Inclusion Criteria:  The chemical attack occurred between 1970 and 2035 for which a confirmation was made by reliable authorities (e.g.: US Intelligence community); The chemical attack was part of a conventional military operation, mass attack, political assassination or terrorist event; The chemical attack cause at least one casualty who required the assistance of the health care professionals (e.g.: physicians, nurses, paramedics and other health care specialists) during a medical extraction from the incident site up-to an admission into a medical facility; Medical information concerning the chemical exposures is accessible to health care professional for filling out the electronic case report form (eCRF); The completion of the eCRF is only in English language; and An Ethical Review Board approval is obtained by each medical center participant  Exclusion Criteria:  • Despite the are no exclusion defined criteria, a negative response to one of the inclusion criteria results to an exclusion.