Environment News Service  [Printer-friendly version]
December 9, 2005


[Rachel's introduction: "Human health is strongly linked to the
health of ecosystems, which meet many of our most critical needs,"
says Maria Neira of the World Health Organization. A new report, just
released, is "a wake-up call for healthcare professions around the
world," she says.]

GENEVA, Switzerland -- Sixty percent of the benefits that the global
ecosystem provides to support life on Earth -- fresh water, clean air,
abundant wildlife and a relatively stable climate -- are being
degraded or used unsustainably with negative effects on human health,
finds a new report released today by the World Health Organization

"Ecosystems and Human Well-being: Health Synthesis," explores the
complex links between the preservation of healthy and biodiverse
natural ecosystems and human health.

"Over the past 50 years, humans have changed natural ecosystems more
rapidly and extensively than in any comparable period in human
history," said Dr. Lee Jong-wook, director-general of the World Health

"This transformation of the planet has contributed to substantial net
gains in health, well-being and economic development," said Dr. Lee,
adding that not all regions and groups of people have benefited
equally from this process.

In the report, scientists warn that harmful consequences of ecosystem
degradation to human health are already being felt and could grow
worse over the next 50 years.

"The benefits should be acknowledged," said Dr. Carlos Corvalan of
Purdue University, WHO's lead author on the report. "But these
benefits are not enjoyed equally. And the risks we face now from
ecosystem degradation, particularly among poor populations directly
dependent on natural ecosystems for many basic needs, has to be

The Health Synthesis Report is WHO's contribution to the broader
Millennium Ecosystem Assessment, a four year series of studies and
reports, involving over 1,300 scientists, considering impacts on human
wellbeing, past, present and future.

Ecosystem services are absolutely vital to preventing disease and
sustaining good health, the Health Synthesis report emphasizes.

"Nature's goods and services are the ultimate foundations of life and
health, even though in modern societies this fundamental dependency
may be indirect, displaced in space and time, and therefore poorly
recognized," writes Dr. Lee in his Forward to the report.

Many serious human diseases have originated in animals, and so changes
in the habitats of animal populations that are disease vectors or
reservoirs, may affect human health, sometimes positively and
sometimes negatively, the report explains.

Sometimes the environmental circumstances leading to disease
transmission are complex. For example, the Nipah virus is believed to
have emerged after forest clearance fires in Indonesia drove carrier
bats to neighboring Malaysia, where the virus infected intensively
farmed pigs, and then crossed to humans.

Intensive livestock production, while providing benefits to health in
terms of improved nutrition, has also created environments favorable
to the emergence of diseases, the report points out. Increased human
contact with wild species and "bush meat" as a result of encroachment
in forests and changes in diet also create opportunities for disease

Trends ranging from forest clearance to climate-induced habitat
changes also appear to have impacted certain populations of
mosquitoes, ticks and midges, altering transmission patterns for
diseases like malaria and Lyme disease.

Deforestation also endangers health by intensifying the effects of
natural disasters such as floods and landslides, resulting in reduced
crop yields. This impairs the nutritional status of households and
diet deficiencies harm children's physical and mental development. In
turn, this can impair the livelihoods of farmers and limit the options
open to their children.

Pressures on ecosystems could have unpredictable and potentially
severe future impacts on health, the report states. Regions facing the
greatest risks include sub-Saharan Africa, Central Asia, parts of
Latin America, and certain areas in South and Southeast Asia.

Harm to ecosystems needed for human nutrition and safe drinking water
as well as dependence on solid fuels such as wood and charcoal are
viewed as some of the most serious problem areas.

Degradation of fisheries and agro-ecosystems are factors in the
malnutrition of some 800 million people around the world, the WHO
report finds, echoing the findings of many other reports from United
Nations and nongovernmental organizations. At least an additional
billion people experience chronic micronutrient deficiency.

Infectious waterborne diseases claim 3.2 million lives, approximately
six percent of all deaths globally. Over one billion people lack
access to safe water supplies, the report finds, while 2.6 billion
lack adequate sanitation.

Related problems of water scarcity are increasing, partly due to
ecosystem depletion and contamination, WHO warns in the report.

After cutting down the trees, charcoal production is the next step in
conversion of the Amazon rainforest to cattle ranching. Here a
charcoal burner's hut in the Brazilian state of Amazonia produces
solid cooking fuel. Burning it can lead to respiratory problems.

About three percent of the global burden of disease has been
attributed to indoor air pollution, a major cause of respiratory
diseases. Most of the world's population uses solid fuels to cook and
heat, a factor in deforestation as well as indoor air pollution.

On the other hand, health benefits are derived from having a full
complement of species, intact watersheds, climate regulation and
genetic diversity, the authors say. Stresses on freshwater sources,
food-producing systems and climate regulation could cause major
adverse health impacts.

"Human health is strongly linked to the health of ecosystems, which
meet many of our most critical needs," said Maria Neira, director of
WHO's Department for the Protection of the Human Environment.

Neira says the report is a wake-up call for healthcare professions
around the world. "We in the health sector need to take heed of this
in our own planning, and together with other sectors, ensure that we
obtain the greatest benefit from ecosystems for good health -- now and
in the future."

Copyright Environment News Service (ENS) 2005.