Study On Decontaminants For Radioactive Isotopes Contamination Wound

Nuclear energy is widely used in the fields of energy,military,medical treatment,testing,and so on.In the conducting process of various nuclear tests,human beings may have cuts,stab wounds,explosive injuries,burns and other injuries.These wounds may be contaminated by radioactive materials.After entering the human body through the wound,the radioactive materials would be transferred to the blood,muscle,liver,kidney,bone and other organs,and cause serious harm to human health.In order to reduce the long-term and persistent harm to human health caused by radioactive materials,rapid treatment of radioactive contaminated wounds is considered to be one of the most effective ways,therefore,the development of high efficiency decontaminant for radioactive contamination wound has great significance to the protection of human health.In this paper,three chelating agents?EDTA·Na₂,DTPA,EDTMPA?and two adsorbents?carboxymethyl chitosan,sodium alginate?were selected to prepare decontamination agent.The formulation of decontamination agent was studied by single factor testand orthogonal experiment according to decontamination efficiency.The preparation method of decontaminant was studied according to the properties of the ingredients,and the physical and chemical properties of decontaminant were determined.One-time wound pulse washing system was used to wash the animal wound created by perforating the skin.The washing conditions such as the decontaminant volume,contaminated liquid volume and contaminated time were optimized.The decontamination efficiency of different radionuclides contaminated wound in rats and rabbits were measured.According to the safety evaluation method of disinfectant in Technical Standard for Disinfection,the safety evaluation experiments of one-time integral skin irritation,one-time damaged skin irritation,acute eye irritation,acute oral toxicity and accumulative toxicity were carried out.The following main results were obtained:?1?The screening of formulas:When the concentrations of EDTA·Na₂ and EDTMPA were 0.6 and 0.01 mol/L respectively,the decontamination efficiency for Cs⁺contaminated rat wound were upto 74.15%and 76.06%respectively;which were significantly higher than that of normal saline?p<0.01?.When the concentrations of sodium alginate and carboxymethyl chitosan were 4 g/L and 3 g/L,respectively,the decontamination efficiency for Cs⁺-contaminated rats wound were upto 68.22% and 74.22%respectively,which were significantly higher than that of normal saline?p<0.01 or p<0.05?.The decontamination efficiency of lidocaine acid solution on the wound of Cs⁺contaminated rats showed an increasing trend with the increase of concentration,and reached 79.46%when the concentration was 1%?m/V?.One time skin irritation test showed that EDTA·Na₂,carboxymethyl chitosan,sodium alginate and lidocaine hydrochloride were non-irritating and could be used as the formulas of decontaminant.?2?Preparation of decontaminant:According to the decontamination efficiency of chelating agent and adsorbent on Cs⁺contaminated wound,EDTA·Na₂,sodium alginate,carboxymethyl chitosan and lidocaine hydrochloride were selected as the main components of decontaminant.The mass ratio of each component was determined by orthogonal test,and the formula group of decontaminant was determined to be EDTA·Na₂:15%?mxv?,carboxymethyl chitosan:0.1%?mxv?,sodium alginate:0.2%?mxv?and lidocaine hydrochloride:1%?mxv?,the rest was pure water.The pH value was 6.98,the density was 1.00±0.01g/cm³,and the content of EDTA·Na₂ was 14.85±0.03%.After being placed at-5?and 40?for 24 hours,there was no odour,no white precipitation and discoloration,no turbidity,and the decontaminant had stable properties.?3?The decontamination efficiency of decontaminant:The decontamination efficiency decreased with the increase of contaminated liquid concentration.The decontamination efficiency increased with the decontaminant volume,and when decontaminant volume was higher than 50 mL,the volume had little effect on the decontamination efficiency.The contaminated time decreased the decontamination efficiency.The decontamination efficiency for different metal nuclides contaminated wound of rats were:Co²⁺:81.94±2.58%,Mn²⁺:80.39±6.48%,Sr²⁺:78.00±3.00%,Ni²⁺:85.19±4.04%,Cs⁺:77.30±4.67%.The decontamination efficiency for different metal nuclides contaminated wound of rabbits were:Co²⁺:41.67±3.57%,Mn²⁺:71.03±4.96%,Sr²⁺:55.21±3.52%,Ni²⁺:65.67±3.21%,Cs⁺:42.90±4.10%.?4?The safety evaluation of decontaminant:One-time integral skin irritation index was 0,and the integral skin irritation intensity grade was non-irritating.One-time damaged skin irritation index was 0,and the damaged skin irritation intensity grade was non-irritating.The decontaminant did not stimulate the eyes of New Zealand white rabbits,and the cornea of rabbit eyes did not appear turbid and other unusual symptoms.There was no obvious deepening of folds,congestion,bleeding,swelling and other visible destruction in iris.There were no tears,congestion,secretion increase and other symptoms in conjunctiva,and the conjunctival blood vessels were normal without abnormal color.In the acute oral toxicity test,the dose for ICR mice was 5g/kg body weight,and there was no death condition within 14 days.It could be judged that LD50 was more than 5000mg/kg body weight,and the decontaminant was actually non-toxic.In the accumulative toxicity test,ICR mice did not show limb convulsions,dysphoria,anorexia,reduced activity,clumsy behavior,and other unusual symptoms.No death occurred in ICR mice within 20 days.The accumulative toxicity grade was weak accumulative toxicity.Using EDTA·Na₂,sodium alginate,carboxymethyl chitosan and lidocaine hydrochloride as the main components,a radionuclide contaminated wound decontaminant was developed for the treatment of various radionuclides?Co,Mn,Sr,Ni and Cs?contaminated wound,and achieved a high decontamination efficiency.The preliminary safety evaluation test showed that this decontaminant met the safety requirements of wound disinfectant and was suitable for decontamination of radionuclide contaminated wound in nuclear accidents.The decontaminant studied in this paper had completed the laboratory research in accordance with the requirements of the national disinfectant product declaration,which has laid a technical foundation for the product approval declaration and development.