Article: J: D. LALONDE; M. BRADLEY (CANADA)

11 Years of Air Quality Monitoring in Afghanistan

Environmental factors can present serious risk factors to deployed military personnel. These factors may include hot humid climates, disease vectors as well as environmental hazards - both manmade and natural - that may be present in the background.
This article describes the Canadian Armed Forces Deployable Health Hazard Assessment Team and its tasks.

Introduction

In addition to the risks associated with modern operations in deployed settings, Canadian Armed Forces (CAF) personnel must cope with environmental factors. The CAF’s Health Services Group has responded to these potential additional risks by creating the Directorate Force Health Protection (DFHP).DFHP’s mission is to protect and promote the health and well-being of the CAF and its members, with leadership, stewardship, and partnership in support of the DND/CAF mission -anytime, anywhere. In particular, DFHP activates its Deployable Health Hazard Assessment Team (DHHAT) to assess potential occupational and environmental hazards in deployed settings when tasked by the Canadian Joint Operations Command (CJOC).

DHHAT is made up of Bioscience Officers, Preventive Medicine Technicians, and is supported by DFHP’s Laboratory Manager, Occupational and Environmental Physicians, Toxicologist, and Industrial Hygienist.DHHAT collaborates with the DFHP’s experts and deployed medical personnel to conduct pre-deployment assessments of potential health hazards in the CAF areas of operation.Once potential hazards are determined, a sampling plan is developed, which DHHAT executes by completing a technical assistance visit (TAV) to the deployed setting.On these TAVs, DHHAT collects environmental samples that will be shipped to an accredited laboratory for analysis.Once the laboratory results are received, they are screened to identify compounds of potential concern (CoPC) to CAF members’ health.Subsequently, DFHP prepares a report that contains proposed mitigation measures to reduce potential occupational and environmental exposures.This report is sent to CJOC, the Command Team in theater, and the Directorate Health Services Operations.

DHHAT was present throughout the CAF’s mission in Afghanistan with 11 TAVs being successfully completed over an 11-year period between 2003 and 2014.The TAVs took place in either Kabul or Kandahar depending on where CAF personnel were living and working.The focus of these Afghanistan TAVs varied depending on each deployment’s specific environmental and occupational concerns.They covered a wide spectrum of monitoring and sampling including air quality measurements, water potability assessments, spill investigations, building material analyses and noise surveys.

The emphasis of this article will be on the air quality in Afghanistan since air quality was the main health concern throughout this mission.Table 1 details when and where the DHHAT TAVs took place, the list of compounds or group of compounds that were measured in air, and which one was identified as being a CoPC to CAF members deployed to Afghanistan.

Table 1: Locations and dates of the Deployable Health Hazard Assessment Team (DHHAT) Afghanistan technical assistance visits (TAVs), compounds measured in air and compounds of potential concern (CoPC) identified.

Location	Date	Compounds monitored in air		CoPC
Kabul	2003 Jun	Total particulates Respirable particulates PM10 Crystalline silica Asbestos fibres Elemental carbon	Metal scan VOC PAH 1-3-butadiene Formaldehyde Acetaldehyde	PM10
Kabul	2003 Oct	Total particulates Respirable particulates PM10 PM2.5 Crystalline silica	Elemental carbon Metal scan VOC PAH 1-3-butadiene	PM10 PM2.5
Kandahar	2005 Jul	Total particulates PM10 Crystalline silica Metal scan	VOC PAH 1-3-butadiene	PM10
Kabul	2006 Feb	Total particulates PM10 Crystalline silica Metals scan VOC	PAH 1-3-butadiene Sulphur oxides Nitrogen oxides	PM10
Kandahar	2007 Oct	Total particulates Respirable particulates Asbestos fibers PM10	Crystalline silica Metal scan VOC PAH	*
Kandahar	2009 Dec	Total particulates Respirable particulates PM10	PM2.5 Crystalline silica Asbestos fibres	PM10 PM2.5 Crystalline silica
Kandahar	2010 ‘120 days of wind’	PM10 PM2.5 Crystalline silica	Elemental carbon VOC PAH	PM10 PM2.5 Crystalline silica
Kandahar	2011 Mar-Apr	PM10 PM2.5	Crystalline silica	PM10 PM2.5
Kandahar	2011 Oct-Nov	Total particulates PM10 PM2.5 Crystalline silica	Elemental carbon Metal scan VOC	PM10 PM2.5
Kabul	2011 Nov-Dec	Total particulates PM10 PM2.5 Crystalline silica Sulfur dioxide Nitrogen dioxide	Carbon monoxide Ozone Metal scan VOC PAH D/F	PM10 PM2.5 Crystalline silica D/F
Kabul	2014 Jan-Feb	PM10 PM2.5	Crystalline silica	PM10 PM2.5

