Bronchoalveolar lavage cellularity. The distribution in normal volunteers.

Bronchoalveolar lavage (BAL) is used to obtain inflammatory cells from the lung. For clinical research, parametric statistics are frequently used to compare cells present in BAL of patients with lung disease with cells present in BAL of normal subjects. To determine if these populations can be compared in this manner we performed BAL on 111 never-smoking, normal volunteers and determined: (1) the mean, median, standard deviation, and range of the cells in BAL; (2) whether the data are normally distributed and satisfy the criteria for use of parametric statistical analysis.