Scientists from around the globe began a week-long conference yesterday aimed at shaping a programme to cut back the use of mercury - a toxic substance which poisons and cripples hundreds of people annually...Widely used for decades in lamps, batteries and electrical equipment because it is an excellent conductor of heat, as well as in thermometers and dental fillings, it can cause permanent damage to the brain, nervous system and kidneys. UNEP says it has also been used in some pesticides and pharmaceuticals, as well as in some skin-lightening creams.