Community health aspects of biomass combustion emissions

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1 Community health aspects of biomass combustion emissions Bioenergy Emissions and Health Impacts Short Course Jeff Yanosky, ScD Penn State College of Medicine Department of Public Health Sciences March 22, 2012

2 Overview Summary of toxicological data related to BCE exposures (slides from Judy Zelikoff, NYU) Summary of results from controlled human exposure studies Summary of (recent) epidemiologic data related to BCE exposures What do data (from human and animal populations) suggest regarding health impacts of exposure to BCE?

3 Penn State Bioenergy Emissions and Health Impacts Short Course (March 22, 2012) Toxicity of Biomass Aerosols (Woodsmoke) Judith T. Zelikoff, Ph.D. New York University School of Medicine Department of Environmental Medicine

4 Domestic wood burning Wood burning stoves were first used by the Chinese in 600 B.C As wood burning uses a relatively inexpensive and renewable energy source, fireplaces and stoves are popular alternatives to other primary and supplemental heating systems Wood burning is a significant source of fine ambient particulate matter (PM 2.5 ) throughout some parts of the U.S. Italy is among the largest markets for wood burning stoves in Europe 30% of all Italian homes use wood for heat and ~5 million homes have a wood-fuelled stove Currently, there are ~13 million woodstoves in the U.S. 1.5 million households use wood as a primary or supplementary source of home heating

5 Sources of woodsmoke Developing nations Indian stove Fireplaces Wood (pellet) stoves Traditional Chinese cookstove Outdoor wood boilers Camping woodsove

6 Outdoor woodboilers Wood-fired boilers that employ primitive technologies are a growing pollution source in the U.S. and EU The average PM 2.5 emissions from one outdoor wood boiler is equivalent to: emissions from 22 EPA certified wood stoves 205 oil furnaces 8,000 natural gas furnaces four heavy duty diesel trucks (on a gram/h basis)

7 What s In Woodsmoke? (Thousands of chemical constituents, many of which are listed as hazardous air pollutants, carcinogens, irritants, and immune modulators) Particulate matter (PM) Inhalable PM 10 Majority are respirable fine, & ultrafine particles ( PM 2.5 ) Gases Aldehydes (e.g., formaldehyde, acrolein) Carbon monoxide Clorinated dioxins (e.g., TCDD) Nitrogen and sulfur oxides Polycyclic aromatic hydrocarbons (e.g., benzo[a]pyrene) Volatile organic compounds Heavy metals Nickel Lead Others Free radicals

8 Reported Health Effects of Woodsmoke Headaches and allergies Breathing difficulties Reduced lung function Exacerbation of existing pulmonary diseases: - asthma, bronchitis, - emphysema, infections Aggravated heart disease Increased susceptibility to lower respiratory tract infections Decreased birth weight

9 Health risks associated with woodsmoke exposure are based on: Toxicological studies In vivo whole animal studies Ex vivo and in vitro cellular studies Epidemiological studies Human exposure studies

10 Toxicological models to study the health effects of woodsmoke (Why include toxicology?) Epidemiologic and (oftentimes) controlled human studies are limited by lack of mechanistic information, as well as by societal concerns, ethical and legal issues, and cost Better exposure and effects data that are relevant to disease states can be correlated Because of these paradigm difficulties, predictive health assessments associated with domestic wood burning require information gained from appropriate toxicological models including human subjects

11 In vivo & in vitro toxicology studies relevant to woodsmoke What have animal and cellular studies told us about the biological plausibility and mechanistic underpinnings of woodsmokeassociated health effects?

12 Repeated/subchronic exposure to woodsmoke produces extensive pulmonary pathology, inflammation & injury, oxidative stress, decreased lung function, reduced immune resistance against infections, and increased lung cancer incidence in rodent models

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14 QUESTION? Does living in an environment where a woodburning device is being operated enhance the incidence/severity/temporality of infectious lung disease in woodsmoke-exposed individuals (particularly children)? And, if so, how?

15 Biomass (woodsmoke) emissions: laboratory generation Zelikoff et al., 2002

16 Inhaled Woodsmoke Reduces Pulmonary Bacterial Clearance in Rats (Zelikoff et al., 2002, 2009)

17 Ex Vivo and in vitro studies demonstrate eye and upper airway (trachea) injury, DNA damage, oxidative stress, and changes in cytokine production & signal transduction

18 In vitro exposure of cultured human cells to woodsmoke preparations produces DNA oxidation and reactive oxygen species The relative change of all measured biomarkers, 20 h after exposure. Mean of the individual ratios between woodsmoke and filtered air, with 95% confidence interval Taken from Danielsen et al., 2008 (Mutat. Res) Relative ROS generation in THP-1 cell cultures exposed for 3 h to WS particles. Each bar represents the mean of cultures exposed to 1.56 (black), 3.13 (white), 6.25 (light gray), 12.5 (hatched), 25 (dotted), and 50 (dark gray) µg/ml PM. *Significantly different from control. Modified from Danielsen et al., 2011 (Chem. Res. Toxicol)

