I. The Issue:
The use and application of radioactive materials in both industry and medicine continues to increase over time.As our knowledge and application of these materials expands, there is also an increased need to study and research these materials.But at the same time the common knowledge of the deleterious effects that exposure to these materials can cause has allowed the term radioactive to become a strong trigger word in modern society.There exists a fine line between useful tool and extremely hazardous material when working with radioactive materials.The key is proper handling, shielding, and control to minimize the risk of accidental exposure to the radiation source.
II. The approach taken:
Our review of the radioactive materials maintained by the school department began when a container of thorium nitrate was discovered in one of the high school science classrooms.In response to this discovery, we surveyed the staff to learn if they were using or aware of any other radioactive materials maintained by the science department.The staff reported that they were not aware of any other radioactive materials present at the school.
Almost immediately we recognized that we did not have even a general summary or list of common radioactive materials.Our efforts to locate such information were unsuccessful.In recognition of this shortfall, we obtained the assistance of the radiation safety officer of the local hospital.This individual conducted a radiological survey of the entire science area.During this effort, we located three additional containers of thorium nitrate, a container of uranium tetrachloride which had been used as a paper weight, three unlabeled multi-chambered containers of radioactive powders, and three radioactive rocks in the geology collection.All of these materials were found in open storage in the classrooms.
Due to the hazards associated with the handling of unsealed radioactive sources, we decided to dispose of the materials discovered at the school. Initially, we contacted the federal Nuclear Regulatory Commission (NRC) for assistance with this problem.The NRC informed us that because the school was not licensed to handle radioactive materials and because of the small amount of materials involved the school was under the purview of the Massachusetts Radiation Control Program.Once informed of our discovery and concerns, the Massachusetts Radiation Control Program readily agreed to accept and dispose of the radioactive reagents. The high school geology instructor was allowed to assume ownership of the radioactive rocks with the condition that the materials not be stored in the school.
III. Observations made:
First, the staff was not aware that the school department possessed radioactive materials.As a result, the staff was not aware that these materials were openly stored in their classrooms.A chance observation prompted our discovery and investigation into this issue.
A radiological survey of the high school science area enabled us to identify and locate the following radioactive materials present in the classrooms: uranium tetrachloride, three unlabeled multi-chambered containers of various radioactive materials, three containers of thorium nitrate, and several radioactive rocks.None of the reagents were labeled to indicate that the contents were radioactive.
The most serious observation was that aside from the rocks, all sources were unsealed powders and could pose a serious health concern when handled or if spilled.Normally, sealed radiation sources are used in educational settings for demonstration purposes.A sealed source is created by sealing or embedding a radiation source in a matrix such as plastic.Often by design radiation may only leave the sealed source from one side or location.The intent of this design is to reduce accidental exposure to the source and to prevent the inhalation or ingestion of the source.Since much of the radioactive material found in the science department was powdered there existed the possibility that this material could be inhaled or ingested whenever the material was handled or spilled.As a result, the shielding or protective effect offered by our clothing and skin would be lost if the material entered the body.Also, once in the body these materials would cease to be relatively harmless radioisotopes and could become potentially lethal in nature.
During our investigation, we made no attempt to accurately determine what type of particles or the energy level of the particles emitted by each source.Based on qualitative information gathered during the radiological survey, all sources were presumed to be alpha and beta emitters.
While surveying the equipment maintained by the high school science department we discovered that the department did possess a broken Geiger counter. The presence of this device suggests that radioactive materials may have been used by the staff at some time.No sealed sources were located during the radiological survey or follow up inspections.
A final observation was that the school department was not equipped or trained to monitor for or manage radioactive contamination.As a result, it was not possible to determine if materials or individuals had been contaminated during the past handling of these materials.
Upon discovery of the radioactive materials, the staff was very supportive in having these materials removed and properly disposed.
IV. Problems or concerns noted:
- The staff was unaware of the presence of radioactive materials in the high school science area.
- None of the materials identified during the radiological survey were labeled as radioactive.
- These materials were stored openly in the classrooms.
- All the radioactive reagents were unsealed sources that could be inhaled or ingested when handled or spilled.
- The school was not equipped or trained to monitor for radioactive contamination.
V. Actions taken:
A.Surveyed the science department for radioactive materials.
After a chance discovery of a radioactive material in the high school science department, we surveyed the staff to determine if they were aware of any other radioactive materials that were present in the school. The staff was not aware of any other radioactive materials present in the science area.In order to ensure the completeness of our review, we had the radiation safety officer of the local hospital conduct a radiological survey of the science area.Using a screening device, this individual located the following radioactive materials in the science area: a container of uranium tetrachloride, three additional containers of thorium nitrate, three unlabeled containers of various radioactive powders, and several radioactive rocks.
B.Due to the health hazards associated with the use and handling of unsealed radioactive sources, we arranged for the proper disposal of the radioactive materials.
Once informed of our discovery and concern, the Massachusetts Radiation Control Program agreed to accept and properly dispose of the radioactive reagents we found in the high school science area.A geology instructor requested and was granted ownership of the radioactive rocks found in the school.
1. Not all radioactive materials are labeled to indicate that they are radioactive, especially if the materials were acquired in the distant past.
None of our materials were labeled to indicate that the contents were radioactive.Therefore, you cannot assume that the container labeling will provide adequate warning for this hazard.
2. Unsealed sources pose serious health hazards.
Unsealed or powdered radioactive sources pose serious health hazards because these materials can be easily ingested or inhaled if mishandled. Once inside the body even minor or low energy radioactive material can become potentially lethal in nature.
3. The presence of Geiger counters, Geiger tubes or scintillation counters may be a strong indication that radioactive materials might be present or have been used at the school.
The presence of this equipment should be considered as a warning that radioactive material is or has been used at the school.As a result, efforts should be initiated to determine if any sources remain at the school.If sources are found, then efforts should be implemented to determine the activity and energy of the source as well as the health and safety hazards associated with the material.This information will enable you to determine how to safely store and handle the material or whether disposal is the most appropriate option.
Tips and Suggestions:
1. Survey the science department staff and review the equipment inventory for indicators which suggest that radioactive materials may be present at the school.
2. Review your chemical inventory for common radioactive materials.
3. Conduct a screening survey of the science department to locate unidentified radioactives.
Use a radiological screening device to attempt to identify and locate radioactive materials present in the school.Expert assistance in conducting this type of review may be obtained from a local hospital, a local hazardous materials response team, utilities, and state public health agencies.
During this investigation, I utilized the resources available via the Massachusetts Department of Pubic Health - Radiation Control Program. I also reviewed guidance information prepared by the U.S. Department of Labor Occupational Safety and Health Administration.Due to regional differences with regard to the management and handling of radioactive materials, I recommend that you consult with your state environmental, health, and occupational hygiene offices, and the regional EPA and OSHA offices prior to initiating your own radiation survey.
prepared by Todd H. Dresser, Environmental Engineer
Burlington Board of Health, 29 Center Street, Burlington, MA 01803