Data source
Date of text
16 Apr 1938
Seat of court
Original language


Type of text
International court
Court name
Arbitrational Tribunal (constituted for that case)
Warren, C. (United States)
Greenshields, R.A.E. (Canada)
Hostie, J.F. (Belgium)
air pollution (stationary sources), compensation, polluter pays principle, transboundary effect

In 1935 a Canadian based corporation (defendant) owned a smelter plant which emitted hazardous fumes (sulfur dioxide) that caused damage to plant life, forest trees, soil, and crop yields accross the border in Washington State in the United States (plaintiff). The United States took Canada to court. The same year a Convention established an arbitral tribunal consisting of two national members and a neutral chairman. The Tribunal was aided by scientific experts appointed by the governments. In its first decision, 1938, the Tribunal concluded that harm had occurred between 1932 and 1937 and ordered the payment of an indemnity of $78,000 as the ‘complete and final indemnity and compensation for all damage which occurred between such dates’.The Tribunal’s second decision (1941), was concerned with the final three questions presented by the 1935 Convention, namely, responsibility for, and the appropriate mitigation and indemnification of, future harm. The Tribunal concluded, with respect to future harm, that: 'no State has the right to use or permit the use of its territory in such a manner as to cause injury by fumes in or to the territory of another or the properties or persons therein, when the case is of serious consequence and the injury is established by clear and convincing evidence'. (Source: Trail Smelter Arbitration, Russel Miller, in: Max Planck Encyclopedia of Public International Law, 2007)