Another heavy fall from nickel miner Talvivaara ensured that the industrial metals and mining sector was the worst performing sector of the day on Tuesday.Talvivaara plummeted again today as market continue to speculate about the impact that last week's gypsum pond leakage at its project in Finland will have on production. Speaking overnight to Finnish broadcaster Yle's current affairs programme A-studio, Talvivaara Chief Executive Harri Natunen said that taxpayers will not have to shoulder the clean-up cost at the mine.According to media reports this afternoon, toxic amounts of nickel have been found at a nearby lake. The Finnish Environment Institute is reported to have said that concentrations now exceeding the level "regarded as harmful to organisms". Uranium concentration is also now thought to be a concern.Shares, at just over the 87p mark, are well off the 130p level seen before the leak was first reported at the start of the month. Watermark, Bellzone Mining and Tri-Star Resources were also heavy fallers today.The industrial metals and mining sector has now lost nearly 13% over the last week; the sector average has dropped by almost a half over the past 12 months.Top performing sectors so far todayFixed Line Telecommunications 2,673.97 +1.24%Media 4,585.66 +0.76%Household Goods & Home Construction 7,896.43 +0.58%Real Estate Investment & Services 1,824.93 +0.55%Beverages 12,913.23 +0.53%Bottom performing sectors so far todayIndustrial Metals & Mining 2,368.22 -3.16%Forestry & Paper 6,845.20 -3.05%Mobile Telecommunications 3,763.23 -3.00%Personal Goods 19,202.54 -2.08%Mining 18,020.24 -1.34%BC