Assessment of the Department of Veterans Affairs Airborne Hazards and Open Burn Pit Registry (2017) / Chapter Skim
Currently Skimming:
5 Analysis and Interpretation of Exposures Data
5 Analysis and Interpretation of Exposures Data
Pages 105-128
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 105... ...
It summarizes information on respondents' exposure to burn pits and other important service-related airborne exposures; discusses the registry's limited capacity to provide reliable estimates of the magnitude, duration, and frequency of the exposures; and explicates the committee's approach to using the exposure-related information that is available. An approach to analyzing the exposure information collected by the registry is then presented.
|
From page 106... ...
Occupational duties, for example, may put some service members in close proximity to burn pits and other sources of airborne pollutants. Some exposures would be expected to be of relatively short duration: Joint Base Balad had a large burn pit, but the base functioned as a transit stop, resulting in a short-duration exposure for many service members passing through (IOM, 2011)
|
From page 107... ...
, they do yield some information about the constituents and ambient levels of airborne toxicants that may have been present on bases with burn pits. A 2011 review of air monitoring efforts at Joint Base Balad conducted by a committee of the Institute of Medicine (IOM, 2011)
|
From page 108... ...
. Limitations of Exposure Information Emissions from burn pits were only one of the many potential exposures experienced by military personnel deployed to the Southwest Asia theater of operations.
|
From page 109... ...
The NRC committee further concluded that to appropriately investigate health effects resulting from exposure to a complex mixture of pollutants, the monitoring strategy needs to be tailored to the specific goals and hypotheses that future health-surveillance and research studies are designed to address (NRC, 2010)
|
From page 110... ...
EXPOSURE INFORMATION COLLECTED BY THE AH&OBP REGISTRY The exposure information collected by the AH&OBP Registry questionnaire consists of self-reports of deployment exposures, occupational activities, and personal habits. The result is qualitative information on individuallevel exposures or exposure potential.
|
From page 111... ...
. The committee focused on those later two questions, which characterized exposure to burn pits: • Did your duties during these dates include the burn pit (examples include trash burning, hauling trash to the burn pits, burn pit security, trash sorting at the burn pit)
|
From page 112... ...
found Participants were more likely to report exposure to burn pits on deployment segments during which they were located at bases with documented burn pits compared to deployment segments at locations with no documented burn pits. Specifically, 97 percent of deployments to Joint Base Balad, 89 percent of deployments to Contingency Operating Base Speicher, and 88 percent of deployments to Camp Taji [which had burn pits]
|
From page 113... ...
For example, if a large number of individuals who report a particular job duty participate in the registry and report a specific exposure, there is no way of differentiating among several possibilities -- whether that reflects a large number of individuals who have those job duties, whether there was a greater motivation on the part of those with certain job duties to enroll in the registry, or whether a greater proportion of individuals with those job duties were exposed. The IOM's 2011 report Long-Term Health Consequences of Exposure to Burn Pits in Iraq and Afghanistan highlights additional potential issues with the use of the registry data, beyond those identified earlier that are associated with using such data in general.
|
From page 114... ...
Descriptive Statistics The committee focused its analysis on six potential sources or types of airborne emissions: burn pits, dust (including sandstorms and desert environment) , diesel, exhaust, and fuel (including jet fuel, combat, construction, and soot [the last for 1990–1991 Gulf War respondents only]
|
From page 115... ...
Respondents with No Exposure A small proportion of respondents indicated that they were not exposed to airborne hazards or open burn pit emissions. With regard to burn pit exposure, fewer than 18% of deployment segments represented in the registry were not near burn pits (1.2.D)
|
From page 116... ...
N (%) N 1.2.A Were you exposed to soot, ash, smoke, or fumes from the Gulf War oil fires?
|
From page 117... ...
: burn pits (1.2.D) , sewage ponds (1.2.I)
|
From page 118... ...
These metrics can be used themselves or combined to provide a distribution of overall exposures to multiple potential agents. Because of the qualitative nature of the information collected, ordinal variables expressing low, middle, or high levels were created for each of six exposures of interest (burn pits, dust, diesel/exhaust/fuel, combat, construction, and Gulf War oil-well fire soot)
|
From page 119... ...
