OVEREXPOSURE LEADING TO RADIODERMATITIS IN INDUSTRIAL GAMMAGRAPHY

1. OVEREXPOSURE LEADING TO RADIODERMATITIS IN INDUSTRIAL GAMMAGRAPHY CHOUCHANE C, HAMMOU A

2. INTRODUCTION • Ionizing radiation (IR) are largely used in industry in Tunisia • The non destructive testing (NDT) are the most common using Iridium sources • Cases of accidental overexposure of workers was observed and reported in many countries in this field of practices • The causes of accident are often due to human fault or lack of equipment manipulation or maintenance or lack of respect of the radiation safety rules or the combination of these factors as it is the case we are reporting

3. Objectives • Report a typical deterministic effects of ionizing radiation eg radiation burns • Disseminate the lessons learned • Recommendations to prevent such accidents in industrial gammagraphy

4. Report of the event • Workers in industrial radiography were victims of an accident that caused a radiation skin burns in a worker observed in Tunisia in n 2008 and the follow up until today . • Our study consists of two parts: • Analytical study and etiological an observation burning suite has a radiological accident in a patient occupationally exposed to IR. • Post study: based on: • The description of the workstation • The simulation of the accident which has allowed us to calculate: • Physical doses received by the victim in collaboration with an expert from the IAEA (International Atomic Energy Agency); • Biological doses paramagnetic resonance in collaboration with an expert IRSN (Institute for Radiological Protection and Nuclear Safety in France ).

5. Hammou Chouchane Chadha

6. Report of the event • 23 March 2008 Three workers from a radiography company located in Tunis, Tunisia were working at a construction site in Rades, Tunisia,their assignment was to conduct non-destructive testing of welds in a spherical steel tank under construction, for the storage of butane gas The accident occurred Sunday at 22h at the top of the tank, and at the height of a scaffold 18 m. • The gamma radiography source was an 80.1 Ci (2.96 TBq) Ir-192 sealed; the source activity when delivered to the company was 118.8 Ci (4.396 TBq) on 10 February 2008.

7. Worker A (assistant) Recently recruited, without prior training on technical radiography and radiation protection rules, he was helping set up the radiographic exposures on the outside of the sphere. He had not received formal training on radiography techniques nor radiation protection, provided some on-the-job training, he was very unfamiliar with the operation of the gamma radiography system (camera) and understood little about the safety procedures and the radiation hazards. • Worker B (another assistant) was responsible for placing the radiographic film in the proper location inside the sphere. After setting the film in place, he would exit the sphere and return to the trailer until the exposure was completed.

8. Worker C (supervisor) is the qualified Operator and was the leader of the three-person team. He was the only person qualified to operate the gamma radiographic device. After setting up for a 12 minute exposure, the supervisor (C) left the construction site to retrieve some unexposed film from the company office a few kilometres away. He did not send of the assistants to get the film, because neither of them had a drivers license. Before leaving, worker C instructed worker A to terminate the exposure after 12 minutes. He was instructed to turn the crank on the remote control to pull the source back into the camera (shielded housing) and then set up the equipment for the next exposure. • Blocking the source in the duct ejection occurred Worker A handled without success: Failing to position the source to the proper position he disconnected the guide tube from the exit port. The source was still attached to the drive cable and was hanging outside the exit port, so he disconnected the source with this right hand, transferred it his left hand, and then placed it in his left front pocket.

9. He banged on the sphere to inform the other assistant (B) that they needed to go to the trailer. Worker A walked down the steps to the bottom of the sphere where he met worker B, and they proceeded to walk to a construction trailer about 50 meters away. • In the trailer, they sat on opposite sides of a small desk for about five minutes and discussed what happened on the top of the sphere. It was reported that worker A did not know that he had the source in his hands. He thought it was just a part of the radiography device that had broken off. He handed the source to worker B who held it for approximately 10 seconds; he (B) saw the “Black Skull” danger symbol and the word “radiation” on the source. At that point, worker B gave the source back to worker A and told him that he thought this was the source and it was very dangerous. Worker A placed the source on the desk and they decided to call their supervisor (C) to inform him of the incident, it took about two additional minutes for worker A to find his phone and turn it on. Then, worker A left the trailer to call worker C; leaving worker B in the trailer alone for an additional minute.

