Gregory A. Burr, CIH
Leonard M. Zwack, SeD
National Institute for Occupational Safety and Health
Regional Office of World Health Organization
OFFICE OF THE PAHO / WHO
REPRESENTATION FOR BARBADOS, EASTERN CARRIBEAN STATES
P.O. BOX 508,
TELEPHONE: (246) 426-3860
FAX: (246) 436-9779 I 228-5402
Highlights of this Evaluation
The Health Hazard Evaluation Program received a technical assistance request from the Pan American Health Organization to evaluate the indoor environmental quality at Basseterre High School in St. Kitts.
The request was submitted on behalf of the Government of the Federation of St. Christopher and Nevis.
What We Did
• We did walk-through surveys of all12 school buildings on the Basseterre High School campus.
The school was unoccupied during our evaluation.
• We checked for moisture, water damage, and mold inside the buildings.
• We measured temperature, relative humidity, carbon monoxide, hydrogen sulfide, and total volatile organic compounds.
• We did lead paint testing.
• We checked the airflow in the chemical fume hood in the chemistry classroom.
What We Found
• We saw no widespread mold. We saw visible water stains in some buildings. This suggests past or current water infiltration. Some of these stains may be from a leaking roof.
• We saw bubbling and peeling paint in some classrooms.
• We saw active water leaks in two buildings on the eastern campus. One was in the home economics classroom, the other in the girl’s bathroom.
• In the naturally ventilated classrooms the relative humidity was not always kept below 65%.
• We detected a faint odor of hydrogen sulfide (also called sewer gas) after running water taps in two science labs. We measured very low concentrations. The odor quickly disappeared after running the water, suggesting that that the odor was likely from dry drain traps.
• We measured very low concentrations of carbon monoxide and total volatile organic compounds.
• We did not detect lead in paint samples.
• We saw evidence of termite infestation in multiple areas.
What Basseterre High School Officials Can Do
• Fix active roof leaks in all school buildings. Investigate the roof above the classrooms on the western campus for leaks.
• Hire a licensed professional mechanical engineer to assess the school’s ventilation systems.
Consider installing mechanical ventilation in all classrooms and occupied spaces.
• Stop any additional environmental air sampling and proposed soil sampling for bacteria.
• Create a health and safety committee that includes management and employees.
• Create a system for employees to report building concerns and to receive feedback on how issues were resolved.
What Basseterre High School Employees Can Do
• Report signs of water intrusion to school officials.
• Report work-related health concerns to school officials.
• See an occupational medicine physician about health problems you think may be related to work.
• Join the health and safety committee.
We evaluated indoor environmental quality concerns at Basseterre High School. We saw no widespread mold, but did observe water damage likely from leaking roofs and pipes in some buildings. We found low levels of hydrogen sulfide in science labs that seemed to be from dry drain traps. Relative humidity levels in the naturally ventilated school classrooms were above recommended guidelines. We recommended that a comprehensive ventilation assessment be conducted, and that all roof and pipe leaks be fixed.
ANSI/ ASHRAE American National Standards Institute/ASHRAE
BHS Basseterre High School
CARIRI Caribbean Industrial Research Institute
CARPHA Caribbean Public Health Agency
co Carbon monoxide
EPA U.S. Environmental Protection Agency
IEQ Indoor environmental quality
NIOSH National Institute for Occupational Safety and Health
PAHO Pan American Health Organization
RH Relative humidity
TVOCs Total volatile organic compounds
The National Institute for Occupational Safety and Health (NIOSH) received a request from the Pan American Health Organization (P AHO) to evaluate the indoor environmental quality (IEQ) at Basseterre High School (BHS) in St. Kitts. The request was submitted on behalf of the Government of the Federation of St. Christopher and Nevis (St. Kitts). This report summarizes our activities, findings, and
On May 13, 2015, we held an opening meeting with representatives from the St. Kitts Ministry of Education, the Ministry of Health, the Public Works Department, an environmental consultant, and BHS stakeholders, including school employees and teacher union representatives. We explained to the attendees that because our evaluation of BHS had been shortened due to a last minute flight cancellation, a closing meeting via conference call or teleconference would be scheduled by a P AHO representative once our report was issued.
