TOKYO (AFP) - A UN conference to sign a historic treaty aimed at reining in the use and emission of mercury began on Monday in Kumamoto, near Minamata, the site of Japan's worst-ever industrial poisoning.
Delegates from some 140 countries and regions are scheduled to attend the five-day conference in the country's southwest, organisers said.
The conference comes after a January agreement on details of the world's first legally binding treaty on mercury, a highly toxic metal.
Preparatory meetings kicked off on Monday at the venue, the organisers said, while local media said the treaty is likely to be adopted unanimously on Thursday.
The treaty has been named the Minamata Convention on Mercury, in honour of the Japanese city around 2,000 people died and many more were made sick by mercury dumped by a local factory.
Delegates are to visit Minamata on Wednesday to mourn the victims.
The treaty will take effect once ratified by 50 countries - something organisers expect will take three to four years.
Mercury, also known as quicksilver, is found in products ranging from electrical switches, thermometers and light-bulbs, to amalgam dental fillings and even facial creams.
Serious mercury poisoning affects the body's immune system and development of the brain and nervous system, posing the greatest risk to foetuses and infants.
The treaty sets a phase-out date of 2020 for a long line of products including mercury thermometers, while the text gives governments 15 years to end all mercury mining.
But environmental groups say the treaty falls short in addressing artisanal small-scale gold mining, a major source of large amounts of the heavy metal, which also directly threatens the health of miners.