Novel research efforts focusing on development and application of bioaccessibility methods to predict trace element contaminant bioaccessibility and bioavailability have greatly increased globally. Advances in bioavailability science has led to implementation of bioavailability and bioaccessibility methods that predict bioavailability into risk assessment and remedial strategy of contaminated soil. Select advances in the science of bioaccessibility methods to predict soil trace element bioavailability to human and ecological receptors will be highlighted in the presentation. Specifically, the ability of several international bioaccessibility methods to predict relative bioavailable arsenic (RBA As) for 12 contaminated sites. In general, bioaccessibility methods were predictive of RBA As for arsenic contaminated soils but several methods underpredicted RBA As when applied to the 12 contaminated sites. Arsenic speciation alone was not predictive of IVBA or RBA As. However, As speciation is very important to provide information on the ability of bioaccessibility methods to predict RBA As results. Supplemental contaminant source information (i.e., arsenic speciation) may be required for proper selection of methods by risk assessors to accurately predict RBA As and human exposure. Specific advances important to implementation of bioaccessibility methods to adjust bioavailability and human and ecological exposure to Pb in industrial and/or urban soils will be presented.