Page 41 - Occupational Health & Safety, February 2017

Lung biopsies revealed some workers in the industry suffer from constrictive bronchiolitis obliterans, which causes the smallest airways in the lung to become scarred and constricted, blocking the movement of air.
final diagnosis, doctors of affected workers initially thought that the symptoms might be due to asthma, chronic bronchitis, em- physema, pneumonia, or smoking,” NIOSH reported on this page.
The agency says affected workers should be promptly referred for further medical evaluation if they have a persistent cough; persistent shortness of breath on exertion; frequent or persistent symptoms of eye, nose, throat, or skin irritation; ab- normal lung function on spirometry test- ing; or accelerated decline in lung function. “Physicians should advise workers about any suspected or confirmed medical con- dition that may be caused or aggravated by work exposures, about recommenda- tions for further evaluation and treatment, and specifically about any recommended restriction of the worker’s exposure (in- cluding removal from the workplace) or use of personal protective equipment. To date, most cases have shown little or no response to medical treatment. Affected workers generally notice a gradual reduc- tion or cessation of cough years after they are no longer exposed to flavoring vapors, but abnormalities on lung function tests and shortness of breath on exertion per- sist. Several with very severe disease were placed on lung transplant waiting lists. Workers exposed to flavorings may also experience eye, nose, throat, and skin ir- ritation. In some cases, chemical eye burns have required medical treatment. While most workers with very severe flavoring- related lung disease have shown evidence of bronchiolitis obliterans, it is possible that some workers exposed to flavoring chemicals may develop new-onset asthma or exacerbation of pre-existing asthma.”
Workers and safety managers are asked to report lung problems they suspect might be related to work with flavorings to NIOSH, which can conduct health hazard evaluations in such cases, and the agency recommends that cases be reported to local and state public health departments.
Jerry Laws is the editor of Occupational Health & Safety.
REFERENCES
1. https://www.cdc.gov/niosh/topics/flavorings/ 2. https://www.cdc.gov/niosh/docs/2016-111/
pdfs/2016-111-ExecSum.pdf
Although 2,3-pentanedione is used as a substitute for diacetyl, it, too, is of concern because of structural similarities to diace- tyl and because animal studies have shown similar respiratory toxicity, the document’s executive summary states.
“We know these flavoring compounds can pose a great risk for workers who may be exposed on the job, causing serious and irreversible damage to their lungs,” said NIOSH Director Dr. John Howard, M.D., MPH. “This Criteria Document reflects not only our review of the science and understanding of the hazard, but also out- lines our recommendations for controlling workplace exposures to these compounds. With the release of this document, NIOSH is taking an important step in protecting the health and safety of all those who may be exposed to these compounds while on the job.”
The document summarizes current scientific knowledge and proposes mea- sures such as engineering controls for curbing work-related exposures to both compounds, based on the current state of knowledge.
NIOSH already conducted numerous studies; reviewed the scientific literature on exposures, toxicology, and engineering controls; and subsequently conducted a quantitative risk assessment before issuing the document, which it said had undergone a rigorous scientific process including peer, stakeholder, and public review. NIOSH continues to collect information through its Health Hazard Evaluation program for companies where workers may be exposed to the compounds.
Researching Flavorings-Related Lung Disease
For more information and resources to reduce the risk of obliterative bronchiolitis associated with occupational exposures to flavorings, visit NIOSH’s topic page1 on fla- vorings-related lung disease: https://www. cdc.gov/niosh/topics/flavorings/
The agency’s topic page cites the well- known August 2000 case in which the Mis- souri Department of Health and Senior
Services requested technical assistance from NIOSH in an investigation of oblit- erative bronchiolitis, in former workers of a microwave popcorn plant in Jasper, Mo.
NIOSH eventually researched the case in collaboration with the microwave pop- corn industry and flavorings manufactur- ers, using the findings in a 2004 NIOSH Alert titled “Preventing Lung Disease in Workers Who Use or Make Flavorings.”
The executive summary2 notes that diacetyl and 2,3-pentanedione are found in cigarette smoke and in some flavored e-cigarettes. The document’s third chapter discusses increased prevalence of airway obstructions in smokers who are exposed to diacetyl versus smokers generally in the U.S. population. “Most importantly,” it says, “because diacetyl causes obstructive lung disease and because smoking causes obstructive lung disease, the presence of di- acetyl in cigarette smoke in no way dimin- ishes the need to control diacetyl exposures in employees.”
“Although much remains unknown regarding the toxicity of flavoring-related chemicals, employers and workers can take steps to address working conditions and work practices that place workers at risk,” according to the agency. This obstructive lung disease can be severe: Lung biopsies revealed some workers in the industry suf- fer from constrictive bronchiolitis obliter- ans, which causes the smallest airways in the lung to become scarred and constrict- ed, blocking the movement of air.
“The main respiratory symptoms ex- perienced by workers affected by oblitera- tive bronchiolitis include cough (usually without phlegm), wheezing, and worsening shortness of breath on exertion. The severity of the lung symptoms can range from only a mild cough to severe cough and short- ness of breath on exertion. These symptoms typically do not improve when the worker goes home at the end of the workday or on weekends or vacations. Usually these symp- toms are gradual in onset and progressive, but severe symptoms can occur suddenly. Some workers may experience fever, night sweats, and weight loss. Before arriving at a
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FEBRUARY 2017 | Occupational Health & Safety 37