Respiratory Symptoms and Lung Functional Impairments Associated with Occupational Exposure to Asphalt Fumes

M Neghab, F Zare Derisi, J Hassanzadeh

Abstract


Background: Controversy exists as to the potential of asphalt fumes to induce respiratory symptoms and lung functional impairments.

Objective: To examine the respiratory effects, if any, of occupational inhalation exposure to asphalt fumes.

Methods: In this cross-sectional study, 74 asphalt workers and 110 unexposed employees were investigated. The prevalence of respiratory symptoms among subjects was investigated by a standard questionnaire. Additionally, the parameters of pulmonary function were measured both, prior to exposure and at the end of work-shift. Furthermore, to assess the extent to which workers were exposed to asphalt fumes, total particulate and the benzene-soluble fraction were measured in different worksites.

Results: The mean levels of exposure to total particulate and benzene-soluble fraction in asphalt fumes were estimated to be 0.9 (SD 0.2) and 0.3 (SD 0.1) mg/m3, respectively. Mean values of FEV1, both prior to the exposure (89.58% [SD 18.69%] predicted value) and at the end of shift (85.38% [SD 19.4%]), were significantly (p<0.05) smaller than those of the comparison subjects (93.88% [SD 13.93%]). Similarly, pre-shift (87.05 [SD 8.57]) and postexposure (89.95 [SD 6.85]) FEV1/FVC ratio were both significantly (p<0.01) lower than those of the unexposed employees (107.56 [SD 9.64]). Moreover, the prevalence of respiratory symptoms such as cough and wheezing in exposed employees were 41% and 42%, respectively. The corresponding values for comparison subjects were 10.0% and 3.6%, respectively (p<0.001). The pattern of changes in parameters of lung function in asphalt workers was consistent with that of chronic obstructive lung disease.

Conclusion: Significant decrements in the parameters of pulmonary function as well as, a significant increase in the prevalence of respiratory symptoms in asphalt paving workers compared to their unexposed counterparts provided evidence in favor of a significant association between exposure to asphalt fumes and lung function impairments.


Keywords


Asphalt; Respiratory function tests; Signs and symptoms, respiratory; Occupational exposure; Mastic asphalt; Questionnaires; Benzene; Worksites; Threshold limit values; Air borne disease



doi: 10.15171/ijoem.2015.473


 pISSN: 2008-6520
 eISSN: 2008-6814

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