Following the opening meeting we began our IEQ evaluation of BHS, which was unoccupied. We walked through the BHS campus to familiarize ourselves with the layout and mechanical ventilation systems (where present) of the numerous buildings that comprised the school. On May 14, 2015, the Minister of Education, the Minister of Health, and the Attorney General of St. Kitts arrived at BHS and we updated them on our activities and our observations. A PAHO representative was present during this update.
BHS was constructed in 1956, with additional school buildings added over the years (several as recently as 2012-2013). BHS is divided into two campuses (western and eastern) and includes 12 separate classroom buildings. In 2013, it had a staff of about 80 and about 800 students. We were told that BHS was designed to house 300 students.
BHS was closed in the fall of 2014 in response to ongoing IEQ concerns (odors, mold, and sewer problems); no students were attending BHS, and no teachers or other employees were working there on a daily basis. At the time the school was closed, staff concerns reportedly included skin irritation, fungal infections, coughing, headaches, thickening of skin (back of neck, elbow, and neck), vertigo, cancers, and
Prior to our site visit we reviewed two consultant reports pertaining to BHS:
• Caribbean Industrial Research Institute (CARIRI) report entitled: “Ambient Air Quality
Monitoring and Fume Hood Velocity Testing,” dated October 6, 2014.
• Caribbean Public Health Agency (CARPHA) technical review report entitled: “Interim Results Report-Result for ambient air quality monitoring for CO, HzS, CH4, and TVOCs,” dated September 2014.
We visually assessed all BHS buildings for potential mold contamination. We also used the following instruments to check for the presence of hidden moisture or water damage:
• A FLIR TG165 imaging infrared thermometer. We used this direct-reading device to identify potential moist or water-damaged areas in surfaces such as walls, floors, and ceilings. It uses infrared thermal imaging technology to react to temperature differences to identify dry and wet materials, even materials that are not readily visible, such as those behind drywall or above a suspended ceiling.
• A TRAMEX Moisture Encounter Plus nondestructive moisture meter. This handheld direct-reading device measures interior wall moisture levels. We used the moisture meter to confirm if suspected moist areas identified by the infrared thermometer were actually moist.
We measured temperature and relative humidity (RH) at four locations in BHS buildings on the western campus using Onset HOBO Pro data loggers. These temperature and RH measurements were collected from 8:00 a.m.-5:00p.m. on Thursday, May 14, 2015. These characteristics can affect how employees perceive their indoor environment. We also conducted spot checks of temperature, RH, and carbon monoxide (CO) throughout both the eastern and western campus of the school using a calibrated TSI QTrak ™ Indoor Air Quality monitor.
We measured hydrogen sulfide (commonly called sewer gas) concentrations in a newly renovated chemistry laboratory on the western campus. On the basis of previous consultant reports and statements made by school officials during our opening meeting, hydrogen sulfide was a concern by many BHS staff when the school was occupied. We used a direct-reading MultiRAE Lite portable gas monitor that is
We measured total volatile organic compound (TVOC) concentrations at multiple locations throughout both the eastern and western campus of the school. We used the MultiRAE Lite portable monitor to measure TVOCs as isobutylene, with a limit of detection of 1 part per million.
We tested for lead paint on painted surfaces in un-renovated and renovated locations using SKC, Inc. Full Disclosure® wipes. The limit of detection of the method is 0.18 micrograms oflead per sample. We evaluated the airflow into the chemical fume hood in the chemistry laboratory using a calibrated TSI QTrak ™ Indoor Air Quality monitor with a thermoanemometer probe.
Finally, we visually examined the improvements made to BHS buildings since 2012 to address previously identified building and sewer problems. These included leaking roofs, improper sewer line vents, breaks in drain lines, the chemical storage room exhaust system, and malfunctioning septic tanks and “soak away” systems.
Most of the buildings on the BHS campus were single-story masonry structures with pitched metal roofs over wooden trusses. Several recently built classroom buildings had wood walls with metal roofs. The largest building, the two-story main high school located on the western campus, was connected to an auditorium, a library, and administrative offices. This two-story building had a pitched metal roof over the
main building, and a flatter concrete roof over a wooden covered walkway that extended along each side of the building. An asphalt membrane had been installed over the concrete roof in 2014 to fix water leaks.
