Advantages and disadvantages of toxicity testing

There are many applications of toxicity tests but in general they have been used as an environmental tool to provide information about  

From all these uses it is clear that the main advantage of bioassays is that they can provide information about toxicity. However, the strongest disadvantage is that the bioassays cannot identify the substance causing an effect (Scroggins, 1999). This is one of the reasons why toxicity testing should be complemented with chemical characterization. 

Associated with this first advantage, toxicity tests are used to measure directly the whole sample toxicity, without identifying and analyzing each pollutant individually. Whole-effluent bioassays are probably more representative of the total toxic effect of the complex effluent mixture. Toxicity tests give an integrated answer of the total effect of diverse toxicants in a given complex effluent. 

Toxicity test results expressed in terms of harm to living organisms are more credible or comprehensible than chemical data to non-specialists (Sergy, 1987). They can also be less expensive than comprehensive chemical analysis. However, a toxic finding could be misleading if used in a simplistic way, e.g. failing to allow for dilution or mitigating factors. 

Toxicity testing has been a contentious issue. Its opponents argue that toxicity tests are complex, expensive and imprecise. In spite of these arguments, as standardized toxicity tests are developed and their interpretation and regulatory applications are refined, it is clear that toxicity tests will become powerful instruments for pollution monitoring and control. They measure directly the potential environmental effects of complex mixtures and provide information that cannot be obtained by any other means. 

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