Pb: Causes the damage to the Nervous system.
　　 Cd: Caused the damage to skeleton, kidney system
　　 Hg: Causes the damage to the central Nervous system.
　　 Cr6+: Causes the flaw to the hereditary gens.
　　 PBB: Intense abnormality-causing agent.
　　 PBDE: Intense abnormality-causing agent.