ROSEMORE MIDDLE SCHOOL
(a/k/a WHITEWALL RESIDENTIAL MERCURY SPILL ASSIST)
WHITEWALL, FRANKLIN COUNTY, OHIO
The Health Assessment Section (HAS) of the Ohio Department of Health assisted the Ohio Environmental Protection Agency, the Franklin County Health Department, and the Whitehall City Fire Department in responding to a mercury spill May 14, 2003 at the Rosemore Middle School located in Whitehall, Ohio. The spill occurred after a student brought approximately five teaspoons of mercury to the school in a metal vial that he discovered in his grandfather's garage to the school. The mercury was first spilled in the school's music/choir room during the first period of the day. The student poured a small amount of mercury on the floor of the choir/music room and then encouraged approximately 4-6 other students to stomp and run through the visible mercury, causing it to disperse all over the room. The student then placed the remaining mercury in his pocket and went on to his next class. During the third period of the day, the student possessing the mercury was approached by another student who offered to buy the remaining mercury for $4. The vial of mercury then changed hands. The second student carried the mercury with him for the remainder of the day until he reached the final period of the day. During the final period, the second student proceeded to pour the mercury on the window sill and on the ground outside the window of a second classroom. Several other students watched the exhibition, and at least one student physically touched the mercury. After the end of the school day, the student took the remaining mercury home with him, where it appears that he spilled the majority of the remaining mercury in his family's bathroom.
At approximately 7:30 p.m. on the same day, one of the students who had witnessed the mercury being poured in the school told his mother what had happened. The mother immediately called the Central Ohio Poison Control Center, which notified the Whitehall City Fire Department and the Ohio Environmental Protection Agency. The Whitehall City Fire Department responded to the school and discovered visible mercury on the floor of the music/choir room. The fire department attempted to clean as much visible mercury as it could. The Whitehall fire chief then visited the student whose mother had called the poison control center in an attempt to determine the extent of the mercury contamination and to make sure that the students had not contaminated other structures, including their homes. The initial student provided the names of three other students who had contact with the mercury. The fire chief visited the homes of each of the four children and brought them, along with the clothing that they had been wearing for the day, to the school for decontamination. Upon interviewing the students, the fire chief was able the recover the remainder of the mercury in its original container and prevent any additional spills. The fire department also collected the clothing of the janitorial staff that had been reported to have cleaned the classrooms prior to the fire department's response.
On May 15, 2003, HAS staff arrived at work to see news of the Rosemore School mercury spill on the front page of the newspaper. HAS staff immediately contacted the Ohio Environmental Protection Agency to offer any assistance that may be needed. At this point, Ohio EPA staff had not yet been on site and was still acquiring information. HAS staff were invited to attend a briefing being held at the Whitehall City Fire Department. After arriving at the fire department, HAS staff contacted the Franklin County Health Department to invite its members to join the meeting and to offer any assistance that may be needed, because the county health department has the authority to give final occupancy clearance after a mercury spill. During the initial mercury response on May 14, 2003, the fire department made the conservative decision to instruct all students who attended school the day of the spill to dispose of their clothing and to visit their physicians. After the initial briefing, a better understanding of the spill was obtained and it was decided to change the message to state that students should place their clothes and shoes in a plastic bag and put the bag outside and await further instruction as to whether the items needed to be disposed of or could simply be washed and used again. The students were also advised that it was not necessary to see their physicians unless the students knew that they had direct contact with the mercury. HAS staff were interviewed by the local television media, and the staff delivered this new message to the public during the interview.
After the morning briefing, HAS and Ohio EPA recommended that all equipment that was used to clean the spill be isolated until it could be evaluated. It was also recommended that janitorial staff be evaluated for exposure to mercury vapors.
After the initial briefing, interviews were conducted with students who were known to have contact with the mercury during the school day to determine how many students may have had direct contact with the mercury and to figure out if any of the students may have taken mercury home with them, either intentionally or unintentionally, by transporting the mercury on their clothing or shoes. If a student was found to have had direct contact with the spilled mercury, the agencies involved would attempt to determine the extent of the contact and would also conduct a screening of the clothing and home to determine if any mercury had been brought home and caused additional contamination. The interview team consisted of members of the Ohio EPA, HAS, and the Franklin County Health Department, as well as an employee of the U.S. EPA contractor, Tetra-Tech, who conducted the screening of the homes and property using a Lumex RA915+ mercury vapor analyzer.
