Introduction: Whereas air pollutants have been measured in incinerator working areas, few studies have focused on the effects of these pollutants on the lung function of incinerator workers. In France, a study was performed among workers at two urban incinerators, aimed at identifying a link between exposure to different pollutants in incinerator plants and respiratory lung function impairments.
Methods: A follow-up of lung function was carried out on 83 incinerator workers from two incinerator plants, comparing them with a group of 76 non-exposed workers recruited by the same occupational physician. Workers' lung functions were measured during their yearly occupational medical examination, for 3 years. The American Thoracic Society quality criteria were used to control the quality of the flow-volume curves.
Results: Base-line lung functions were lower among incinerator workers than among non-exposed workers. The few significant differences were indicative of obstructive symptoms. During the first year the differences observed between the two groups were close to the significant threshold value of 5% for FEF(75)/ PV and FEF(25-75)/PV. During the third year significant differences covered three parameters: FEF(50)/PV, FEF(25-75)/PV and FEF(25-75)/FVC. After smoking habits (pack-years), medical history of allergy or lung diseases and the examination centres had been taken into account in a linear regression, the reduction of FEF(75)/PV in the first year and FEF(25-75)/FVC in the third year was linked to exposure in incinerator plants. There was no significant association between exposure and the differences observed in the FEF(25-75)/PV in the first year or in the FEF(50)/PV and the FEF(25-75)/PV in the third year.
Conclusion: This analysis of incinerator workers' lung functions has identified some lung impairments among workers exposed to incinerator air pollutants compared to non-exposed workers, thus indicating possible obstructive disorders among incinerator workers. However, these impairments are moderate and in accordance with the low levels of airborne pollutants identified in a previous study.