‘Endocrine disruptor’ is a term originally used to refer to certain substances that were found to cause harmful effects in some species of wildlife by interfering with the functioning of their hormones.
Hormones are naturally-occurring substances produced in the body as part of the ‘endocrine’ system. They act as chemical messengers which help control a wide range of processes ranging from reproduction to immunity, metabolism and behaviour.
Known effects on wildlife
The first noticed effects included changed sexual characteristics in alligators affected by persistent pesticides (now banned) in lakes polluted with waste.
In the UK, feminisation of fish has been seen in rivers near sewage works, mainly due to natural female hormones and the contraceptive pill in the sewage effluent.