Barriers to the Foliar Uptake of Lead

Abstract

Abstract Cuticles of leaves and fruits were studied to determine the ability of these structures and their waxes to prevent movement of lead into the plant. Only extremely small amounts of lead could penetrate the cuticles, even after extended exposure. Removal of the waxes permitted increased penetration of some cuticles, and penetration seemed more related to species of plant than to thickness of the cuticle. Additionally, living plants were challenged by aerosols of lead bromochloride in an exposure chamber. Virtually all of the lead added to plants in this manner could be removed by chloroform rinse or mild acid washes, suggesting that the lead remained as a topical coating on the foliage. No significant amount of lead could be found in roots, fruit, or new shoot growth following exposure to lead aerosols.