A framework to consider
health effects of indoor air pollution in
the China Environmental Cost Model
Ramon Arigoni Ortiz
Bjorn Larsen
The World Bank
Environment and Social Development Unit
East Asia & Pacific Region
29 May 2016
Ramon Arigoni Ortiz
ecprao@bath.ac.uk
1
The Chinese Environmental Cost Model and
Valuation of Environmental Health Risks
(CECM&VEHR) project


Aim to provide environmental pollution costs for China.
Components (studies):





Water pollution health impacts;
Acid rain damages – crop output reduction, material and forestry
damage
Air pollution health impacts;
Focuses on ambient (outdoor) air pollution in forty-seven
cities in China, which account for 40% of the total urban
population and 60% of the total urban GDP in China.
Does not include health effects of indoor air pollution.
29 May 2016
Ramon Arigoni Ortiz
ecprao@bath.ac.uk
2
Objectives




Review the recent international and Chinese literature on
health impacts of indoor air pollution in order to identify
best practices for estimating health effects of indoor air
pollution;
Propose an adaptation of the Chinese Environmental Cost
Model (CECM) so that it can account for indoor air
pollution health effects as well;
Provide some material for discussion among the experts
involved in the CECM&VEHR project;
Generate the order of magnitude of health costs associated
with IAP in China.
29 May 2016
Ramon Arigoni Ortiz
ecprao@bath.ac.uk
3
Why is it important to consider health costs of indoor
air pollution in China?



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A large number of Chinese households (rural and urban)
still dependant on coal and biomass fuels (solid fuels) for
cooking and heating (World Bank, 2001 and 2004);
The magnitude of exposure to indoor air pollution is still
high in China, especially among the poor population;
Indoor air pollution is responsible for about twice the
deaths and five times the disability-adjusted life years lost
related to urban air pollution in developing countries
(Smith and Mehta, 2003);
E.g. attributable deaths – WPR-B (WHO, 2002):


29 May 2016
Urban air pollution
Indoor smoke from solid fuels
Ramon Arigoni Ortiz
ecprao@bath.ac.uk
: 355,000
: 503,000
4
How to estimate the health impacts of indoor air
pollution? Literature summary.
Approach
Methodology
Data
Pollutantbased
Exposureresponse
extrapolation
Concentrations for indicator pollutants; Exposureresponse relationships from urban outdoor studies;
Current rates of morbidity and mortality.
Fuel-based
Disease-bydisease
summation
Exposure surrogates, usually fuel type; Relative
risks from studies of specific diseases in specific
populations experiencing exposure surrogates;
Current rates of morbidity and mortality.
Child
survival
Survival
analysis
Survival curves for different risk factors based on
household surveys.
Crossnational
Regression
Analysis
Cross-country comparisons of national-level data
on health and energy conditions.
29 May 2016
Ramon Arigoni Ortiz
ecprao@bath.ac.uk
5
The fuel-based approach

Recommended by WHO (Desai et al., 2004);
Steps
Description
Obtain key data Exposure levels and disease burdens.
Calculate
attributable
fractions

Calculate the
attributable
burdens
Multiply attributable fractions by corresponding disease
burdens, and calculate attributable burdens for each
disease/age/sex grouping.
Final results
Sum attributable disease burdens to obtain the total burden
disease from solid fuel use.
Uncertainty
Identify and discuss sources of uncertainty in the data.
29 May 2016
Using exposure levels, relative risks, and
% exposed x relative risk  % unexposed  1
% exposed x relative risk  % unexposed
Ramon Arigoni Ortiz
ecprao@bath.ac.uk
6
Recent Chinese epidemiological studies (1)
Health outcome or
endpoint
Pollutant or
fuel
Notes
Reference
Bronchitis; Cough
with phlegm,
phlegm
Coal smoke
(heating)
Children; Chongqing,
Guangzohou, Lanzhou,
and Wuhan
Qian et al.
(2004)
Lung cancer
Residential
radon
China – not specified; no
full-text available
Lubin,
(2003)
Lung cancer
Coal smoke
Adults; China – not
specified; no full-text
available
Kleinerman
et al. (2002)
Asthma
Coal smoke
Children (6-11); Beijing
Zheng et al.
(2002)
Cough, phlegm,
wheeze, asthma
PM10 and SO2
Adult women; rural
Anqing
Venners et
al. (2001)
29 May 2016
Ramon Arigoni Ortiz
ecprao@bath.ac.uk
7
Recent Chinese and intl. epidemiological studies (2)
Health outcome or
endpoint
Pollutant or
fuel
Notes
Reference
Lung cancer
Daily stirfrying
Adult women; Singapere
Chinese population
Seow et al.
(2000)
Lung cancer
Rapeseed oil
(cooking)
Adult women; Shanghai
Zhong et al.,
(1999)
Wheeze, asthma
Wood and hay
smoke; coal
Adults >14; rural Anhui
Xu et al.
(1996)
ALRI, asthma,
Solid fuels
COPD, lung cancer
Children (<5 – ALRI);
adults (> 30)
Desai et al.
(2004)
ALRI, asthma,
Solid fuels
COPD, lung cancer
Children (<5 – ALRI);
adults (> 14)
World Bank
(2002)
29 May 2016
Ramon Arigoni Ortiz
ecprao@bath.ac.uk
8
Proposed framework to include health effects of
indoor air pollution





