a traffic disruption. This temporal measure was followed, on 16 February, by a blockade of Route 135 and the bridge, which links Colón with Paysandú in Uruguay. All these earlier actions were targeted to impact the public hearings of Cumulative Impact Study, held by IFC on 14 and 16 in both Montevideo and Buenos Aires. On 20 February the Uruguayan government decided to accuse Argentina before the Organization of American States, for its lack of action on the matter of the blocks. The same day, the Supreme Court of Argentina rejected the case presented by Argentines against Uruguay, returning it to Guillermo Quadrini, federal judge of Concepción del Uruguay. The School of Chemistry of the University of the Republic, Uruguay, released an open letter to Uruguayan society on 22 February. They reported that TCF-derived paper can be recycled fewer times than ECF-derived paper. The TCF process is 5% more expensive, and needs 10% more fuel and wood to make the same amount of paper than ECF process; therefore, it releases 10% more greenhouse gases. The letter stated that ECF and TCF are accepted as "best available technologies" in developed countries, and toxic emissions are minimal (specially dioxins), which implies that emissions depend on management and controls, not on whether TCF or ECF processes are used. March 2006 During their state visits to Chile on 11 March for the inauguration of President Michelle Bachelet, Presidents Néstor Kirchner and Tabaré Vázquez met and discussed the situation personally. They jointly asked the participants for the suspension of both the construction of the pulp mills and the roadblocks, in order to discuss the matter. Two new meetings were scheduled, to take place in Anchorena, Uruguay, and Mar del Plata, Argentina. In the following days President Vázquez was harshly criticised by the political opposition and backtracked publicly, stating that Uruguay "will not negotiate under pressure". The Gualeguaychú Environmental Assembly met with Governor Busti to hear the proposal, but then decided to keep the blockade for the moment and reconsider. On 16 March about 10,000 people demonstrated in Fray Bentos, Uruguay for the pulp mills. Gualeguaychú lifts the blockade The Assembly gathered again, with an unusually large attendance, on 20 March. After discussing several proposals, they voted to lift the blockades on Route 136 and the Libertador General San Martín Bridge (which had lasted 45 days), starting the following day, and wait 7 days for the