The costs of training ($100 per person) could be averaged over five years, provided miners were continuing to use the same types of retorts, leading to an approximate cost of $3/kg mercury per year for those five years.
培训成本（100美元/人）可由五年进行平摊，前提是，矿工继续使用同一类型的蒸馏罐，这样一来，这五年里每年每捕获一千克汞需3美元。