In addition to PAHs, workers are also exposed to asbestos, silica, amines, arsenic, cadmium, lead, nickel, vanadium, hydrocarbons, sulfur dioxide, sulfuric acid, and aldehydes; "The main body of evidence came from two cohort studies of coal-gasification workers in the United Kingdom and Germany, and a case-control study nested within a cohort of French gas- and electricity-production workers;" A Group 1 carcinogen: cancer of the lung; [Reference #1] "These evaluations were typically produced at a time when the available data provided a clear indication of increased cancer risk in an occupational group, but not enough information to identify a causal agent. While such broadly defined carcinogenic agents can lead to general industrial hygiene interventions, provide support to compensate exposed workers and stimulate research to identify specific causes, they have limited utility for informing specific prevention activities and may be affected by changes in process, materials and exposure levels over time." [
PMID 29769352]