Fig. 3 shows the contributions of the most significant substances to the identified key categories (i.e., human toxicity, marine ecotoxicity, and metal depletion). The most significant substances in human toxicity are lead, arsenic, and mercury to air, which are mainly generated from Ag paste, electricity, and glass production. Similarly, copper and nickel to air, which are mainly generated from Ag paste and glass production, are the dominant substances for the marine ecotoxicity category. For the metal depletion category, Ag used for Ag paste production has the most significant contribution