout” of this axis, manifested by low cortisol levels in the long term.

For the research, hair samples were collected from adults 14 years after the tsunami. “An important finding is that people with low cortisol levels have worse physical and psychosocial health 14 years after the tsunami, evidence of the long-term effects of the stress caused by the tsunami and its aftermath,” says Duncan Thomas, one of the leaders of research.

“The lessons we learned from following people in Aceh for 20 years provide important insights into the potential long-term effects of climate change on populations in the US and around the world,” notes Elizabeth Frankenberg, also principal investigator.