quantification of indoor air pollution & estimating its...
TRANSCRIPT
Quantification of Indoor Air
Pollution & Estimating its
Health Effects in
Northwest Bangladesh
Leah T. Le, Karen C. Chang, Abdullah Al Masud,
Mohammad Alauddin, Mahmood Hossain,
Philip K. Hopke, Zohir Chowdhury
ETHOS Conference
Kirkland, Washington
January 28th – 30th, 2011
Outline
Background
Motivation
Objectives
Methods
Results
CO & PM2.5 correlation
Health effects
Conclusion
Future Work
Where is Bangladesh?
• WHO’s Millennium Goal: Improve health in rural communities
• Install improved cookstove to reduce exposure to harmful air
pollutants.
• Epidemiological studies found links between
indoor air pollution (IAP) and
• Acute respiratory infection (ARI)
• ~25% of all deaths in children under five &
~40% of deaths in infants
• Chronic obstructive pulmonary disease (COPD)
• Lung cancer
• Affects everyone living in the house, namely women (cooks)
• Disconnection between knowledge of improved and un-improved
stoves before & after installation
• No detailed research done in Bangladesh, yet
What Inspired Us?
• Hypothesis:
• Improved stoves continue to produce low PM2.5
concentration 1 year after installation.
• Objectives:
1) Understand general IAP in Saidpur, Bangladesh
2) Characterize indoor air pollution 1 year after
installation of improved stoves
3) Focus on Carbon Monoxide & PM2.5
Concentrations
Relationships
Health Effects
What Did We Aim to Achieve?
What Stoves Did We Use? • Improved stoves designed by Bangladesh Council of
Science and Technology (BCST)
• Iron gate and chimney
• 3 model types: 1-pot, 2-pot, and 3-pot stance
• Thermal efficiency tested by Appropriate Rural
Technology Inc. (ARTI)
• Water boiling test
Start
Cold
Mud
Stove
(minutes)
BCST
Stove
(minutes)
1-pot 20 13
2-pot ND 18
Start Hot 1-pot 17 10
2-pot ND 13
What Did We Do?
Intensive monitoring:
• Measured for 4 days
•2 households
• BCST improved stove kitchen
• Traditional mud stove kitchen
• Purpose:
1) Check accuracy and reliability of co-located
instruments for cross-calibration with
industry accepted measurements
(gravimetric)
2) Detailed characterization of PM2.5 and CO in
kitchens of both stove types
What Else Did We Do? Extensive monitoring:
• Measured for 1 day
• 40 households
• 50% with BCST improved stove
• 50% with un-improved mud stove
• Purpose:
• Statistically quantify PM2.5 and CO
concentrations in both stove kitchens
(a) BCST Improved Stove (b) Un-improved Mud Stove
DUST TRAK Q-TRAK
UCB
HOBO
Instrumentation
Results from Intensive Monitoring?
Figure 1(a) Figure 1(b)
Figure 1(c)
What Else from Intensive Monitoring?
Elemental Carbon: 22-23%
Organic Matter: 45-47%
Chlorine: 16-20%
Potassium: 6-7%
Results from Extensive Monitoring?
Figure 3(a)
Figure 3(b)
CO to PM2.5 Correlation: CO
predictor of PM2.5?
Our Model: (Use CO as a proxy for PM2.5) Unimproved :
PM2.5 (mg/m3) = 0.54 (0.25, 0.83) x CO (mg/m3) + 1.09 (-0.02, 2.20), R2 = 0.74
Improved: PM2.5 (mg/m3) = 0.36 (0.26, 0.45) x CO (mg/m3) + 0.33 (-0.19, 0.84), R2 = 0.81
All Data: PM2.5 (mg/m3) = 0.37 (0.26, 0.49) x CO (mg/m3) + 0.71 (0.14, 1.28), R2 = 0.65
And?
PM2.5 (mg/m3) CO (mg/m3)
Mud Stove BCST Stove Mud Stove BCST Stove
Mean 1.92 1.38 4.90 2.97
Median 1.77 0.73 2.54 1.96
Standard Deviation 1.59 1.27 6.29 2.29
Standard Error 0.37 0.29 1.37 0.49
Minimum 0.22 0.11 0.23 0.28
Maximum 5.85 4.22 25.88 7.13
Range 5.63 4.11 25.65 6.85
Count, N 20 19 21 22
• Percent Reduction
• PM2.5 = 59%
• CO = 23%
What About Health Effects? • Relative Risk (RR) for cardiovascular disease (CDV) from
inhaling PM2.5 of indoor biomass burning (Smith & Peel, 2010)
• RR = 1.5
• 50% higher than normal
• Increased risk of chronic obstructive pulmonary disease
• Coexistence of COPD and CDV (Mannino & Buist, 2007)
• Soluble vs. Insoluble (Raabe et al., 1999)
• Soluble PM travels through bloodstream and GI tract, where
activation and deactivation of toxin and carcinogens occur
•Insoluble PM may cause bronchial irritation, foreshadowing
congestion, soreness, and cough
• Alveoli can swell, leading to coughing and shortness of
breath
What About Other Health Effects? • CO-COHb Relationship:
• X = 0.009 + 0.264(Y) for the mean (Lee et al., 1994)
• X is the percent (%) of COHb in blood
• Y is the breath CO concentration (ppm)
• 1-hr CO* exposure:
• Mud Stove: 10.63%
• BCST Stove: 8.80%
• 8-hr CO* exposure:
• Mud Stove: 3.84%
• BCST Stove: 2.49%
• Symptoms when COHb is less than 15-20%
• Nausea, vomiting, dizziness, blurred vision and headache
*Note: Mean CO concentration derived from values above median to show
maximum at risk potentiality.
What Can We Conclude? •59% & 23% reduction in PM2.5 & CO emission,
respectively, from improved stoves after 1 year. But not
significant
• Predominate chemical species: EC, OM, Chlorine, and
Potassium
• As long as they continue to be exposed to such CO &
PM2.5 concentrations, cooks are potentially suffering
from mild symptoms every day, all year, every year.
• Fuel use patterns and cooking practices seen in this
population are likely to be comparable to much of
Bangladesh.
What Does the Future Hold? • Call for stove design(s)
• Durable
•Affordable
• Culturally suitable
• Low maintenance
• Further investigation on larger scale to quantify IAP
from cookstoves in rural communities in Bangladesh
• Widespread installation of improved stoves throughout
the community, not just a few selected households
Special Thanks •Baby and Khadeza (field workers)
•Research Participants
•Concern Bangladesh, Inc.
•Mustafiza Hossain (Concern Worldwide in Saidpur,
Bangladesh)
•Berdine Heckmann (San Diego Air Pollution Control
District (SD APCD))
•ABM Zakaria (Exonics Technology Center (ETC) at Dhaka,
Bangladesh )
Contact: [email protected]