Team members were initially given a list of four students who were known to have been in contact with the mercury. The first interview was conducted with the student who brought the mercury to school. During that interview, the student admitted that he had taken the mercury from his grandfather's garage and brought it to school. The student lives at his grandfather's residence. He stated that no mercury was spilled at his home. Screening the residence with a Lumex RA915+ mercury vapor analyzer determined that no mercury was present in the home at levels of health concern. The student's grandfather stated that several months ago, he had spilled a small amount of mercury in the garage when he was instructing his grandchildren to leave the mercury alone. Screening of the garage resulted in the discovery that there were detectable mercury vapor levels up to 50.0 micrograms per meter cubed (ug/m3). The garage was sealed with caution tape, and the grandfather was instructed to remain out of the garage and to await further instruction on how to proceed in attempting to decontaminate the garage. During this initial interview, team members were given the names of two additional students who may have had contact with the spilled mercury, thus bringing the total to six students.
During the interview with student #2, he admitted that after the mercury was spilled in the choir/music room, he ran through the mercury and kicked the beads, causing them to disperse throughout the room. He stated that he did not knowingly take any of the mercury out of the classroom. A screening of his shoes and the entrance to the home detected only low levels of mercury vapor that were below levels of health concern.
Student #3 also admitted to stepping on the mercury in the choir/music room, but he said that he did not remove any of the mercury from the classroom. His mother stated that his clothing had already been washed so that it could not be screened. A screening of his shoes and home did not reveal any elevated mercury vapor levels.
Student #4 was the student who bought the mercury from student #1. It was reported that this student poured the mercury on the window of classroom 113 in the Rosemore Middle School. The home of Student #4 was also the home from which the fire department recovered the remaining mercury. During the interview with this student, he admitted buying the mercury during his third period class and showing it to two additional students, bringing the interview total to eight. The student indicated that he did not spill any of the mercury until the final period of the day, when he poured the mercury on the window sill of Room 113. After the school day was over, he took the mercury home and proceeded to play with the mercury in the upstairs bathroom of the home, where he spilled some of the mercury in the trash can and on the floor. Team members were unable to screen this student's clothing and shoes because they had been confiscated by the fire department the night before and were being held at the school for future screening and decontamination. An initial screening of the home indicated elevated mercury vapors up to 3.3 ug/m3 in the breathing zone on the first floor of the home and up to 5.8 ug/m3 on the second floor. Mercury vapor levels in the bathroom where the mercury was spilled were measured up to 52.0 ug/m3.
The Agency for Toxic Substances and Disease Registry (ATSDR) has established a residential mercury vapor action level of 1.0 ug/m3 and an evacuation level of 10.0 ug/m3 for residential housing. Because of the elevated mercury vapor levels in Student #4's home, several recommendations were made to the family. The family was instructed to stay out of the bathroom until decontamination could be attempted. Decontamination was attempted by removing the carpet and trash can from the bathroom and placing the material outside. The house was then closed up and heated to a temperature of 75 degrees Fahrenheit an an attempt to vaporize any remaining mercury. After an hour, the heat was turned off and the house was opened up and allowed to ventilate until it could be screened again. After approximately three hours, the house was screened again and the mercury vapor levels had greatly decreased. Mercury vapor levels on the first floor were detected up to 0.44 ug/m3, and on the second floor in the bathroom the vapor levels were up to 0.78 ug/m3. Both these levels are below the ATSDR recommended action level of 1.0 ug/m3. The family was advised to continue venting the home for a few more hours to allow the mercury vapor level to continue to diminish.
Student #5 witnessed the mercury's being spilled on the window sill during the final period of the day. The student does not think that he came into direct contact with the mercury, and said that he did not bring any of the mercury home with him. Screening of his shoes and clothing did not reveal elevated mercury vapor levels.
Student #6 was the student whose mother called the poison control center to report the mercury spill at the school. The student's clothes had been collected by the fire department and were being held for screening. Team members were analyzed the student's home and the shoes that he was wearing the day of the spill. Mercury vapors were not detected in the home or on the shoes at or above levels of health concern.
Student #7 stated that he was shown the mercury by student #1 prior to the start of school and also may have stepped in the mercury that was spilled in the choir/music room. Screening of his shoes, clothes, and residence detected low levels of mercury vapor (0.9-0.99 ug/m3) but not at levels of health concern. The family was advised to allow the shoes and clothing to "air out" for the rest of the day prior to the student's wearing them again.
