Medical staff contributions to thirdhand smoke contamination in a neonatal intensive care unit

Non-smoking policies are strictly enforced in neonatal intensive care units (NICUs), which may still become contaminated by thirdhand smoke (THS), posing potential health risks to medically fragile infants. Study aims were to explore contamination routes by characterizing nicotine levels (THS proxy) found on the fingers of NICU medical staff and to assess finger-nicotine correlates.

NICU medical staff were surveyed regarding smoking and electronic nicotine devices (ENDS) use/exposure, and household characteristics. Approximately 35% of staff were randomly selected for a finger-nicotine wipe. Three separate quantile regressions modeled percentiles associated with: presence of any finger nicotine, finger-nicotine levels above the median field blank level (i.e. 0.377 ng/wipe), and finger-nicotine levels two times the median blank.

The final sample size was 246 (n=260 approached; n=14 refusals). Over three-quarters (78.5%) reported some exposure to tobacco smoke or ENDS vapor/aerosols. After field-blank adjustments, the median nicotine level (ng/finger wipe) was 0.232 (IQR: 0.021-0.681) and 78.3% of medical staff had measurable finger-nicotine levels. Both being near smoking in friends'/family members' homes and finger-surface area were related to elevated finger-nicotine levels (p<0.05) in the median blank model.

Almost four in five NICU staff had measurable finger nicotine, with finger surface area and frequency of reported exposure to tobacco smoke in friends'/family members' homes emerging as important correlates. Future research will determine the impact of THS on NICU infants. Medical personnel working in a NICU should be cognizant of secondhand smoke and THS, particularly inside friends'/family members' homes, to reduce potential NICU contamination and infant exposures.