APPORTIONING THE SOURCES OF LEAD IN-HOUSE DUSTS IN THE LONDON BOROUGHOF RICHMOND, ENGLAND

The sources of particulate lead in houses in the London Borough of Ric hmond, England have been investigated using automated scanning electro n microscopy in conjunction with energy dispersive X-ray spectroscopy. Compositional and size information was collected on lead-bearing part icles from density and size fractionated floor dusts from 16 residence s of various ages. A classification scheme based on the analysis of di fferent types of lead source particles was used to categorize the hous e dust particles as either auto exhaust, road dust, garden soil, paint , high temperature process emissions, lead of common origin or miscell aneous lead-bearing. Classification results based on both populations of particles and estimated particle volumes suggest that paint, road d ust and garden soil are the major contributors of particulate lead to the Richmond households. The primary contributing source in the 64-100 0-mum size range of the house dusts appears to be paint. In the 0-64-m um size fraction of the dusts paint, road dust and garden soil all mak e significant contributions. Variations in the contributions made by t he major sources appear to be unrelated to the age of the homes.