Commentary on the Risk Assessment of Lead by the Food Safety Commission of Japan.

This article describes in detail the process of and the basis for the risk assessment of lead, started as a self-tasking assessment in April 2008 and finalized in June 2021 by the Food Safety Commission of Japan (FSCJ). Discussion points addressed in the working group set under the FSCJ in April 2019 are also presented in this commentary. To reflect the overall exposure to lead from various sources, blood lead level (BLL) was used as the basic metric for the assessment. For the evaluation of effects on human health, the approach of overall weight of evidence was taken, rather than selecting one critical endpoint, in consideration of the uncertainties inherent to epidemiological studies, particularly those examining the effects associated with low-level lead exposure. The overall evidence compiled for the assessment suggested that BLLs in the range of 1-2 μg/dL might be associated with some effects on human health. The representative value of BLL for the entire population was difficult to obtain due to the lack of a national population-based survey in Japan. Instead, the current average BLL of the Japanese population was estimated based on recent studies conducted in Japan. The estimated average exposure level was below or equal to 1 μg/dL and close to the levels at which some effects on human health might occur, as suggested by epidemiological studies. Hence, the continued enforcement of measures to reduce lead exposure is indispensable. Furthermore, a national human biomonitoring program to continuously assess the exposure status of the Japanese population, which can be ultimately used for assuring the effectiveness of control measures, is needed.