Code	Occupation Description (1980)	Total # Employees (Male & Female)	Total # Female Employees
225	SCIENCE TECHNICIANS, N.E.C.	77
594	PAVING, SURFACING, AND TAMPING EQUIPMENT OPERATORS	545
595	ROOFERS	5,399
675	HAND MOLDERS AND SHAPERS, EXCEPT JEWELERS	1,950
709	GRINDING, ABRADING, BUFFING, AND POLISHING MACHINE OPERATORS	375
727	SAWING MACHINE OPERATORS	375
804	TRUCK DRIVERS, HEAVY	1,194
844	OPERATING ENGINEERS	2,076
855	GRADER, DOZER, AND SCRAPER OPERATORS	1,708
856	INDUSTRIAL TRUCK AND TRACTOR EQUIPMENT OPERATORS	36
869	CONSTRUCTION LABORERS	1,664
TOTAL		15,401

*(1) The estimates for each occupation apply across the surveyed industries in which the agent was observed. Not all industries were surveyed, and not all agents were observed in all surveyed industries. (2) When using the estimates, standard errors associated with estimates should be considered. (3) Potential exposures to a chemical agent are categorized as actual (i.e., the surveyor observed the use of the specific agent) or tradename (i.e., the surveyor observed the use of a tradename product known to contain the specific agent). The estimates presented in the table combine both categories.