Risk/benefit analysis of prohibition of the mercury electrode process in caustic soda production

This study attempts a risk-benefit analysis of the Japanese government decision of the prohibition of the mercury electrode process used for production of caustic soda in 1973. The reduction in human health risk and the costs incurred due to the decision are evaluated, on the basis of which an implicit value of its benefit-risk (BRR) ratio is estimated. Human health risk is evaluated in terms of loss of life expectancy, which enables us to quantify and compare human health risks, irrespective of cancer or noncancer toxic risks. The value of BRR of the decision is calculated to be 570 million yen, approximately U.S. $5.7 million, per life-year saved. Comparing the BRR values of a couple of other policies enacted or proposed in Japan, ranging from 24 to 45 million yen per life-year saved, its value is very high. This result implies that the decision in study is not cost-effective.