Methodology: HALITOSIS Program

Although the "Hg Approximate Levels In Teeth Or Sputum Informational Screening" program is meant only for amusement, HALITOSIS provides a quick, screening method for peoples' exhaled mercury levels.

Apparatus:

• Model 2537A Mercury Vapor Analyzer
• Short 1/4" Teflon® sampling line
• Supply of small straws. (Usually purloined from the nearest bar)
• Drinking glass to hold supply of straws. (Source as above) 
   

Method:

1. The analyzer is set to sample continuously at 5 minute cycles. A 2.5 minute cycle time would offer higher throughput, but that would defeat the whole point of wanting to pass the time.) The flow rate of the analyzer is set to 1.5 litre/min.
2. At the start of a measurement cycle, a willing participant is given a straw and instructions on how to blow into the analyzer. The straw is placed into the end of the sample line. Since the straw is not a tight fit, any excess exhalation flow is vented and any shortfall in the exhalation rate are made up with ambient air.
3. The instructions generally consist of something like: "Take a deep breath. Exhale slowly and steadily though the straw. Keep blowing until you run out of breath. There is no need to cough up a lung or anything, just take your time. Please don't pass out. There is no prize for the highest (or lowest) reading."
4. During the remainder of the sampling cycle, the analyzer will sample ambient room air. This is a good time to record the person's name and affiliation and the time of the sample. It takes about 2 minutes after the end of the sampling period for the result to become available. The next person may be sampled during this period since the dual cartridge design of the Model 2537A allows continuous sampling with overlapped analysis.
   
   It's generally a good idea to record the ambient levels before and after a series of tests to get some idea of the background. The reported readings are not corrected for background.
   
   

Observations and Comments

1. The method does not control for the rate of exhalation, the exhalation time or the total exhaled sample volume. The actual concentrations in breath are likely to be far higher than reported using this method since the majority of time is spent sampling background air.
2. The method does not enforce standard conditions prior to sampling. It is well known that the mechanical action of chewing or the chemical and thermal effects of drinking hot beverages (particularly coffee) will liberate relatively large amounts of mercury from fillings. The only limits imposed by this method is that we don't allow half eaten pizza to be fed into our inlet line since we have found that it clogs the filters.

One must not lose sight of the fact that the potential health effects of mercury amalgam fillings is a serious issue. Our Links page has one or two web sites dealing with this topic.

The Model 2537A clearly demonstrates that people with mercury amalgam fillings can, under certain circumstances, excrete relatively large concentrations of elemental mercury in their breath. With appropriate front end apparatus, the Model 2537A could easily yield quantitative data. The 2.5 minute cycle time allows relatively high sample throughput and provides ample sensitivity for any measurement that could be contemplated.