Here’s what we know for sure about the air at Casey Middle School: It smells bad.
Since the new, $33 million rebuilt school opened in August 2010 and became home to just under 600 students and about 50 teachers, reports have circulated of air that smells like rotten eggs and, sometimes, feces. Air monitors brought into the school have identified levels of hydrogen sulfide (H2S), a colorless, flammable gas known for its rotten egg smell.
Those levels, according to reports from now multiple third-party monitoring agencies, are below the levels that immediately trigger cause for concern for adults in the work place.
But here’s the thing: That may not be true for children.
During the few days they’ve tested, the school district’s contracted monitoring companies have found levels of gas that briefly exceeded the levels the U.S. Environmental Protection Agency (EPA) recommends for prolonged exposure for sensitive populations, including children and the elderly. While the levels are generally low, just around the threshold for a noticeable odor, depending on whose standards are being consulted, they have also been documented increasing ten-to twentyfold in a matter of minutes. At one point, they surged from .003 parts per million (ppm) to .021 ppm in 10 minutes.
Students and teachers have reported getting sick with symptoms that match those expected of exposure to hydrogen sulfide — at much higher levels than what the air monitors have shown on the days they have been utilized. Air quality reports have also shown that the increased levels of hydrogen sulfide essentially go to sleep at night, dropping from the 0.004 ppm and 0.005 ppm levels recorded over the course of the day to 0.001 ppm and 0 ppm overnight, suggesting that the source of this poisonous gas may be tied to human activity.
Despite having hired several third party contractors to identify the source of the H2S, the school district still doesn’t know where it’s coming from.
At this point, parents and teachers and other concerned parties have started to say that after four years of tinkering, it’s time for more drastic measures. At a special meeting on Tuesday, Feb. 24, for the Boulder Valley School District Board of Education to review the situation, it sounded like some board members have begun to consider more radical options and are already pushing for increased transparency to families — before they enroll their children at Casey.
The public comment portion of the meeting saw parents and teachers voicing the concerns they’ve been bringing to the district for years now about the school’s air quality. Their list of symptoms includes headaches, dizziness, nausea, mouth sores and menstrual disruption.
Jenna Moran came to the meeting to tell the board about her son, Fletcher. Since starting at Casey in the fall, her usually healthy child has been sick for a month’s worth of days, including two weeks over winter break. His classes have been relocated from rooms with rotten-egg odor to the gym or lunchroom.
“Why is this going on when the EPA is saying that the levels that you’re saying are safe, the EPA says doesn’t apply to children?” she asked. “It seems to me like it needs to be shut down and the problem needs to be sorted out.”
Val Wheeler, an eighth grade language arts teacher at Casey and member of the faculty advisory committee for the school, said that the district received a letter in 2011 from a doctor who stated “that low levels of hydrogen sulfide will cause health effects.”
This year, within a month of school opening, people were already reporting health effects, which included dizziness, bloody noses, nausea, headaches and other pain, inflammation and joint pain, she said. As many as 27 of the fewer than 50 teachers have cited health complaints in meetings and surveys, she said. Two have been removed from their rooms because of irritants in the air. What if just as high a percentage of children are also affected by the building, she asked.
Kris Thacker, a math teacher at the school, was hoarse when she took the podium. Having been an educator for 16 years, she says, she knows that her worn out voice can’t be attributed to stress.
“I can tell you every Monday when I go in, I’m going to get sick by Tuesday and my mouth is going to burn,” she said. “I know by Friday I’m not going to taste or be able to drink.”
Her son, a student at Casey, often goes home with headaches. Her husband also spoke to the board, suggesting that five years later, maybe it’s time to think the problem is more than a few dried-out P-traps.
“I took a big risk by coming here because I am not tenured, but I know morally and ethically that this is not right,” Thacker said. “I love what I do. I’m passionate about what I do and every day I try to get kids to pay attention but I can’t even talk to them. … The kids there, they’re not learning. … And my job is to teach them, can I do that without a voice? Can I do that without being able to taste my food? I’m going to tell you no, but I sure fake it every day, because I want to let them know that Casey is a good place to be, gases or not.”