19 Summary of toxicological health outcomes

20 Woodburning: An Air Pollution Problem Woodburning represents the largest source of particulate matter (PM) air pollution generated by residential sources One million tons of wood are burned annually in some U.S. and EU communities (>15,000 tons of PM annually) Heating with a woodstove for 1 season generates as much pollution as driving a car 130,000 miles. One open hearth fireplace at the upper range of emissions produces PM equivalent to about 1,770 average smokers, or >3-300 HP diesel trucks running at full throttle.

21 Particulate matter (PM) & associated health effects WHO guidelines for PM (10 µg/m 3 for PM 2.5 and 20 µg/m 3 for PM 10 ) are often exceeded in urban settings Epidemiological and controlled human studies show cardiac effects of ambient PM in healthy/compromised humans at concentrations relevant to urban PM levels PM exposure during pregnancy is linked to low birth weight and preterm delivery Chronic PM exposure has been linked with increased global incidence of lung cancer, CVD, and non-accidental mortality Animals exposed by inhalation to concentrated fine-sized air particulates (CAPS) reveal PM-associated health effects

22 Inhaled New York City concentrated ambient particulate matter (CAPS) at 65 µg/m 3 increases the severity of ongoing bacterial pneumonia in rats 18 h post-exposure Inflammation and consolidation of lung tissue Air PM

23 Effects of CAPS inhalation on pulmonary bacterial burden relative to control in previously-infected rats ** Significantly different p<0.01 from (0) time post-caps exposure *Significantly different p<0.05 from (0) time post-caps exposure Zelikoff et al., EHP 2002

24 Steps for the assessment of domestic biomass heating leading to legislation & policy change Component I Combustion, formation & measurements Component II Atmospheric combustion properties & characteristics Component IV Cost benefit Capacity building C Legislation and policy change Component III Toxicity Cleaner biomass fuels

25 Conclusions & Recommendations Based on toxicological findings, chances are great that woodsmoke poses a significant health threat to exposed individuals, particularly to those most at-risk sub-populations. Toxicological studies provide biological plausibility and strong experimental evidence relating to the potential of woodsmoke to produce adverse health effects. Short- and long-term toxicological studies yield relevant information after a shorter time period than would be needed to conduct epidemiological studies - and for substantially less money. Use of animals at all stages of life (i.e., developmental) and of both sexes will provide information useful for risk assessment of woodsmoke-impacted individuals.

26 Knowledge gaps and needs More descriptive and mechanistic woodsmoke studies of all types, particularly those associated with reproduction and development, immune competence, cardiovascular disease, and cancer More dedicated funding for research examining the health effects and underlying mechanisms of woodsmoke toxicity in relation to disease outcomes

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28 Points of discussion food for thought Do woodsmoke-generated particles differ in toxicity from other ambient particulate matter? Possible wood burning alternatives are they any safer? Woodsmoke-induced mechanisms related to adverse human health outcomes what are they? How are policy changes brought about - are they needed? What are the knowledge gaps and what types of studies are needed for a better understanding of woodsmoke toxicity?

29 Selected studies of respiratory health effects of PM 2.5 (<2006) Exposure Results Reference PM 10 levels below the US air quality standard of 150 µg/m³ Highest (night-time 12-hour average) PM µg/m³ Decreased lung function in asthmatic children associated with an increase of 10 µg/m³ in PM h PM 2.5, mean 12 µg/m³ Increased asthma hospital admissions (< 18 years): RR=1.15 (11 µg/m³ PM 2.5 increase) 24-h mean PM µg/m³ 24-h PM µg/m³, mean 10.4 µg/m³ 24-h PM µg/m³ (95% CI), mean 10.6 µg/m³ 24-h Total carbon µg/m³ (95% CI), mean 4.6 µg/m³ Increased asthma hospital admissions (< 65 years): RR=1.04 (12 µg/m³ PM 2.5 increase) Increased asthma symptoms in children: RR=1.17 (10 µg/m³ PM 1 increase) Increased respiratory emergency departments visits; RR=1.013 (7.7 µg/m³ increase in PM 2.5 ) Increased respiratory emergency departments visits; RR=1.023 (3.0 µg/m³ increase in total carbon) Koenig et al. (1993) Norris et al. (1999) Sheppard et al. (1999) Yu et al. (2000) Schreuder et al. (2006)

30 Controlled human exposures to woodsmoke Methods 13 subjects exposed to wood smoke and clean air in a chamber during two 4-h sessions, 1 week apart PM 2.5 levels during wood smoke exposure were μg/m 3, and number concentrations were 95, ,000/cm 3. About half of the particles, by number, were ultrafine (<100 nm) in size Levels representative of smoky indoor environment Blood and urine samples were taken before and after the experiment. Results: Exposure to wood smoke increased: Blood markers of CVD risk (serum amyloid A) and coagulation Urine markers of inflammation and lipid peroxidation (free 8- iso-prostaglandin2α) From Barregard et al. 2006

31 Woodstove generation system and human exposure chamber Partial flow of flue gas (a), flow of filtered indoor air (b), supply of air terminal device (c), ventilation outlet (d), and connection hole for instruments (e) Taken from Sallsten et al., 2006 (Inhal. Toxicol.)