Tab.1: Locations and dates of the Deployable Health Hazard Assessment Team (DHHAT) Afghanistan technical assistance visits (TAV s), compounds measured in air and compounds of potential concern (CoPC) identified.

Notes:

PM= particulate matter

PM¹⁰= PM equal to or less than 10 µm in diameter

PM^2.5= PM equal to or less than 2.5 µm in diameter

VOC= volatile organic compounds

PAH= polycyclic aromatic hydrocarbon

D/F= dioxins and furans

* PM10 results from this TAV were unreliable due to a sampling error

Identification of compounds of potential concern

Each Afghanistan TAV generated thousands of individual air quality results.In order to sort through these results and pick out those that were most likely to cause either short-term or long-term adverse health effects (also called compounds of potential concern or CoPC), each result was compared to the most up to date internationally recognized health benchmarks, guidelines or standards.Exceeding these typically conservative thresholds does not necessarily imply that adverse health effects would occur but rather raises the need to conduct a toxicological assessment.

The Afghanistan air quality results were screened using the current American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Values (TLV) time-weighted average (TWA).The National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL)-TWA was another health-based standard used to assess contaminants in air.For airborne compounds with no existing ACGIH or NIOSH standards, public health-based ambient air criteria were employed, such as the United States Environmental Protection Agency (US EPA) national ambient air quality standards for particulate matter and the Ontario ambient air quality criteria for dioxins and furans (D/F).

The ACGIH TLV-TWA and the NIOSH REL-TWA are standards derived for occupational airborne exposures.They represent airborne concentrations of substances to which nearly all workers can be repeatedly exposed over their entire working lifetime without adverse health effects, based on an 8-hour workday and a 40-hour work week.These occupational standards are not completely suitable for CAF personnel in deployed settings because CAF personnel could be exposed to compounds in air for periods exceeding the standard 8-hour work day and 40-hour workweek.However, the duration of their deployment is much less than a working lifetime.On balance, it is believed that these occupational health thresholds provide a reasonable, though conservative, comparative benchmark for occupational airborne exposures while on deployment.Airborne contaminants that were measured at levels that were below the TLV-TWA or REL-TWA would not be expected to produce long-term adverse health effects in CAF members.

From all of the air quality sampling and monitoring performed in the 11 years of TAVs in Afghanistan, only three analytes exceeded their respective health threshold on at least one occasion and were therefore identified as a CoPC; crystalline silica, D/F, and PM (Table 1).Crystalline silica exceeded its health standard on three separate TAVs, two to Kandahar (2009, 2010) and one to Kabul (2011).D/F measured above the health guideline in 2011 from a TAV to Kabul.PM produced consistently high results on at least one occasion from all the TAVs completed in Afghanistan.Potential health impacts of crystalline silica, D/F, and PM will be discussed below.