Focus on indoor air pollution from solid fuel use in China;
Consider the health endpoints strongly associated with IAP
(ALRI, COPD and lung cancer), and the moderately related
to IAP (asthma);
Separate the exposed population between those exposed to
ambient air pollution (urban population) and indoor air
pollution (rural households);
Consider the health impacts of indoor air pollution in
specific population groups – children under 5 years-old and
adults older than 15 (although including adult men is
debatable);
Use selected Chinese odds-ratios, when available;
29 May 2016
Ramon Arigoni Ortiz
ecprao@bath.ac.uk
9
Estimating the attributable fraction of disease
 P (indoor).ORi  1 
.Ci
Ci (indoor)  
 P (indoor).ORi  1  1 
Ci(indoor)
Ci
P(indoor)
ORi
29 May 2016
annual new cases of endpoint (i) associated with
indoor air pollution;
total annual cases (all causes) of endpoint (i);
rural population using solid fuels as a % of total
population;
odds ratios for endpoint (i);
Ramon Arigoni Ortiz
ecprao@bath.ac.uk
10
Sources of data
Endpoints
Ci / fi
P (indoor)
Mortality
Present mortality rate per province Percentage of total
and age groups;
population using solid fuel
for cooking or heating per
Health Statistical yearbooks.
municipality;
Municipal yearbooks.
Morbidity
Present frequency of endpoint, per
province and age group; Medical
records;
Health Statistical literature and
Household Health Survey 1998
(cases not treated by a doctor).
29 May 2016
Ramon Arigoni Ortiz
ecprao@bath.ac.uk
Percentage of total
population using solid fuel
for cooking or heating per
municipality;
Municipal yearbooks.
11
Suggested odds-ratios
Health
outcome
group
OR
Uncertainties
(95% CI)
ALRI
all
1.73
1.42 – 2.12
Qian et al. (2004)
COPD
Adult female
2.34
1.82 – 3.25
Estimated based on
Desai et al. (2004)
COPD
Adult male
1.52
1.00 – 2.72
Estimated based on
Desai et al. (2004)
Asthma
Children
1.50
1.10 – 1.90
Zheng et al. (2002)
Asthma
Adults
1.51
1.05 – 2.17
Xu et al. (1996)
Lung cancer
Adults
1.29
1.03 – 1.61
Kleinerman et al.
(2002)
29 May 2016
Ramon Arigoni Ortiz
ecprao@bath.ac.uk
source
12
Numerical exercise (1) – baseline data
Data
Population WPR-B
Year
Source
Value
2001 WHO (2002) Annex table 2
1,546,769,965
Adult female (> 14) 2001 WHO (2002) Annex table 2
565,809,729
Adult male (> 14) 2001 WHO (2002) Annex table 2
584,221,841
Children under 5 2001 WHO (2002) Annex table 2
122,849,937
% of China pop. in
WPR-B region
2000 Smith and Mehta (2003)
citing WHO (2002)
% of rural population
in China
2001 China Statistical Yearbook
(2003)
62.34%
% of Chinese rural
households using solid
fuels
1999 Leiwen and O’Neil (2003)
78.32%
29 May 2016
Ramon Arigoni Ortiz
ecprao@bath.ac.uk
84%
13
Numerical exercise (2) – mortality baseline data
Mortality cases year 2001 – WPR-B region (WHO, 2002)
Value
ALRI – children under 5
231,000
ALRI – adult females
121,000
ALRI – adult males
110,000
COPD – adult females
737,000
COPD – adult males
588,000
Asthma – adult females
17,000
Asthma – adult males
16,000
Lung cancer – adult females
107,000
Lung cancer – adult males
