ASBESTOS AND OTHER FIBRE LEVELS IN BUILDINGS

Abstract

A Nuclepore filter/SEM method was used to determine the airborne concentration of asbestos and other fibres in office and plant buildings. The monitoring/SEM/XRMA conditions were chosen to match the collection efficiency, fibre detectability and convenience of the membrane filter/optical microscope method. Additionally, the SEM/XRMA technique provides identification of counted fibres and a detection limit of 1 fibre 1. ⁻¹ under the routine conditions of occupational hygiene sampling. Application of the method to the collection of 193 air samples in the occupied areas of 22 asbestos-containing office and plant buildings gave the following asbestos counts: 22 fibre 1. ⁻¹ (1 sample); 3 fibre 1. ⁻¹ (3 samples); 2 fibre 1. ⁻¹ (5 samples); 1 fibre 1. ⁻¹ (22 samples); 0 fibre 1. ⁻¹ (162 samples). Organic fibre levels ranged from 63–0 fibre 1. ⁻¹ (median=4 fibre 1. ⁻¹ ). Mineral (non-asbestos) fibre levels ranged from 13 to 0 fibre 1. ⁻¹ (median=1 fibre 1. ⁻¹ ).