Polluted with PFOA

PFOA Detected In The Blood Of Former Daikin Employees Is 298 Times The National Average / 3 Out Of The 5 people With The Highest Concentrations Are Former Employees

2024.04.16 13:13 Nanami Nakagawa

The “Osaka PFAS Contamination and Health Study Group” held a press conference on March 31, 2024. The group has been conducting a PFAS epidemiology survey since last fall. The target audience was 1192 people in the Kansai area, the largest survey in Japan. Interim results have been released after the blood analysis of 459 people was completed.

What has come to light is the high levels of exposure among people who worked at the Daikin Industries Yodogawa Plant, which manufactured PFOA.

The person with the highest PFOA concentration was 596.6 ng/ml, 298 times the national average of 2 ng/ml. It was also revealed that at least three of the top five of the 459 people were former Daikin employees.

It’s not just former Daikin employees. The blood concentrations of residents of Settsu City and Higashiyodogawa Ward, Osaka City, near Daikin’s Yodogawa Plant, were also higher than those in other areas. One in five people tested in both regions had concentrations above the German government’s standard.

PFAS is a general term for more than 10,000 types of organic fluorine compounds. Among the most toxic substances are PFOA and PFOS. The WHO has recognized PFOA as “carcinogenic,” and it is assessed at two levels above PFOS.

“Highest concentration I’ve ever analyzed”

At the press conference, Koji Harada, an associate professor of environmental health at Kyoto University Graduate School, gave a report. Harada is currently analyzing the blood of 1192 people whose blood was collected at all 49 venues from September to December 2023.

He has overseen PFAS blood testing across the country. Harada was also in charge of conducting PFAS testing on around 650 persons in the Tama area of Tokyo, where PFAS pollution from US military bases has been detected.

Harada was surprised by the highest concentration of 596.6ng/ml as of the interim report.

“This is the highest value I’ve ever analyzed.”

What does this value mean?

According to a national survey conducted by the Ministry of the Environment in 2022, the national average blood concentration was 2 ng/ml. 596.6ng/ml is 298 times that amount.

Clinical guidance from the National Academies of Sciences, Engineering, and Medicine in the United States, which is adopted by the U.S. government, warns that patients with a total level of seven PFAS, including PFOA, of 20 ng/ml or higher “should receive treatment that takes into account risks such as kidney cancer, testicular cancer, ulcerative colitis, and thyroid disease.”

The German Environment Agency has also issued a standard called “HBM-II.” Based on human health surveys (epidemiological studies), a PFOA standard value of 10 ng/ml has been set as a guideline for preventing health risks.

According to US and German standards, 596.6ng/ml is a value that raises concerns about health effects.

Identifying the cause of ex-employee exposure

According to the “Osaka PFAS Contamination and Health Study Group,” the person with a high concentration of 596.6 ng/ml was a former employee of Daikin’s Yodogawa Plant.

The Daikin Yodogawa Plant in Settsu City, Osaka Prefecture, has been manufacturing and using PFOA since the 1960s. Daikin announced that it had stopped the production of PFOA in 2012, but PFOA is highly persistent, and once taken into the body, it accumulates for many years.

DuPont, one of the world’s eight top PFOA manufacturers, along with Daikin, once caused significant PFOA contamination in the area surrounding their operations. Factory employees were exposed to high levels of PFOA at the same time.

Harada and other researchers are currently working to determine the cause of the former Daikin employee’s exposure.

However, the former Daikin employee was not the only one exposed to high levels.

Of the 459 people, the woman with the second highest concentration (127.7ng/ml) and the woman with the fifth highest concentration (83.3ng/ml) were also found to have previously worked at Daikin.

At least three of the top five were former Daikin employees.

1 in 5 people exceed German standards

At the press conference, it was also reported that PFOA concentrations were high in Settsu residents and Osaka City Higashiyodogawa Ward residents. Both residents live near the Daikin Yodogawa Plant.

【Average value】


Residents of Settsu (181 people): 9.41ng/ml


Residents of Higashiyodogawa Ward, Osaka City (49 people): 7.25ng/ml

More than one in five people exceeded the German Environment Agency’s PFOA standard (10ng/ml).

【Number and percentage of people with 10ng/ml or more】


Residents of Settsu: 40 out of 181 (22.1%)


Residents of Higashiyodogawa Ward, Osaka City: 11 out of 49 (22.4%)

Regarding this result, Harada said the following:

“I have been conducting PFAS tests in cities such as Tokyo, but there have been relatively few cases in which the German Environment Agency’s standard limits have been surpassed. In Higashiyodogawa Ward, Osaka City (next to Settsu City and next to Daikin Industries), 22.4% of the population meets German norms. The fact that it exceeds that is noteworthy.”

“Avoid the same fate as asbestos”

The “Osaka PFAS Contamination and Health Study Group” has been operating a PFAS consulting clinic since January of this year. Normally, the government should be responsible for the establishment of outpatient clinics. Despite being the most polluted location of PFOA in the country, Osaka Prefecture has not taken any action. The doctors involved with the group, frustrated by the crisis, took the initiative in establishing the system themselves.

The consultation was conducted by six doctors on patients whose levels surpassed 20ng/ml. Each patient was interviewed for 30 minutes and given diagnostics such as an abdominal echocardiogram. Followed up with detailed examinations as necessary.

At the press conference, Dr. Kenji Nakamura, who was in charge of the consultation outpatient clinic, gave a report.

Dr. Nakamura usually treats mainly occupational diseases. He also has experience working as a doctor for patients with lead poisoning and asbestos.

“Looking at the current PFAS pollution, it is very similar to the asbestos problem. When the problem first started, the government believed, ‘It’s not a very toxic substance.’ I ask the government to avoid the same fate as asbestos.”

From now on, the group will allow anyone to visit its outpatient consultation clinic. There are plans to increase the number of clinics from two to ten.

Associate Professor Koji Harada of Kyoto University Graduate School (Photo by Nanami Nakagawa)

(Originally published in Japanese on March 31, 2024. Translation by Mana Shibata.)

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