I was thinking today that we often hear levels of pollutants or toxins like mercury (in connection with fih) or aflotoxin (in connection with peanuts) reported in ppm (parts per million). I think this can be a bit confusing to us ‘laypeople’ for two reasons. First of all, as soon as we hear parts per million, we think “Wow, a low number is a teeny weeny weeny amount”. Second, we don’t really have a good understanding of how a particular toxin affects our bodies, so we don’t really understand the implications of it being x ppm or y ppm. In some cases, 5 ppm would be absolutely negligable, and in others it would be relevant, depending on the interaction with our bodies.
All of this lead me to want to understand this better. First, I found this
useful page
on wikipedia that gave ppm and ppb some
grounding in everyday life. For instance, 1 ppm is one drop of ink in a
150 litre drum of water.
Second, I found
a site that presents information on chemicals in the context of
toxicity and environmental risk.
posted at 14:59 on Tue, 28 Mar, 2006 |
path: /living
All material copyrighted by Jen Schellinck. All rights reserved.