Rising cancer levels in animals

Manmade chemicals are increasing cancer rates in animals - threatening some with extinction, according to a report published in Nature.

The report, 'Wildlife Cancer: a conservation perspective', said high cancer levels were found in wildlife populations living in environments heavily contaminated with chemicals.

It also said there was a danger that cancer levels could lead some species such as the Tasmanian devil into extinction.

'Relationships between tumour development and environmental contamination are strongly suggested by scientific data,' said report authors Denise McAloose and Alisa Newton citing the examples of liver and skin cancer suffered by fish living in industrialised waterways.

In Beluga whale populations living in Canada's St. Lawrence Estuary, an area polluted by the aluminum smelting industry, cancer is second biggest cause of death.

The report also found a similarity in cancer rates and tumour types between different species and said wildlife populations could act as 'important indicators of environmental discord.'

Tasmanian devil

The authors said in some cases the high levels of cancer may not be linked to manmade chemicals.

It said Devil facial tumour disease, not known to be linked to pollution, had decimated the Tasmanian devil population by 53 per cent since 1996 causing it to be listed as an endangered species by IUCN in 2008.

With predictions of a further 70 per cent reduction over the next decade the species could soon face extinction.

'If efforts fail and the Tasmanian devil disappears, it will represent the first known instance of a contagious cancer causing the extinction of a species,' said the report.

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Nature report