Health and Safety

9 questions and answers on chrysotile and health

• Question 5

  Can exposure to one single asbestos fibre kill?

  Answer:

  It should be realized that it is almost physically impossible to test this proposition experimentally. It is virtually impossible to challenge cells, tissues or whole animals to one single fibre, because of the ubiquity of asbestos fibres; it should be realized that one milligram of asbestos may contain several hundred million respirable fibres. Furthermore, it is a universally acknowledged fact that experimental protocols call for a minimum dose of several hundreds of thousands of fibres in order to induce observable effects.

  On the other hand, the following facts may help in reaching sensible judgement:

  1. Every 60 seconds, the lungs of a normal person handle some 10 liters of air.
  2. In the general environmental air of cities and rural areas, concentrations of approximately 1 fibre per liter (possibly a little more or a little less, depending on circumstances of location, weather conditions, etc.) are found around the world.
  3. It follows from these two observations that every day, 14,400 liters of air (10 liters x 60 min. x 24 hrs), each one containing 1 fibre, transit through the lungs of a "normal" non-occupationally exposed person.

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