Nearly all classrooms had operable sash or louvered windows and relied on natural cross ventilation. Some rooms had wall or window fans to assist the cross ventilation. Most administrative offices, the auditorium and library, and a few classrooms had mechanical ventilation (individual air conditioning unit ventilators). We were told that renovations of most of the BHS buildings on the western campus had been completed (some as recently in the spring of 2015), but several classrooms and restrooms on the eastern campus were in a partially renovated condition.
Review of Consultant Reports
CARIRI: Ambient air sampling was conducted for CO, hydrogen sulfide, methane, and TVOCs over 5 days at six locations on the BHS campus. Wind speed, wind direction, temperature, RH, and rainfall were also recorded over this period. Most of the CO sample
CARPHA: A technical review of the above 2014 CARIRI report. The CARPHA investigators recommended using the World Health Organization guideline for interpreting ambient hydrogen sulfide concentrations (0.1 parts per million averaged over 24 hours) and
Mold and Moisture Survey- Western Campus
In the two-story main high school building we saw water stains suggesting past or current water infiltration. We saw water stains on the walls and ceiling in first and second floor classrooms. These water stains are likely due to a leaking roof. We also observed bubbling and peeling paint on beams in the classrooms (Figure 1 ). In the adjoining auditorium, we noticed water stains on the wall of the auditorium
We saw water damaged walls and ceilings, but no active mold growth, in an adjacent free-standing single-story building that housed the wood shop and machine shop (Figure 4). We believe the water leaks were from what appeared to be a damaged and potentially leaking metal roof.
We saw a small area of what appeared to be mold on the exterior facade of the two-story main high school building just above the entrance to the principal ‘s office at the front of the school (Figure 5). We were told that mold had been found in this building and that the walls had been cleaned with chlorine bleach.
In the library we saw bowed ceramic floor tiles on the west end of the room and peeling paint on the south wall. These could result from water infiltration. In the mechanical (technical) drawing classroom and the art classroom we saw water stains below the wall-mounted air conditioning units. These stains were likely from condensate that was improperly draining from the air-conditioners.
Mold and Moisture Survey-Eastern Campus
We saw active water leaks in two buildings on the eastern campus. In the home education classroom that was undergoing renovation, water was leaking from an exposed water pipe and pooling on the exposed dirt floor where a sink and cabinet had been removed (Figure 6). We also saw an interior water leak in the recently renovated girl ‘s bathroom. In this instance water was pooling on the floor near the toilet stalls
Temperature, Relative Humidity, and Carbon Monoxide
Temperatures in the air-conditioned principal ‘s office ranged from 66 degrees Fahrenheit (°F)-74°F, and RH levels ranged from 43%-60% between the hours of 8:00a.m. and 5:00p.m. on May 14, 2015. In the newly renovated and air-conditioned biology laboratory the temperature ranged from 75°F-78°F, and the RH ranged from 31 o/o-39%. In the two naturally ventilated classrooms we checked (Room 5G5 and Room 5G2, Figure 8) the temperatures ranged from 82°F-85°F, and RH levels ranged from 54%-70%.
We compared the temperature and RH levels to American National Standards Institute/ASHRAE (ANSIIASHRAE) thermal comfort guidelines for summer [ANSIIASHRAE 2013]. The ANSIIASHRAE Standard 55-2013, Thermal Environmental Conditions for Human Occupancy, specifies conditions in which 80% or more of the occupants would be expected to find the environment thermally acceptable
Concentrations of CO ranged from 0.3 parts per million to 1.3 parts per million, throughout various buildings on the western campus. We did not detect CO in the buildings on the eastern campus. We compared the measured CO levels to the United States Environmental Protection Agency’s (EPA) National Ambient Air Quality Standards [EPA 2014]. All CO concentrations measured at BHS were well below the EPA’s 8-hour ambient air quality standard of nine parts per million and the 1-hour standard of 35 parts per million.
