The tropospheric burden of arsenic has been estimated from representative global surface concentrations and an estimated small particle tropospheric scale height of 3.9 km to be ∼8×108 g As. Total atmospheric arsenic emissions from both natural and anthropogenic sources have been estimated to be 31×109 g As/yr. On a global basis the major source of atmospheric arsenic appears to be from anthropogenic volatilization processes, and the major natural sources of arsenic appear to be volcanoes and the terrestrial biosphere. Total atmospheric arsenic removal is estimated to be 30–50×109 g As/yr. The global tropospheric residence time of arsenic appears to be about 9 days.

Various matrices have been found to affect the flameless atomic absorption analysis of arsenic with the Heated Graphite Atomizer. Sodium in the presence of sulfate presents the most serious interference. The use of magnesium In these solutions is described to enhance the sensitivity and control the interference effects. Environmental matrices have been analyzed for arsenic by this method. Results are consistent with those obtained by standard addition and neutron activation techniques.

Three samples of marine aerosols were collected from a 20 m high tower on the coast of Bermuda using a high volume cascade impactor. The elements Na, Al, Fe, Mn, Sc, Th, and Co were found primarily on particles with aerodynamic equivalent radii of approximately 1 µm or greater and their source is likely either the sea (Na) or crustal weathering. However, the elements Cu, Zn, As, Cd, Pb, Sb, Se, and Hg are present in concentrations too high to be explained by a bulk seawater or normal crustal weathering source. The major mass of these elements is present on particles with equivalent radii less than 1 µm;, suggesting that a volatile phase is critical at some stage of the atmospheric lifetime of these anomalously enriched elements in mid‐ocean marine aerosols.

Particulate and vapor concentrations of atmospheric as have been measured over various marine and continental areas. Particulate samples were collected on double Whatman 41 filters. Particulate‐vapor samples were collected using an in‐line filter system with a 0.45‐μm pore size Nuclepore filter as a particle prefilter in front of two Whatman 41 filters impregnated with tetrabutylammonium hydroxide and glycerol for vapor As collection. Arsenic determinations were by destructive neutron activation. The data from the Nuclepore‐impregnated filter samples indicates that the major fraction of As in the atmosphere is particulate but a vapor component of As is detectable, most frequently associated with high sampling temperatures and high total As concentrations. With the data presented here, estimates of representative global near‐surface concentrations of atmospheric arsenic have been made.

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