10. The supervisor (C) returned to the construction site to verify if it was truly the source that worker A removed from the device. Worker A entered the trailer first and was there for approximately 30 seconds before worker C joined him. They were in the trailer for approximately 30 more seconds and worker C verified that it was the source and they both exited the trailer to a safe distance. • After moving to the main gate of the constructions site about 100 meters away, worker C called worker D (Company Technical Manager) to inform him of the incident. Worker D picked up a 2-meter long remote handling tool from the office and drove to the site. He instructed worker C to go up to the top of the sphere to get the camera and leave it near the trailer. To recover the source, worker C put the camera inside the trailer near the entrance. Worker D entered the trailer and used the remote manipulator to pick up the source and put it into the camera. Worker C stood 2 meters outside the trailer to verbally guide worker D in placing the source in the camera. When the source was placed in the camera the shutter was closed and the device was locked. • To determine if that was actually the source, the guide tube and remote control mechanism were attached and an unused film was exposed for three seconds. Workers C and D reported that the device functioned correctly.

11. 24 March 2008 Worker D did not report the incident to the appropriate regulatory agencies, but did arrange for blood test to be conducted on the four workers involved. They visited a general practitioner (GP) that day to discuss the incident and do determine if there were any medical concerns. Worker D reported that the doctor told him the blood counts were normal and they were perfectly healthy

12. Immediately after accident worker A reported itching of the hands without other abnormalities. •   He received a blood laboratory tests and was sent to a GP clinical examination unremarkable and prescribed nan anti topic cream • 2nd week: redness, increased warmth of the hands and the appearance of a brown spot at the left hand. • Day14: consultation with an internal medicine specialist who finds free circulation of lesions suggestive of recent burns, without known cause, with both hands, more pronounced in the left hand.Worker A was given antibiotics and antiseptics for infection control. • Day15: Worker A had a 2nd consultation and report exposure to RI

14. Day 25 Specialist of internal medecine contacted Pr. A; Hammou (CNRP) to inquire about the hazards from seeing a patient exposed to a radiation source. He explained the medical condition and history of Worker A. Pr A. Hammou requested that the Dr contact Worker A and bring him to the CNRP immediately for an interview and evaluation. • CNRP DIRECTOR Pr A. Hammou discovered the accident. •   The examination showed the presence of blisters at the palmer and dorsal five fingers right, plus a left palmer side involvement. • There is also a cupboard erythematous localized at the upper part of the left thigh with a localized depilation

15. CNRP sent Worker A to the specialized Burns center for evaluation and possible care. •  The specialist concluded to burns 2nd degree intermediate and deep and performed excision of the blisters and prescribed a symptomatic an antalgic drogue

16. Specialized therapeutic care to Worker A • Pr .A. Hammou immediately reported to the IAEA and the IRSN accident as well as the Minister of health in order to obtain support to send the victim to a specialized center abroad to evaluate the radiation exposure of the other workers and to take measures against the Gammaradiography society . • IRSN recommended the transfer of the patient to the hospital of the Armey instruction in Percy in Clamart, Paris a highly specialized center for the treatment of severe radiation burns • J36: Hospitalization and support involving transplants thin skin on the fingers of both hands and adjuvant injection of autologous mesenchymal stem cells. • The immediate postoperative course was favorable and the healing was complete. Worker also received pressotherapy by compression gloves

17. Follow up • Painful extremities and insomnia with subungual secondary aseptic osteolysis of the phalanges , requiring the repetition of cell therapy in Percy Hospital with amputation of the pad of the distal phalanx of the left index

18. After 2-year follow up • Painful inguinal necrosis in the right middle finger leading to distal phalanx osteolysis • Local treatment and systemic antibiotics. • Evolution: spontaneous expulsion of distal phalanx

19. After 3 years • Severe dermatitis necrosis previously healthy appearance part: right atrial and left index •            Local treatment, and request for an opinion with the doctor at the hospital Percy for a possible re-hospitalization

20. The NDT place and the machine

21. The workplace • NDT (nondestructive testing) work was conducted in in a construction site of a spherical steel tank for the storage of liquid butane gas. • Worker A assistant was assigned to operate the “gammagraphe” to perform the NDT tests at the outer surface of the sphere. • Worker B places the radiological film in the inner side at the internal surface of the sphere

22. The Equipment used: •  "GammaMat" TSI5 / 1 serial number 428, equipped with a sealed source of iridium (192Ir) a 80.1 Ci (2.96 TBq) Ir-192 sealed; the source activity when delivered to the company was 118.8 Ci (4.396 TBq) on 10 February 2008. • The dose rate at one meter on 23/03/2008 was 385.19 mSv / h.

