Each operative was asked to perform a reproducible forced expiratory volume in one second (FEV1) and a forced vital capacity (FVG) (greatest value of three values within 5%). A single dry wedge spirometer (Vitalograph, Bucks, UK) was used for the entire study and measurements were made by one of two investigators (DF and AMF). The FEV1 and FVC were then converted to percentages of predicted values for further analysis with prediction equations,7 based on a non-smoking healthy European working population. Percentages of predicted values have been used as these were thought to be the most easily manipulated, understood, and most clinically relevant to investigating textile workers. Only those operatives of white Caucasian extraction have been used in subsequent analysis.