32 Controlled human (toxicology) studies demonstrate upper airway irritation, oxidative stress, DNA strand breaks and increased cardiovascular risk factors

33 Medians with 90% confidence intervals (13 healthy subjects) Taken from Barregard et al., 2006 (Inhal. Toxicol.) Differences in serum amyloid A immediately (0) and 3 and 20 h after exposure to clean air and woodsmoke Differences in factor VIII to von Willebrand factor (vwf) ratios immediately (0) and 3, 20 h after exposure to clean air and woodsmoke

34 Differences in morning levels of factor VIIIc in plasma (kiu/l) after and before exposure to clean air and woodsmoke Taken from Barregard et al., 2006 (Inhal. Toxicol.)

35 Epidemiologic & clinical human studies: health outcomes associated with woodsmoke exposure Pulmonary COPD, asthma symptoms/ incidence, arterial hypertension, chronic bronchitis, lung function, infection Cancer Hypopharyngeal and lung cancers, genotoxicity Cardiovascular CVD risk factors Human Health Effects Increased morbidity & mortality Reproductive/ Developmental Low birth weight, pre-term birth

36 The very young The elderly The chronically ill Groups at Risk People recovering from illness Pregnant women and their unborn People who exercise Approximately 50% of the American and EU population are at risk!

37 Recent epidemiological evidence for differential particle toxicity Sarnat et al. (2008) Study design Time-series analysis in Atlanta, GA Daily emergency department visits and daily air pollution levels (lag 0 effects), including PM 2.5 mass and several source indicators derived using speciated filter analyses and application of factor analytic/chemical mass balance techniques

38 Toxicity of biomass emissions vs. PM 2.5 From Sarnat et al. 2008

39 Findings from Sarnat et al Only suggestive evidence for an association with PM 2.5 mass at lag 0 Most importantly, effects seem to be driven by secondary aerosols, with several other components having lower effect estimates Suggests differential particle toxicity Biomass effects are elevated and second highest These are lag 0 outcomes

40 Another time-series study Daily respiratory admissions (<19 years ) in CA during the cool season (lags 0 and 3) (Ostro et al. 2009) Effects of daily PM 2.5 mass and several of its components evaluated Effect of lag structure (0 vs. 3 days) investigated

41 From Ostro et al. 2009

42 Brochiolitis and BCE exposure Age-matched case-control study of infants (n=11,675) in British Columbia, Canada (Karr et al. 2009) Wood-smoke land-use regression model identified wood-burning areas, and temperature and levoglucosan measurements characterized wood burning days OR adj wood smoke of 1.08 (95% CI, ) Adjusted for sex, First Nations status, maternal education, age, income-level, parity, smoking during pregnancy, and initiation of breastfeeding Results suggest the burden of bronchiolitis, the leading cause of hospitalization in the first year of life in North America, increased due to wood smoke related exposures Interestingly, no effects found for PM 2.5 or PM 10 mass Effects of traffic and local point-sources also identified

43 Other studies Franklin et al Higher PM 2.5 mortality effects for Al, SO 4 2-, and Ni, but not K Very limited chronic epidemiologic data using wood-smoke-specific PM exposure marker RCT of woodstoves- Decreases in BP and STsegment depression among those changed to plancha (McCracken et al. 2007, 2010)

44 Research needs Other pollutants Levels of UFP from ICI wood-fired boiler Engineering controls? Affected by operating conditions? Importance for acute respiratory impacts (URI/LRI, asthma exacerbations, etc.)? To what extent are these effects dependent on UFP composition? CO an effective indicator for combustion efficiency?

45 Research needs BCE emissions similar to tobacco smoke (Naeher et al. 2007) Need better characterization of ICI wood-fired boiler PM 2.5 and CO emission rates Sufficiently protective for other pollutants? Future acute/chronic epidemiologic studies Include measurements of levoglucosan or other woodcombustion-specific markers (delta-c) in routine PM 2.5 speciation monitoring? Examine exposure to wood-combustion-specific PM 2.5 marker(s) and incidence of sensitive health endpoint(s) before and after operation of an ICI wood-fired boiler

46 Thank you