Crystalline Silica

Crystalline silica is a basic component of soil, sand, granite and has three main forms: cristobalite, tridymite and α-quartz.The predominant species of crystalline silica in Afghanistan is α-quartz (Engelbrecht et al., 2008).Indeed, when detected, all crystalline silica results from the Afghanistan TAVs where observed to be of the α-quartz form.Crystalline silica, including α-quartz, is a mechanical irritant to lung tissue and has been listed by the ACGIH as an A2, suspected human carcinogen (ACGIH, 2015).There is evidence that some forms of pulmonary fibrosis are risk factors for human lung cancer and sufficient exposure to crystalline silica can cause some of these forms of pulmonary fibrosis (ACGIH, 2010).Crystalline silica can be found as both aged, and newly fractured.Newly fractured α-quartz is mainly associated with industrial processes (mining, drilling, sandblasting, glass manufacturing, quarries and foundry work); it represents the higher health risk of the two forms, and is the driving factor for the A2 carcinogen designation.Aged α-quartz is predominantly found in the environment and has low cancer association, but does represent a mechanical irritant health hazard.Sites surveyed in Afghanistan (Bagram, Khowst) by the Desert Research Institute showed no evidence of freshly fractured quartz grains (Engelbrecht et al., 2008). In all instances, quartz grains examined by the Desert Research Institute from Afghanistan were consistent with environmental aged quartz and had rounded edges (Engelbrecht et al., 2008).

Crystalline silica results from the Afghanistan TAVs were compared to the ACGIH TLV-TWA of 25 ug/m3 and α-quartz exceeded this health standard on 3 separate TAVs, in 2009 and 2010 (Kandahar) and in 2011 (Kabul).The 2009 Kandahar TAV had all air samples for crystalline silica below the analytical detection limit of 12 ug/m3 except for one sample taken at Patrol Base Sperwan Ghar (PBSG), which produced a result right at the TLV-TWA of 25 ug/m3.This highest concentration of α-quartz could have been the result of operational activities that occurred at the time of the sampling.The firing of howitzer guns at PBSG was observed to increase both total dust and respirable dust.This would indicate that gunnery activities could be responsible for the elevated ambient crystalline silica result at PBSG.

DHHAT conducted additional sampling in Kandahar in 2010 with a special focus on crystalline silica due to the 2009 results.The DHHAT TAV in 2010 was purposely conducted over the dusty summer months (also known as the ‘120 days of wind’ period) in order to capture crystalline silica concentrations during their peak.Sampling occurred at three locations in Kandahar in 2010: Kandahar Air Field (KAF), Forward Operating Base Ma’Sum Ghar (FOB MSG) and PBSG.69 samples were taken, 24 at KAF, 18 at MSG and 27 at PBSG.Of the 24 samples taken at KAF, 5 exceeded the TLV-TWA and ranged from 26 ug/m3 to 39 ug/m3. The exceedances all occurred during the evening when PM concentrations were observed to be at their peak. All of the MSG samples were below the analytical detection limit of 12 ug/m3.

Crystalline silica (α-quartz) sampling at PBSG was conducted over three days (25-27 August 2010), coincided with an important sandstorm that commenced 24 August 2010, and ended on 27 August 2010.This event was reported by the NASA earth’s observatory and was visible from their Aqua satellite (Figure 1).Of the 27 samples taken at PBSG, 18 were above the TLV-TWA and in some cases, the α-quartz levels were more than double the TLV-TWA.The α-quartz levels remained high throughout the sampling period regardless of the time of day as the high dust concentrations remained suspended in the air. When the dust event subsided late on 27 August, the α-quartz levels also diminished to below or near the TLV values.

Fig. 1: NASA Aqua satellite image shows a widespread sandstorm over Afghanistan that commenced 24 August 2010 . This image was captured during the ‘120 days of wind’ period. http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=45425

With the CAF having ceased operations in Kandahar, the DHHAT sampled for crystalline silica at 5 locations in Kabul in 2011.From the 76 samples collected at that time, two α-quartz samples exceeded the TLV-TWA of 25 ug/m3:one sample taken at the Kabul International Airport (KAIA) of 34 ug/m3, and another taken at Camp Eggers of 27 ug/m3. The overall α-quartz average was well below the TLV-TWA of 25 ug/m3 as most samples were below the laboratory detection limit of 12 ug/m3.The possible sources of α-quartz include wind generated desert sand as depicted in Figure 1 but also, vehicle and airborne traffic at these locations.