A response endorsing exposure to Gulf War oil-well fire soot was assigned a score of 6, whereas 0 was assigned to responses reporting no exposure. The exposure potential scores were transformed into categories of exposure potential reflecting assumed low, medium, and high potential for exposure so that each service member had one estimate of exposure potential for each exposure variable.
|
From page 120... ...
No = 0 No exposure = 0 Yes = 3 + Lowest tertile = 1 = 0 to 6 Middle tertile = 2 Highest tertile = 3 Dust exposure potential based on responses to Questions 1.4C, 1.3C, and 1.3F: 1.4.C 1.3.C 1.3.F Lowest tertile = 0 Lowest tertile = 0 Lowest tertile = 0 Middle tertile = 1 + Middle tertile = 1 + Middle tertile = 1 = 0 to 6 Highest tertile = 2 Highest tertile = 2 Highest tertile = 2 Diesel, Exhaust, and Fuel exposure potential based on responses to Questions 1.3C, 1.3.D, and 1.3E: 1.3.C 1.3.D 1.3.E Lowest tertile = 0 Lowest tertile = 0 Lowest tertile = 0 Middle tertile = 1 + Middle tertile = 1 + Middle tertile = 1 = 0 to 6 Highest tertile = 2 Highest tertile = 2 Highest tertile = 2 Combat exposure potential based on responses to Questions 1.3.A, 1.3.B, and 1.3.C: 1.3.A 1.3.B 1.3.C No = 0 Lowest tertile = 0 Lowest tertile = 0 Yes = 2 + Middle tertile = 1 + Middle tertile = 1 = 0 to 6 Highest tertile = 2 Highest tertile = 2 Construction exposure potential based on the response to Question 1.3.F: 1.3.F Lowest tertile = 0 Middle tertile = 3 = 0 to 6 Highest tertile = 6 Gulf War Oil-Well Fire Soot exposure potential based on response to Question 1.2.A: 1.2.A No = 0 = 0 to 6 Yes = 6
|
From page 121... ...
All six exposure potential variables were statistically significantly correlated, with one exception. Construction and Gulf War soot from oil fires were the only two not correlated (R = 0.02, p = 0.15)
|
From page 122... ...
The greatest difference occurred between the percentage of Gulf War service members with medium exposure potential to burn pits (49.7%) and those of all respondents (41.8%)
|
From page 123... ...
, the committee felt it was appropriate to create a variable that would characterize exposure to these pollutants. To do so, it used the composite exposure potential variable created to qualitatively express the potential exposure to all six main sources (burn pits, dust, diesel/exhaust/fuel, combat, construction, and Gulf War oil-well fire soot)
|
From page 124... ...
. As shown in Figure 5-5, reported burn pit exposure by year of deployment could be interpreted as an indicator of registry or deployment data validity because there were fewer reports of high burn pit exposures in Kuwait than 70 High-Level Exposure Potential to Burn Pits 60 Percent of Deployments Reporting 50 40 30 20 10 0 Year Iraq Afghanistan Kuwait FIGURE 5-5 Percentage of deployments reporting high exposure potential to burn pits by country and year of deployment.
|
From page 125... ...
As noted early in this chapter, the use of burn pits in Iraq and Afghanistan began to decline in 2009, and one would thus expect to see a dip in the number of deployments for which high burn pit exposure was reported after 2009. While the percentage of deployments to Iraq with high burn pit exposure potential shows a relatively steady decline since 2003, there is no notable deviation around 2009.
|
From page 126... ...
in addition to burn pits, and because there are insufficient data by which to determine which sources contributed the most or posed the most harm, the committee chose to weigh each potential exposure equally and to focus on the totality of exposures. Specifically, the metrics combined responses to multiple questions into single indicators of potential exposure for each of six exposures of interest: burn pits, dust, diesel/exhaust/fuel, construction, combat, and Gulf War oil-well fire soot.
|
From page 127... ...
2011. Long-term health consequences of exposure to burn pits in Iraq and Afghanistan.
|
From page 128... ...
U.S. Department Of Veterans Affairs: 10 things to know about burn pits.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.