Thacker told Boulder Weekly she has vomited during class on more than one occasion. She also said that she has taken photographs of air quality monitors that show concentrations of hydrogen sulfide far higher than the levels documented during the week-long periods outside companies have come in to monitor the air quality. Photographs of monitors posted to the website fixcaseynow.org show levels as high as 0.6 ppm compared to the contractors’ reports showing levels most often around 0.005 ppm. That’s more than 100 times the H2S level found by contractors.
Luana Rubin said she recently removed her 12-year-old daughter from Casey, having had her blood tested and found what at least one physician called “shockingly high” levels of thiosulfate, a marker for hydrogen sulfide poisoning. The district has asked to review medical records of any child supposedly sickened by the building, but Rubin stated that her attorney advised her against giving those records over. She called on the district to take immediate action: “If you cannot fix the school in two weeks, please evacuate the school.”
“The testimony that we have here, the parents, the staff, people I’ve talked to, indicate that this problem is not any better. … We’re not ready to put it to bed. The efforts so far have failed. Something new needs to happen,” said Heather Ryan. “Four years of tinkering hasn’t worked. We can’t just continue to pour water down a few P-traps.”
Alan Godman spoke about his 12-year-old daughter, who has daily headaches and nausea.
“Putting aside the acute symptoms, I’d ask if any of you can say that there are no long-term effects,” he said. “The presence of hydrogen sulfide has been confirmed and these levels are anything but acceptable.”
Godman also suggested closing the school until the source of the gases can be identified and permanently alleviated, or shutting down systems to use a process of elimination to determine which contribute to the gases, and looking carefully at the geothermal system for the school. He pointed to information from the Union of Concerned Scientists that the main byproduct of geothermal energy is hydrogen sulfide.
What hydrogen sulfide is, where it comes from and its associated effects
Hydrogen sulfide, a colorless and flammable gas considered extremely hazardous, has a rotten egg smell. It occurs naturally in crude petroleum, natural gas and hot springs, and is also produced by the bacterial breakdown of organic materials and human wastes — coming from landfills and human and animal wastes. Petroleum and natural gas drilling and refining, wastewater treatment, coke ovens, tanneries and paper mills can all produce the gas. It’s heavier, collects in low-lying, poorly ventilated areas — basements, sewer lines, telephone vaults and manure pits.
Hydrogen sulfide is rapidly absorbed by the lungs, says the Occupational Safety and Health Administration. Once there, it distributes to the blood, brain, lung, heart, liver, spleen and kidneys.
Low concentrations can be detected by smell, but that sense dulls to the gas after over exposure — too much time, or too much gas in a single dose. Low levels of the gas can irritate the eyes, nose, throat and respiratory system, causing burning eyes, coughing and shortness of breath. People with asthma may find it difficult to breathe.
On repeated exposure to low levels, a person may experience eye inflammation, headaches, fatigue, irritability, insomnia, digestive disturbances and weight loss. Moderate exposure can cause more severe levels of those symptoms, and can include an accumulation of fluid in the lungs, dizziness, nausea, vomiting and staggering.
“Repeated exposure can result in health effects occurring at levels that were previously tolerated without any effect,” says the Occupational Safety and Health Administration fact sheet on hydrogen sulfide.
About the levels
People can smell hydrogen sulfide at levels as low as 0.0005 ppm, according to OSHA. Eye irritation is said to begin at 10 ppm.
At Casey, monitoring in March 2014 by Quality Environmental Services and Technologies, Inc. recorded maximum levels of .004 ppm and .006 ppm in the three rooms monitored. In October, the same company again monitored hydrogen sulfide in the building, and found maximum readings of .005 ppm, .006 ppm and .021 ppm in the rooms monitored.
These are consistently described in communications from the evaluating agency as levels well below even the thresholds for noticeable odor, much less “nuisance” odors, which they peg at .008 ppm and .040 ppm, respectively.
