Know the Rules

drips of water

As University researchers, we are entrusted to conduct experiments with animals, to collect human subject data of all kinds—everything from blood samples, to observations of motor coordination and behavior, to demographic information—and we work in the environment using toxic chemicals of all sorts. Problems arise when people do not stop to think about the implications of their actions; or are simply unaware of the rules.

Let me tell you a true story. My research deals with the effects of the air pollutant ozone on plants. We had a couple of laboratories in a multi-purpose building where other scientists worked in unrelated areas and we had limited knowledge of what they did. One day, one of the graduate students in my group was treating plants with ozone in a controlled environment chamber. All of a sudden, the ozone levels shot up from the controlled level of 0.15 ppm to some huge number above 50 ppm. The student panicked and shut off the ozone generator and the valve on the oxygen tank; at those levels she knew the plants would have been fried.

Since the chamber received charcoal-filtered air and had multiple air exchanges each hour, the levels should have returned to background in a matter of minutes. But an hour passed and the level was still at 50 ppm. Having a nose that is calibrated for ozone, I decided to check. I went into the chamber briefly and detected no ozone. At 50 ppm my nose would have burned severely; I can easily smell 0.06 ppm ozone. We were perplexed, but assumed the analyzer was malfunctioning. We did not have another analyzer easily available at that time. (This was early in my career before I had back-up equipment). We planned to send the analyzer back to the manufacturer in a few days and left the equipment running.

Interestingly, after 24 hours the analyzer was again reading background. About a week later, one of the students came into my office with an unusual report. He had been talking to a student in one of these adjoining labs I spoke of earlier; it happened to be an engineering lab. The engineering student had casually mentioned to the graduate student in my laboratory that a week ago he had broken a 50 cc manometer (manometers are glass tubes designed to measure pressure) and was wondering how to clean up the mercury that had spilled out—one week later.

To give you an idea of how much 50 cc of mercury is, it is 100 times the amount of mercury in the thermometer you may have in your medicine cabinet. Now mercury, like water, evaporates: It goes from the liquid state, the state it exists in the manometer, to the gaseous state at room temperature. Thus, as soon as the mercury left the manometer and hit the floor, it began to vaporize. The other important feature of mercury is that it splatters as it hits the ground, forming lots of little beads. Well, mercury is not something you want to be breathing in, as it is a neurotoxin. So I called the Department of Environmental Health and Safety here on campus, and they came over and helped clean up this accident.

In the process of cleaning up the mercury, guess what happened? You got it, the ozone monitor started to act up again. I called the manufacturer and asked if mercury could interfere with the proper functioning of the analyzer? Yes, it certainly could, they replied. For months after this episode, every time anyone swept up in the lab where the manometer had been broken, our ozone monitor would act up a bit, indicating that there were still some traces of mercury out there that were being exposed to the air.

As a postscript, the graduate students in my lab all had their blood checked and fortunately, the mercury levels were within background levels. The moral of the story is: If you have an accident, be responsible; have enough knowledge of what you are working with to know the perils; but regardless, never try and cover up. You cannot protect yourself, those around you, or the environment that way.

Eva J. Pell, Ph.D., is vice president for research and dean of the Graduate School at Penn State, and publisher of this magazine. For more information on research safety, contact the Office for Regulatory Compliance; 814-865-1775;; or see

Last Updated January 01, 2002