Thousands of workers in banana plantations marched in Davao City Friday afternoon and demanded that the House of Representatives scrap a measure banning the aerial spraying of fungicide.

Marchers screamed and hooted down a number of speakers calling for the ban as a panel of legislators conducted a public hearing on the matter at the Apo View Hotel, with hundreds of anti-riot policemen keeping watch on the demonstrators.

The House committee on ecology heard testimonies about the toxicity chlorothalonil and mancozeb, the two fungicides commonly applied to stop fungi from attacking bananas in large plantations in Davao City and Davao del Norte.

Members of the panel trooped to Barangay Camocaan in Hagonoy, Davao del Norte to see for themselves the alleged victims, including one who was supposed to have died a long time ago.

Opponents of the aerial ban claimed that fungicides are ipso facto poisons that must not be used at all while defenders of aerial spraying said there is little scientific proof that the low concentrations of the fungicide could lead to ailments.

As a result of the visit and the evidence provided by defenders of aerial spraying, some members of the House expressed doubt whether the ban could still be maintained.

Anthony Sasin, spokesman of the Philippine Banana Growers and Exporters Association (PBGEA) told the Manila Bulletin that the solution used in aerial water is largely water mixed with banana oil and mancozeb, with the fungicide technically borne in droplets that stick to the leaves and fronds of bananas.

"When applied, the solution could only cover 0.33 percent of a meter per hectare," he noted.

Sasin added that the protocol for aerial spraying is very strict, with flaglines determining which aerial could be sprayed at any time.

No aerial spraying could be done if the wind is 3 kilometers per hour (kph) and when the temperature is 82 degrees Fahrenheit, he stressed.

A former official of the Bureau of Plant Industry (BPI) told the House panel that the usually finicky Japanese have not made a case against Philippine bananas. The country exports up to 90 percent of its bananas to Japan after Latin American countries started to supply Russia and other nations in Europe.

Sasin said that Japanese authorities have subjected Philippine bananas to strict inspection, with samples being grounded and analyzed to determine if they comply with minimal levels of toxicity. "Our bananas have passed their stringent tests and we wonder why our compatriots insist on the ban," he added.

Health Secretary Francisco Duque has issued an order for the ban to be maintained until aerial spraying is proven to be safe.

Banana workers were perplexed by the order since two experts on fungicide spraying who conducted the peer review of the study undertaken by Dr. Allan Dionisio of the University of the Philippines in Manila said the date used "were inconclusive" and could not be used as a basis for the ban.