Complex sentence: The CDC has reported on occupations which were routinely exposed to ALS between 1981 and 1983 during this time the occupation with the highest number of workers exposed was registered nurses followed closely by funeral directors.
Split into simpler sentences: The CDC has reported on occupations which were routinely exposed to ALS between 1981 and 1983. During this time, the occupation with the highest number of workers exposed was registered nurses, followed closely by funeral directors.