When two pollutants are combined and their effects are greater than the sum of the individual effects, this is called what?

The phenomenon where two pollutants combine to produce an effect greater than the sum of their individual effects is referred to as synergism. This occurs when the interaction between the substances leads to a more pronounced or intensified result, often resulting in greater toxicity or a more significant health impact than would be expected if each pollutant acted independently.

Understanding synergism is crucial in environmental health because it highlights the complexities of assessing risks posed by multiple pollutants present in the environment. This concept is especially important in fields such as toxicology and environmental science, where the combined effects of chemicals can often lead to unexpected outcomes that may not be apparent when evaluating each substance in isolation.

In contrast to synergism, commensalism describes a relationship between two organisms where one benefits and the other is neither helped nor harmed, which does not apply to the context of pollutant interactions. Magnification typically refers to the process where substances increase in concentration as they move up the food chain, while multiplication would refer to basic mathematical operations and is not relevant in this context. Thus, the correct terminology in discussing the combined effects of pollutants is synergism.