Carcinogenicity of organic fractions of particulate pollutants collected in New York City and administered subcutaneously to infant mice.

Groups of randomly bred infant Swiss mice were given s.c. injections of suspensions of (a) an organic extract of particulate atmospheric pollutants collected in New York City; (b) derived acidic, basic, neutral, aliphatic, aromatic, and insoluble fractions; and (c) three oxyneutral subfractions, in total doses of 10, 20, and 40 mg. Each test group consisted of a minimum of 44 mice; concurrent controls were comprised of 81 untreated and 86 solvent-treated mice. There were wide variations in the overall Carcinogenicity and incidence of tumors in various organs in different test groups. High incidences of hepatomas were found in males given injections of the basic fraction and to a lesser extent in males and females given injections of the organic extract. The incidence of lymphomas was high, particularly in females given injections of basic, aliphatic, and aromatic fractions and oxyneutral subfractions. Additionally, high incidences of solitary and multiple pulmonary adenomas were found in mice given injections of basic, neutral, and aromatic fractions and oxyneutral subfractions. Coexistent multiple tumors were also found in mice given injections of basic and aromatic fractions and oxyneutral subfractions. Injection site tumors were rare.