The Challenges In Monitoring And Control Of Indoor Air Pollution

Transcription

The Challenges In Monitoring And Control Of Indoor
Air Pollution Due To Combustion In Kitchens In Urban
And Rural Areas
Rural
Urban
Rashmi S. Patil
Professor
Centre for Environmental Science and Engineering,
Indian Institute of Technology, Powai, Mumbai- 400 076 India
Email: [email protected]
Background:

The most dominant source of indoor air pollution (IAP) is fuel
combustion in kitchens.

These sources, though small, have exposure effectiveness about tens
or hundreds of times greater than large scale outdoor sources, so
they have high health risk potential.
Objectives:

Monitoring and assessment of exposure due to fuel combustion in
kitchens of different socio-economic groups.

Identification of mitigation measures for exposure reduction and
evaluation of the resultant health and economic benefits
2
Various Types of Kitchens
Combustion in
Kitchens
Rural Regions
(Biomass Fuel)
Domestic
Urban Slums
(Biomass/
Kerosene)
Urban Regions
Commercial
( Kerosene/
LPG)
Others
(Schools/
Hospitals)
Middle/ Upper Income
Group
(Kerosene/ LPG)
3
(I) Biofuel Combustion In Rural Kitchens

Biofuels (wood, crop residues and animal dung) account for
60% of world air pollution exposure especially in developing
countries.

Biomass combustion in kitchens has three major issues:
¾
Health : High conc. of air pollutants
¾
Climate : Emissions of GHGs and black carbon which contribute
to global warming
¾
Energy : Low energy efficiency exerts stress on fuel demand,
natural resource base and human labor and time.
4

In India about 90% of rural population depends on
biofuels.

Several Interventions:
¾

Improvement in stoves, fuels, ventilation and child care
practices.
Under a National Program of Improved Smokeless Stoves
(SI) by Government of India
¾
¾
¾
Subsidized several million stoves installed in rural areas.
But, program not very successful and stoves not readily
adopted
Very little data on performance of SI in actual field
conditions.
5

Comparative study on exposure
assessment of traditional and
improved biostoves in tribal villages
on a longitudinal basis

Sampling Protocol:
¾
Cooking Session:
Kitchen
Living Room
Personal
¾
Indoor Background: Between Meals
Outdoor:
Outside House
Far Away
¾
6
Mean RPM and CO Concentration During Cooking
Sessions for Traditional (ST) and Improved Stoves (SI)
RPM (μg m-3)
¾
CO (ppm)
1173 ± 1059
AREA
SAMPLING
(LIVING
ROOM)
628 ± 672
9.8 ± 6.8
570 ± 692
540 ± 654
409 ± 473
4.5 ± 4.4
%
REDUCTION
37%
(p=0.021)
54%
(p=0.0026)
35%
(p=0.0034)
54%
(p= 0.0087)
DELHI, INDIA
(1999) (ST)
1200
1370
-
12
STOVE TYPE
PERSONAL
SAMPLING
(COOK)
AREA
SAMPLING
(KITCHEN)
TRADITIONAL
906 ± 1167
IMPROVED
During cooking RPM conc. at the centre is more compared to near the stove
due to plume shadow effect.
7
EXPOSURE ASSESSMENT
STOVE TYPE

RPM EXPOSURE (mg h m-3)
COOKING
INDOOR
DAILY
BACKGROUND INTEGRATED
TRADITIONAL
2.97
1.46
4.79
IMPROVED
1.37
1.11
2.85
Average 40 % reduction in daily-integrated exposure
(p<0.0001)
Average 54 % reduction in exposure due to cooking
(p<0.0001)
The average daily-integrated exposure in concentration units
is 200 μg m-3 for ST and 118 μg m-3 for SI
8
Economic Evaluation of Health Benefits

Physical impacts of the improved stoves like reduced emissions, fuel
saving , less cooking time etc are easy to perceive
A bigger incentive for stove adoption was the communication of monetary
gains due to health benefits
Methodology:

