A cross sectional study on the occupational airborne exposure and the prevalence of self-reported asthma, and respiratory symptoms amongst workers in selected factories in Nairobi, Kenya

# Background Inhalation of airborne particulate matter of less than ten microns diameter (PM~10~) in workplaces causes a variety of respiratory ailments and symptoms. This cross-sectional study was conducted on factory production workers (N=388) to investigate the association between occupational airborne exposure to PM~10~ and the prevalence of asthma and respiratory symptoms amongst factory workers in selected Nairobi factories. # Methods The Touhilampi respiratory health questionnaire was modified to include home environment and used in this study. PM ~10~ concentrations of the working environment breathing zones was also measured using air Samplers and a 24-hour average recorded for each of the five factories. Lung function tests of all the respondents using Spirometers were also recorded. # Results The results show that the highest percentage of the factories (33.0%) had a mean concentration of 17.16 mg/m^3^ of PM~10~. A considerable percentage (41.5%) of respondents had cough with wheezing or whistling sound. The mean concentration in mg/m^3^ of PM~10~ for factory environment among respondents who reported cough without flu/cold was significantly higher (14.19mg/m^3^) than to those who indicated otherwise (12.56 mg/m^3^) (*P*=0.005). Respondents with FEV~1~/FVC % (ratio of the forced expiratory volume in the first one second to the forced vital capacity of the lungs) of less than 80 normal predicted value had significantly more proportion of cough without flu/cold (44.3% \[odd ratio OR=1.62; 95% confidence interval CI=1.03-2.56; *P*=0.038\] as compared to those who had FEV~1~/FVC% of 80 and above normal predicted value (33.0%). # Conclusions Most of the factories had high levels of PM~10~ concentration possibly leading to respiratory health problems. The relevant Government agencies should be enabled to make efforts towards reducing the same.