Riccardo Liguori In the 1990s, the use of diclofenac decimated the bird of prey population. A study reveals the link between this ecological catastrophe and increased human mortality
@Canva
It may sound like science fiction, but the disappearance of vultures in India is having devastating consequences for human health and the country’s economy.
The reason is simple: these birds clean up infected carcasses and, by doing so, reduce populations of other scavengers like wild dogs, which can spread diseases such as rabies. Additionally, without vultures around, farmers dispose of dead livestock by dumping them in water sources.
This is evidenced by a study currently available as a working paper and soon to be published in the American Economic Review, which indicates that the near-extinction of these birds in the 1990s has led to annual economic damages of $70 billion.
The crucial role of vultures in the ecosystem
Often considered repugnant and associated with death, vultures play a crucial role in maintaining ecosystem balance. In India, where the cattle population exceeds 500 million, vultures have historically been essential to public health.
Diclofenac: the Poison that decimated vultures
In the 1990s, the introduction of diclofenac, a nonsteroidal anti-inflammatory drug used in livestock, had a devastating impact on vultures that fed on their carcasses. In just over a decade, their population plummeted by 99%, from 50 million to just a few thousand.
Half a million deaths and $70 billion in damages
The study, conducted by Anant Sudarshan, an environmental economist at the University of Warwick, and Eyal Frank, an environmental economist at the University of Chicago, estimated that the disappearance of vultures caused over 500,000 human deaths in India between 2000 and 2005.
To establish this, the researchers overlaid maps of vulture habitats with those of Indian administrative districts and examined medical records from over 600 districts.
Before 1994, human mortality rates in the examined districts averaged about 0.9% per 1,000 people. By 2005, areas that traditionally hosted large numbers of vultures saw a 4.7% increase in human mortality rates, equating to approximately 104,386 additional deaths per year. Meanwhile, mortality rates in districts not typically home to vultures remained stable at 0.9%.
Additionally, the economic damages caused by disease spread and water pollution were estimated at around $70 billion per year. The team calculated this based on the economic value that Indian society places on saving a single life.
In 2006, the Indian government decided to ban the use of diclofenac. This was undoubtedly an important step in the right direction, but the recovery of the vulture population will be long and challenging.