Change in RPM Exposure
Dose Response Parameter :
Additional annual mortality
risk per person per 1 µg/m3
change in PM
Change in annual mortality
risk for improved stove
Value of Statistical Life
(VSL= WTP/change in risk)
Annual benefit of mortality
risk reduction per person
Cost of improved stove
(Life Span of 5 years)
= 82 µg/m3
= 8.26 x 10-6
= 6.77 x10-4
= 6.4 x 106 INR
= 4330.00 (~80 USD)
= 210.00 INR
9
¾ The improved smokeless stoves have several
benefits of health, climate and energy but other
challenges for the promotion of intervention are:

Dissemination :
*
*

Placement :
*

Proper installation
Training needed for maintenance
Proper ventilation and dispersion
Awareness and Education :
*
Communication of health benefits
10
(II)

Exposure Assessment for Low Income
Population Groups in Urban Areas:
Study Region:
¾
Urban slums near industries.
¾
Worst Outdoor Air Pollution : Vehicles + Fugitive
¾
Worst Indoor Air Pollution :
Low Grade Fuel
Dense Houses/ Poor Ventilation
Poor Nutrition/ Health
Outcomes of the Study :
¾ Personal Exposure (PE) levels and its variation
¾ Risk factors effecting PE and Health
¾
Health linkages with PE
¾
Models for exposure prediction and health benefit assessment.
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PERSONAL EXPOSURE TO RPM
RPM Exposure in μg/m
3
Personal Exposure (PE) to RPM
408
450
400
293
330
350
300
250
200
150
153
100
70
100
50
0
WHO
NAAQS
AAQ
TP
COW
AOW
WHO, NAAQS: Standards
AAQ: Ambient Air Quality
TP: Traffic Police
COW: Casual Outdoor Workers
*PE > NAAQS, f = 3.3
> WHO,
f = 4.7
> AAQ,
f = 2.2
AOW: All Outdoor Workers
12
An Int Study : NOX measurements ( ppb) in 11
countries ( Harvard Univ ,US)
[HARVARD
UNIV., US]
City
and Country
Indoor (I) Outdoor (O)
Personal
I/O
ratio
Taejon, Korea
Bombay, India
Sapporo, Japan
Manila,
Philippines
38.7±18.2
40.8±17.1
23.1±14.1
23.4±11.3
41.7±16.2
38.7±13.7
22.0±13.8
25.0±11.5
50.0±28.5
43.7±16.0
28.3±14.2
25.8±6.5
1.0±0.5
1.1±0.6
1.5±1.6
1.0±0.2
London, UK
21.7±12.4
42.3±5.1
29.3±6.4
0.6±0.3
Boston, US
19.2±15.8
33.7±20.1
28.0±10.7
0.6±0.4
Geneva,
Switzerland
8.3±6.3
11.9±5.5
11.0±5.0
0.8±0.6
I/O > 1 for all Asian Countries
13
Components of Total Daily Exposure To RPM
(mg h/m3)
RPM Exposure in
mg h/m3
10
8
6
4
2
0
Others
Residential
Marol
( Low Ambient
Level)
Sakinaka (High
Ambient Level)
Combined
(Average)
Occupational
Site
Residential Exposure ~ Outdoor Exposure

Rural v/s Urban area
(i) PM5 levels almost same during cooking
(ii) But exposure levels due to cooking as a fraction of daily exposure
was about 75% in rural and 20% in urban areas respectively.
14
Modeling for Exposure and Health Benefit
Assessment

Air pollution management strategies were evaluated based on exposure
reduction and health benefits

Model Used: Ben MAP (Benefits Mapping and Analysis) of USEPA

BenMAP modified to use personal exposure as basis rather than
ambient concentrations.