However, the World Health Organization’s air quality guideline for exposure averaged over a 24-hour period is 0.0106 parts per million. According to Earthworks, the World Health Organization also recommends that “concentrations not exceed 0.005 ppm over a 30-minute period to avoid substantial complaints about odor.” Earthworks also reports that state standards for exposure to hydrogen sulfide over a 24-hour period range from .00065 ppm in Massachusetts to .2 ppm in Oklahoma.
Casey’s reports show it exceeding Massachusetts’ standard, but staying well below Oklahoma’s.
According to Occupational Health & Safety, the EPA and the Agency for Toxic Substances and Disease Registry estimates safe lifetime exposure levels at 0.7 parts per billion — or 0.0007 parts per million — and the Agency for Toxic Substances and Disease Registry lists 30 parts per billion as the acceptable level for chronic exposure. EPA health scientists recommend no more than 15 ppb for residences — and set a safe exposure level for sensitive populations, including children and the elderly, at 0.00014 ppm.
That limit is well below the levels found at Casey.
The EPA’s Integrated Risk Management System has published information that suggests that children, and neonatal animals, could be susceptible to neurological effects from concentrations of hydrogen sulfide greater than 0.6 mg/m3, or 0.400 parts per million. Those levels are well above what reports from contractors have documented at Casey. However, they are below the levels documented in photographs released by one teacher.
Overexposure has led to a variety of symptoms in the central nervous system including dizziness, nausea and headache.
At the far opposite end of the spectrum from what anyone has seen in or near Casey, the real horror stories emerge. Levels associated with abrupt physical collapse are estimated to be 500 ppm to 1,000 ppm, and pulmonary edema to 250 to 500 ppm. The EPA’s Toxicological Review of Hydrogen Sulfide notes that using the odor as a warning isn’t an adequate system — levels of 100 ppm to 200 ppm can lead to the loss of smell and olfactory paralysis. The EPA estimates the odor threshold at .003 ppm to .02 ppm — lower than the levels cited by the school district.
Case studies included in the EPA’s Toxicological Review of Hydrogen Sulfide describe how a 14-year-old boy and his father died after finding a discarded cylinder of hydrogen sulfide in a dump where a local refinery had been discarding waste. The boy died immediately; his father died trying to rescue him. Both bodies were the deeply bluish purple color associated with oxygen deprivation.
Also, a 20-month-old child that lived near a coal mine that was emitting hydrogen sulfide exhibited abnormal eye movements and was unable to stand, and a brain scan suggested toxic encephalopathy. But it all resolved within weeks after his admission to the hospital and the burning tip on the coal mine that was emitting hydrogen sulfide was extinguished. The maximum recorded hydrogen sulfide level in that family’s home, which was monitored for four months, was 0.6 ppm.
From studies of communities with prolonged exposure to hydrogen sulfide come reports of effects to the central nervous and respiratory systems, as well as to blood. Workers exposed to pulp and paper mills saw an increase in cardiovascular-related deaths.
And what about cancer? The EPA says studies have been inadequate to determine the carcinogenic potential of hydrogen sulfide.
The EPA does say, however, that there is anecdotal evidence that children may be more susceptible than adults to hydrogen sulfide exposure.
The history of air quality complaints at Casey
Reports started coming from Casey in December 2010, after the school opened in August 2010 following a multi-million dollar redesign that earned it the highest level of certification from the United States Green Building Council’s Leadership in Energy and Environmental Design (LEED). Casey was the first school in Colorado and one of only two middle schools in the country to attain that level of certification, according to a BVSD press release. The redesign kept two of the original 1924 school building exterior walls and incorporated a row of solar photovoltaic panels, a rooftop garden, natural daylighting and a ground source heat pump that provides 90 percent of the school’s heating and cooling.
The building scored the highest level LEED certification, platinum, by earning points for reduced water use, sustainability of the site itself and optimized energy performance. LEED also scores for indoor environmental air quality, which was among the school’s two lower-scoring categories. The design did not earn points for outdoor air delivery monitoring, mold prevention, increased ventilation or indoor chemical and pollution source control. The bulk of its points in that category came from use of low-emitting materials, daylight and acoustical performance.
