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Recent studies on pulmonary clearance and toxicity of heavy metals (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Cd, Hg and Pb) and Al (light metal) are reviewed together with comparative pulmonary toxicity among these metals. Metabolism and effects of Cd, Cr and Ni deposited in the lung have been relatively well investigated because these three elements are considered to have carcinogenic potency, but toxicological studies seem to be insufficient for the other elements. Solubility of metal compounds in the bronchoalveolar milieu depends on physical and chemical form (salts, oxide, sulfide, etc.) and may play a major role in pulmonary clearance rate, acute toxicity and carcinogenecity. Therefore, attention should be paid to the species of elements present in the environmental and work place atmosphere. The current Threshold Limit Values (TLV) for gallium, aluminium and zinc oxides might not be adequate and should be thoroughly reexamined. Toxicological priorities relevant to the work environment are discussed.