The Effect of Limestone, Crush Rock and Asbestos/Cement Dust Particles on the Ventilatory Function Parameters of Chronically-Exposed Workers in Calabar Municipality and Akamkpa Local Government Areas of Calabar, Cross River State, Nigeria

Abstract

A comparative study of the influence of limestones, crush rock and asbestos/cement dust on the respiratory function parameters of exposed workers was carried in Calabar, Mfamosing and Old Netim, both of Akamkpa Local Government Area, Cross River State, Nigeria. One hundred and fifty adult male workers, non-smokers exposed for at least five years and 150 adult control groups from the College of Medical Sciences and Graduate School of the University of Calabar of the same age, weight and height were studied. The forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were determined using dry wedge vitalograph spirometer, while the peak expiratory flow rate (PEFR) was determined using the mini Wright peak flow meter. The data were statistically analysed and the result showed a mean FVC of 3.3L, FEV1 of 2.5L and PEFR of 467.6L/mm among Asbestos/cement workers. Also a mean FVC of 3.38L, FEV1 of 2.38L and 469.0L/mm for limestone workers, FVC of 3.56L, FEV1 of 2.56L, PEFR of 453.2L/mm for crush rock workers and a mean FVC
of 4.12L, FEV1 of 3.34L, PEFR of 594.0 for control group. There were no significant differences between the ventilatory function parameters (FVC, FEV1) in all the workers (P>0.05), but there were significant differences in PEFR values in the groups of workers (P<0.05). Thus, the asbestos/cement workers and crush rock workers had significantly lower respiratory indices than limestone quarry workers exposed over the same period of time (P<0.05). The FVC, FEV1 and PEFR in all the test groups showed a negative correlation or regression for all the durations of exposure or years of service (p<0.05). It is concluded that follow-up studies will be required to ascertain the extent of chronic lung damage or impairment in these
workers.