Which of the following factors determines how harmful an introduced chemical will be on the environment? a. type of chemical b. concentration c. weather conditions d. all of the above

The correct answer is option (d) all of the above.

The chemicals present in the environment may or not may not be harmful. The toxicity of the chemicals depend on many factors. Not all chemicals are are harmful to environment, some chemicals are always present in the environment and are useful or harmless. So, it depends on the type of chemical. Also, some chemicals are nontoxic at a particular level, but when it rises above a certain level, it is toxic to the environment. The weather condition also affect the toxicity of the chemical, for example some chemical such as sulfuric oxide is not a toxin, but when it is combined with water from the clouds it causes acid rain.