In this paper, a procedure of estimating embodied emission intensities of toxic substances regulated by the PRTR law is presented. The procedure based on PRTR data and an Input- Output (I-O) table consists of the following 3 steps. (1) Direct emissions of toxic substanses based on I-O categories are estimated by allocating PRTR data to the I-O categories. (2) The I-O table is modified according to the results of investigating the industries responsible for the emissions of toxic substances. (3) Total emissions of the toxic substances are estimated by using a Leontief inverse matrix. This procedure has been applied to calculating the embodied intensities of lead emissions to water, air and soil systems and to landfill