Biodiversity vital to human health

Straits Times 24 Oct 09;

PAEDIATRICIAN Aaron Bernstein spoke on the relationship between biodiversity and human health at this week's Asean Conference on Biodiversity at Republic Polytechnic.

He argues that biodiversity provides us with food, clean air and sources of medicine, and that its loss can have an impact on health, for example, the spread of infectious diseases such as the Nipah virus.

Dr Bernstein, 32, who studied human biology at Stanford University and trained in medicine in Chicago, is co-author of Sustaining Life: How Human Health Depends On Biodiversity, with Harvard Nobel laureate Eric Chivian.

He will give a public lecture on the same topic next Tuesday at 10am at the Singapore Botanic Gardens.

# How would you communicate the urgency of protecting biodiversity for human health to people in cities?

There are a couple of things. One is making the urban environment as biodiverse and rich as possible, so that people can see the difference between what was and what is.

(In 1995) in Chicago, where I grew up, hundreds and hundreds of people died in one summer because it was too hot.

Then the city started greening rooftops, planting these gardens on the tops of buildings. As a result, fewer people died of heat-related problems.

When people understand that something is important to their health, they see it in a very different way.

People in the rainforest know that cutting down trees and unsustainably harvesting things will damage their livelihood.

What people in urban centres don't understand is that their health depends on rainforests too - those rainforests store a huge amount of carbon, and cutting them down will have a huge impact on climate change.

# But often, people fail to conserve biodiversity not because they don't recognise its importance but because of their poverty and immediate needs. How do you solve that?

Governments need to do everything possible to relieve poverty, so these people can continue to live in a part of the world they have lived in forever, and not sacrifice the resource they know is critical to their survival.

In Ecuador, for example, there is some of the most pristine rainforest in the world.

The indigenous people who live there have been offered money for the oil there.

But would the developed world be willing to pay for this very small part of the rainforest so that these people do not have to sacrifice their resources?

# But how do you put a value on ecosystem services, and who pays for that?

The question of putting a value on ecosystem services is very dangerous. It suggests that by putting a price tag on nature, we can in the future somehow buy it back, which is a really dangerous thing to think about.

For example, how do you value (cancer drug) Taxol? In 1960, before the drug was discovered, you would have valued its source, the Pacific yew tree, at zero. In 2000, you would value it at $1.6 billion. But it could have gone extinct even before the drug was discovered.

I view ecosystem valuation as a necessary evil, because the political world operates on fiscal responsibility.

# You mention things going extinct before their benefits can be discovered - can you talk about that?

Gro Brundtland, the former director- general of the World Health Organisation, said: 'The library of life is on fire and we don't even know all the titles of the books yet.'

For instance, the gastric-brooding frog swallows its fertilised eggs and basically vomits young frogs, but the tadpoles aren't digested because they produce compounds that stop the stomach secreting acid.

That could have been key to treating peptic ulcer disease, but that research had to be stopped because both species of gastric brooding frogs went extinct in the 1980s.

Peptic ulcer disease affects tens of millions, costs billions of dollars to treat. In these frogs, we might have had a new way to treat these diseases. But they're gone. We cannot buy them back. We cannot put a price tag on them. We just can't.