Japan's Environment Ministry announced Tuesday that it is planning to develop guidelines to help municipalities identify sources of potentially dangerous chemicals. They're being found in several parts of the country and above the government's target level.

The group of organic fluorine compounds are known as PFAS. They have been used to coat frying pans and make water-repellent sprays.

Studies in the US and elsewhere have found that the substances are hazardous, and are said to increase the risks of cancer and hamper child development.

They have been found at 81 locations in 13 prefectures, including Tokyo. The government was unable to identify the source of PFAS in almost all of the cases.

The Environment Ministry set up an expert panel to examine the situation. Members suggested the government come up with a specific method to track down the source of contamination.

Associate Professor Harada Koji of Kyoto University Graduate School of Medicine is a panel member. He says it is necessary to keep track of the history of PFAS use, not only at the present, but also in the past.

Harada says the government must also involve companies that have used PFAS in their products.