[en] Highlights: • Crystals related to barite, uranium and silicium are identified. • Hot spot evidenced by electron microscope. • Crystals NORM component. • Inclusion mechanism of 212 Pb and 210Po is suggested. • Non uniform NORM in oil pipe scale. -- Abstract: Radioactive related pollution due to suspended particulate matter dispersion is an important workplace and health care issue. Recycling oil production ducts and contaminated production equipment, represent a health hazard to workers and public alike. Radioactive plate-out NORM scales with crystal deposit is analyzed by different techniques; results provide proper information on physico-chemical features and emitted alpha particles. Recommendations for handling and recycling procedures are included in relation to health risk and radiological hazard.