We turned on the water faucets over classroom sinks in two science labs because of concern that hydrogen sulfide was being emitted from the water. We used a Draeger colorimetric detector tube to measure for hydrogen sulfide over the lab sinks while the water was running from the faucet. These tubes change color in the presence of hydrogen sulfide, and the length of the color change corresponds to the relative airborne concentration of hydrogen sulfide. Although we smelled a faint “rotten egg” odor, no hydrogen sulfide was detected (minimum detectable concentration was 0.2 parts per million). We did not detect hydrogen sulfide using the MulitRae Lite direct-reading monitor (minimum detectable concentration was 0.1 parts per million). The hydrogen sulfide odor was faint, and it rapidly dissipated after running the water for a short time. The odor threshold for hydrogen sulfide can vary from person-toperson and has been estimated to be as low as 0.01 parts per million, a concentration well below the limit of detection of our instruments [OSHA 20 15]. We suspect that the hydrogen sulfide odor was in the air that was pushed up from the dry sink traps by the draining water. The water had not been run in these sinks for quite some time, and the traps had become dry. If the sinks had seen occasional use, the traps would not dry out, and the faint hydrogen sulfide odors would likely disappear.
Lead Paint Testing
We collected three wipe samples on painted surfaces in the two-story high school building on the western campus to test for lead. Two of the wipe samples were taken from surfaces that appeared to have not been recently painted. One wipe sample was taken on a wall in the second floor audio and lighting control room overlooking the auditorium, and the second sample was from a stairway railing where old paint was
Fume Hood Testing
We measured the face velocity of a Labconco Protector® chemical fume hood in the chemistry classroom with the hood sash fully open and with it halfway closed. In both instances the hood was empty. With the hood sash fully open the average face velocity was approximately 125 feet per minute (average of nine measurements taken across the hood face). With the sash halfway open the average face velocity was
We saw evidence of termite infestation in the following areas:
• biology laboratory (interior recently renovated with new cabinets and paint, Figure 9)
• clothing and textile vocational room (Figure 1 0)
• office between the technical drawing classroom and a staff room
We visually examined the improvements made to BHS buildings since 2012 to address prior building and sewer problems, such as:
• leaking concrete roofs
• cracked plaster on walls and ceilings
• improperly vented sewer lines
• breaks in sewer drain lines
• malfunctioning septic tanks and “soak away” systems
As far as we could determine these problems had been addressed. For example, we did not see any sewer lines that were not vented above the roof line. We did not see any drain line breaks, and we did not see any indications of problems with the septic tanks or “soak away” systems, such as surface ponding of water. We did not open or inspect the inside of the septic tanks or “soak away” systems because most tanks were buried under several feet of soil. We also did not inspect non-visible drain lines in walls or underground. Following our site visit we received a drawing of the BHS campus from the Ministry of Education showing the locations of existing, new, and condemned septic tanks and soak-away systems. We do not know if this drawing identified all systems on the campus.
We found a malfunctioning exhaust fan in the remodeled chemical storage room adjacent to the chemistry room. In addition, this exhaust fan was controlled by a nearby light switch. Therefore, even if the exhaust fan was operational, when the lights to the room were turned off, the exhaust fan would also tum off. This arrangement could allow chemical vapors to accumulate in the storage room. A solution to this potential
We saw what appeared to be rodent droppings in the physics lab underneath the sink near the teacher’s desk and in the storage room next to the technical drawing room, and bird droppings in a covered outdoor walkway where birds were roosting. We saw openings in the exterior wall of the boy’s bathroom on the east campus that could allow rodents and insects to enter (Figure 11). We found unsecured and uncapped
We did not detect TVOCs in any of the buildings on the BHS campus, with the exception of one classroom on the eastern campus that was undergoing renovation and had construction debris inside of it. We measured 2 parts per million ofTVOCs inside that classroom. Previous IEQ studies have measured widely ranging TVOC concentrations in indoor air, as well as differences in the mixtures of compounds
We did not evaluate the maintenance history and overall performance of the wall-mounted airconditioners on the BHS campus. Although some air conditioners were turned on for our evaluation, we do not know the condition of the air filters or whether these units were operating as designed.
