Since Paracelsus (1493 - 1541) it is known that is the dose that differentiates a poison from a remedy. We now know that other factors, such as stage gives life, age, nutrition, disease and exposure to chemicals, among other factors should also be considered.

The paradigm shift in toxicology involves a transition from a science 'in vivo" to study parameters such lethal dose for half the population of animals in laboratory test conditions, for a science ' in vitro ' with studies in the key events and processes of the target molecule, cell responses and the adverse effects on human health and the environment. We work to integrate these different types of knowledge (Meek et al, 2014).

The European Chemicals Agency, in its program of registration, evaluation, authorization and restriction of chemicals, estimated circa 100,000 chemicals in use, with discussions on methods for evaluating toxicity of 30% of those. The toxicology program of PAHO aims to strengthen the health sector in chemical safety, through the promotion of strategies and policies that generate monitoring programs for chemical safety, with attention to information and support centers in toxicology, to address health effects from chronic and acute exposures.

The training of health personnel and promotion of multisectoral dialogues with different actors of interest are needed to develop methodologies for assessment and risk mitigation based on available guidelines.  

References

Steven G. Gilbert 2012. A Small Dose of Toxicology, 2nd Edition. Healthy World Press

Meek, ME et al. 2014. New developments in the evolution and application of the WHO/IPCS framework on mode of action/species concordance analysis. J. Appl. Toxicol. 34: 1-18.