Texas Pesticide Applicator Practice Exam

What does the term "toxicity" refer to?

1. The ability of a substance to enhance health

2. The capacity of a substance to injure or poison living systems

3. The measurement of environmental pollution

4. The process of chemical neutralization

The correct answer is: The capacity of a substance to injure or poison living systems

The term "toxicity" specifically refers to the capacity of a substance to injure or poison living systems. This definition encompasses a wide range of effects that substances can have on organisms, including short-term acute effects and long-term chronic effects. Toxins can range from substances that cause mild irritation to those that can be lethal, affecting various biological systems such as the nervous system, respiratory system, or organs. Understanding toxicity is crucial in fields like agriculture and pest control, where the use of pesticides can pose risks not only to targeted pests but also to non-target organisms including humans, wildlife, and beneficial insects. The other options do not accurately capture the essence of toxicity. For instance, while enhancing health can involve the use of beneficial substances, it does not relate to the potential harm that toxic substances can cause. Measurement of environmental pollution speaks to another critical aspect of environmental science, but it does not define toxicity specifically. Lastly, chemical neutralization refers to the process of rendering a chemical substance inactive or less harmful, which is a remedy rather than a characteristic or property of a substance itself.