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The School Shut Down by Dangerous Gases

The Belmont Learning Complex is not the first California school to fall under a cloud of dangerous gases. That distinction appears to belong to an elementary school in the town of Clearlake, located 100 miles north of San Francisco in rural and scenic Lake County. Mysteriously appearing gases, including methane, plagued Burns Valley Elementary for more than a decade, eventually leading the Konocti Unified School District to shut down one wing of the school after years of health complaints. The gases may have contributed to the death of a teacher.

In February 1980, while working late one day, Burns Valley teacher Betty David nearly passed out in her classroom in the school’s "Pomo" wing, which contained three classrooms. Odorous gases, an ongoing problem in the Pomo wing since its construction in 1947, were suspected. For years, faculty and students had complained about headaches and shortness of breath. The wing was closed down, and specialists from various health and environmental agencies began investigating.

The following month, David died in Redbud Hospital of congestive heart failure and hypertensive heart disease. While her death was never officially linked to her fainting spell, concern among parents and school officials mounted.

An investigation found levels of two potentially dangerous gases, carbon dioxide and methane, that far exceeded expected background levels. The level of carbon dioxide in David’s classroom was 4,000 parts per million, over ten times the expected background level, said Air Pollution Control Officer Bob Reynolds of the Lake County Air Quality Management District. In the nearby lounge, levels were approximately 100 times the normal concentration, according to Reynolds’ findings. Methane in David’s classroom was detected at 500 ppm — roughly 100 times the normal background level. Methane levels in the lounge were 1,000 times the expected concentration.

While it makes up a small percentage of the air we breathe every day, carbon dioxide can cause nausea, dizziness, vomiting, and even loss of consciousness at the levels found in the Pomo wing lounge. Methane is flammable, but measurements did not record explosive concentrations, even though the readings were above normal. Both methane and carbon dioxide can displace oxygen, thereby hampering breathing and reducing the flow of oxygen to the brain — which would explain the reported symptoms. Each gas is odorless, though methane sometimes is found with hydrogen sulfide, a toxic gas with a distinctive rotten-egg smell.

Analysts soon determined that gas levels were highest following periods of heavy rain. Reynolds, who spent 15 years periodically investigating the phenomenon, theorizes that the source of the problem is a natural reservoir of gas that vents into the area. Geothermal or volcanic activity may play a role. The naturally occurring gases usually dissipate harmlessly into the atmosphere through dry soil, but during heavy rain, the soil is saturated, making it more difficult for gases to escape. Some of this gas then follows the alternative path of least resistance, which happens to be the dry foundation of the Pomo wing.

Following the recommendation of the state health department, a ventilation system was installed to exchange inside air for outside air — "nothing sophisticated" in the words of Assistant Superintendant Doug Baumgart. Initially, the vents were turned on for only an hour each day before classes began. However, after 1988 tests recorded still-elevated levels of carbon dioxide, analysts recommended running the vents continuously, despite their noisiness. Later test results were mixed; sometimes carbon dioxide levels were normal, sometimes not.

But folks in Lake County seem more patient with dangerous gases than Southern California residents. Despite safety concerns, two of the three classrooms in the Pomo wing remained open until 1995, when another round of high carbon dioxide readings prompted the school district to close the Pomo wing permanently.

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