Apparent resistance to fall in forced vital capacity in children with increasing mass level of fine particulate: A physiological phenomenon

Abstract

Forced vital capacity (FVC) of children in the age group 10–12 years are reported as a function of quantum increase in PM2.5 level in ambient air. The data are reported for the children in the categories based on their respective body mass index (BMI). FVC (% predicted) values decreased with increasing level of PM2.5. The subjects are found to respond in a selective manner as plateau was observed for FVC values against some selected ranges of PM2.5 concentration levels (74 µgm−3 to >117 µgm−3). To explain this unusual behavior, sac theory is proposed which explains the observations of FVC for subjects of all categories with different BMI values.