Tantalkers:Question 2: Do tanning lamps change in output (irradiance) from the start of the first session of the day to the end of the fifth consecutive session? (Note: Our protocol was to have a 3 minute "cool down" period between the 20-minute sessions in order to simulate the conditions on a busy day.)Answer 2: Hold on to your hats because the results of this study raises more questions than it answered!I won't bore you with the details, percentages, readings, etc.; rather, I will get right to the "bottom line" of the study. At the start (1st half) of the first session, the 20-minute MTI (maximum timer interval) sunbed took 20 minutes to reach 4.0 MED (or "te") which means it was rated at 20:20. At the end of the 5th session (2nd half), it took 30 minutes to reach 4.0 MED for a 20:30 rating. That means the "drop off" in output (irradiance) changed the 20-minute sunbed into a 30-minute sunbed! (Note: As a check, I went down on Thanksgiving day and checked several other units (100 w & 160 w) in two different salons and found that this pattern was universal and consistent.) Therefore, I assume that this "drop off" has been occuring in busy tanning salons for as long as the indoor tanning industry has existed and we just haven't, perhaps, realized it until now.What does this data mean? There AT LEAST 3 possible explanations (theories) to help make resolve this dilemma.1. Since we don't have clients complaining about not developing a tan when we are running at full capacity, this study lends credibility to data I presented in Chicago (and that will be featured in a future article). I showed that, while the tolerance to UVR increases as a persons natural skin color gets darker (and so they are less likely to sunburn), the amount of UVR (dose) that is required to cause them to tan is not much higher for a skin type 4, 5 or 6 than it is for a subtype 2A!2. Many clients (ours anyway) state that they feel that the room and sunbed must be "warm" before they can tan adequately. In fact, many of our clients request a time when the sunbed will have been used several times immediately before they use it. I believe that this stems from the fact that we feel "heat" when we tan in sunlight. Therefore, is there something about a higher "temperature" that actually helps in the tanning process or is it just psychologigal? (As a matter of fact, I have several scientific articles supporting this point of view!)3. Both theories must be considered.OK, tantalkers, Thanksgiving is over, so please help me chew on this "data" for awhile. Have you noticed this phenomenon? Have you ever had complaints from your clients that they didn't tan well after the sunbed had been used several times immediately before they used it?When Barbara Grant gets back next Monday we will do the following experiments: (1) allow a 10 minute and 20 minute "cool down" period between sessions and see if we can figure out the "optimal" time between sessions; (2) artificially "cool down" the room as far as we can and see if a cooler room results in less "drop off" of output; (3) artificially "heat up" the room to approximately 90 degrees to see what happens. We will report these results late next week.Some thoughts: Now, perhaps you can see why it is so important that we standardize the testing of sunlamps and sunbeds. The more we learn, the more we realize that the current situation with no standard protocol is unacceptable. For instance, if a manufacturer wanted to get a longer "te" time (time to 4.0 MED) to submit to FDA for marketing purposes, they would simply make the measurement after 5 or 10 consecutive sessions.Also, this experiment CLEARLY points out why I recommeend that lamps be tested the first thing in the morning and read 5 minutes (or 25%) into the session. In the results shown above, if you read the first half of the 1st session and the last half of the 5th session, one could erroneously conclude that the lamps should be changed after onl |