S

ynthetic and naturally occurring chemicals released
into the environment can have disastrous effects on
reproduction, and are becoming a matter of global
concern. These environmental endocrine disruptors
(EEDs) have major impacts on sexual development
in humans as well as populations of wild animals.
EEDs have been identified in many everyday items, including
plastic bottles and food containers, canned foods, fresh foods,
detergents, toys, cosmetics and pesticides. Some EED
compounds naturally occur in introduced plant species such
as soya and subterranean clover. Many of these compounds are
commonly used in agriculture, suburban environments and in
the home.

EED levels in the Australian environment are on the rise, and

in many instances exceed levels known to have devastating

effects on animal populations in the USA and Europe. EED

levels are especially high in areas surrounding intensive live-

stock operations, in waterways surrounding wastewater treat-

ment plants, paper mills and in agricultural areas.

With reduced rainfall and extended drought conditions

becoming a regular event over much of Australia, these toxic

chemicals can become highly concentrated in catchments,

posing a significant risk to many native species dependent on

such resources.

It is now widely accepted that many diseases and develop-

mental disorders observed in mammals are the result of expo-

JAN/FEB 2016|| 35

Reproductive Threats

to Australia’s Marsupials

ANDREW PASK

Chemicals used in agriculture, industry and household goods can have effects on marsupial

fertility as profound as sex reversal.

Marsupials are especially sensitive to alterations to their hormonal environment during development. These hormonal alterations can

have a profound effect on sex determination, causing sex reversal in some cases and reduced fertility. Credit: Marilyn Renfree/Geoff Shaw