Ron Wyzga, SC. D., FASA Senior Technical Executive AWMA Annual Meeting June 25, 2014

Ron Wyzga, SC. D., FASA Senior Technical Executive

AWMA Annual MeetingJune 25, 2014

Commentary on the Critical Review Public Health and Components of Particulate Matter:

The Changing Assessment of Black Carbon

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Critical Review

• Good compendium of literature• Rightfully points to role for BC• Needs to go beyond BC

– other components– surrogacy– BC, OC as mixtures

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Rohr – Wyzga Paper

• Reviewed literature through February 2012

• Epidemiology, toxicological, human clinical studies

• Acute studies only (exposures ≤ 1 week)

• No judgments about study methods, analyses

• Studies had to consider at last 2 components and PM2.5

• Quantitative results were presented

• Considered the most significant positive result

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Results – Epidemiological Studies Overall

• 39 studies considered PM2.5 and at least 2 components

• CVD response

21/39 significant association and at least with PM or component

2/39 significant association with PM, but not component

17/39 significant association with components, but not PM

Carbon-containing components gave more significant associations than PM2.5

24/28 studies considering carbon-containing particles found significant associations

9/35 studies considering sulfates found significant associations

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Results Epidemiological Studies II

• Respiratory responses

15/26 studies for carbon-containing particles

12/27 studies for sulfates

• Asthma

7/20 studies for carbon

• Not much consideration of metals in epi studies– Ni, V, Cu, Si, K found greatest effects

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Limitations/Caveats

•Considered any significant positive results

•Methodologies not evaluated

•No consideration of measurement error

•Multiple comparison issue

•Surrogacy issue

•Two pollutant models not addressed

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Ito et al Results

150 Cities(components)

64 Cities (components)

YearWarm

SeasonCold

SeasonYear

WarmSeason

Cold Season

PM2.5 x x x x - x

Sulfate - - - - - x

OC x x x x - x

EC x - x x - x

Nitrate x - - - x -

x = statistically significant

150 Cities(components)

64 Cities (components)

YearWarm

SeasonCold

SeasonYear

WarmSeason

Cold Season

x - x x x x

- - - x x -

x x x x x -

x - x x - x

- - - - - -

CVD Hospitalizations Respiratory Hospitalizations

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Overall Conclusion

• No major component is exonerated

• More evidence for carbon-containing particles– Definition needs to be clarified– Need to go beyond EC

• Some concern for metals, especially Ni, V with cardiovascular and respiratory; Al, Si with respiratory endpoints

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Health Analyses of Thermal Desorption Data

Atlanta & Birmingham (2006 - 2009), Dallas (2006 – 2007)

Health Data:– Medicare enrollees (>64 yr)– Total emergency CVD and respiratory related hospital admissions

Air Pollution Data:– PM2.5 condensed-phase primary OC species (TD-GCMS)

grouped by their chemical structure• At least 75% non-missing observations• At least 50% above the LOD• IQR/median > 0.3• All criteria satisfied in all 3 cities

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Thermal Desorption Data: Atlanta, Birmingham, Dallas Combined Total CVD

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Conclusions

• EC, OC are mixtures

• Some components may be more important in predicting health effects than others

• Need more detailed measurements to unravel air pollution – health issue

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Possibilities for EC

• EC bad actor• EC, others bad actors• EC + other bad actors• EC a surrogate