Fig. 2.

Proportion of sites acutely affected by different chemical groups. The chemical groups analyzed were insecticides (Ins), fungicides (Fung), organotin compounds (OrgTins), herbicides (Herb), polycyclic aromatic hydrocarbons (PAH), brominated flame retardants (BFR), and other compounds (chemical groups with five or fewer sites acutely affected which comprised polychlorinated biphenyls, halogenated alkanes, and phenols). The groups of organisms considered were fish (represented by P. promelas), invertebrates (represented by D. magna), and algae (represented by P. subcapitata). Acutely affected sites were all sites with maximum concentrations exceeding 1/10 of the LC₅₀.