Decrements in lung function and respiratory abnormalities associated with exposure to diacetyl and 2,3-pentanedione in coffee production workers

Abstract

Coffee production workers are exposed to complex mixtures of gases, dust, and vapors, including the known respiratory toxins, diacetyl, and 2,3-pentanedione, which occur naturally during coffee roasting and are also present in flavorings used to flavor coffee. This study evaluated the associations of these two α-diketones with lung function measures in coffee production workers. Workers completed questionnaires, and their lung function was assessed by spirometry and impulse oscillometry (IOS). Personal exposures to diacetyl, 2,3-pentanedione, and their sum (SumDA+PD) were assigned to participants, and metrics of the highest 95th percentile (P95), cumulative, and average exposure were calculated. Linear and logistic regression models for continuous and binary/polytomous outcomes, respectively, were used to explore exposure-response relationships adjusting for age, body mass index, tenure, height, sex, smoking status, race, or allergic status. Decrements in percent predicted forced expiratory volume in 1 second (ppFEV1) and forced vital capacity (ppFVC) were associated with the highest-P95 exposures to 2,3-pentanedione and SumDA+PD. Among flavoring workers, larger decrements in ppFEV1 and ppFVC were associated with highest-P95 exposures to diacetyl, 2,3-pentanedione, and SumDA+PD. Abnormal FEV1, FVC, and restrictive spirometric patterns were associated with the highest-P95, cumulative, and average exposures for all α-diketone metrics; some of these associations were also present among flavoring and non-flavoring workers. The combined category of small and peripheral airways plus small and large airways abnormalities on IOS had elevated odds for highest-P95 exposure to α-diketones. These results may be affected by the small sample size, few cases of abnormal spirometry, and the healthy worker effect. Associations between lung function abnormalities and exposure to α-diketones suggest it may be prudent to consider exposure controls in both flavoring and non-flavoring settings.

Impacts of risk assessment data, assumptions, and methods: Considering the evidence for diacetyl and 2,3-pentanedione

“…The health effects resulting from exposures to the relatively low levels of diacetyl observed in these investigations (average and highest 95% percentile personal TWA exposures below 25 and 100 ppb, respectively) have not been extensively or systematically studied. However, the analyses conducted by Virji et al ( 14 ) have provided evidence that exposures to these levels of diacetyl and 2,3-pentanedione emitted (1) naturally from coffee roasting and grinding, and (2) from flavorings added in processing flavored coffee, may be associated on average with small decrements in lung function and further, in at least one case, with clinical disease as described by Harvey et al ( 15 ).…”

“…Virji et al ( 14 ) investigated exposure-response relationships using data from cross-sectional exposure and health surveys from 17 coffee facilities. Personal exposures to diacetyl, 2,3-pentanedione, and their sum were assigned to participants using their work history information and a job exposure matrix developed using data from the exposure surveys ( 8 ).…”

“…Virji et al ( 14 ) demonstrated a statistically significant association between exposure to both diacetyl and 2,3-pentanedione and decrements in lung function and abnormalities. Of interest, the most consistent associations between exposure to α-diketones (diacetyl, 2,3-pentanedione and the sum of the two) and lung function abnormalities were observed using the highest 95th percentile exposure during the on-average 4-year work-history, which is described by the authors as a surrogate of peak exposures.…”

“…These results are generally consistent with previous epidemiological findings from exposures to added flavoring chemicals in which workers were exposed to much higher concentrations of diacetyl over longer periods of time. While Virji et al ( 14 ) posit that the lack of associations between forced expiratory volume in one second (FEV 1 ) or the ratio between FEV 1 and forced vital capacity (FEV 1 /FVC) and average or cumulative exposure in their analysis precludes a direct comparison with the analysis presented in the NIOSH criteria document ( 1 ), it is worth noting that among flavoring workers, the authors reported negative associations between cumulative exposure to diacetyl, 2,3-pentanedione and their sum, and the percent predicted FEV 1 , albeit with a small sample size ( n = 71).…”

A normative database of free-breathing thoracic 4D dynamic MRI images and associated regional respiratory parameters of healthy children

“…Respiratory anomalies can be caused by a plethora of disease conditions, including those associated with chest wall abnormalities [1], muscle weakness [2], and lung disease [3][4][5]. In children, early onset scoliosis (EOS) refers to spine curvature that is present before 10 years of age, which may be associated with heart and lung problems and can lead to respiratory insufficiency [6].…”