Assessment of pulmonary functions in young adults--three cross-sectional studies.

This study reports the results of 3 cross-sectional surveys and demonstrates a birth cohort effect for pulmonary functions in students admitted to our Institute in 1974, 1986 and 1991. Improvement in height, weight and haemoglobin of students was accompanied with improvement in ventilatory (FVC, FEV1/FVC%,FEF25-75%) as well as diffusion functions (TLCO(SB), Dm, VC), specially in Group 2 and 3. Study of some vital statistics of state of Haryana from 1974 to 1992 significantly visualizes this period as period of green revolution and industrialization of the state. These quantitative indices are responsible for improvement of physical parameters and pulmonary functions of younger subjects. It is concluded that in view of the expected improvement in socio-economical status of developing countries and health of their individuals, physical and functional norms reported by different laboratories must be periodically reviewed.