Two field experiments, one from November 24 to December 14, 1981, and the second from February 19 to 27, 1982, was conducted at Igloolik, Northwest Territories, Canada, to study the composition and mass size spectrum of arctic haze aerosol. In addition, measurements were made of sulphur dioxide and sulphate. Mass size distributions were obtained for Cl-, NO3-, SO4=, Mg++, Na+, and NH4+ and for elements Cl, Na, V, Mn, I, and Br. The marine aerosol component at larger particles sizes is separated from the anthropogenic aerosol component at smaller particle sizes. Anthropogenic components (NH4+, SO4=, V, and Mn) are found predominantly on submicrometer aerosols. Marine components (Cl-, Na+, and Mg++) are predominantly supermicrometer in size. Results for No4- and Br indicate that a gas phase component or precursor may exist in the arctic. Different transport during periods of the February experiment indicates higher concentrations for the haze aerosols and SO2 when the trajectories are from Asia. SO2 was found in concentrations of 0.3--4.3 gm3 and exceeded sulphate in mass Possible explanations for the SO2/SO4= concentration ratio are given.