ANNALS OF ENERGY AUDITING:
Suicide in Sendai

by Alan Meier

During one of Professor Hiroshi Yoshino's visits, we went out to dinner at Cafe Venezia. The restaurant was crowded but the pasta was tasty (even though I knew that he would have preferred his native Japanese cuisine). As usual, I was talking too much--we were sharing a large carafe of wine--and so the discussion drifted to the subject of being an expert witness at a trial. I described my adventure as an expert witness in a dispute between two utilities in Hawaii. I testified about the ability of consumers to easily switch from gas to electric appliances. My testimony was delayed a few days, forcing me to wait in Honolulu. I enjoyed being paid to collect a suntan on the beaches of Waikiki.

As my story ended, I filled our glasses again. I asked Professor Yoshino, "Have you ever been an expert witness?" It was probably a dead-end question because I had heard that the Japanese avoided lawsuits wherever possible. But I was tired of talking and Yoshino had been unusually quiet, too.

Yoshino hesitated, as if he was trying to decide both how to answer and how to say it in English.

"Yes, I was an expert in a trial once," he finally replied, "but it was not as pleasant as your experience in Hawaii." He slowly sipped the wine, again hesitating as if to carefully compose the next sentence.

"You have been to my home town, Sendai, so you are familiar with the kind of apartments that we have." He waited for me to acknowledge that, yes, I remembered the thousands of two-story, wood-frame apartment buildings in Sendai (and in all of Japan for that matter). Each apartment consisted of one or two rooms, a kitchen nook, and a bathroom. Many were smaller than 200 ft2. One or both rooms had the traditional tatami mats, on which people ate, watched TV, or slept. A typical building had six units on each floor.

"This building was occupied by lower- to middle-income single persons and couples. The construction quality was rather low. As you can imagine, the thermal performance of this building was terrible; it had no insulation and air could easily leak from one unit to another.

"A student living in a ground-floor apartment decided to commit suicide by taking sleeping pills and turning on the oven. Now, you must remember that in Sendai we use city gas, not natural gas, in our stoves and water heaters."

In fact, I hadn't remembered that, but I vaguely recalled that city gas was created by pyrolysis of coal. The resulting gas could be burned like natural gas except that it was rich in carbon monoxide (CO). In America, we commit suicide by turning on the car engine in a closed garage. In both cases, it is the CO that kills. I recalled reading that the few persons rescued at the edge of death have reported that it was not an unpleasant way to go.

"But the student did not die. The neighbors suspected that something was wrong and broke into the apartment. They discovered him, unconscious. They called an ambulance and rescue team. He was revived and eventually recovered."

The way Yoshino talked, this sounded like the end of the story. I looked at him, puzzled, "So what was the trial about?"

"The woman upstairs," Yoshino replied.

I waited for him to start what was clearly the second part of the story.

"You see, a woman lived in the apartment above the student's apartment. She was sleeping at the time. You know that city gas is buoyant. The city gas rose through various leaks in the ceiling and filled the upstairs apartment with gas. In fact, the upstairs apartment filled first. The city gas accumulated at the ceiling and slowly expanded downwards as it displaced the normal air in the two apartments.

"The neighbors discovered the dead woman the next day. She had died of carbon monoxide poisoning."

Always quick to jump to conclusions, I asked, "So the police accused the student of murdering the woman upstairs?"

"No," Yoshino explained, "it was a civil suit. The family of the woman sued the rescue team for negligence."

My bewilderment was obvious, even in the dim light of the restaurant. Yoshino continued, "You see, the parents argued that the rescue team knew city gas rises, so the team should have checked upstairs as a matter of routine."

"Why did they need an expert witness?" I asked.

"The rescue team argued that the woman upstairs was already dead by the time they arrived. This is because the city gas filled the two apartments from the top down. The woman must have received a fatal dose of CO long before the student downstairs. So, even if the team had checked upstairs, the woman would have been dead. The team's negligence was not responsible for the woman's death.

"The case hinged on the concentrations of the carbon monoxide in the two apartments. I was called to estimate the rate at which the carbon monoxide accumulated upstairs and the length of the woman's exposure prior to the arrival of the rescue team.

"This was a challenging task," Yoshino continued, "The rate of gas production was simple to measure because I could inspect the stove, but the fate of the gas was more complicated because the apartments were very leaky in every direction." Yoshino grabbed a paper napkin and sketched the configuration of the apartments. Arrows representing the flows sprouted from the stove and through walls of adjoining apartments and upwards.

"Natural infiltration carried some of the gas out the windows and external walls. This rate depended on their leakiness, wind speed, and air temperatures. I used sulfur hexafluoride tracer gas to measure the leakage through each path. With this information, I could estimate the rate of carbon monoxide entering the woman's apartment upstairs. Then I had to essentially repeat the process to estimate the rate at which the gas would accumulate upstairs.

"I had to take many factors into account. For example, she was sleeping on the floor, so the carbon monoxide layer took longer to reach that level than if she were sleeping in a bed or was simply standing up and walking around. I devoted several weeks to this case.

"In the end, I demonstrated that the woman received a fatal exposure of carbon monoxide at least four hours before the ambulance team arrived. The judge was convinced, and ruled in favor of the rescue team. Afterwards, I prepared a paper on the study and it was published in a Japanese journal on law and medicine.

"You might think that this is a rare case but many people in Japan still burn kerosene in unvented heaters. About 15 Japanese die each winter from carbon monoxide poisoning. Those deaths, and this one in Sendai, could be avoided now. In Japan, about a third of the homes have carbon monoxide alarms. If there had been an alarm upstairs, the woman would have awoken long before her life was in danger."