To solve the haze problem, countries need to cooperate rather than just hold each other responsible for pollution; they should also view the problem in terms of economic interdependence, said legal experts at a conference on transboundary pollution on Thursday.

Singapore Institute of International Affairs think-tank chairman Simon Tay suggested four key elements that make transboundary pollution agreements successful: agreed-on standards and monitoring of pollution, deeper scientific understanding of the harms that pollution cause, regional institutions, and domestic constituencies that speak out against pollution.

Currently, these are absent from the Asean agreement on Transboundary Haze Pollution. For example, the effects of long-term exposure to air pollution are known. But the effects of seasonal haze that lingers for days or weeks should also be studied.

University of Oslo environmental-law emeritus professor Hans Christian Bugge agreed, adding that cooperation involved setting common goals and targets, and a long-term commitment from parties.

And, Prof Tay said, countries are connected by trade and finance flows. So agriculture firms, traders and banks have a role to play in supply chain management too, to prevent the illegal burning that causes haze. "It has to be a private sector, national and international or regional effort," he said.

The two-day conference at Orchard Hotel, convened by the Centre for International Law at the National University of Singapore, was organised "to raise awareness in the region about rights and responsibilities under international law, and explore mechanisms of cooperation and problem-solving," said Professor Tommy Koh, who is chairman of the centre's governing board and who chaired the conference panels with Professor S. Jayakumar, chairman of the centre's international advisory panel. Some 100 academics and officials attended the conference.