Martinique and Guadeloupe are currently facing "an extremely serious crisis linked to the massive use of pesticides for a great many years," Professor Dominique Belpomme said in a report obtained by AFP Monday.
On Tuesday Belpomme is to submit his findings to the French National Assembly, highlighting the dangers posed by the long-term use of chlordecone, also known as kepone, on banana crops.
Chlordecone, which kills weevils, was banned in France's Caribbean territories in 1993, but it was used illegally -- often sprayed by aeroplanes -- up to 2002.
"The situation is extremely serious. The tests we carried out on pesticides show there is a health disaster in the Caribbean. The word is not too strong. Martinique and Guadeloupe have literally been poisoned," Belpomme told the capital's Le Parisien newspaper.
"The poisoning affects both land and water. Chlordecone establishes itself in the clay and stays there for up to a century. As a result the food chain is contaminated, and especially water. In Martinique most water sources are polluted," he said.
According to the cancer specialist, the impact on health will be "more serious than the tainted blood" scandal -- in which some 4,000 French people were infected with blood contaminated with the HIV virus in the 1980s.
"The rate of prostate cancer is major. The French Caribbean is second in the world ranking. Extrapolations show that nearly one male in two will be a risk of developing prostate cancer," he said.
"In addition the rate of congenital malformation is increasing in the islands. And women are having fewer children than 15 years ago. The standard theory is that this is because of the pill, but I think it is linked to pesticides," he said.
Agriculture Minister Michel Barnier said the situation was "very serious" and promised to "treat the question of chlordecone with the greatest openness."
But Health Minister Roselyne Bachelot sought to play down the report, saying it "raises questions" but "brings no formal response".
"These concerns need to be confirmed by high quality scientific research," she said.
Christian Choupin, head of the Martinique and Guadeloupe Banana Producers' Association also said Belpomme's report was unscientific.
"One has the impression that people are dying like flies in the French Caribbean, which is far from the reality," he said.
The French islands produce 260,000 tonnes of bananas a year, worth some 220 million euros (305 million dollars). The industry, which employs 15,000 people, also receives 130 million euros in EU aid.
In August Hurricane Dean destroyed all the crop in Martinique and some 50 percent in Guadeloupe. Barnier said this represented an opportunity to rebuild the banana plantations "with zero pesticides."
Belpomme said chlordecone does not affect the fruit itself because the contamination "is confined to the skin".