Since complaints about the odor began, the school has made adjustments to its drains, vents and filtration systems to mitigate complaints. During the 2010-11 school year, staff and students were relocated to other areas of the building due to gas concerns. In the years that have followed, staff and students have reported health concerns they feel are attributed to hydrogen sulfide.
The school district has reiterated that the levels of hydrogen sulfide found in the school during air monitoring tests in that year and the years that followed have always been far below levels deemed safe.
“We believe Casey is a safe learning environment while we continue to fine tune the building’s systems,” Assistant Superintendent Don Orr said during the Feb. 24 meeting. That’s a belief supported by views from medical professionals and industrial hygienists.
The district’s efforts to mitigate the concerns over hydrogen sulfide odor have included addressing issues with floor drains, internal sanitation and air filters, as well as working to re-balance the air pressure — the school has been recorded exhibiting negative air pressure, meaning it pulls air in rather than pushing it out and dispersing it into the environment — and increase fresh air flow. Smoke tests also located cracks in the pipes that were either part of the original installation or failed shortly thereafter.
In November and December, complaints of odor brought BVSD staff out to Casey to test for hydrogen sulfide. Their reports show they found none of the gas in the rooms tested, but as recently as December, have identified structural problems that might be contributing to the odors. Rooftop vents are positioned such that heavier gases might be pouring right down the side of the building where they can enter classrooms through windows. They did document a “distinct” hydrogen sulfide smell on some areas of the roof and determined that the charcoal filters on air vents needed to be replaced. BVSD staff also found a leak in the sanitary sewer system in the crawl space near the air handling unit for the main office and south classrooms and repaired that leak.
The school has also been tested for carbon monoxide and carbon dioxide, which were found within acceptable OSHA levels. The building’s air handling units were adjusted anyway and testing in January showed reduced levels of those gases.
Indoor Air Diagnostics, one of the companies hired to inspect air at Casey, suggested that the city’s sewer system could be responsible for the gas coming in to Casey. Subsequent investigations determined that not to be the case. Quality Environmental Services and Technologies, Inc., which monitored sewer-line pressure for a week, recommended that BVSD add sewer vent lines near the kitchen grease trap to neutralize air pressure and consider extending the existing sewer vent lines farther from the building.
“This is a relatively new building, so we’re working some of the bugs out,” Boulder Valley School District Superintendent Bruce Messinger said during the Feb. 24 board meeting.
Indoor air quality monitoring results have been reviewed by the Boulder County Health Department, State Health Department and National Jewish Health. The latest round of data collected is still being analyzed, but initial reports don’t show levels that exceed cause for concern. The school may consider some ongoing monitoring to address parent concerns, Messinger said, and BVSD technicians are on call to conduct immediate onsite air quality tests if concerns are reported.
“We have not received any medical opinion that the building has ever been unsafe,” Messinger said.
Messinger and Don Orr, assistant superintendent of operations and leader of the presentation to the board on the history of remediation efforts at Casey, failed to point out that the highest levels reported were documented this December — after the many mitigation measures said to have put the school, as Messinger said, on the track to putting this issue to bed once and for all.
During the meeting, Board of Education members Shelly Benford and Tom Miers grilled Messinger, Benford asking about the devices used to measure air quality, the methods for selecting when sporadic monitoring has taken place and the standards applied to consider the level of hydrogen sulfide found in the building to be safe.
Told that the district is using equipment that measures air contaminants down to 3 to 5 parts per billion, Benford asked Messinger, “Are you aware that the EPA has put safe levels at 0.00014 parts per billion? These measurements are not going that low, so how would we pick up levels that low?” Messinger says he’s in conversations with the EPA to get a device that measures quantities that low.
“Again, we’re confident that we’ll be fine,” he said.
In Colorado’s climate, P-traps, which rely on liquid present to block odors, often dry out and many schools require replacing liquid in those traps as maintenance to block hydrogen sulfide odors — which he said are detected everywhere.
“We have reports of hydrogen sulfide in our buildings across the district regularly, so we just need to get to the point that it isn’t a pattern that’s consistent in any one building and that’s what we’ve been dealing with,” Messinger said.
