Radiation is toxic to the human body, and increased levels can cause injury to tissue systems from free radical damage. Exposure can be acute or chronic, and symptom severity depends on many factors like total dose, dose rate, distribution of dose and the susceptibility of the patient to the radiation. Tissue systems with greater rates of cell division, such as the hematopoietic and gastrointestinal systems, typically fare worse as the necessary cell turnover is interrupted by widespread cell death.
Leukopenia
Leukopenia is the decrease in leukocytes, or white blood cells, that are among the body's primary defenses against infection. Immunosupression usually results, especially for opportunistic infections that are not typically found in healthy hosts.
Thrombocytopenia
The destruction of platelet progenitor cells results in a decreased platelet count that is not initially very responsive to therapy. Clinical consequences include petechiae and increased susceptibility to prolonged bleeding.
Lymphopenia
The destruction of lymphocytes, which are another type of cell used by the immune system, is unique in that the extent of destruction can be of prognostic value. At levels of 1200/µL, significant poisoning has most likely not occurred; but if after 48 hours the levels are between 100/µL and 500/µL, there should be suspicion of significant--possibly lethal--poisoning.
Anemia
Anemia is usually not as serious of a problem, as red blood cells have a longer half life (roughly two months) compared to the other elements of blood. This is why destruction of the progenitor cells that create red blood cells is not noticed until later, at which point the patient is usually stable and does not require the intensive therapy necessitated by acute radiation poisoning.
Warning
If you or anyone you know suspects radiation poisoning, go to the emergency room. Acute poisoning has a high morbidity/mortality rate, and a physician is the best person to evaluate a patient both clinically and with the aid of laboratory tests/imaging to make the right decisions.
References
- "Cecil Medicine, 23rd Edition;" Goldman; 2007
- "Rosens Emergency Medicine, 7th Edition;" Marx; 2009
