Respiratory Symptoms, Sensitization, and Exposure–Response Relationships in Spray Painters Exposed to Isocyanates

Abstract

Rationale: Associations between oligomeric isocyanate exposure, sensitization, and respiratory disease have received little attention, despite the extensive use of isocyanate oligomers. Objectives: To investigate exposure-response relationships of respiratory symptoms and sensitization in a large population occupationally exposed to isocyanate oligomers during spray painting. Methods: The prevalence of respiratory symptoms and sensitization was assessed in 581 workers in the spray-painting industry. Personal exposure was estimated by combining personal task-based inhalatory exposure measurements and time activity information. Specific IgE and IgG to hexamethylene diisocyanate (HDI) were assessed in serum by ImmunoCAP assay and enzyme immunoassays using vapor and liquid phase HDI-human serum albumin (HDI-HSA) and HSA conjugates prepared with oligomeric HDI. Measurements and Main Results: Respiratory symptoms were more prevalent in exposed workers than among comparison office workers. Log-linear exposure-response associations were found for asthmalike symptoms, chronic obstructive pulmonary disease-like symptoms, and work-related chest tightness (prevalence ratios for an interquartile range increase in exposure of 1.2, 1.3 and 2.0, respectively; P < 0.05). The prevalence of specific IgE sensitization was low (up to 4.2% in spray painters). Nevertheless, IgE to N100 (oligomeric HDI)-HSA was associated with exposure and workrelated chest tightness. The prevalence of specific IgG was higher (2-50.4%) and strongly associated with exposure. Conclusions:The results provide evidence of exposure-response relationships for both work-related and non-work-related respiratory symptoms and specific sensitization in a population exposed to oligomers of HDI. Specific IgE was found in only a minority of symptomatic individuals. Specific IgG seems to be merely an indicator of exposure.

Different respiratory phenotypes are associated with isocyanate exposure in spray painters

“…The current cross-sectional study was carried out in a subset of a population of workers in the Dutch spray painting industry [7]. At the time of selection, results for specific antibodies against diisocyanates measured by ImmunoCAP assay (Phadia, Uppsala, Sweden) were available from the baseline population.…”

“…Questionnaire and exposure estimates Questionnaire items were as previously described [7]. For statistical analyses respiratory symptoms suggestive of chronic obstructive pulmonary disease (COPD) and asthma were clustered into: COPD-like symptoms (chronic cough, chronic phlegm or shortness of breath); and asthma-like symptoms (wheezing or chest tightness).…”

“…Exposure assessment for these agents is challenging [6] and few epidemiological studies incorporated an exposure assessment component. As a result, exposure-response information for isocyanate oligomers is extremely limited.The present authors recently demonstrated an association between exposure and (work-related) respiratory symptoms and isocyanate-specific sensitisation in a population of 581 spray painters exposed to mainly hexamethylene di-isocyanate (HDI) oligomers [7]. To further investigate the nature of respiratory health effects caused by isocyanates, a more detailed medical evaluation was performed in a subset of the current population.…”

“…The present authors recently demonstrated an association between exposure and (work-related) respiratory symptoms and isocyanate-specific sensitisation in a population of 581 spray painters exposed to mainly hexamethylene di-isocyanate (HDI) oligomers [7]. To further investigate the nature of respiratory health effects caused by isocyanates, a more detailed medical evaluation was performed in a subset of the current population.…”

Biomonitoring Hexamethylene Diisocyanate (HDI) Exposure Based On Serum Levels Of HDI-Specific IgG

“…Isocyanate-specific IgG are not normally found in human serum (the chemicals are man-made and do not exist naturally), but are present with a relatively high prevalence among exposed workers (Welinder et al, 1988;Lushniak et al, 1998;Redlich et al, 2001;Pronk et al, 2007). The dose-response relationship between isocyanate exposure and isocyanate-specific serum IgG has been difficult to quantify, given the challenges of exposure monitoring; however, positive correlations have been reported from epidemiologic studies of isocyanate-exposed workers, based on timed task-derived personal exposure estimates (Pronk et al, 2007). Similar associations of allergen-specific IgG and exposure have been documented for other occupational allergens, e.g.…”