Some samples of the α-quartz forms of crystalline silica taken from Afghanistan did yield results that exceeded its ACGIH TLV-TWA.However, the exceedances occurred infrequently and mainly during important dust events.Therefore, considering the short deployment period (6-12 months compared to a lifetime of working in an industry), the maximum α-quartz levels anticipated, and the fact that the bulk of this silica is not newly fractured but rather aged as observed by the Desert Research Institute, the long-term risk posed by crystalline silica to CAF personnel deployed to Afghanistan is considered negligible.However, acute health symptoms could have been expected from exposures to high concentration of crystalline silica such as during sandstorms.These symptoms could have included irritation to the eyes, nose, throat and lungs.

Dioxins and Furans

Dioxins and furans (D/F) are the generic terms for polychlorinated dibenzo-para-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF). D/F have no commercial purpose; they are formed as by-products of combustion and in many industrial processes.The main D/F exposure sources in Afghanistan are likely the domestic burning of plastics, burning of municipal waste, and combustion of wood and hydrocarbons.D/F are highly persistent in air and soil; they can be transported to remote areas via winds and deposited in soils and sediments.

There is no ACGIH TLVs or NIOSH RELs for D/F.To put the Afghanistan D/F results in perspective, they were compared to the Ontario ambient air quality criteria (AAQC) of 0.1 pg TEQ/m3 (MOE, 2011) and also compared to concentrations measured elsewhere around the globe (Figure 2).DHHAT collected 21 D/F samples at 4 locations in Kabul in 2011.DHHAT did not collect D/F during other TAVs due to the difficulty in getting the specialised D/F sampling equipment into theatre.D/F sampling occurred in Kabul because it was felt that it represented the worst-case scenario concerning the potential presence of D/F in air.The bowl landscape surrounded by mountains promotes inversions and traps persistent compounds in air like D/F.A much larger volume of air needs to be processed to reach the required low D/F analytical detection limit.D/F is measured in picograms or pg, which is equal to one trillionth of a gram (10-12), compared to other analytes such as metals that are measured in milligrams or mg equal to one thousandth of a gram (10-3).

The D/F analyses conducted in Kabul in 2011 indicated that most results were above the Canadian urban background levels and the AAQC of 0.1 pq/m3 TEQ.The results are contained between the concentrations reported in Beijing, China and Balad, Iraq (IOM, 2011; Figure 2).It is believed that these higher levels of D/F in Kabul may be the result of increased use of plastics as a fuel source for heating and cooking in Kabul (IOM, 2011).

Figure 2:Dioxins and furans (D/F) concentrations measured at four camps during the 2010 Kabul TAV in relation to Canadian urban levels from 2011, the Ontario ambient air quality criteria limits (MOE, 2011), and studies completed in China and Iraq.The levels from Beijing were averaged over three districts and the level from Balad was a ‘worst case scenario’ (IOM, 2011).

The D/F samples taken on the 2011 DHHAT TAV to Kabul yielded results that surpassed the health-based guideline, and thus a toxicological assessment was performed.The toxicological assessment consisted of a D/F risk characterization conducted in two ways, firstly by comparing the estimated daily intake resulting from inhalation of Kabul air to published acceptable daily intakes, and secondly, by predicting a body burden of D/F that would have resulted from the 9 month deployment to Kabul.

The estimated daily D/F dose for the average CAF member deployed to Kabul was estimated at 0.17 pg TEQ/kg bw/day or less than 20% of the D/F toxicity reference value of 1 pg TEQ/kg bw/day (MOE, 2011).Considering that the conservatively estimated daily D/F is lower than the toxicity reference value even when the estimated background exposure to D/F is added to the calculation, the risk of adverse health effects for CAF members from airborne D/F in Kabul was considered to be negligible.Moreover, the predicted body burden of CAF members deployed to Kabul for nine months was estimated to be much lower than the body burden toxicity reference value (0.2 pg TEQ/g lipid versus 12 pg TEQ/g lipid).It was therefore concluded that a nine month deployment to Kabul contributed minimally to the background body burden of CAF members and no significant risk of adverse chronic health effects from this exposure would be expected.