No airborne exposure standards specific to the nonindustrial indoor environment exist. Likewise, no exposure guidelines for mold (or other microbes) in air exist, so it is not possible to distinguish between “safe” and “unsafe” levels of exposure. Therefore, measuring indoor environmental contaminants, such as CO, hydrogen sulfide, methane, and TVOCs, has seldom proved helpful in determining the cause of the
Pertaining to the topic of environmental sampling, during our opening meeting on May 12, 2015, with St. Kitts government officials and BHS stakeholders, the question of collecting soil samples for Escherichia coli (also called E. coli) to evaluate septic tank and soak-away systems on the BHS campus was asked. We do not believe this sampling is needed; we did not see any drain line breaks or indications of problems such as surface ponding of water. Additionally, the presence of naturalized populations of E. coli in temperate soils may interfere with its use as an indicator offecal contamination [Ishii et al. 2006].
What we have found beneficial in addressing IEQ concerns is measuring comfort indicators such as temperature and RH to provide information about the thermal comfort of the space, and verifying that these parameters are within applicable ANSVASHRAE guidelines for indoor environments. In mechanically ventilated and occupied spaces, we can measure indicator pollutants such as carbon dioxide
One of the most common deficiencies we have found over many years of conducting health hazard evaluations in nonindustrial indoor environments is the improper operation and maintenance of ventilation systems. BHS had some classrooms and office spaces that had air conditioning systems installed, but we did not determine if there was a maintenance plan in place for these systems. An analysis
Exposure to microbes is not unique to the indoor environment. No environment, indoors or out, is completely free from microbes, not even a surgical operating room. Microbes present in indoor air that are relevant to health include pollen and plant spores coming from outdoors; bacteria, fungi, algae, and protozoa from indoors and outdoors; and microbes and allergens spread from person to person, and from
The type and severity of symptoms related to mold exposure in the indoor environment depends on the extent of the mold present, the extent of the individual’s exposure, and the susceptibility of the individual (for example, whether he or she has preexisting allergies or asthma). Sufficient epidemiological evidence indicates an association between occupancy in damp buildings and upper and lower respiratory tract
We did not find any major mold problems at the school during our assessment. The hydrogen sulfide odor that we smelled in the chemistry lab was likely due to a dry drain trap, and not from the water supply or from a leaking septic tank. Most of the classrooms were naturally ventilated and ANSIIASHRAE guidelines state that natural ventilation is not considered practical in hot and humid climates because it
On the basis of our fmdings, we recommend the actions listed below to create a more healthful workplace. We encourage the school administrators to form a labor-management health and safety committee to discuss the recommendations in this report and to develop an action plan. Those involved in the work can best set priorities and assess the feasibility of our recommendations for the specific situation
Our recommendations are based on the hierarchy of controls approach. This approach groups actions by their likely effectiveness in reducing or removing hazards. In most cases, the preferred approach is to eliminate hazardous materials or processes and install engineering controls to reduce exposure or shield employees. Until such controls are in place, or if they are not effective or feasible, administrative measures and/or personal protective equipment may be needed.
Engineering controls reduce exposures to employees by removing the hazard from the process or placing a barrier between the hazard and the employee. Engineering controls are veiy effective at protecting employees without placing primary responsibility of implementation on the employee.
1. Consider installing mechanical ventilation in all classrooms and occupied spaces; natural ventilation is ineffective in controlling humidity in occupied spaces. In the naturally ventilated classroom we tested, the RH was above the ANSI/ ASHRAE recommended maximum of 65%.
2. Fix the leaking roofs above the wood and machine shops, and repair the water-damaged materials inside the buildings. Fixing the roof will prevent further water damage to the interior of the building.
3. Investigate the roof above the main classrooms in the western campus for leaks and signs of water damage. Evidence of water infiltration to classrooms on the first and second floors suggests there may be roof leaks.
4. Confirm that the BHS drawing provided to us during our evaluation is a comprehensive inventory of all septic tanks and soak-away systems on the BHS campus, including existing, new, and condemned systems. A complete listing of these systems could be used for scheduling
5. Remediate the small amount of mold on the exterior fac;ade of the school building in front of the principal’s office. We do not recommend using liquid chlorine bleach or other disinfectants to clean mold. Soaps and disinfectants alone are generally effective in removing mold unless sewage contamination has occurred. We recommend following manufacturer’s recommendations when using any cleaning product. More information on cleaning products and mold remediation is available from the following websites:
6. Fix the leaking water pipe in the home education room and the leaking toilet in the girl’s bathroom on the eastern campus.
