Effect of Particle Size on Lead Absorption from the Gut

Abstract

The relationship between particle size and absorption of lead particles from the gastrointestinal tract of the rat has been investigated. Preparations of metallic lead of particle size between 0 and 250μ were incorporated in laboratory rat diets and absorption determined by measurement of tissue lead concentrations attained under standard conditions. An inverse relationship was found between particle size and lead absorption; this relationship was most marked in the 0 to 1001μ range. A five-fold enhancement of absorption was observed from the diet with lead particles of mean size 6μ, compared with 197μ particle size. Lead absorption from dried paint films containing lead chromate and lead octoate was measured using a similar technique. A marked enhancement of absorption was observed for both paints when particle size was reduced from 500 to 1,000 μ to < 50μ.