Indoor Pollutants May Promote Wheezing in Preschoolers

Higher concentrations of specific volatile organic compounds (VOCs) in daycare centers were significantly associated with an increased risk for wheezing in children who attended these centers, based on data from more than 500 children.

“There is an increasing concern about of the role of Indoor Air Quality (IAQ) in development of respiratory disorders like asthma, especially in children whose immune system is under development, and they are more vulnerable to the effects of poor air quality,” said lead author Ioannis Sakellaris, PhD, of Université Paris-Saclay, Villejuif, France, in an interview. However, the effects of specific pollutants on the health of young children in daycare settings has not been examined, he said. 

In a presentation at the European Respiratory Society Congress, Sakellaris reviewed data from the French CRESPI cohort study, an epidemiological study of the impact of exposures to disinfectants and cleaning products on workers and children in daycare centers in France.

The study population included 532 children (47.4% girls) with a mean age of 22.3 months (aged 3 months to 4 years) in 106 daycare centers. A total of 171 children reportedly experienced at least one episode of wheezing since birth. 

A total of 67 VOCs were measured during one day, and concentrations were studied in four categories based on quartiles. The researchers evaluated three child wheezing outcomes based on parental questionnaires: Ever wheeze since birth, recurrent wheeze (≥ 3 times since birth), and ever wheeze with inhaled corticosteroid use. The researchers adjusted for factors including child age and parental smoking status and education level.

Overall, ever wheezing was significantly associated with higher concentrations of 1,2,4-trimethylbenzene (odds ratio [OR] for Q4 vs Q1, 1.56; P = .08 for trend), 1-methoxy-2-propylacetate (OR, 1.62; P = .01), decamethylcyclopentasiloxane (OR, 2.12; P = .004), and methylisobutylcetone (OR, 1.85; P < .001).

The results emphasize the significant role of IAQ in respiratory health, Sakellaris told Medscape Medical News. “Further efforts to reduce pollutant concentrations and limit sources are needed,” he said. In addition, more studies on the combined effect of multiple VOCs are necessary for a deeper understanding of the complex relations between IAQ and children’s respiratory health, he said.

Pay Attention to Indoor Pollutants

“Since the COVID-19 pandemic, the use of cleaning products and disinfectants has exploded,” said Alexander S. Rabin, MD, of the University of Michigan, Ann Arbor, Michigan, in an interview. Although many of these cleaning agents contain chemicals, including VOCs, that are known respiratory irritants, little is known about the relationship between VOCs and children’s respiratory outcomes in daycare settings, said Rabin, who was not involved in the study.

“I was struck by the wide array of VOCs detected in daycare settings,” Rabin said. However, the relationship to childhood wheeze was not entirely surprising as the VOCs included the known irritants benzene and toluene, he added.

The results suggest that exposure to VOCs, not only in cleaning agents but also building materials and other consumer products in daycare settings, may be associated with an increased risk for wheeze in children, Rabin told Medscape Medical News. 

However, “it is important to know more about confounding variables, including concurrent rates of respiratory infection that are common among children,” said Rabin. “As the authors highlight, further work on the compound effects of multiple pollutants would be of interest. Lastly, it would be helpful to clearly identify the most common sources of VOCs that place children at greatest risk for wheeze, so that appropriate steps can be taken to mitigate risk,” he said.

The original CRESPI cohort study was supported by ANSES, ADEME, Fondation de France, and ARS Ile-de-France. Sakellaris and Rabin had no financial conflicts to disclose.