The 20-year follow-up of five victims externally exposed in " 4.26" 60Co radiation accident in Henan province / 中华放射医学与防护杂志

ABSTRACT

Objective:To investigate the late effects induced by external ionizing radiation through long-term follow-up of the victims exposed to 60Co radiation source at " 4.26" accident in Henan in 1999, and to provide valuable experience in the radiological medicine. Methods:Medical observations of the clinical symptoms, signs, eye lens examination and previous medical history of the five exposed victims were performed and recorded. The changes of the laboratory routine examinations, immune function, thyroid function, reproductive hormone levels, tumor markers, radiation genetic indicators as well as ultrasound examination of thyroid, cardiac, reproductive system, electrocardiogram, chest CT were systematically reviewed.Results:The typical radiation-induced cataract was found in " Mei" 2-3 years after 60Co accidental irradiation. 13 years after irradiation, the cataract surgery and intraocular lens implantation in left eye were performed followed by the same operation in right eye in November 2019. Different degrees phacoscotasmus under the posterior capsule or equatorial part of the eyes were also found in the rest of victims. ECG result of " Mei" indicated myocardial ischemia 7 years after accident. " Tian" confirmed diagnosis coronary heart disease 12 years after irradiation, and the surgery about coronary angiography heart stent implantation was taken at 20 years after irradiation. Five victims showed increased serum total cholesterol and/or triglycerides, and 4 victims showed bilateral or unilateral common carotid atherosclerotic plaque formation. Higher levels of thyroid stimulating hormone (TSH) were observed in " Mei" at 11 years after the irradiation. The thyroglobulin antibody (TGA)and thyroid microsomal antibody (TMA) were obviously increased in " Yi" , accompanied by thyroid uneven found by ultrasound. The thyroid nodules in " Mei" and " Min" were observed at 15 years after irradiation. The diagnosis of diffuse large B cell lymphoma(DLBL) in " Tian" was confirmed at 13 years after irradiation. Slightly higher of Neuron-specific enolase(NSE) were found in " Tian" , " Min" and " Yi" . A small nodule was detected from chest CT of " Tian" . Most of the chromosome aberrations observed in peripheral blood lymphocytes from the victims were stable chromosomal aberration such as translocation (t) with a few dicentric chromosome (dic) and acentric fragment (ace) in " Wang" and " Tian" . Conclusions:Ionizing radiation can cause variable degrees of deterministic effects in lens, thyroid gland and cardiovascular circulatory system and stochastic effects such as neoplasm. The genetic damages will last long in the patients.