Particulate Matter

Particulate Matter (PM) is a complex mixture of small particles and liquid droplets.PM is made up of a number of components, including acids (such as nitrates and sulfates), organic chemicals, metals, and soil or dust particles (US EPA, 2013).PM equal to or less than 10 µm in diameter, is known as PM10.PM equal to or less than 2.5 µm in diameter, is known as PM2.5.Figure 3 is a graphical interpretation of PM10 and PM2.5.The size of particles is directly linked to their potential for causing health effects.Smaller particles (less than 2.5 µm in diameter) are of particular concern because those are the particles that penetrate deep into the lungs.

There are no ACGIH TLV or NIOSH REL standards for PM10 and PM2.5.Thus, Afghanistan PM results were compared to the United States Environmental Protection Agency (US EPA) national ambient air quality standards for PM and their corresponding air quality index (AQI) categories.Table 2 details the different 2013 AQI categories for PM2.5 and PM10.

Table 2.The 2013 United States Environmental Protection Agency (US EPA) National Ambient Air Quality Standards for Particulate Matter and corresponding color-coded Air Quality Index (AQI) (US EPA, 2013).

AQI Category	PM2.5 mg/m3	PM10 mg/m3
▬ Good	0 – 0.012	0 – 0.054
▬ Moderate	>0.012 – 0.0354	>0.055 – 0.154
▬ Unhealthy for sensitive groups	> 0.0355 – 0.0554	> 0.155 – 0.254
▬ Unhealthy	> 0.0555 – 0.1504	> 0.255 – 0.354
▬ Very Unhealthy	> 0.1505 – 0.2504	> 0.355 – 0.424
▬ Hazardous	> 0.2505 – 0.5004	> 0.425 – 0.604

Notes:

PM¹⁰= PM equal to or less than 10 µm in diameter
PM^2.5= PM equal to or less than 2.5 µm in diameter

Figure 3: Graphical interpretation of PM10 and PM2.5.Image courtesy of the US EPA

Every DHHAT TAV completed in Afghanistan had PM10 samples collected and analyzed systematically.As research into the field of PM evolved, the importance of conducting PM2.5 sampling became known and was implemented on every TAV from 2009 onwards.Figure 4 depicts mean 24h-average PM results grouped for all the sites and date surveyed within a given TAV in relation to the US EPA AQI categories. The average PM2.5 results measured throughout the Afghanistan TAVs fall within the moderate to the unhealthy AQI categories while the average PM10 results extend above the hazardous AQI category.The highest mean concentration for both PM2.5 and PM10, as was the case for the α–quartz form of crystalline silica, occurred during the 2010 TAV to Kandahar during the ‘120 days of wind’ period.The highest levels of PM and silica during the 2010 TAV to Kandahar were temporally associated with dust events as shown by the NASA satellite imagery (Figure 1).

Based on the air quality surveys, CAF members deployed to Afghanistan were potentially exposed to PM2.5 and PM10 at concentrations sufficient to pose a short-term health risk such as eye irritation, nose, throat and respiratory symptoms such as cough and sputum production.While these symptoms were possible during general ambient conditions in Afghanistan, they were probable during a dust event, when the majority of personnel (whether healthy or predisposed), could be expected to demonstrate some symptoms and those with pre-existing respiratory conditions such as asthma could be expected to experience worsening of their symptoms.

Although acute air quality related symptoms while deployed were probable, it is unlikely that the exposure to infrequent, short-term dust events would produce long-term health effects.There is little evidence in the scientific literature to support clinically significant delayed onset or long-term health effects following high exposures to PM during a relatively short-term deployment (6 months).However, research in this field is limited as large, long-term studies are required and the unusual patterns of potential exposure (pertaining to a 6-month military deployment) are relevant to only a very small group of people. The majority of the PM research has focused on the adverse health effects on the general population over a long-term exposure to ultrafine urban fossil fuel derived PM, which has been associated with increased cardio-pulmonary disease and mortality in the general population.The US EPA AQI is based on this health research.There is less research and knowledge about the long-term effects of short-term exposure to high levels of PM in relatively healthy troops.This makes the interpretation of exposure limits and health risk assessments a challenge.On-going research mainly from the US Army Public Health Command pulmonary working group will hopefully shed light on these issues.

