Thus, the current 16 PAHs measured is a good predictor of PAH presence in the sample, and is representative of the PAH list for which SQGs are generally available. However, this review could not assess whether this subset was a good predictor of overall PAH toxicity, which will be a function of the specific combination, levels and bioavailability of PAHs in a sample. A third workshop recommendation was that EC consider the examination of PCBs based upon the measurement of individual

congeners rather than aroclors, since these compounds provide a better platform of information INCB024360 chemical structure with which to evaluate toxicity and assess bioaccumulation potential. The current DaS aroclor-based LAL could not be used with the congener data reported in the study database for a critical assessment of this recommendation. However, a hypothetical conversion of this SQG to a congener-based one suggested that it was comparable in its outcomes to other DM PCB LALs. We found that most

congener-based PCB SQGs were based upon the ICES7 list of PCBs, and that the sum of these correlated well with total PCBs for a sample reported in the database, though this was biased by the fact that these congeners were by far the most reported ones. Gamma-secretase inhibitor EC will likely wish to give a high priority to the review of the basis for PCB evaluation in the DaS program, and provision of congener-based action levels and guidance similar to that used in other countries. A fourth workshop recommendation was that EC further considers the question of inclusion of a broader range of organic compounds in the assessment. Although the addition of extra pesticides on the CCME list had a minor impact on the conservatism of an assessment protocol when compared to the expansion of a metals list, the addition of the extra pesticides (lindane, aldrin

and HCB) and tTBT in the Consensus SQG list did result in a significant Tideglusib increase in conservatism. Thus, we found that the addition of some organic compounds for which SQGs were available significantly increased the proportion of samples assigned to Tier 2 or Tier 3, though the degree to which this happened depended upon the conservatism of the LAL and UAL levels. It should be noted that, due to the approach applied, this review focused only on organic contaminants for which SQGs were generally available, primarily a set of pesticides, but it is possible that a broader range of organic analytes (assuming data and SQGs were available) would provide similar results.