A Hospital Mystery in the Alps

On a ridge, nestled at the foot of the Swiss Alps is a beautiful ten story hospital.  The facility has a parking garage at the bottom and a helicopter pad on the roof.  Throughout its history, this hospital has had its share of problems.  One of the most notable instances was when a helicopter was attempting a landing on the rooftop heliport.  Strong and variable winds coming up the valleys on either side of the ridge made the landing difficult.  The winds caused the helicopter to crash, but that is not this story.

One day in this hospital, a medical team consisting of a doctor and nurses passed out in a short procedure operating room.  Obviously, something had caused them to faint, but air quality tests were run with negative results.  Over the next few months other hospital workers began to feel ill.  With little known as to the cause of the illnesses, the workers’ union was threatening a strike.  It was then that I received a call from a French friend asking me to investigate the problem.

When I arrived at the hospital, I met with the group charged with determining what was happening.  We discussed the various illnesses that were occurring and how the list of victims had grown to over 300 people.  There was great concern about preventing whatever was happening from continuing.

To provide some perspective, the hospital was built into the side of a ridge next to the road that wound up into the Alps.  It overlooked two picturesque valleys on either side.  It was of modern construction and well outfitted with up-to-date medical equipment and hospital utilities.  To begin my investigation, I started examining the building from the ground up, in the parking garages.

In some instances, exhaust fumes from the cars using a garage could work their way into a building.  However, what I found was that the garage in general was well sealed from the main building.  The crawl spaces were also well sealed.  The garage was naturally ventilated by the winds blowing up the valleys.  Similarly, the loading dock and emergency entrance were not sources of fumes.

Working my way up the building from the first floor, I found opened windows in common areas and offices.  It is possible that these would affect airflow from the building’s heating, ventilating, and air conditioning (HVAC) system, creating stagnated spaces where fumes could accumulate.  Upon inspection I determined that the HVAC system was of good quality with air intakes high on the building well away from any source of pollution, including smoke from the chimneys below in the valleys.  The patient rooms were well ventilated, as were the offices and other spaces in the building.  Nothing overt was to be found as causing a problem.  So what was happening?

While assessing the available information, I remembered a book that I had read about Dr. John Snow of London, and how he had discovered the cause of a cholera outbreak there in 1854.  He mapped the individuals who had contracted cholera and found they had a common source of water.  Due to sewage from local residences typically draining into underground streams, the local water pump from which the nearby populace drew their water was found to be the source of the infection.  Removing the pump handle stopped the outbreak.  Improved sanitation minimized future risk.  With this in mind, I decided to map the outbreak in the hospital.

I was given building plans as well as a list of each person affected and their locations within the hospital when they began to feel ill.  Most of the incident sites were above the ground floor.  None were in the garages.  Interestingly, most of the people affected fell ill or smelled something bad near the janitor’s closets.  So, the apparent thing to do was to check the janitor’s closets.

Like most janitor’s closets, those in this hospital had janitorial supplies and floor sinks.  The supplies included floor cleaning detergent and 12% bleach solution (twice as strong as the 6% bleach used in the U.S.).  When mixed, these compounds produced several gases, including chlorine.  Most tellingly, a janitor’s closet with these chemicals was adjacent to the initial breakout in the operating room which had connected drains with the janitor’s closet floor sink.  It was established that when janitors cleaned, they would pour the used cleaning solutions down the floor sinks, where the detergent and bleach solutions could mix.  The gases produced had the potential to bubble up through the janitor’s drain and adjacent drains, depending upon the soil pipe layout.  During an operating procedure, due to the connected drains, a large bolus of gases entered the operating room and catastrophically effected the operating team.  Thankfully, the HVAC system saved them from asphyxiation.

All this was discussed with the hospital staff and the board of directors.  I recommended that the openable windows be permanently closed to re-establish the designed airflow in the building.  This would help keep the building well ventilated as originally planned.  I also recommended that the cleaning chemicals be changed to types that would not produce offensive and dangerous gases.

When I returned home from my trip, my friend called and said the director of the hospital wanted to erect a statue of me in the town square. I knew that he was joking but was pleased to hear that they were happy with the results of my work.  The director implemented my recommendations, avoided a strike, and re-established the good name of the hospital.

Author:  Albert L. de Richemond, P.E. – Mechanical Engineer

aderichemond@ces-experts.com

Direct:  610-889-0760