23. The source was recovered by company employees on 23 March 2008 and placed back into the gamma radiography camera. An exposure was made to determine that it was actually the source and that the camera was functioning properly. A qualified technician evaluated the camera on 29 April 2008 and reported that the system operated properly.

24. Simulation of the accident by CNRP/IAEA/ IRSN • CNRP team conducted simulation of the accident which led to the estimation of the whole body dose : 1.09Gy to worker A • Estimation and dose calculation is compleated by IAEA and IRSN • For Dose estimation : Times and distance measurements are based on interviews and measurements during accident reconstitution • Worker A : TOTAL DOSE 1.09E+03 mSv • Worker B : TOTAL DOSE 5.28E+01 mSv • Worker C : TOTAL DOSE 1.69E+00 mSv • Worker D : TOTAL DOSE 1.02E+00 mSv

25. The dosiymetric reconstruction which was completed by the IRSN

26. Comments • The Non-Destructive Testing (C.N.D.) is a set of methods to check the status of integrity of structures or materials, without degrading during the roduction, use or under maintenance. •   It uses SEALED SOURCES • Risks of industrial radiography: •   The "radiologists' operators are among the most exposed to RI in normal working conditions as well as in accident conditions • Radiological burns or dermatitis: main result characterizing the acute radiation syndrome localized to the skin showing the effects of deterministic IR effects

27. Radiodermatitis • It is a burn without a contact with a heat source or caustic products gradual onset and insidious • severity depends on the type of radiation, dose and dose rate, duration of exposure and the anatomic site of the lesion. • 3 Phases are described • The initial phase is characterized by an increase in local heat and erythema •   Phase of clinical latency may take several weeks , no physical signs •   The Active phase whose manifestations are directly related to the intensity dose,

28. The dermatitis (continued) Active Phase • Erythematous dermatitis, is a pink erythema, homogeneous, sometimes accompanied by swelling. • Dry dermatitis: 10 or 15 days after the onset of erythema which gives way to a dry desquamation, then a temporary or permanent pigmentation. Transient hair removal can also occur. • Exudative dermatitis: erythema is complicated by blisters and stinging and itching whose failure leaves exposed dermis vesicles, the patient has a burning sensation • Radionecrosis: Upon reaching the basal layer is added that the endothelial cells of the subcutaneous tissue with ischemia and necrosis

29. The dermatitis: clinical evolution: intense pain, is an excellent functional premonitory sign predictive of unfavorable recurrence of the radiodermatitis • Evolution is unpredictable • The most complication is the appearance of a basal cell carcinoma and squamous cell carcinoma occurs less frequently on the bed of a radiodystrophy

30. Radiodermatitis: Treatment • Treatment is directly related to the depth of the burn, it is dominated by skin grafting, radiation burn does not offer the same healing conditions than thermal burns and therefore often there has been a failed grafts. • Cell therapy seems to emerge as an adjuvant treatment, complementary and inseparable from modern surgery in the management of acute localized irradiation, allowing for conservative treatment of very serious injuries

31. Radiological accidents in industrial radiography : Predisposing factors • The equipment malfunctions • The regulatory offenses • The loss or theft of a source. • The absence or lack of regulatory control • Non-compliance with work procedures • Lack of operator training • Defects in maintenance • Human errors : lack of vigilance • Combined factors

32. Radiation protection organization • Radiation protection is based on three fundamental principles: • Justification of practices. • Optimization: based on the ALARA principle • Exposure dose limitation • The protection means • the distance from the source • screens personal and collective protective devices use • The minimisation of time of exposure •   Dose limitation: as recommended by the ICRP : • The annual effective dose limit is set at 20 mSv for exposed workers and 1 mSv for unexposed workers

