Which of the following is true about toxicity?

The statement regarding toxicity that is accurate indicates that toxicity is dependent on both the substance in question and the organism that comes into contact with it. This means that different chemicals will exhibit varying levels of toxicity depending on their specific chemical properties. Additionally, different species of organisms have unique biological responses to these substances, which can lead to varying degrees of toxicity. For instance, a chemical that is highly toxic to fish may not have the same effect on humans or other types of aquatic organisms. This concept highlights the importance of considering both the nature of the toxic substance and the ecological context when assessing risk and health impacts in aquatic pest management.

In contrast, other options present misconceptions. Toxicity definitely does not apply solely to synthetic chemicals, as natural substances can also be toxic. Furthermore, toxicity is not a static phenomenon that remains constant across different environments; it can be influenced by various factors such as water temperature, pH levels, and the presence of other substances. Lastly, the idea that toxicity reduces with increasing concentration is inaccurate; typically, higher concentrations of a toxic substance are associated with increased toxicity, at least up to a certain threshold. Understanding these principles is crucial for anyone involved in aquatic pest management.