Section 3: Toxic Effects

Learning Objectives

After completing this lesson, you will be able to:

  • Explain factors that influence the toxicity of a substance.
  • Define types of systemic and organ-specific toxic effects.

In this section...

Topics include:


Did you know?

In December 1984, the world's worst industrial accident occurred in Bhopal, India. More than 40 tons of methyl isocyanate leaked from a pesticide plant, killing thousands of people and injuring hundreds of thousands. Follow-up studies have shown that the incident caused increased mortality and continued effects on health, including airway disease, eye diseases, and pregnancy losses.

The company involved in the leak tried to distance itself from the accident and prevent those affected from learning the true nature of the accident. The legal case went on for years. Eventually, families of the dead received an average of about $2,200. While the company ceased operation at its Bhopal plant after the disaster, it did not clean up the site completely. The plant continues to leak several toxic chemicals and heavy metals into local aquifers.

Survivors of the deadly industrial incident in Bhopal, India in 1984, protesting over the mishandling of the disaster

Figure 1. Survivors of the Bhopal disaster of 1984 protest over the mishandling of the disaster
Bhopal disaster protestors. [Photo]. In Encyclopædia Britannica. Retrieved from