A PASSIVE SAMPLER FOR MONITORING URBAN PARTICULATE - PRELIMINARY-RESULTS

A passive sampling device, developed for personal monitoring of airbor ne dust levels in industry, has been tested as a site sampler in the u rban environment. The device weighs approximately 15g and the essentia l sampling element is a small disc of electret material (polymer carry ing a permanent electric charge). During use it captures particles by electrical attraction, at a rate that depends upon their electrical mo bility, but which is independent of the rate at which air flows past t he sampler. It collects measurable quantities of particulate, though t he sample size tends to be small and correlation with results from con ventional samples has not yet been established. Samplers have been exp osed to urban particulate for periods of up to seven days, without the electret suffering unacceptable loss of electric charge. It has been shown to be potentially useful for long-term monitoring, a situation i n which dispensing with a power source is particularly useful. Being s mall, the passive sampler is easy to hide or camouflage. It has potent ial for multiple simultaneous site sampling and for monitoring persona l environmental exposure.