Su Chun-jen, director of the city government's health department, announced the results of the first stage of the department's checks on the blood samples provided by 570 of some 4,000 residents living in four wards in the city's An-nan district, where the factory operated between 1942 and 1982.

According to the report, one of the surveyed residents had 951 pg. of dioxin in his blood, which is 31 times higher than the U.N.-accepted standard of 32 pg., Su said. However, it was not the highest amount ever found in human body. President of Ukraine Victor Yushchenko was found to have higher amount when he found that he was poisoned, he said.

Su pointed to the factory in question as the Anshun factory of the Taiwan Alkali Industrial Corp. in Tainan City, saying that the factory had changed hands, names and products several times since its construction by the Japanese in 1942.

Originally producing hydrochloric acid, caustic soda, liquid chlorine, and also poison gas for the Japanese navy, by the early 1970s the Anshun factory had become Asia's biggest producer of the pesticide DDT.

After closing in 1982 for economic reasons, it merged with China Petrochemical Development Corporation, which went private in 1994, inheriting TAIC and all its property.

Dioxin, a byproduct of DDT belonging to a dangerous group of chemicals known as persistent organic pollutants (POPs) or the "dirty dozen", can result in illnesses affecting the skin, liver, and immune, nervous and reproductive systems. It has also been categorized as carcinogenic to animals, including humans.

For decades, residents living the Anshun factory have farmed and caught fish and shellfish in the reservoir and ponds surrounding the factory, unaware that what they were eating and selling was poisoned. However, not everyone was oblivious to the danger.

Confidential documents show that the Ministry of Economic Affairs warned TAIC in 1982 that mercury concentrations in fish caught in the reservoir exceeded safe levels for human consumption. Yet this was not brought to public attention, nor did it result in any attempt to prevent the further spread of pollution, or the consumption of fish harvested in contaminated areas.

In July 2005, the Executive Yuan approved a budget of NT$1.3 billion as compensations for affected residents, but it has taken six months for the first small portion of this to reach victims.

The amount of compensation is also a bone of contention. The monthly sum of NT$1,814 per person is intended to pay for continuing medical treatment of various illnesses, including cancer, as well as social welfare and living expenses.

Many regard it as disproportionate to the extent of damage caused to the health and livelihoods of local residents, taking little account of past medical costs and other losses, and failing to discriminate between the varying needs and severity of illness among the population.