“…In the first study to relate parental occupation to childhood cancer, children whose fathers were engaged in "hydrocarbon-related'' occupations were found to be at a twofold higher risk of death from cancer than children whose fathers were not so employed [Fabia and Thuy, 19741. Since this report, other investigators have addressed the question of parental occupation and risk of cancer in offspring, with mixed results [Hakulinen et al, 1976;Kantor et al, 1979;Kwa and Fine, 1980;Zack et al, 1980;Hemminki et al, 1980Hemminki et al, , 1981Peters et al, 1981;Sanders et al, 1981;Gold et al, 1982;Wilkins and Koutras, 1983;Wilkins and Sinks, 1984a,b;Peters and Preston-Martin, 1984;Hicks et al, 1984;Shaw et al, 1984;Vianna et al, 1984;Van Steensel-Moll et al, 1985;Spitz and Johnson, 1985;Olshan et al, 1986;Lowengart et al, 1987;Johnson et al, 19871. With one exception [Sanders et al, 19811, all published articles available for review describe the results of a case-control study in which parental employment information was (in most studies) obtained from either personal interviews or occupation/industry statements on birth certificates.…”