What key concept does toxicodynamics primarily focus on?

Toxicodynamics is fundamentally concerned with the effects that toxic substances have on biological systems at the cellular level. It involves understanding how these substances interact with cellular processes, which includes mechanisms of action, dose-response relationships, and the physiological and biochemical alterations that occur as a result of exposure to toxins. By emphasizing how toxins disrupt cellular functions, toxicodynamics provides crucial insight into the potential health impacts and risks associated with chemical exposure.

The other choices focus on different aspects of environmental health and safety. While the measurement of environmental pollutants pertains to toxicology, it does not address the specific interactions and effects at the cellular level that toxicodynamics examines. Regulations regarding chemical safety involve legislative measures and guidelines designed to protect public health but do not delve into the mechanisms of toxicity. Similarly, the prevention of chemical hazards relates to strategies and practices aimed at minimizing exposure rather than understanding how toxic substances directly influence biological systems.