This article is more than 5 years old. Information may no longer be current.

Infants whose mothers smoke have increased exposure to third hand smoke in NICU

Thirdhand smoke affects infants in the neonatal intensive care unit and is present on incubators, cribs and other furniture due to surface nicotine from smoking visitors, according to recent research published in BMJ.

“This research highlights [third hand smoke (THS’s)] pervasiveness, even in closely guarded health care settings,” Thomas F. Northrup, PhD, assistant professor from the department of family and community medicine at The University of Texas Health Science Center at Houston Medical School in Texas, and colleagues wrote. “Future work is needed to understand exposures and health consequences in such a vulnerable population.”

Northrup and colleagues evaluated urine samples of five infants in the neonatal intensive care unit (NICU) whose mothers were smokers. The researchers analyzed the surfaces of fingers, incubators, cribs and other furniture in the NICU for nicotine, according to the abstract. They also analyzed the infant’s urine for cotinine, trans-3’-hydroxycotinine (3HC) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and 4-(methylnitrosamino)-1-(3-pyridyl)-1- butanone (NNK).

The five participant mothers in the study reported that they smoked regularly; allowed smoking in their car, home, or both; lived with other smokers; and allowed other people who smoked to visit the infant. The mothers said they were light smokers (< 10 cigarettes/day) and visited the infant daily.

In addition to finding cotinine in the infants’ urine samples, they also detected NNAL and 3HC. Northrup and colleagues also found similar surface levels of nicotine on incubators and cribs, which they noted was equal to furniture in a household with smokers that banned indoor smoking.

The researchers said that while the health consequences are not clear, more research is needed to study the effects of whether smoking contributes to the overall mortality rate of this patient population.

“Indeed, the death rate among NICU infants is relatively high and the role of environmental carcinogens is unknown,” Northrup and colleagues wrote. “It may be important to implement hospital policies and interventions to reduce THS exposure, even ahead of collection of causal data, given the potential risks for NICU patients.” – by Jeff Craven

Disclosure: The researchers report no relevant financial disclosures.