Benford also questioned the district’s set levels for safe exposure.
“My understanding that the permissible levels of exposure that Don [Orr] was talking about and that we’ve read are mainly for industrial settings for grown adults,” she said. “Even the EPA and OSHA have said they’re not really sure that there’s any safe level for children, so not sure how Boulder County Public Health or Colorado Public Health can state with certainty that these are the safe levels for children.”
Messinger’s response was to state that we have hydrogen sulfide everywhere, to which Benford pointed out that not every school is producing the crowds at meetings that this school was, gesturing to the meeting room in which nearly every seat was occupied and additional viewers stood in the aisles, and emails of concern and requests for transfer Casey has been receiving.
Parents and teachers have emailed lists of symptoms, she said, and they’re leaving because of those symptoms. Messinger attributed them to other environmental concerns or physical conditions, insisting that they have not found any medical evidence that hydrogen sulfide is the cost. The district is only now beginning to work with a pediatric toxicology specialist at National Jewish and considering whether there are other environmental issues present within the building.
“The symptoms that are described could be caused by many, many things,” he said. They’re working case-by-case to examine the medical files, when available, from teachers and students.
“So when people leave the building either because the student transfers or a teacher does and they’re not experiencing symptoms anymore, what does that lead you to conclude?” Benford asked.
“That’s a source of information, but really I’d probably prefer to have medical tests,” Messinger replied.
Among the 31,000 students in the district, he said, there are children who have a higher sensitivity to environmental factors, such as cleaning solutions and flooring.
“I think one of the concerns is that the symptoms that people are experiencing are not being published in any place that people can see them and say, ‘Oh wait a minute, my child is experiencing that,’” Benford said. She’s repeatedly heard requests that the district be more transparent that something in the air quality at Casey may be affecting students so that parents can make an educated choice before open-enrolling their student into the school.
Messinger argued against that approach.
“We have no medical evidence presented to us to date that there’s anything in that environment,” Messinger said. “Otherwise we would just create fear, an unnecessary or unfounded fear.”
That statement was met with derisive laughter from the crowd.
“It’s disturbing if the air quality is even causing discomfort, [like eyes burning and nausea],” Benford said.
Among her concerns were that Casey community members have expressed frustration with a lack of transparency, and that there’s a sense teachers may not be coming forward with their medical issues out of fear of retribution.
“That’s maybe why you’re not getting the information that you need,” Benford suggested.
Messinger said he hand-delivered workman’s comp doctors information to teachers and staff at Casey and encouraged those who believe they have symptoms to come forward.
“I really find that very upsetting that people would immediately go to some explanation like having a mass delusion about this as opposed to thinking much more logically about it, that maybe some people are affected by what’s going on in that school,” Benford said.
Messinger clarified that message did not come from the district office.
The kitchen, which produces a third of the district’s school lunches, has been named as a possible source for some of the odors and hydrogen sulfide; a grease trap in the kitchen that drains into the sewer may be contributing to the gases.
“There isn’t any indication that there’s a source of toxins or gases coming from the kitchen, but there certainly are smells,” Messinger said. BVSD schools prepared food in regional kitchens; Casey is one of few where cooking actually takes place.
What children and staff are experiencing there he attributes to a difference in sensitivity.
“It doesn’t mean that any of it’s harmful,” he said. “All of these are levels that are well below any health regulation. … Our goal is to have it at a level that’s not detectable.”
The district has followed up with families who have complained of ill effects from the odor and with workman’s compensation doctors who have treated teachers with health issues, he said, and so far, they have not found any connections to the symptoms exhibited in the medical results. At this, heads in the audience shook and someone muttered that that wasn’t true.
Benford also mentioned that the district should consider looking at the school’s geothermal system.
“When I started reading up on this, that was the first thing that popped up was the possibility that boreholes could be leaking hydrogen sulfide gas,” Benford said.
The staff with Indoor Air Diagnostics has said that’s an unlikely source because the geothermal system is a closed system that cycles fluid, and it’s operating now without a flaw — that would likely appear in a loss of water in that system.
