Presentation on theme: "The Health Effects of Particulate Matter From the 9/11 WTC Attacks"— Presentation transcript:
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 airThree Classifications:Very Fine (PM0.1): diameter < 0.1 μmFine (PM2.5): μm < diameter < 2.5 μmCoarse (PM100): μm < diameter < 100 μmTalk about constituents of fine and coarse PM.
3 PM Has Numerous Health Risks Eye, nose, throat, lung irritationIncreased respiratory related hospital admissions and ER visitsAggravated asthmaAggravated coughingDifficult or painful breathing
4 PM Has Numerous Health Risks Decreased lung functionAggravated chronic obstructive pulmonary disease (COPD)Increased deaths from COPD and cardiovascular causesChronic bronchitisIncreased deaths from lung cancer
5 Fine PM Is Worse Than Coarse PM Stays in the air longerPenetrates deeper into the respiratory systemCoarse PM is filtered out in nose and pharynxFine PM deposits inside trachea, bronchi, lungsEPA Recommendations (PM2.5):Sensitive Groups: 40 μg/m3 per dayGeneral Population: 65 μg/m3 per daySay who sensitive groups are.
6 WTC Findings Two studies: UC Davis DELTA EPA Composition analysis Air monitoringAnimal toxicology experiments
7 UC Davis StudyDELTA 8 DRUM Impactor [Taken from Cahill,2003]201 Varick St.WTC1.8 kmCourtesy of MapquestFrom 10/2 to 10/30/01, researchers collected samples at 201 Varick St.Used 8-stage rotating drum impactor to collect samplesAnalyzed samples to determine composition
8 UC Davis Study Found 4/5 classes of hazardous particles: Acidic aerosols - burn cilia and lungsVery fine insoluble aerosols (glass) - pass through the lungs into the bloodstreamFine transition metals (V, Ni, Cu, Hg, etc.) disrupt lung chemistryHigh temperature organics - carcinogensBiological aerosols (bacteria, viruses, molds) - not found
9 UC Davis Study Abnormally high levels of very fine PM Disproportionate amount of coarse PM3.5Figure 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 StudyHigh 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 reactionsHowever, amount of PM steadily declinedBy May 2002, PM < 10% of October levels
13 WTC Findings Two studies: UC Davis DELTA EPA Composition analysis Air monitoringAnimal toxicology experiments
14 EPA Air MonitoringAsbestos – shown (by Prof. Wilson!) to pose insignificant riskOf 9608 samples taken in Lower Manhattan, only 21 samples (0.22%) > screening levelLead – 5/321 (1.56%) > screening levelPM2.5 – 935/91,305 (1.02%) > 40 μg/m (0.04%) > 65 μg/m3Everything 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 violationsShort-term: very many violationsEPA tested throughout the cityLower Manhattan at greater than average risk
18 WTC Findings Two studies: UC Davis DELTA EPA Composition analysis Air monitoringAnimal 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 injuryDid 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 PM2.5Inconsistent/unclear results caused by very low deposition efficiency:Only ~14 μg deposited in lungs vs. 100 μg in Exp. AExperiment CCompare effects of PM from different WTC sitesNo differences!
21 WTC Findings - SummaryHigh levels of PM in short-term, but relatively safe in long-termWTC PM did not cause acute lung injury, although it did increase airway responsivenessBoth 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 exposuresLong-term effectsBoth are possible for residents/workers of Lower Manhattan, especially rescue/cleanup workers
23 RecommendationsEnsure that homes are properly cleaned by licensed professionalsMinimize exposure:Close windowsUse wet vacuumsLimit time outdoors (but do exercise!)
24 Or If You Really Want to Be Safe MOVE TO THE COUNTRY!Avoids WTC dustAlso reduces overall pollution, which is associated with all sorts of health risks