The science of substances and their effects
Since Paracelsus´ (approx. 1493 – 1541) discovery, we know that substances affect the organisms depending on the amount ingested. Therefore, it is necessary to observe qualitative (which substance(s)?), as well as quantitative (which amount or concentration?) information as a basis for toxicological assessments.
With the knowledge of toxicology and with the aid of implementations of standardized toxicological methods we are able to assess the adverse effects of chemical substances on organisms. We distinguish between human toxicology and eco- or environmental toxicology. Whereas human toxicology concerns itself with the effects of substances on humans, ecotoxicology focuses on describing possible damage caused by products or procedures to the environment. Environmental damage can have negative influences on humans, ecotoxicology can primarily be regarded as a tool which promotes protection of health.