English Newsletter

Food Safety Citizens' Watch
English Newsletter

Issue # 16 Special Lecture:
"Hair analysis as a possible way to investigate heavy metal pollution - interim report"

The Food Safety Citizens' Watch was established in April 2003 as a network of experts to monitor developments and make proposals to the government regarding food safety issues from the citizen's point of view.

FSCW General Meeting Special Lecture: "Hair analysis as a possible way to investigate heavy metal pollution - interim report" by Dr. Hiroshi Yasuda, Director of La Belle Vie Preventive Medicine Laboratory


Summary of Lecture by Hiroshi Yasuda
April 26, 2008
Tokyo, Japan

We have conducted investigations to determine the degree of heavy metal pollution in hair from parents and children in Japan. This kind of study is rarely done, so we think the data is very valuable. Among the heavy metals that are needed by the body, intake of minerals through food is necessary to a certain degree. However, there are substances that do more harm, such as mercury, lead and cadmium. In Japan, these are known for the specific diseases they caused in the past, such as Minamata disease (mercury), lead poisoning, and the Itai-itai disease (cadmium). Also, arsenic in milk and water wells have caused health problems. Aluminum is known to cause dialysis encephalopathy syndrome, while copper has caused the Wilson disease. Even though they are all necessary substances, they can cause severe symptoms and disease if the intake is high.

In this study, we looked at the concentrations of harmful heavy metals in hair samples from 34 women (control group), 78 mothers, 49 children (female) and 31 children (boys). We investigated the levels, and generally we found that they were higher in the children than in their mothers.

We found that for both mercury and arsenic there was a positive correlation between levels found in mother and child. For cadmium, lead, and aluminum, there were significantly higher values in the children than in the mothers. Some among the children had 10 times higher levels compared to their mothers.

When we looked at cadmium and lead levels in girls according to their age, we found the highest levels in the 0-3 age group. The highest aluminum levels were in boys in the 0-3 age group. As for minerals that are considered necessary (iron, chrome, manganese and molybdenum), the levels found in all the children are high, while zinc, magnesium and calcium levels are low.

Except for mercury, we have no data about the correlation of concentrations of high levels of heavy metals in hair samples compared to body samples. This correlation has only been studied in the case of the Minamata disease. For other heavy metals, the levels are not well understood.

From 2008, the Ministry of the Environment has started a nationwide investigation by registering 100,000 pregnant women, to see if chemical substances such as mercury have any influence on the growth of the children until the age of 12. This is an unprecedented investigation.