“ The courts of Ohio, under modern principles of the scope of subject matter and in personam jurisdiction, have a claim as compelling as any that can be made out for this Court to exercise jurisdiction to adjudicate the instant controversy, and they would decide it under the same common law of nuisance upon which our determination would have to rest. In essence, the State has charged Dow Canada and Wyandotte with the commission of acts, albeit beyond Ohio's territorial boundaries, that have produced and, it is said, continue to produce disastrous effects within Ohio's own domain. ”

“ The nature of the case Ohio brings here is equally disconcerting. It can fairly be said that what is in dispute is not so much the law as the facts. And the factfinding process we are asked to undertake is, to say the least, formidable. We already know, just from what has been placed before us on this motion, that Lake Erie suffers from several sources of pollution other than mercury; that the scientific conclusion that mercury is a serious water pollutant is a novel one ”

“ Reversing the increasing contamination of our environment is manifestly a matter of fundamental import and utmost urgency. What is dealt with above are only considerations respecting the appropriate role this Court can assume in efforts to eradicate such environmental blights. We mean only to suggest that our competence is necessarily limited, not that our concern should be kept within narrow bounds.
Ohio's motion for leave to file its complaint is denied without prejudice to its right to commence other appropriate judicial proceedings. ”

“ While this Court, and doubtless Canadian courts, if called upon to assess the validity of any decree rendered against either Dow Canada or Wyandotte, would be alert to ascertain whether the judgment rested upon an even-handed application of justice, it is unlikely that we would totally deny Ohio's competence to act if the allegations made here are proved true. ”

“ Dow Canada is incorporated, and does business, in Ontario. A majority of Dow Canada's directors are residents of the United States.
The complaint alleges that Dow Canada and Wyandotte have each dumped mercury into streams whose courses ultimately reach Lake Erie, thus contaminating and polluting that lake's waters, vegetation, fish, and wildlife, and that Dow America is jointly responsible for the acts of its foreign subsidiary. Assuming the State's ability to prove these assertions, Ohio seeks a decree: (1) declaring the introduction of mercury into Lake Erie's tributaries a public nuisance ”

“ As our social system has grown more complex, the States have increasingly become enmeshed in a multitude of disputes with persons living outside their borders. Consider, for example, the frequency with which States and nonresidents clash over the application of state laws concerning taxes, motor vehicles, decedents' estates, business torts, government contracts, and so forth. ”

“ See, e.g., International Shoe Co. v. Washington, 326 U.S. 310, 66 S.Ct. 154, 90 L.Ed. 95 (1945) ; United States v. Aluminum Co. of America, 148 F.2d 416 (CA2 1945) ; ALI, Restatement of the Foreign Relations Law of the United States 2d, § 18. ”