What environmental effect is primarily associated with the breakdown of ozone molecules?

The primary environmental effect associated with the breakdown of ozone molecules is higher UV radiation exposure. The ozone layer, found in the Earth's stratosphere, serves as a protective shield that absorbs the majority of the sun's harmful ultraviolet (UV) radiation. When ozone molecules are depleted, this protection is diminished, leading to an increase in the amount of UV radiation that reaches the Earth's surface.

Increased exposure to UV radiation can have severe consequences for both human health and the environment. It can result in a higher incidence of skin cancers, cataracts, and other health issues in humans, as well as impact ecosystems, particularly affecting marine life and terrestrial plants. Therefore, the breakdown of ozone directly correlates to increased levels of UV radiation exposure, making this the correct choice for the question.