33. National Regulatory framework • In Tunisia a legal framework and institutional framework has been put in place since the early 80s. • The legal system includes: •   Law No. 81-51 of 18 June 1981 relating to the protection against the dangers of ionizing radiation sources. • Law No. 96-41 of 10 June 1996 on waste and control of their management and their disposal including radioactive waste. • Act No. 97-37 of 2 June 1997 on the transport by road of which materials and radioactive sources hazardous materials. •   Decree No. 82-1389 of 27 October 1982 on the organization and powers of the National Centre for Radiation Protection. • Decree No. 86-433 of 26 March 1986 on the protection against ionizing radiation. • 89-1895 Decree of 85 December 1989 on the publication of the Vienna Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency

34. Réglementation Institutional framework : CNRP is placed under the tutele of Ministry of health : • It promotes at national level Radiation protection measures , • Training users of sources in Radiation protection • Emergency preparedness and response • CNRP delivers authorization of activities and sources • Enforces regulations and participate to regulations elaboration. • CNRP is in charge of Technical support laboratories of dosimetry, spectrometry calibration and environmental monitoring

35. PREVENTION OF ACCIDENT • Technical prevention is the individual and collective: • Collective prevention is based on the design premises, the delimitation and marking work zones • Individual prevention is based on the principal means of radiation protection (distance, time display). • medical prevention • Role of the occupational physician • Monitoring the health of workers is the responsibility of the employer; • Visit hiring • Medical monitoring: radiography exposure are external exams are geared toward any haematological, eye (cataracts) and skin. • The occupational physician maintains a medical record that includes the dates and results of dosimetric monitoring and additional medical examinations and double the exposure record • The classification of workers and their training and the study of post • Investigation in case of an accident or incident, monitoring and rehabilitation of the worker and the dissemination return of experience

36. Acute and chronic radiation dermatitis are considered professional in accordance with Table No. 76 of the Tunisian list of tables for Occupational Diseases diseases. Hammou Chouchane Chadha

37. recommandations • Although rare workplace accidents are serious Industrial Radiography • For prevention we offer the following recommendations: • Unconditional compliance with permit conditions and use of sources • The qualification and training of users, technical radiography, the health effects of ionizing radiation and radiation protection principles • control characteristics of the sources with the making available to all workers in a diagram of the apparatus and an image of the source • Maintenance program of the radiography device • the availability of means of radiological protection of individual and collective means of detection, marking, individual and operational dosimetric monitoring.

38. Recordkeeping written on procedures • Compliance with safety and radiological safety of sources in use, transport, storage and finally the management of waste sources by returning to the original supplier • The development, approval and updating emergency procedures • This is the ROLE AND RESPONSIBILITY OF ALL: Authorities, Regulatory, Employer, Worker and Occupational Physician

39. ROOT CAUSE ANALYSIS • deficiencies in the safety culture of the company : The accident could have been prevented had some basic safety practices such as adequate training, supervision, and equipment were provided

40. Radiation Effects Awareness of Medical Community • deficiencies in the medical community to identify radiation injuries • The burn specialist did not recognize the radiation burns and treated the burns as if they were thermal burns. • The internist who treated Worker A did not recognize the radiation burns and only contacted the CNRP after finding out that the worker was exposed to a radiation source.

41. Lessons learned • Medical awareness • training medical personnel in the identification and treatment of radiation injuries, as well as in the overall medical response to radiation emergencies. • IAEA training material and documents :poster ...

42. General recommendations • Improve the awareness of radioactive material users and licensees in regards to emergencies, procedures, and reporting. • Require all workers to be fully qualified before being allowed to use dangerous sources. Licensees should ensure that training, dosimetery and safety equipment are provided.   • Expand the inspection and audit program for authorized users of radioactive material to include more comprehensive inspections prior to issuing a new authorization, and increasing the inspection and audit frequency for existing users.   • Authorize CNRP to immediately stop work or suspend radioactive material authorizations when unsafe practices or working conditions are identified, which involve radioactive materials.

43. Upon receiving notification of an accident or incident involving radioactive materials or radiation producing devices, all operations associated with the material or device should be immediately suspended pending an investigation. • During an investigation of a radiation accident or incident, a complete review of the authorized user’s radiation records should be immediately conducted. This should include training, dosimetry, source maintenance and calibration, radiation detection instrument maintenance and calibration, source usage records.