Compared to unexposed controls, the hairdressers had signs of neutrophilic airway inflammation, higher eNO levels and higher CRP. The hairdressers were exposed to high concentrations of ammonia from hairdressing chemicals and their working conditions were unsatisfactory.

Female hairdressers had higher prevalence of reported asthma and respiratory symptoms than the controls, but these differences reduced markedly when adjusted for age, height, weight and years of education. They had lower lung function measurements than the control group. Increasing the awareness of occupational health hazards and improving the work conditions for the hairdressers in Palestine is needed. Possible bias could be present as hairdressers might have over reported symptoms or lung function measurements might be affected by differences in socioeconomic status between the two groups.

ObjectivesHairdressers are exposed to chemicals at the workplace which are known to cause respiratory symptoms and asthma. This study aimed to examine changes in self-reported respiratory symptoms over 5 years, as well as to examine the lung function decline and determine whether it is within the expected range, to assess the dropout rate and reasons for leaving the profession, and to examine the associations between occupational factors and lung function changes at follow-up.DesignProspective study.SettingFemale hairdressing salons in Hebron city, Palestine.Participants170 female hairdressers who participated in a baseline survey in 2008 were followed up in 2013. A total of 161 participants participated in 2013.Outcome measuresChange in reported respiratory symptoms and change in lung function over follow-up. Dropout from the profession and reasons for it. Differences between current and former hairdressers in respiratory symptoms and lung function at follow-up. Ambient air ammonia levels in 13 salons.ResultsCurrent hairdressers reported more respiratory symptoms in 2013 compared with baseline. Former hairdressers reported fewer symptoms at follow-up. At follow-up, current hairdressers showed a significant decrease in forced vital capacity of 35 mL/year (95% CI 26 to 44 mL/year) and of 31 mL/year (95% CI 25 to 36 mL/year) for forced expiratory volume in 1 s (FEV1). 28 (16%) of the hairdressers quit the job during the 5-year follow-up, 8 (28%) because of health problems. Hairdressers who had been working for 4 years or more at baseline showed a stronger decline in FEV1 compared with those who worked less than 4 years (difference 13, 95% CI 1 to 25).ConclusionsCurrent hairdressers developed more respiratory symptoms and larger lung function decline than former hairdressers during follow-up. Few hairdressers left their profession because of respiratory health problems. Working for more years is associated with lung function decline among current hairdressers.