Evaluation of exposure incident at the Qarmat Ali Water Treatment Plant.
In 2008, employees of Kellogg, Brown, & Root, Inc, filed a lawsuit alleging exposure to toxic chemicals while working to restore the infrastructure in Iraq in 2003. The lawsuit prompted Congress to hold hearings regarding the incident, and when they learned that some National Guard members served as escorts for the KBR employees, they inquired as to whether there was a potential for adverse health effects among Soldiers in these units. The United States Army Center for Health Promotion and Preventive Medicine (USACHPPM) provided information based on an assessment conducted by a special medical augmentation response team-preventive medicine (SMART-PM) which deployed at the time of the incident. To alleviate any questions regarding the assessment, The Surgeon General of the Army requested that the assessment be reviewed by the Defense Health Board.* The review was requested to assess the incident and the information gathered, determine whether the information was sufficient to assess the potential health risk, and decide whether additional actions should be taken.
The Qarmat Ali Industrial Water Treatment Plant located in Basra, Iraq, produced industrial water for use in oil production, and did not produce potable water. The site was in an urban area, enclosed by a perimeter fence, and consisted of several structures lacking sleeping or living quarters. It had been ransacked and was not functional when secured by US military forces. The site was visibly contaminated by sodium dichromate, a corrosion suppression agent used in the water treatment process. Sodium dichromate is an inorganic compound containing hexavalent chromium known to be toxic and carcinogenic to humans and animals. Four groups worked at Qarmat Ali during the time of concern: Kellogg, Brown, & Root (KBR), a US based company contracted to restore the plant to operative status; the US Army National Guard units from Oregon, South Carolina, and Indiana, who provided personal security to KBR; the British military previously present at the site to secure the area; and Iraqi civilians hired by KBR to assist in the restoration effort.
In 2003, Army personnel were assigned to provide security for the KBR workers restoring the industrial-grade water treatment facility at Qarmat Ali, Basra, Iraq. In the summer of that year, contract work crews and safety personnel identified sodium dichromate as a potential occupational hazard in the work environment. Several US Army Soldiers reported to the supporting military medical facility and inquired about the potential health risks posed to them in their role as security detail. Concurrently, KBR initiated containment of the contaminated site and conducted environmental sampling. In-theater military occupational and environmental health specialists addressed the health concerns of the military units at a local "town hall" meeting and requested a SMART-PM conduct an in-theatre assessment. The team consisted of industrial hygienists, occupational medicine physicians, and environmental scientists. The team conducted sampling and medical evaluations for all personnel present at that time, including the Indiana Army National Guard Soldiers and Department of the Army civilians.
THE OCCUPATIONAL AND ENVIRONMENTAL INCIDENT, AND THE ROLE OF THE SMART-PM
Department of Defense Instruction 6490.03 implements policies and prescribes procedures for deployment health activities to
... control or reduce Occupational and Environmental Health (OEH) risks, to document and link OEH exposures with deployed personnel, ... and to record daily locations of deployed personnel. (1(p1))
The instruction requires a trained and equipped staff "to provide support to conduct disease outbreak and OEH exposure incident investigations" (1(p6)) and to ensure reports and documentation are archived. The instruction further notes that
All exposures shall be reported that are immediately hazardous to life or health or that may significantly increase long-term health risks (eg cancer) through appropriate command channels. (1(p6))
Likewise, Joint Chiefs of Staff Memorandum MCM 0028-07 requires preliminary hazard assessments be conducted at sites to summarize and identify anticipated OEH threats and hazards. This memorandum requires
... documentation in the individual medical record ... of any significant occupational and environmental exposures ... (2) (pA-3)
Significant occupational and environmental exposures are defined as
Exposures to OEH hazards that will plausibly result in some clinically relevant adverse health outcome to exposed individuals ... (2) (pA-A-4)
Alternatively, routine or investigative sampling might yield a result that exceeds guidelines and was considered significant.