The 107,000-square-foot facility uses geoexchange heat pump technology and exhaust air heat recovery ventilation systems in an automated building control system that monitors and controls the systems. Each classroom is heated by a water-to-heat air pump that connects to the school’s geoexchange system, which loops pipes underground through 70 vertical boreholes that are 370 feet deep. It’s the school’s primary heating system. The outdoor air delivery system both recovers heat and adds fresh air to the system. Water is heated by a gas-fired condensing boiler domestic water heating system, using a recirculation loop.
Geothermal power plants, in contrast, use open-loop systems that suck water out of the ground and may expose communities to hydrogen sulfide, ammonia, carbon dioxide and radon. One of the primary environmental concerns with generally clean geothermal energy is the release of hydrogen sulfide.
The Journal of Forensic Science published an article in 1998 on a death that occurred at a geothermal power plant, in which a man suddenly collapsed and died shortly after. An analysis of sulfide and thiosulfate in his blood, brain, lung and femoral muscle was similar to those for hydrogen sulfide gas fatal cases. The concentration of thiosulfate in his blood was 48 times higher than control samples and his death was attributed to hydrogen sulfide gas poisoning.
In May 2012, the journal Environmental Research published a three-year study from Iceland linking ambient hydrogen sulfide to increased dispensations of drugs to treat asthma. Researchers compared respiratory illnesses in adults to daily air pollution levels and counted the number of adults who filled prescriptions for asthma-related drugs.
Several air pollutants were monitored, including ozone, nitrogen dioxide and particulate matter. Peak traffic was associated with increases in adults filling prescriptions — as was an increase in hydrogen sulfide. It was one of the first studies to connect hydrogen sulfide with poor respiratory health, according to Environmental Health News. Previous work had connected workers with higher exposures to neurological effects. More research will determine whether other pollutants released from geothermal power facilities also play a role. The study also found that short peaks in air pollutants may cause more respiratory harm than longer averages.
The district’s director of health services consulted with an environmental and occupational health sciences specialist in June, Dr. Karin Pacheco, who stated, “There are many known and unknown toxins in the environment that can harm growing children. As a physician trained in occupational and environmental medicine, however, I would not be concerned about the H2S exposures in the Casey Middle School.”
The reasons cited for that opinion were that the levels at the school “are really, really low,” measuring in levels so low that they leave “a thousand to ten thousand-fold buffer of concentration between what is measured in the school, and what is permitted in the workplace.” The odor is not indicative of a toxic level because the odor threshold is so much lower than the level at which hydrogen sulfide would have health effects. And, she adds, “the fact that students and teachers can still detect an occasional whiff of H2S is, in fact, reassuring.” At higher levels, there’s “odor fatigue” and the nose can’t detect hydrogen sulfide. Pacheco cites an OSHA-permitted eight-hour exposure level of 10 parts per million.
Updated information on the levels detected in the school during the late 2014 air monitoring period and the EPA’s statement that levels greater than 0.00014 are of concern were sent to Pacheco, but she is out of town and was unable to respond.
“I think clearly here are enough people coming forward — parents, members of the community and teachers — to know that this is an issue. We have symptoms, and I don’t want to wait for some rock solid medical proof of sick children to do something about it. I think we need to move forward, even if it means being disruptive to do so for the safety of our children,” Miers said at the conclusion of the special session. “I think the current plan is lacking urgency in what we need to do.”
He proposed constant monitoring of the air quality at Casey, securing the services of a pediatric toxicologist, compromising the LEED certification if necessary to increase air circulation in the building and hiring someone with geothermal expertise to evaluate that system. Benford added that the district needs to make a statement to affirm that some people attending Casey may be affected by the air quality there and that statement should be available in public places, particularly where parents looking to enroll their children at Casey will see it. She and Miers reiterated that any concerns over fears of retribution toward teachers who come forward to cite health concerns they believe are tied to the air quality of the building need to be immediately countered.
She added, “This should be about acknowledging that even medical tests may not be up to measuring whether these children and teachers are being harmed by a toxic gas and we ought to take their word for it.”
