ESTREITO, Brazil (Reuters) - Brazilian state and federal authorities were assessing on Tuesday the risks of water contamination after trucks carrying sulfuric acid and agricultural pesticides plunged into a river on Sunday in a deadly bridge collapse.
The central span of a 533-meter (583-yard) bridge that links the cities of Estreito in Maranhao state and Aguiarnopolis in Tocantins state gave way as vehicles were crossing above the Tocantins River on Sunday afternoon.
The Maranhao state government and the Tocantins fire department confirmed three more deaths in separate statements on Tuesday, raising the death toll to four, and with more than 10 people still missing.
Rescue divers had halted their efforts on Sunday after finding that trucks transporting sulfuric acid had plunged into the river.
"We are waiting for specific institutions to collect and analyze the water so that we, along with 25 divers, can dive to retrieve the victims that are on the bed of the Tocantins River," Maranhao fire brigade Colonel Magnum Coelho said.
According to Brazilian water regulator ANA, three trucks carrying a total of 76 metric tons of sulfuric acid and about 25,000 liters of agricultural pesticides plunged into the river.
In a statement on Monday evening, the agency said it was monitoring the risk of contamination together with Maranhao's environmental secretary, and said that water samples would be collected from the Tocantins River.
It was not immediately clear if the chemicals were leaking, and if so by how much.
"Even though we still don't have final analysis results on pollution, the Environment Ministry identified that the water pH was normal," Maranhao state Governor Carlos Brandao told TV channel CNN Brasil on Monday.
State and federal authorities have told cities that could be affected by the incident to avoid collecting water from the Tocantins River.