Researchers Find "Bahan Kimia Abadi" In The Natural Cat Organ Tsushima Japan

JAKARTA - The Japanese research team found a high concentration of "eternal chemicals" of PFAS that could potentially be carcinogenic in Tsushima leopard paint, a wild forest cat native to Tsushima Island, Japan.

A research team led by Ehime University found the chemicals in the organs of 21 cats examined, raising concerns about the impact pollution on wildlife conservation across Japan.

"For the sake of protecting all wild animals, not just Tsushima leopard cats, there must be a national survey and investigation to identify sources of pollution," said Intermediate professor Kei Nomiyama, quoted by Kyodo News Aug. 25.

Tsushima leopard paint, which inhabits Tsushima Island inTOMa Prefecture, southwest Japan, is listed as a vulnerable species on the Ministry of Environment's endangered Red List of species.

Their number has decreased due to habitat loss and hit animals. The government estimates that around 100 will remain, and zoos in Japan are working to breed this species.

The research team received permission from the ministry to examine the liver and kidneys of 21 stray cats that died between 2022 and 2025, testing 37 PFAS chemicals.

Nearly all cats have PFAS concentrations that exceed the threshold for toxicity in liver cell tests, suggesting potential risks to liver function, according to the study.

Concentration in the kidneys is also considered high, according to the study.

There is no significant difference based on the recorded age, gender, or location.

The concentration of median chemicals of PFAS is eight times higher than the rate found in a study of European stray cats in Germany.

Experts suspect marine debris and illegal disposal as sources of pollution, with concentrations likely accumulated through food chains.

The team also measured persistent organic pollutants, known as POPs, in 19 cats, with some showing very high levels of contamination.

Professor Nomiyama said there was a "big possibility" of pollution related to the decline in the species' population.

PFAS is a general term for a group of more than 10,000 artificial chemicals that include PFOS, or perfluorooctanesulfonic and PFOA acids, or perfluorooctanoic acids.

Used in products such as fire foam and coatings of anti-sket cooking utensils, PFAS is known as "eternal chemicals" because it is very resistant to damage, and accumulated in the ground and water as environmental pollutants.