231,000
29 May 2016
Ramon Arigoni Ortiz
ecprao@bath.ac.uk
14
Numerical exercise (3) – morbidity baseline data
Incidence cases year 2001 – WPR-B region
(estimated from WHO, 2002)
Value
ALRI – children under 5
40,324,271
ALRI – adult females
21,123,823
ALRI – adult males
19,200,448
COPD – adult females (Shibuya et al., 2001)
923,365
COPD – adult males (Shibuya et al., 2001)
1,753,400
Asthma – adult females
1,303,618
Asthma – adult males
2,251,382
Lung cancer – adult females
99,684
Lung cancer – adult males
29 May 2016
260,280
Ramon Arigoni Ortiz
ecprao@bath.ac.uk
15
Numerical exercise (4)
IAP attributable mortality cases in China (2001)
ALRI – children under 5
43,995
ALRI – adult females
23,045
ALRI – adult males
20,950
COPD – adult females
197,602
COPD – adult males
89,093
Asthma – adult females
2,540
Asthma – adult males
2,391
Lung cancer – adult females
10,369
Lung cancer – adult males
22,385
Total mortality cases – all
412,370
Total mortality cases – children and adult women
277,551
Similar result (WHO, 2002)
Similar result (Ezzati et al., 2002)
29 May 2016
(558,000) 468,720
Ramon Arigoni Ortiz
ecprao@bath.ac.uk
(503,000) 422,520
16
Numerical exercise (5) unit values
Health impact
WTP approach
Human capital
approach
Mortality, per death (children)
46,280
21,691
Mortality, per death (adults)
46,280
5,952
7
---
Chronic bronchitis, per case
4,235
---
Asthma attacks, per case
4,235
---
Lung cancer
20,559
---
ALRI, per case
29 May 2016
Ramon Arigoni Ortiz
ecprao@bath.ac.uk
17
Numerical exercise (6)
Health costs associated with IAP (US$ 2001)
China
WTP approach
Human capital approach
Mortality
19,084,370,262
3,146,927,194
Morbidity
5,483,060,515
----
Total economic cost
24,567,430,777
8,629,987,709
Mortality (without adult men)
12,844,990,858
2,344,459,271
Morbidity (without adult men)
2,304,115,465
----
Total cost (without adult men)
15,149,106,323
4,648,574,736
29 May 2016
Ramon Arigoni Ortiz
ecprao@bath.ac.uk
18
Comparing COPD data
Region
Africa
Americas
Eastern
Mediterranean
Europe
South Asia
Western Pacific
29 May 2016
Mortality
Stratum
Deaths/
100000
Incidence /
100000
Prevalence /
100000
COPD death
as % of total
D
17.56
30.48
213.00
1.21
E
17.82
28.00
141.12
1.00
B
19.22
87.39
na
3.21
D
6.88
22.02
221.61
0.92
B
7.05
40.89
480.84
1.41
D
22.21
22.78
218.64
2.26
B
22.27
50.91
668.69
2.49
C
39.72
84.41
1,025.72
2.62
B
22.18
47.05
469.20
3.01
D
43.41
41.83
466.22
4.47
B
85.60
183.61
1,675.49
12.64
Ramon Arigoni Ortiz
ecprao@bath.ac.uk
19
Conclusions

Weaknesses:



Uncertainties:



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Rural population only;
Possible underestimate of health impacts of indoor air pollution.
Non-Chinese odds-ratios;
Adult men;
Confounders (ambient x indoor air pollution; tobacco smoking).
Advantages:



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Easy to estimate;
Part of the data already available (COPD, asthma);
Compatible with up-to-date literature;
Approach recommended by World Health Organization.
29 May 2016
Ramon Arigoni Ortiz
ecprao@bath.ac.uk
20