Temporal and spatial variations of lead concentrations in Atlantic surface waters

The present study reports for the first time on lead concentrations measured in oceanic surface waters from a large geographical area in temporal resolution covering two transects through the Atlantic Ocean from 32°S to 46°N. In 1989, lead concentrations in South and Central Atlantic surface waters were relatively constant at values of 36 pmol kg −1. From 22°N on, lead concentrations then continuously increase northward up to 147 pmol kg −1. The comparison with measurements from 1981 demonstrates that lead concentrations in northeast Atlantic surface waters have halved between 1981 and 1989 reflecting the decrease of lead input from the atmosphere. A similar trend can be demonstrated for the consumption of alkyl leaded gasoline in the United States of America. Lead from this source is transported by the dominant westerly winds into the northwestern North Atlantic also influencing the northeastern parts.