Student #8 was the final student interviewed. This student was present to witness student #4 pouring the mercury on the window sill during the final period of the day. Student #8 also admitted placing his finger in the mercury after it was poured out. Screening of his shoes and clothes indicated slightly elevated mercury vapor levels of 2.46 ug/m3 , which is still below the ATSDR-recommended disposal level of 10 ug/m3 for personal property. The student was advised to allow his clothes and shoes to sit outside for the rest of the day to allow the mercury to continue to vaporize. Mercury vapor was not detected at elevated levels in his home.
After the interviews with the students, it was concluded that the team had a good idea of the extent to which the mercury had been handled both in and out of the school. At this time, it was decided to scale back the media message and advise parents and students of the current situation. The Whitehall fire chief held a media briefing and presented the message that unless the student had been directly contacted by Ohio EPA, ODH, or the Franklin County Health Department, there was no need to keep personal clothing and shoes in plastic bags. Parents of students were advised to wash their children's clothing and allow them to wear it as usual. Parents were also advised that it was unnecessary to contact their physicians to obtain a mercury screening because it was unlikely that they were exposed to mercury vapors at high enough levels or for long enough periods of to develop adverse health effects.
Rosemore School Mercury Clean-up
HAS staff were not directly involved with the clean-up of the mercury spill at the Rosemore Middle School. The spill was confined to two classrooms (music/choir room and room 113) and to a small portion of the hallway outside the music room. There was also a small amount of mercury spilled in the grass outside the window in Room 113. Initial mercury vapor concentrations in the music/choir room as read by the Lumex RA915+ were greater than 58 ug/m3, which is the upper detection limit of the Lumex. The school was closed for two days to allow for clean-up of the impacted classrooms and outside soils.
HAS receives calls for assistance on school and residential mercury spills on a regular basis. It is not uncommon for the calls to include homes with small children. Possible routes of exposure to mercury include inhalation, ingestion, and dermal absorption; however, the primary pathway of concern is inhalation of mercury vapors.
Inhalation of high levels of elemental mercury can cause permanent neurological damage and kidney impairment. ATSDR recommends that breathing zone mercury levels not exceed 1.0 ug/m3 (ATSDR 2001). This recommended level is based on both animal studies and human epidemiological studies that describe the health effects of inhalation of mercury-contaminated air. Workers who were exposed to mercury vapors in an occupational setting at levels above 1.0 ug/m3 exhibited hand tremors, increases in memory disturbances, and slight evidence of autonomic nervous system dysfunction. The ATSDR minimal risk level (MRL) for mercury in air was derived from the lowest observed adverse effect level (LOAEL) of 26.0 ug/m3. Because workers were exposed only during working hours, the LOAEL was adjusted to account for continuous exposure. The resulting value was divided by an uncertainty factor of 10 to protect sensitive human subgroups and by a factor of 3 because a LOAEL was used rather than a no observed adverse effect level (NOAEL). The resulting MRL is 0.2 ug/m3. An MRL is defined as an estimate of the daily exposure level to a hazardous substance that is likely to be without appreciable risk of adverse, non-cancer health effects. The ATSDR recommended value for a residential setting of less that 1.0 ug/m3 is an action level that, if exceeded, would prompt the need for further clean-up or other remedial action.
Breathing zone measurements in the home of student #4, in the garage of student #1, and at the Rosemore Middle School initially exceeded these standards. After removal of several property items and one cycle of heating and ventilating, the mercury vapor levels in the home were reduced to below the ATSDR screening level of 1.0 ug/m3. Clean-up of the school was conducted by a contractor hired by the school district. After remediation and mercury removal, all mercury vapor levels in the school were reduced to below 1.0 ug/m3. The owner of the garage with elevated mercury vapors was advised by Ohio EPA on how to proceed with clean-up. HAS has not been able to determine if the garage has been remediated.
Children may be at a greater risk than adults from certain kinds of exposure to hazardous substances at sites of environmental contamination. Children engage in activities such as playing outdoors and hand-to-mouth behaviors that increase their exposure to hazardous substances. They are shorter than adults, which means they breathe dust, soil, and vapors close to the ground. Their lower body weight and higher intake rate results in a greater dose of hazardous substance per unit of body weight. The developing body systems of children can sustain permanent damage if toxic exposures are high enough during critical growth systems.
