Environmental Exposure Surveillance in a Combat Theatre Coleen Baird, MD, MPH US Army Center for Health Promotion and Preventive Medicine I have no disclosures to make

Range of Exposures in Deployed Settings Range of Exposures in Deployed Settings Occupational/Personal Sampling- Individual Exposures Occupational/Personal Sampling- Individual Exposures –Actionable for surveillance or other –Archive for general information, document “negative exposure” Ambient Sampling: Exposure Not Clearly Linked to an Individual Ambient Sampling: Exposure Not Clearly Linked to an Individual –Epidemiological formation of cohort –Population level risks Potential Exposures- based on defined “reasonable probability” Potential Exposures- based on defined “reasonable probability” –May be actionable –May lack sampling information

Air Exposure Concentration ‘Continuum’ Air Exposure Concentration ‘Continuum’ IDLHTLVs EPA: ambient air standards mg/m 3 ug/m 3 Terrorist attack; accidental release industrial operations; accidental releases past practices; uncontrolled emissions multiple low-level exposures, continuous, long-term Single exposure Lifetime exposure minimal severe significant

Refined Exposure Assessments Refined Exposure Assessments Exposures identifiable to an individual or Similarly Exposed Groups (SEGs) Exposures identifiable to an individual or Similarly Exposed Groups (SEGs) –Exposed by nature of location or occupation such as asbestos, lead, burning trash –Requires an exposure assessment and identification of group/SEG constituents –Relatively easy to put into medical records –May require individual surveillance

Ambient or Routine Exposures Ambient or Routine Exposures Greater likelihood of being “low” Greater likelihood of being “low” Lower likelihood of health effects Lower likelihood of health effects Cohorts more readily “defined” thru available data sources Cohorts more readily “defined” thru available data sources Exposures to those in defined cohort more variable Exposures to those in defined cohort more variable

Ambient Environmental Monitoring Ambient Environmental Monitoring Air: PM/metals/volatile organics in the ambient environment of the sampler Air: PM/metals/volatile organics in the ambient environment of the sampler –PM levels high, but variable –Most other findings rare Large population at risk/Base camp level Large population at risk/Base camp level Exposures not uniform Exposures not uniform –Movement –Distance from sampler –Indoors –Convoys/Trash

Ambient Environmental Monitoring Ambient Environmental Monitoring Challenges linking location data (population at risk) to health data Challenges linking location data (population at risk) to health data Outcomes may be diluted due to misclassification of exposure, non-specific outcomes Data not readily interpretable by most providers

Incident or Unplanned Events Incident or Unplanned Events Greater likelihood of being “high” Greater likelihood of being “high” Greater likelihood of health effects Greater likelihood of health effects Lower likelihood of actual measurement Lower likelihood of actual measurement Typically involve fixed but hard to define cohort Typically involve fixed but hard to define cohort

Principles of Medical Surveillance Under the NRP Principles of Medical Surveillance Under the NRP Maintain the physical and mental health of responders/Identify new clinical entities/Assess adequacy of PPE Maintain the physical and mental health of responders/Identify new clinical entities/Assess adequacy of PPE Participation should be confidential and voluntary Participation should be confidential and voluntary There should be a centralized mechanism to capture data related to individual and collective exposures There should be a centralized mechanism to capture data related to individual and collective exposures

Principles of Medical Surveillance Under the NRP Principles of Medical Surveillance Under the NRP Creation of a registry of workers at the site Creation of a registry of workers at the site Exposure assessment strategies should be developed and implemented to protect workers and guide interventions Exposure assessment strategies should be developed and implemented to protect workers and guide interventions Each individual should receive detailed and interpreted biomedical and exposure data Each individual should receive detailed and interpreted biomedical and exposure data Risk communication needs to be an integral part Risk communication needs to be an integral part

Enhanced exposure analyses UNCLASSIFIED

2003 Sulfur Fire 2003 Sulfur Fire Multiple samples taken over weeks at various locations* Multiple samples taken over weeks at various locations* Health care provided on site by a special team* Health care provided on site by a special team* Documented in medical record* Documented in medical record* Exit physical standardized for firefighters Exit physical standardized for firefighters Roster of firefighters obtained and archived* Roster of firefighters obtained and archived* Health outcome analysis* Health outcome analysis*

Long Term Follow-up Defined cohort Defined cohort –Small numbers Poorly defined cohort Poorly defined cohort –Exposures variable –Weak exposure/ weak inclusion »Misclassification bias »Rare outcomes/unusual coding

Lessons Learned Lessons Learned Traditional IH surveillance possible in deployed setting if equipment/skill sets available Traditional IH surveillance possible in deployed setting if equipment/skill sets available Ambient sampling has proven difficult to integrate into routine medical care Ambient sampling has proven difficult to integrate into routine medical care “Incident driven” events pose a challenge for data collection, and potentially for long-term follow-up “Incident driven” events pose a challenge for data collection, and potentially for long-term follow-up