A preliminary or phase I site assessment may have identified the contamination if there was sufficient evidence to raise the suspicion. Alternatively, during an occupational and environmental health assessment, past practices, visible ground contamination, or other findings may have led to a more detailed and specific assessment. In this instance, visible contamination at a worksite prompted an evaluation by the contractor, and the Soldiers who escorted them to the site were concerned. Their expressed concerns prompted the request for additional assessment support through command channels. The request for a special medical augmentation response team was received by USACHPPM, and a SMART-PM staffed with personnel appropriate to the situation was formed. The team deployed to conduct sampling to assess the risk, and to provide medical evaluations and risk communication.
SPECIAL MEDICAL AUGMENTATION RESPONSE TEAM ACTIONS
Between September 30 and October 24, 2003, the SMART-PM sampled surfaces within the water treatment plant, the air within and outside the plant, and the soil outside the plant. By the time the team arrived, the contractor had contained the contamination with an asphalt cover, and thus air sampling did not identify any samples above the Military Exposure Guidelines (MEGs) for air. The soil sampling results exceeded the MEGs for soil only outside the fence line of the plant. Prior to encapsulation, 3 of 48 samples of air were found to exceed the MEGs for hexavalent chromium. These values did not exceed the Permissible Exposure Limits, set by the Occupational Safety and Health Administration, which define the amount to which workers may be exposed for 40 hours a week for a working lifetime. However, the MEGs, designed for use on deployments, recognize that military personnel could be exposed to contaminants in air 24 hours per day, for periods from one to 15 years, if the sources were continuous. As such, the MEGs are lower than comparable workplace standards. This means that they are more conservative, and they are also set not to be an effect level at which adverse outcomes occur, but are screening values that indicate a need for further assessment. As the sampling conducted by the SMART-PM did not produce results that exceeded any limits, the concern for health effects was low.
However, as stated previously, these results were obtained following encapsulation. It was known that some samples had exceeded the long-term MEGs for chromium. To address the potential that exposures prior to encapsulation were higher, and may be of concern, it was decided that medical evaluations of those onsite should be conducted. Medical evaluations were offered to the members of both security forces and Department of Defense civilians. While KBR employees performed repairs to the plant prior to discovery and containment of the sodium dichromate powder, security forces and civilians spent much less time at the site. The routes of exposure of concern were determined to be inhalation and skin contact. The evaluations included the administration of exposure and symptom questionnaires, and medical examinations tailored to assess chromium exposure. Elements in the exams included a medical history, a general physical examination, and blood and urine testing (whole blood chromium levels, complete blood counts, serum chemistries, liver and renal function tests), routine urinalysis, chest x-rays, and spirometry testing. The medical evaluations were conducted within 30 days of the last potential exposure at the site. Under occupational standards, a physical examination targeting the skin and respiratory system must be conducted within 30 days of an overexposure, focusing on the presence of characteristic lesions ("chrome holes") associated with hexavalent chromium exposure. These lesions were commonly seen in occupational groups in the US which worked with hexavalent chromium at levels above the current occupational limits. The specific testing for chromium, or biomonitoring, was particularly useful in this instance. Typically, if individuals are exposed to metals, or solvents or many other types of substances, they typically "clear" the body directly or are metabolized within hours to days. For this reason, many of the biomonitoring tests are useful only if performed soon after exposure. When hexavalent chromium enters the body, it is taken into red blood cells where it remains for the life of the red blood cell, which is 120 days. Whole blood testing, which includes red blood cells, provided an indication of exposures up to 4 months prior to the test, prior to encapsulation. This testing, available at the Armed Forces Institute of Pathology, was performed.
Less than 30% of examined individuals reported symptoms, and the symptoms reported were nonspecific irritation, with eye and throat irritation being the most common. None of the individuals exhibited classical symptoms of overexposure to chromium. As might be expected when nonspecific testing is performed, some individuals were identified with minor abnormalities on urinalysis, liver function tests, pulmonary function tests, etc, but these abnormalities were minimal, few in number, and had multiple potential etiologies. Abnormal findings were not correlated with time onsite by history, and did not support a significant exposure to hexavalent chromium. The SMART-PM concluded that the reported symptoms could be related to existing personal medical conditions and desert environment-related exposures, such as heat, sand, dust, and wind. Whole blood testing for total chromium was done at the Armed Forces Institute of Pathology. Most tested individuals had levels of total chromium below the detection limit. Average values were not elevated when compared with nonoccupationally exposed general population ranges.