Children who breathe metallic mercury vapors at high levels for extended periods of time may develop a disorder known as acrodynia, or pink skin. The symptoms of this disorder include severe leg cramps; irritability; and abnormal redness of the skin, followed by peeling of the hands, nose, and soles of the feet. Itching, swelling, fever, fast heart rate, elevated blood pressure, excessive salivation or sweating, rashes, sleeplessness, and/or weakness may also be present. This disorder may also occur in teenagers and adults. Exposure to mercury vapors is more dangerous for young children than for adults, because inhaled mercury vapors easily pass into the brain and nervous system of young children and may interfere with the development process. Exposure to high levels of mercury vapor can also cause lung, stomach, and intestinal damage. Death due to respiratory failure has resulted from cases of extreme exposures.
Exposure to mercury vapors in the school was likely limited to the time spent in the classrooms at which mercury was spilled, and the exposure would have been minimal. There are no known instances in which exposure to relatively low levels of mercury vapors for short periods of time have resulted in adverse health effects. It is unlikely that any of the students who were exposed to mercury in the school would develop adverse health effects.
The residents in the home of student #4 were exposed to elevated levels of mercury vapors for approximately 24 hours. After remediation efforts, the mercury vapor levels were returned to background levels. Students who had direct contact with the mercury were advised to consult with their physicians. It is unlikely that exposures at these homes would have resulted in any lasting or severe health effects for the residents or for children.
Breathing zone levels of mercury vapor posed an urgent public health hazard to students and faculty of the Rosemore Middle School as a result of the spill of mercury in two classrooms. The school district should be commended for its prompt and thorough response to mitigate any further exposure to students and staff. After remedial efforts were completed, the levels of mercury vapor in the school returned to background levels.
The levels of mercury vapor in the home of student #4 posed an urgent public health hazard to the residents living in the home. HAS, Ohio EPA, the U.S. EPA contractor, and the Franklin County Health Department assisted the homeowner with technical advice and real-time monitoring of mercury vapor levels. Health education was provided to advise homeowners on how to reduce the levels of mercury quickly in their homes by opening windows and doors and ventilating the homes. The response of the Ohio EPA, the Franklin County Health Department, the U.S. EPA contractor, and HAS, along with the cooperation of the homeowner, allowed the spill to be remediated and the levels of mercury vapor in the home to be lowered to below health screening levels.
The levels of mercury vapor in the garage of student #1 pose a potential public health threat to residents in the home as a result of the elevated levels of mercury vapor in the garage. There is evidence that children in the home spend time in the garage and have the potential to be exposed to mercury vapor and possibly track mercury to other locations. The homeowner was advised to restrict entrance to the garage until a time could be arranged for Ohio EPA to provide technical assistance in reducing the mercury vapor levels in the garage. HAS was unable to confirm whether the garage has been remediated at this time.
The following recommendations were made in the course of the investigation by HAS:
1. Isolate potentially mercury-contaminated personal property in plastic bags and place outside home.
2. Parents whose children who had direct contact with the spilled mercury were advised to consult their physicians to determine the extent of exposure. Janitorial staff who cleaned the school after the mercury was spilled were advised to consult their physicians to determine if this staff were exposed to elevated levels of mercury vapor.
3. Leave clothing and shoes with residual mercury outside overnight to allow for further mercury reduction.
The recommendations listed above were all implemented, and thus there is no need for further action at this site. HAS will follow up with Ohio EPA to determine if the garage with elevated mercury levels was properly remediated.
Agency for Toxic Substances and Disease Registry. 1999. Toxicological profile for mercury, update. Atlanta: US Department of Health and Human Services.
United States Environmental Protection Agency. 2003. Integrated Risk Information System (IRIS). Substance file for mercury.
Eric Yates, Health Assessor
Robert Frey, Ph.D., Principal Investigator
This Rosemore Middle School Mercury Spill Assist Health Consultation was prepared by the Ohio Department of Health under a cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR). It is in accordance with approved methodology and procedures existing at the time the health consultation was begun.
Alan W. Yarbrough
Technical Project Officer, SPS, SSAB, DHAC, ATSDR
The Division of Health Assessment and Consultation, ATSDR, has reviewed this public health consultation and concurs with the findings.
for Chief, State Program Section, SSAB, DHAC, ATSDR