1. The Health Effects of Particulate Matter From the 9/11 WTC Attacks

2. What is Particulate Matter?
PM is visible air pollution (haze)
PM exists in the air as aerosols: suspensions of solid and liquid particles in the air
Three Classifications:
Very Fine (PM0.1): diameter < 0.1 μm
Fine (PM2.5): μm < diameter < 2.5 μm
Coarse (PM100): μm < diameter < 100 μm
Talk about constituents of fine and coarse PM.

3. PM Has Numerous Health Risks
Eye, nose, throat, lung irritation
Increased respiratory related hospital admissions and ER visits
Aggravated asthma
Aggravated coughing
Difficult or painful breathing

4. PM Has Numerous Health Risks
Decreased lung function
Aggravated chronic obstructive pulmonary disease (COPD)
Increased deaths from COPD and cardiovascular causes
Chronic bronchitis
Increased deaths from lung cancer

5. Fine PM Is Worse Than Coarse PM
Stays in the air longer
Penetrates deeper into the respiratory system
Coarse PM is filtered out in nose and pharynx
Fine PM deposits inside trachea, bronchi, lungs
EPA Recommendations (PM2.5):
Sensitive Groups: 40 μg/m3 per day
General Population: 65 μg/m3 per day
Say who sensitive groups are.

6. WTC Findings Two studies: UC Davis DELTA EPA Composition analysis
Air monitoring
Animal toxicology experiments

7. UC Davis Study
DELTA 8 DRUM Impactor [Taken from Cahill,2003]
201 Varick St.
WTC
1.8 km
Courtesy of Mapquest
From 10/2 to 10/30/01, researchers collected samples at 201 Varick St.
Used 8-stage rotating drum impactor to collect samples
Analyzed samples to determine composition

8. UC Davis Study Found 4/5 classes of hazardous particles:
Acidic aerosols - burn cilia and lungs
Very fine insoluble aerosols (glass) - pass through the lungs into the bloodstream
Fine transition metals (V, Ni, Cu, Hg, etc.) disrupt lung chemistry
High temperature organics - carcinogens
Biological aerosols (bacteria, viruses, molds) - not found

9. UC Davis Study Abnormally high levels of very fine PM
Disproportionate amount of coarse PM3.5
Figure 3. Anomalous Size Distribution of Aerosols from the WTC [Taken from Cahill, 2004]
WTC PM shows uncharacteristic peaks at 3 μg and 0.25 μg. WTC Sulfates show uncharacteristic peak at 0.25 μg

10. UC Davis Study
High levels of very fine PM  “extraordinarily large number of particles that have the ability to penetrate deep into the lung”

11. But It’s Not That Bad!
During October, enough PM in the air to cause acute reactions
However, amount of PM steadily declined
By May 2002, PM < 10% of October levels

13. WTC Findings Two studies: UC Davis DELTA EPA Composition analysis
Air monitoring
Animal toxicology experiments

14. EPA Air Monitoring
Asbestos – shown (by Prof. Wilson!) to pose insignificant risk
Of 9608 samples taken in Lower Manhattan, only 21 samples (0.22%) > screening level
Lead – 5/321 (1.56%) > screening level
PM2.5 – 935/91,305 (1.02%) > 40 μg/m (0.04%) > 65 μg/m3
Everything else (organics, metals) < 1%

15. EPA Air Monitoring If only 0.04% > 65 μg/m3, why does PM2.5 matter?
Long-term: very few overall number of violations
Short-term: very many violations
EPA tested throughout the city
Lower Manhattan at greater than average risk

17. EPA Air Monitoring Short-term (before Dec. 19)
31/170 = 18.24% > 65 μg/m3
81/170 = 47.65% > 40 μg/m3
Long-term (after Dec. 19)
0/142 = 0% > 65 μg/m3
18/142 = 12.68% > 40 μg/m3

18. WTC Findings Two studies: UC Davis DELTA EPA Composition analysis
Air monitoring
Animal toxicology experiments (mice)

19. EPA Animal Toxicology Experiment A
Compare effects of WTC PM2.5 to ROFA (toxic control) and MST (low toxicity control)
Results:
Aspiration of 100 μg WTC PM directly into the lungs did not cause acute lung injury
Did cause significant increase in airway hyperresponsiveness (narrowing of bronchial tract)

20. EPA Animal Toxicology Experiment B Experiment C
Investigate effects of nose-only exposure to WTC PM2.5
Inconsistent/unclear results caused by very low deposition efficiency:
Only ~14 μg deposited in lungs vs. 100 μg in Exp. A
Experiment C
Compare effects of PM from different WTC sites
No differences!

21. WTC Findings - Summary
High levels of PM in short-term, but relatively safe in long-term
WTC PM did not cause acute lung injury, although it did increase airway responsiveness
Both studies concluded that general population not at significant risk, but sensitive groups should reduce exposure

22. Weaknesses in Studies UC Davis and EPA failed to investigate:
Effects of chronic/repeated exposures
Long-term effects
Both are possible for residents/workers of Lower Manhattan, especially rescue/cleanup workers

23. Recommendations
Ensure that homes are properly cleaned by licensed professionals
Minimize exposure:
Close windows
Use wet vacuums
Limit time outdoors (but do exercise!)

24. Or If You Really Want to Be Safe
MOVE TO THE COUNTRY!
Avoids WTC dust
Also reduces overall pollution, which is associated with all sorts of health risks