Too many factors to generalize but the effect from all sources of ionizing radiation is cumulative over a lifetime. Peak intense exposures may be the worst, but it depends on what organ is exposed (thyroid is very sensitive compared to the fingers).
Factors:
1. Single vs Three Phase Systems
2. Low Dose vs Normal Dose vs High Spot Fluoro; Pulsed vs Non-Pulsed Fluoro
3. Hands in the field of the beam (20-100 times the dosage compared to scatter radiation)
4. Time of exposure
5. Use of high energy exposures (eg. lateral views require 3-5 times as much radiation as AP)
6. Obesity of patients
7. Shielding (lead strips below the table reduce 95%+ scatter radiation in the AP, face shields, glasses leaded, etc)
8. Collimation (reduces radiation 50-66%)