Editing Persistent organic pollutant (section)

=== Additive and synergistic effects ===
Evaluation of the effects of POPs on health is very challenging in the laboratory setting. For example, for organisms exposed to a mixture of POPs, the effects are assumed to be [[Additive effect|additive]].<ref name="Harrad, S. 2010">ed. Harrad, S., "Persistent Organic Pollutants" (2010).</ref> Mixtures of POPs can in principle produce [[Synergy#Toxicological synergy|synergistic effects]]. With synergistic effects, the toxicity of each compound is enhanced (or depressed) by the presence of other compounds in the mixture. When put together, the effects can far exceed the approximated additive effects of the POP compound mixture.<ref name="Walker, C.H. 2001"/>