Psychosocial stress in children is found to enhance the effect of traffic-related pollution on the development of asthma. Based on this observation, the researchers of this study attempted to investigate the relationship between the adverse effects of traffic-related pollution on the respiratory system and household-associated stress in children. In this study, 1,399 children were examined for psychosocial stress and exposure to components of traffic pollution, such as NO and NO2, near their schools and homes. It was confirmed that the adverse effects of pollutants on pulmonary health were more apparent in children living in a more stressful family environment.
Respiratory problems like asthma are found to be more prevalent in children exposed to traffic-related air pollution (TRP) near their homes. Populations with less social connections or high psychosocial stress seem to be more sensitive to health problems caused by air pollution. The exact mechanism behind this association is not yet known; however, the researchers suggest that this may result from oxidative damage induced by TRP, which is further aggravated by inflammatory responses caused by psychosocial stress. These collectively result in airway inflammation. This led to the hypothesis that children living understress caused by problems related to parents and households are more sensitive to lung damage caused by TRP.
* For this study, 1,399 children aged 10 to 12 years, and belonging to eight different communities from Southern California were examined.
* Respiratory health and lung function were assessed. The history of respiratory illnesses and exposure to traffic pollution were determined based on a questionnaire answered by the participants’ parents.Details on parental psychosocial stress and demographic information like race and income were also obtained with the help of a questionnaire.
* Parental stress was measured based on their responses in the questionnaire. A standard “Perceived Stress Scale” (PSS) was used to estimate the stress levels.
* The exposure to traffic-related pollutants was estimated by measuring the levels of pollutants like NO and NO2 in their schools and communities.
* An annual clinical follow-up wasthen conducted to diagnose the onset of asthma or impairment of lung function.
* Parental stress varied markedly. On a scale of 0 to 16, the average stress was 3.9. About 11.5 percent of parents reported no stress, 20 percent reported stress at more than seven on the PSS scale. The levels of perceived stress were higher in Asian and Hispanic families, when compared to whites.
* High stress was associated with low socioeconomic status. Less educated parents, annual income less than $30,000, lack of health insurance, presence of cockroaches at home, second-hand smoke, and lack of air conditioners at home were associated with higher psychosocial stress. One smoker in the family increased stress levels 1.7 times.
* Higher levels of pollutants such as oxides of nitrogen in the neighborhood were correlated with decreased lung capacity and breathing efficiency.
* When the collective effects of parental stress and TRP were taken into account, it was found that the negative effects of TRP were more pronounced in children from households having higher stress levels.
Further studies are needed to pinpoint the biological pathways involved in stress-related inflammatory response. According to the authors, one limitation of this study is that the pollutants were measured at the center of the school. The levels of pollutants at various locations of a school are different.The outdoor levels of pollutants should have been taken into account, as children spend a considerable time in outdoor activities, where their lung function is higher. Furthermore, in this study, the personal stress of the children was not taken into account.
This study is the first to demonstrate an association between parental stress, TRP, and respiratory disorders in children. Higher exposure to TRP causes inflammatory and oxidative stress, leading to cellular damage and airway inflammation. This is further aggravated by stressful conditions, increasing the sensitivity of children to pollution-related respiratory problems like asthma.Growing up in a stressful environment at home and school increases the chances of developing pollution-related respiratory problems.Therefore, the authors suggest the regulation of TRP in the neighborhood and schools, which will reduce the risk of respiratory disorders in children who are vulnerable to psychosocial stress.
For More Information:
Parental Stress Increases the Detrimental Effect of Traffic Exposure on Children’s Lung Function
Publication Journal: American Journal of Respiratory and Critical Care Medicine, June 2011
By Talat Islam; Robert Urman; Department of Preventive Medicine, Keck School of Medicine, Los Angeles, California