Exposure assessment is the next step following identification of a potential hazard. Ideally, exposure monitoring can be conducted and compared to relevant standards. Typically, if adequate sampling results in levels below standards, no further action is needed. In this instance, the initial monitoring indicated a need for further assessment, based on exceedance of the MEGs prior to encapsulation. As the MEGs are conservative, they can be used as a screening guide to direct further action. In this instance, those actions were additional sampling, which indicated that encapsulation had been a successful protective action.
This was complemented by physical examination and biomonitoring, which did not indicate that significant exposure had occurred. The findings are based upon exposure assessment, including the identification and quantification of exposure, and assessment of potential risk based upon prior knowledge of dose response relationships. Analysis of the materials/specimens collected is affected by time between collection and analyses (degradation), quantity of materials/specimens gathered, and most importantly, the limits of detection. The end product of the interpretation of findings of the above analyses is a scientifically-defensible estimate of risk for the exposed individuals given the limitations of both measures of exposure and response. The estimate of risk is likely to be qualitative, such as low, medium, or high, but should dictate specific actions. These could be 1) no further action, 2) retain roster of those involved and consider passive epidemiological surveillance, 3) retain a roster of population at risk and conduct active epidemiological surveillance, and 4) recommend certain screening or other examinations at some set interval.
In this instance, estimation of the risk determined no significant risk, and no anticipation of future health outcomes. As such, the findings were communicated to the individuals involved, information was placed in their permanent medical records, and they were instructed to note the incident on their post-deployment health assessment form. When the Defense Health Board evaluated this incident, they determined that the risk assessment conducted was "timely, comprehensive, and appropriate for the potential risk posed to service members." (3(p1)) They acknowledged that USACHPPM
met or exceeded the standard of practice for occupational medicine in regard to the exposure assessment and medical evaluation conducted in 2003 for Soldiers potentially exposed to hexavalent chromium. (3(p9))
They concluded that there was no expectation of any future adverse health outcomes. Additionally, they recognized that the anticipation, recognition, evaluation, and intervention in such situations often requires expertise beyond assets on the ground.
The actions taken to address the situation of the potential exposure to hazardous materials at the Quarmat Ali Water Treatment Plant are a case study of how on-scene preventive medicine and medical personnel correctly collaborate in the recognition, evaluation, and response to environmental risks in a deployed environment. Resources are available to assist in these types of situations. As was done in this case, deployed preventive medicine personnel and medical personnel are strongly encouraged to seek additional support through USACHPPM if they are faced with an exposure incident.
(1.) Department of Defense Instruction 6490.03: Deployment Health. Washington, DC: US Dept of Defense; August 11, 2006.
(2.) Office of the Chairman, Joint Chiefs of Staff. Memorandum MCM 0028-07, Procedures for Deployment Health Surveillance. Washington, DC: US Dept of Defense; November 2, 2007. Available at: http://amsa.army.mil/Documents/JCS_PDFs/MCM-0028-07.pdf.
(3.) Defense Health Board. Defense Health Board Review of the US Army Center for Health Promotion and Preventive Medicine Assessment of Sodium Dichromate Exposure at Qarmat Ali Water Treatment Plant. Falls Church, VA: US Dept of Defense; 2008. Report DHB 2008-06.
Coleen Baird Weese, MD, MPH
* The Defense Health Board is a Federal Advisory Committee to the Secretary of Defense. It provides independent scientific advice/recommendations on matters relating to operational programs, health policy development, health research programs, and requirements for the treatment and prevention of disease and injury, promotion of health and the delivery of health care to Department of Defense beneficiaries. Information available at http://www.health.mil/dhb/default.cfm.
Dr Weese is Program Manager for Environmental Medicine, US Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, Maryland.