- Changes to the environment that are sweeping the planet
are bringing about a rise in infectious diseases, the United Nations Environment
Programme (Unep) has warned.
-
- Loss of forests; the building of roads and dams; urban
growth; the clearing of natural habitats for agriculture; mining; and pollution
of coastal waters are promoting conditions under which new and old pathogens
can thrive, according to research published today in Unep's Global Environment
Outlook Year Book for 2004/2005.
-
- Ailments previously unknown in human beings are appearing,
such as the Nipah virus, which until recently was found normally in Asian
fruit bats, according to the report.
-
- Nipah's emergence in the late 1990s as an often fatal
disease in humans has been linked to a combination of forest fires in Sumatra
and the clearance of natural forests in Malaysia for palm plantations.
In searching for fruit, bats were forced into closer contact with domestic
pigs, giving the virus its chance to spread to humans.
-
- Climate change in particular may aggravate the threats
of infectious diseases in three ways, the report suggests. First, by increasing
the temperatures under which many diseases and their carriers flourish.
-
- Second, by further stressing and altering habitats. For
example, the geographic range and seasonality of two of the world's most
serious mosquito-borne infections, malaria and dengue fever, are very sensitive
to changes in climate. Also, Neissseria meningitidis, a common cause of
meningitis, can be spread many miles in the dusty conditions that occur
following prolonged drought in the Sahel.
-
- Third, climate change may increase the number of environmental
refugees who are forced to migrate to other communities, or even countries.
This in turn will also favour the spread of diseases from one location
to another.Overall, it seems that intact habitats and landscapes tend to
keep infectious agents in check.
-
- The issue of environmental degradation and a rise of
many new and old infectious diseases is a complex, sometimes subtle one
that is causing increasing concern among scientists and disease specialists.
-
- Many scientists are now convinced that ecological disruption,
dramatic environmental change, and poor handling of human and animal wastes
are playing an important part in the spread of diseases such as malaria,
bilharzia, Japanese encephalitis, and dengue haemorrhagic fever.
-
- The report is based on research by some of the leading
specialists. They include Tony McMichael of the Australian National University,
Bernard Goldstein of the University of Pittsburgh and Jonathan Patz of
the University of Wisconsin.
-
- ©2005 Independent News & Media (UK) Ltd.
-
- http://news.independent.co.uk/
|
