Air pollution exposure seems to worsen lung function, and low-income children seem particularly vulnerable. One proposed reason for their susceptibility is co-exposure to high parental stress, which is worse in low-income families. Although that may sound hokey, psychosocial stress has been shown to increase oxidative stress, airway inflammation, and steroid resistance. (These findings have been best demonstrated in children with asthma.)
Islam et al used data from 1,399 children (average age 11) in the Southern California Children’s Health Study, which included their parents’ self-reported psychosocial stress levels (the validated perceived stress scale), the kids’ spirometry, and measures of air pollution (oxides of nitrogen or NOx). Children with asthma were excluded to try to isolate the pure effects of air pollution and psychosocial stress. The intriguing results:
- Children living in low-income households who were exposed to high levels of NOx air pollution didn’t have reduced lung function (FEV1), if their parents reported low stress levels.
- However, children with stressed-out parents who were exposed to NOx had declines in FEV1 in a dose-response relationship (for every 22 parts per billion increase of NOx near the home, FEV1 fell by 4.5 mL).
We pathophysiology-happy MDs tend to pooh-pooh the mind-body connection, but it may be at our peril. The ongoing Adverse Childhood Experiences Study (ACE study) by CDC and Kaiser Permanente hypothesizes that through unclear mechanisms, a large proportion of chronic illness (in children, who become adults) may be directly attributable to high psychosocial stress and trauma during childhood. They’re accumulating a growing body of supporting public health literature, and one feature in the New Yorker.
Islam T et al. Parental Stress Increases the Detrimental Effect of Traffic Exposure on Children’s Lung Function. Am J Respir Crit Care Med 2011;184:822-827.