Particulate Matter and Health Effects

1. Particulate Matter and Health Effects US Army Center for Health Promotion and Preventive Medicine GOOD AFTERNOON GENERAL, I AM LTC TIM MALLON, THIS BRIEFING IS TO BRIING YOU UP TO DATE ON THE CHANGES WE MADE TO THE PREGNANCY PROFILE. NEXT SLIDE���GOOD AFTERNOON GENERAL, I AM LTC TIM MALLON, THIS BRIEFING IS TO BRIING YOU UP TO DATE ON THE CHANGES WE MADE TO THE PREGNANCY PROFILE. NEXT SLIDE���

4. Particulate Health Effects �Particulate matter� is the generic term for a broad class of physically and chemically diverse substances that exist in ambient air as discrete particles (liquid or droplets) over a wide range of sizes Originate from a variety of stationary and mobile sources Physical and chemical properties vary greatly with time, region, meteorology and source category Size/sourceSize/source

5. Particulate Health Effects EPA National Ambient Air Quality Standards: U.S Clean Air Act EPA Administrator charged with listing pollutants, which, in the administrators judgment cause or contribute to air pollution which may be reasonably anticipated to endanger either public health or welfare and to issue air quality criteria for them Primary standards define a level of air quality, the attainment and maintenance of which, in the judgment of the administrator, based on the criteria and allowing for an adequate margin of safety, is requisite to protect the public health � Ozone as an example particle size and health effects concern changed withtimeIncludes dust, dirt, soot, smoke, and liquid droplets Transformation of emitted gases such as SO2 and VOCs Effects of concern for human health include respiratory, cardiovascular disease, alterations in the bodies defense system, carcinogenesis, premature death Ozone as an example particle size and health effects concern changed withtimeIncludes dust, dirt, soot, smoke, and liquid droplets Transformation of emitted gases such as SO2 and VOCs Effects of concern for human health include respiratory, cardiovascular disease, alterations in the bodies defense system, carcinogenesis, premature death

6. Particulate Health Effects Current standards under review since 1994� Industry and the American Lung Association involved the courts to issue a final standard �Although our understanding of health effects of PM is far from complete�. Based on epidemiological evidence of a range of �serious health effects and ambient concentrations� focus on fine and course particles Revisions to the PM NAAQS published in the FR July 1997 Included PM 2.5 �

7. 1997 NAAQS Multiple legal challenges PM 2.5 standard considered to be amply justified by �growing body of empirical evidence� Vacated revisions to the PM 10 standard, not appealed Industry concerned about impacts due to emissions �areas of non-compliance tracked

8. US Studies reviewed by EPA EPA Hazardous: 505-604 ug/m3 What studies and what endpoints? Endpoints and values: Asthma admissions: PM 10 42.5 ug/m3 Respiratory symptoms/adults PM 10 44 ug/m3 Mortality PM 10 Up to 365 ug/m3

9. EPA NAAQS 2004 Epidemiological studies show consistent positive associations of exposure of ambient PM to with health effects including mortality and morbidity (numerous caveats) Public health impact large due to large number of individuals exposed Variation in PM composition acknowledged Levels still under debate�research funding and planning �

10. Historical Issues 1930�s-1950�s : Episodic severe pollution associated with increased mortality and morbidity�London, Pennsylvania Considered �harvesting� or mortality displacement Cardiovascular and respiratory impacts

11. More Recent Concerns 1994 Meta analysis: Dockery and Pope 1% increase in total deaths with 10 ug/m3 increase in PM10 Mass and concentration of particle mix rather than chemical species 1% increase in inpatient admissions for respiratory/10 ug/m3 Decreases in FEV and peak flow�

12. Health Effects Research Institute Health Effects Institute Research Report May 2004-- NMMAPS (20 cities) �No threshold for all cause and cardio/respiratory mortality as low as 10 ug/m3 with a probable threshold for all other cause mortality� �But: Exposure error may obscure threshold Various cities curves differ: statistically relevant? Random error? Impact on composite curve Associated with levels below ambient concentrations

