A study shows that parents’ high stress makes children more prone to lung damage from air pollution than children whose parents have a low level of stress, according to media reports Monday. The subjects in this study are about 1,400 children living in different places in southern California. Air pollution levels vary according to the places where the children lived, from six parts per billion of nitrogen oxides to 101 parts per billion. The study confirms that lung function of children living in high-stress homes got roughly five percent worse, when the average amount of nitrogen oxides in the air increased by 22 parts per billion. However, for those children from low-level homes, they are not affected by the same increase in pollutants. Nitrogen oxides refer to a binary compound of oxygen and nitrogen, causing damage to lung tissue and aggravating children’s asthma.