7. Conduct a comprehensive assessment of the school’s ventilation. There were standalone airconditioners in several classroom buildings and these units require regular maintenance, including routinely changing the air filters and checking the operation of the outside air damper. From a visual perspective, many air conditioners did not appear to have received regular maintenance.
8. Adjust the airflow in the laboratory fume hood in the chemistry classroom to provide an average face velocity of 100 feet per minute and install a quantitative airflow monitor that indicates whether air is flowing into the hood’s exhaust system.
9. Consult with a pest removal company to remediate termite infestations in the east and west campuses.
10. Alter the power supply to the exhaust fan in the chemical storage room. The exhaust fan should run continuously or be placed on a timer so it provides ventilation to the room during occupied hours.
11. Properly cap and secure all compressed gas cylinders and install missing safety devices on the abrasive grinding wheel in the machine shop.
Administrative controls are management-dictated work practices and policies to reduce or prevent exposures to workplace hazards. The effectiveness of administrative changes in work practices for controlling workplace hazards is dependent on management commitment and employee acceptance. Regular monitoring and reinforcement is necessary to ensure that control policies and procedures are not
1. Stop any further ambient air sampling for hydrogen sulfide, methane, CO, and TVOCs; and any proposed soil sampling for bacteria.
2. Ask employees to report signs of moisture intrusion to the facilities maintenance staff. The facilities maintenance department should establish a system for responding to requests and notifying the requestor what is being done and when the work is complete.
3. School employees who continue to experience perceived work-related health concerns should see an occupational health physician.
4. Implement a formal system for reporting building concerns to the principal or the facilities maintenance manager. This system can be paper or electronic and should include a mechanism to let staff know when and how the problem is fixed.
5. Implement an IEQ management plan for each of the schools in St. Kitts and Nevis. Select an IEQ manager or administrator with clearly defined responsibilities, authority, and resources. This individual should have a good understanding of each building’s structure and function and should be able to effectively communicate with occupants. This proactive approach can help prevent IEQ problems from occurring. Although comprehensive regulatory standards specific to IEQ have not been established, useful guidance is available from organizations such as ASHRAE, NIOSH, and the EPA. The EPA has several publications on IEQ, including the Indoor Air Quality Tools for Schools Action IGt, which can be found at http://www.epa.gov/iaq/schools/toolkit.htrnl. This document discusses IEQ in detail and includes information on common problems, investigative techniques, and solutions to specific problems. Additional resources include the EPA Healthy School Environments Assessment Tool, available at http://www.epa.gov/schools/, which helps school districts establish and manage comprehensive school facility self-assessment programs. It contains an environmental health and safety checklist and is designed to be easily customized to reflect state and local requirements and policies. The basic elements of a good IEQ plan include the following:
• Properly operating and maintaining the heating, ventilating, and air-conditioning equipment, including accommodating staff who work during hours when the air handling system(s) is routinely cycled off, to ensure that adequate ventilation is provided
• Overseeing the activities of occupants and contractors that affect IEQ (e.g., housekeeping, pest control, maintenance, food preparation)
• Maintaining and ensuring effective and timely communication with occupants regarding IEQ
• Educating building occupants and contractors about their responsibilities in relation to IEQ
• Proactively identifying and managing projects that may affect IEQ (e.g., redecoration, renovation, relocation of personnel)
• Designating a school employee representative who can speak for the teachers and other employees and can assist with communication
Another IEQ resource is the NIOSH “Indoor Environmental Quality-Dampness and Mold in Buildings” topic page (http://www.cdc.gov/niosh/topics/indoorenv/mold.htrnl). NIOSH is also developing an observational dampness and mold assessment tool. For additional information or to receive a form and instructions for using this assessment tool, contact NIOSH at
http://www .cdc. gov/nioshltopics/indoorenv/mold.htrnl#8.
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We thank Godfrey Xuereb, Sally Edwards, and Patrice Lawrence-Williams from P AHO for coordinating the logistics of our site evaluation. We also thank officials from the Ministry of Education, Ministry of Health, and Public Works Department for assistance during our evaluation.