Media centre

Our lives depend on a healthy planet

Dr Maria Neira, WHO Director, Department of Public Health, Environmental and Social Determinants

Commentary
3 June 2015

Every day we depend on biodiversity (the sheer variety of life found on Earth) to keep us alive and healthy. The air we breathe, the water we drink, the foods we eat and the medications we take are all by-products of a healthy planet.

But our world, and the diversity of life it supports, is under threat. Deforestation, pollution, greenhouse gas emissions, draining of wetlands, climate change, globalization and other factors of modern life are wiping out species and damaging ecosystems at unprecedented rates.

When we damage the Earth, we damage our own health. Human beings are as susceptible as any other species.

"Many of the global health challenges that we face today, including infectious diseases, malnutrition and noncommunicable diseases, are all linked to the decline of biodiversity and ecosystems."

Dr Maria Neira, WHO Director, Department of Public Health, Environmental and Social Determinants

Every breath we take depends on another life, another species. Many of the global health challenges that we face today, including infectious diseases, malnutrition and noncommunicable diseases, are all linked to the decline of biodiversity and ecosystems.

When we think of the spread of infectious diseases, like malaria, we must think about the insect that helps transport the disease to humans— the mosquito. As forests are destroyed, mosquito diversity is being reduced and only the strongest species are surviving. And in many cases the strongest mosquito in the forest is the best at transmitting malaria.

Meanwhile, large-scale human transformation of the environment has also brought us in closer contact with wildlife that harbour many pathogens including the Ebola virus and Lyme disease.

1. Limits food, medicine production

As the world’s population continues to grow, competition for land and water resources to produce food, energy and housing is fierce.

We need a wide variety of animal and plant life for adequate human nutrition so that populations are neither malnourished nor obese. Rich biodiversity provides ecosystems with natural pest management, soils with nutrients needed for healthy crops, and the insects that are needed to pollinate plants like olive, almond and apple trees.

We rely on biodiversity to produce traditional medicines and aide in the development of pharmaceuticals that keep our communities healthy. Plant biodiversity provides both health and economic benefits, as plants have been the single greatest source of natural medicines to date – from aspirin to cancer drugs. When we lose plant species, we lose the opportunity to discover potential drugs in the future.

2. More air pollution, less clean water

Changes to the environment also threaten our supply of freshwater. Ecosystems help regulate the flow of water and help regulate the amount of sediments and contaminants in our water resources. It is estimated that more than 768 million people still rely on unimproved water supplies that often have high levels of contamination. Loss of biodiversity reduces the planet’s ability to cleanse itself of these contaminations, bringing about waterborne and water-related diseases.

With continued urbanization, air pollution is causing harm to both human and ecosystem health. WHO estimates that 1 in 8 deaths globally is caused by air pollution, making it the world’s largest single environmental health risk. It is also damaging plant and tree life needed to help regulate air quality.

3. Protecting the living world

While biodiversity lies outside the traditional roles of the health sector, it is vital for those of us working in public health to partner with other sectors, particularly those working in conservation and the sustainable use and management of natural resources, to ensure human health is at the forefront of environmental policies.

Since 2000 the world has been making progress on the Millennium Development Goals. People have been brought out of poverty, access to safe water has been increased, and the spread of HIV and malaria has been reduced. But, the global health challenges we will face in the coming years will stem from how well we manage and respond to environmental changes resulting in biodiversity loss.

Together with the Convention of Biological Diversity, WHO recently launched a new report - Connecting Global Priorities: Biodiversity and Human Health, a State of Knowledge Review. We hope this report will provide a useful reference as we move into the Sustainable Development Goals and post-2015 development agenda. As the world adopts new goals, it has a unique opportunity to highlight biodiversity’s role as a key foundation for both sustainable development and human health.

Today, on World Environment Day let’s urge everyone to take action to keep our planet healthy. All of us have a role to play. It starts with protecting our natural resources and consuming with care. After all, there is only one Earth, but more than 7 billion lives depending on its precious resources.