Cook, Hewett and Hieger then linked the specific spectroscopic fluorescent profile of benzopyrene to that of the carcinogenic component of coal tar, the first time that a specific compound from an environmental mixture (coal tar) was demonstrated to be carcinogenic.
Cook, Hewett e Hieger asociaron o perfil fluorescente espectroscópico específico do benzopireno ao do compoñente carcinóxeno do alcatrán de hulla; era a primeira vez que se demostraba que un composto específico dunha mestura ambiental (alcatrán de hulla) era carcinóxeno.