13. World Health Organization 2004 WHO 2004 Meta-analysis and time series study of particulate matter Morbidity outcomes: �Cough and increase in medication use� Morbidity and mortality confirm NMMAPS results, limited data WHO estimates 500,000 premature deaths due to PM Small variations at very low levels are associated with health effects without a threshold

14. American Heart Association 2004 Plausible mechanistic pathways related to cardiovascular impacts with ambient concentrations�ranging from arrhythmias to sudden death, vaso and arterial constriction Human studies support this

15. Research Questions National Research Council: Research Priorities for Airborne Particulate Matter 2004: Particulate Composition Susceptible Subpopulations Combined Effects �

16. Deployed Troops Particulate matter is the most ubiquitous health risk encountered in deployed settings Levels regularly exceed US standards�sometimes by orders of magnitude Risk not readily amenable to controls �

18. PM in Deployed Settings vs. US NAAQS PM 10 24 Hr 150 ug/m3 PM 10 Annual 50 ug/m3 1 Year MEG was set at 70 ug/m3 US troops lack �susceptible� subpopulations SWA PM not uniformly associated with co-pollutants

19. SWA PM 10 Measurements 1408/1672 samples exceed PM10 annual MEG (84%) 360 ug/m3 is the mean for OIF locations (Iraq, Kuwait, Qatar) EPA Hazardous cut point is 425 ug/m3 (24 hr. value) � 46,000 ug/m3 is the highest concentration recorded at LSA Viper in Iraq in April 2003 The�next highest value is 17,000 ug/m3 at the same location the next day� �

20. Potential Health Implications Annual average approaches 24 hour �Hazard level� EPA considers this level hazardous for all populations Composition different than US PM However, sustained exposures can overwhelm clearance mechanisms Depending on particle size, inflammatory changes can be significant

21. Potential Health Implications Impact to DNBI Asthmatic exacerbations Deployed force represents a wider age and health range�Pre-existing conditions? Relationship to chronic conditions?

22. PM 10 measurements Few controls to reduce exposure: Reduce dust Reduce exposure time during dust storms Personal protective equipment Refrain from PT during dusty periods Administrative controls: Move !

23. PM 10 and URI in Bosnia Statistically significant association between URI ratios and PM10 weekly maximums Weekly averages not as strongly associated as weekly maximums URI is a broad category �

24. Unresolved Respiratory Issues Acute Eosinophilic Pneumonia Unexplained Bronchiolitis with Severe Respiratory Distress, Fort Campbell Pulmonary Function Testing and Anecdotal Complaints �

25. Pollutant Emissions - Atypical

26. SPOD PM 10 Levels No expected health effects (7%) Increased likelihood of aggravation of lung conditions?? Minor respiratory effects? (73%) Increased aggravation pre-existing conditions, minor respiratory effects�. (5%) 425 Significant risk of aggravating existing conditions, respiratory effects likely especially after increased activity, prolonged durations (16%) *Health effects for 24 hour levels

28.  Risk assessment limited to use of information from concentration-response relationships�..broad generalizations subject to much uncertainty Health risks are associated with exposure to PM alone or in combination with other air pollutants, compositions vary PM 2.5 studies indicate higher risks Impacts to mission are unclear

29.  Review the autopsies of combat casualties to determine if any inflammatory or other changes in the respiratory system are evident and unrelated to pre-existing or incidental pulmonary conditions. Enhanced surveillance�particle size distribution, characterization, long-term patterns, relative toxicity?? Communication of risk of new-onset smoking Consideration of personal protective equipment at least in limited circumstances

30. Recommendations DNBI Surveillance: Identify exposed cohorts Given the varying levels of exposure that occur at different base camps or other deployed locations, evaluate cardiovascular and respiratory outcomes Compare data from different locations and between cohorts with varying levels of exposure during and post deployment