A review of the EpiNATO and Disease and Injury Surveillance System (DISS) data reflecting the time of the dust event in 2010 did not indicate any rise in clinic/hospital visits for respiratory illness. However, this lack of association could also reflect the difficulty in establishing transient PM-related health effects to short-term PM exposures.

Exposures to high PM levels during dust events can be mitigated by personnel reducing heavy outdoor activities as well as by moving indoors.This change in activity was promoted, in the Afghanistan deployed setting, by the cessation of air operations in times of poor visibility, which in turn resulted in cessation of patrols.

Figure 4.Mean 24h-average particulate matter (PM) concentrations for each Afghanistan technical assistance visit (TAV) in relation to the 2013 United States Environmental Protection Agency (US EPA) Air Quality Index (AQI) categories.The lines are the top breakpoints of the corresponding color-coded AQI category.The error bars are the standard deviations.

Conclusion

Over the 11 years of ambient air quality results from Afghanistan, thousands of samples were taken from various compounds or groups of compounds; PM, crystaline sillica, asbestos fibres, VOCs, metals, elemental carbon, PAHs, D/F, sulfur oxides, nitrogen oxides and ozone.Based on all the monitoring and the sampling conducted, three analytes were identified as compounds of potential concern to CAF members deployed in Afghanistan; D/F, crystalline silica and PM.The D/F toxicological assessment revealed no significant risk of adverse chronic health effects would be expected.However, CAF members’ exposures to PM and crystalline silica were, at times, enough to pose acute health effects such as eye, nose, and throat irritation as well as respiratory symptoms.Although there is currently little scientific evidence to support clinically significant delayed-onset or long-term health effects following these sporadic high exposures, research in this area is limited and still ongoing, making definitive interpretation of health risk assessments a challenge.

Final Remarks

DFHP employs DHHAT in a variety of ways, and DHHAT’s role is a diverse one that spans beyond air quality monitoring.DHHAT was activated for various TAVs in the recent years; in the aftermath of the Haiti earthquake in 2010, in 2013 to Israel and in 2015 to Kuwait.DHHAT also fulfills domestic taskings such as providing support to OP NANOOK in the Canadian Arctic for Joint Task Force North, and completing occupational and environmental health surveys for the Submarine Safety program.For additional information on DHHAT, its role and publications, visit the following CAF Health Services Website: http://cmp-cpm.mil.ca/en/health/personnel-providers/deployable-health-hazard-assessment-teams.page.

References

ACGIH (American Conference of Governmental Industrial Hygienists).2010.Silica, Crystalline: alpha-Quartz and Cristobalite: TLV(R) Chemical Substances 7th Edition Documentation.ACGIH, Cincinnati, OH.

ACGIH (American Conference of Governmental Industrial Hygienists).2015.Threshold limit values for chemical substances and physical agents and biological exposure indices.ACGIH, Cincinnati, OH.

Engelbrecht, J.P., McDonald, E.V., Gillies, J.A., Gertler, A.W.2008.Department of Defense Enhanced Particulate Matter Surveillance Program.Desert Research Institute (DRI), 2215 Raggio Parkway, Reno, NV 89512-1095.

IOM (Institute of Medicine) of the National Academies.2011.Long-Term Health Consequences of Exposure to Burn Pits in Iraq and Afghanistan.The National Academies Press, Washington, DC.

MOE (Ontario Ministry of the Environment). June 2011. Ontario Air Standards for Dioxins, Furans and Dioxin like PCBs.

http://www.downloads.ene.gov.on.ca/envision/env_reg/er/documents/2011/010-7193.pdf

US EPA (United States Environmental Protection Agency). 2013.National Ambient Air Quality Standards for Particulate Matter.Federal Register / Vol. 78, No. 10 / Tuesday, January 15, 2013 / Rules and Regulations.

http://www.gpo.gov/fdsys/pkg/FR-2013-01-15/pdf/2012-30946.pdf