Japan to study health impact after PFAS detection raises concern

Japan will launch a study on the health impact of potentially harmful chemicals known as per- and polyfluoroalkyl substances (PFAS). Some researchers warned of adverse effects on human after high concentration levels of PFAS were detected in various parts of the country, which fueled concern among residents.

PFAS, used in various products such as frying pan coatings and water-repellent clothing, have been detected in high concentrations in human blood and water bodies at places near Self-Defense Forces and U.S military bases, as well as industrial areas in recent years. Levels exceeding the standard set by the Japanese government were reported near Yokota Air Base in western Tokyo and the U.S. Navy base in Yokosuka, southwest of Tokyo, and in a drainage channel in an industrial park in Fukushima Prefecture and areas surrounding a chemical factory in Shizuoka Prefecture. In February 2024, PFAS found in well water close to the local Seno River in Higashihiroshima City, Hiroshima Prefecture, were 300 times the provisional 50 ng limit.

PFAS are known as persistent organic pollutants, or "forever chemicals," because they are extremely persistent in the environment and human body. They don't degrade over time, and could accumulate and lead to health problems such as liver damage, thyroid disease, obesity, fertility issues and cancer.

The government-led study, planned for three years from around June 2024, will be conducted by Hokkaido University, Hyogo Medical University and National Institute of Health Sciences.

In the study, Hokkaido University will use data on concentration levels of 39 kinds of PFAS contained in the blood of around 700 people from the fetal stage to late teens to examine the substances' impact on their fat metabolism and development. Hyogo Medical University will conduct experiments on mice to probe whether the substances suppress the immune system and reduce the effectiveness of vaccinations, while the National Institute of Health Sciences will seek to elucidate the mechanism of their toxicity at the molecular level.

(With input from Xinhua; cover image via CFP)