Law of Tiny Numbers

Forty-two times a small number is still a small number. cf. Law of Huge Numbers

Small numbers stay small

In research, you will find results such as the following:

Over 33.6 h of measurement, mean fine particulate levels were 1.7 times higher when smoking was observed than when it was not (7.9 vs 4.8 μg/m3; p->0.0001). - From Patel, Thomson & Wilson (2012)

Overall, deployed cotinine levels were 2.1 times the in port levels in non-tobacco using submariners - From Yarnall, Hughes, Turnbull & Michaud (2012)

More troubling were the findings of nicotine on or in the bodies of nonsmokers who had moved into dwellings formerly occupied by smokers. Nicotine levels were seven to eight times higher on the fingertips of nonsmokers who’d moved into a smoker’s home compared to nonsmokers who had always lived in a nonsmoking home.

In the first example, examining the effect of smoking outside, if 4.8μg/m³ of fine particulate matter (of any sort) in the air is not considered harmful, then 7.9μg/m³ (of which an implied 3.9μg/m³ is tobacco by-products) certainly won't be.

In the second example, using a marker which indicates among other things the presence of nicotine (not tobacco, or smoke - nicotine) a halving of cotinine between someone in the presence of SHS (or who's been eating tomatoes) and someone in an enforced environment where there is no SHS (or tomatoes) is apparently a big deal. Or, may be the fact that SHS (or potatoes) only double the background level of cotinine isn't really a big deal.

Finally in the third example,there would appear to be some sort of, one would assume minute, background level of nicotine even when there are no smokers around. When there are, this minute level is multiplied by 7-8 times to result in... a still minute level.