Inputs into the integrated health assessment model:
¾
¾
¾
Exposure Model: ambient air quality, I/O model, time activity
The concentration response functions for various health endpoints
like bronchitis, URI and hospital admission.
Economic model for valuation of various health endpoints.
15
Observed Baseline
Ambient Concentrations
Predicted Control
Scenario Ambient
concentrations
Reduction in
Population level
exposure
Regulatory
Strategies
Predicted
Concentration in
Micro-environments
Population
Distribution and Time
Activity Patterns
Predicted Control
Personal Exposure
Reduction
in Health
effect
Incidence
(mortality
and
morbidity)
Monetary
Benefits
Reduction in
Personal exposure
Predicted Baseline
Personal Exposure
Framework for health benefit assessment of various control strategies
e.g.: Change in cooking fuel from kerosene to LPG gave economic benefits for
reduction in mortality and morbidity as INR 515.29 (11.4USD) per capita per year.
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(III) Domestic Combustion in Urban Kitchens

Study done in typical middle income households, where LPG
(Liquefied Petroleum Gas) fuel is used.

PM5 conc. during cooking ranged as high as 348- 2882 μg/m3.

PM during cooking is generated from:
I.
II.
Fuel combustion
Cooking process : like frying produces very large fraction of PM and
condensable vapors.

Cooking contributed about 30% to 48% of total daily exposure.

Considerable variation in exposure between homes mainly due to air
exchange rate.

Three control techniques for exposure reduction were tested:
¾
¾
¾
Natural ventilation
An exhaust fan
An electric chimney
17
Concentration of Air Pollutants in μg/m3 with Different
Control Techniques During Cooking Session
Concentration in μg/m3
Type of
Pollutant

Percent Reduction in
Concentration
Natural
Ventilation
Exhaust
Fan
Electric
Chimney
With Exhaust With Electric
Fan
Chimney
PM5
1828.25
681.11
1188.45
63
35
NO2
23.32
16.49
21.32
30
8.6
SO2
21.29
15.92
16.22
25.3
24
CO
0.021
0.006
0
71.4
-
Exhaust fan seems to be more effective than the costly electric
chimney.
The study indicated that the most cost-effective way to reduce
indoor exposure is to ensure proper ventilation through
appropriate building design codes.
18

The particulate respiratory dose for Indian women was estimated using lung deposition
model.

Input data: Particle mass size distribution (PSD) and Physiological data on women.

Biomodal distribution was obtained for both cooking and non-cooking periods.

Non-Cooking : Dominant Coarse mode 1-2 μm.
Cooking
: Dominant Accumulation mode 0.1-0.3 μm
Non-Cooking Session
Cooking Session
19
Average particulate doses per day (μg day-1) during cooking and noncooking sessions for Indian Women
Lung Region
Daily dose (μg day-1)
Pulmonary
Tracheabronchial
Nasopharyngeal
Total
Cooking
Mode 1 (Fine)
46.93
14.18
21.10
82.21
Mode 2 (Coarse)
88.75
28.54
23.51
140.80
Total
135.67
42.72
44.61
223.01
Non-cooking
Mode 1 (Fine)
7.04
2.25
1.86
11.15
Mode 2 (Coarse)
43.92
14.25
22.85
81.02
Total
50.96
16.50
24.71
92.17

Highest deposition was observed in pulmonary region during
cooking with severe health impacts
About 18% and 40.8% of the inhaled particles of accumulation
mode and coarse mode respectively are deposited in the respiratory
tract during cooking session
Physiological data of Indian subjects needed for accurate prediction.
20
(IV) Combustion In Commercial Kitchens

Commercial Kitchens (CK) are
defined as places where
customer pays for food
consumed.

These are critical hot spots of
IAP because:
High fuel consumption
(~ 100kg of LPG/ day)
Long operating time
More people exposed
(workers and customers)
21

Moreover these are not considered as occupational work
environments like industries.

Hence, no regulations exist for air pollution or kitchen
design.

It’s observed that kitchen is the most neglected of hotel/
restaurant ventilation system.

There are about 5200 in Mumbai city and they contribute
about 23% of total ambient PM load (NEERI, 2004)
22

Apart from air pollution a
major challenge in these
kitchens is high waste heat
load which causes severe
thermal discomfort and
sickness to workers.

Hence, a study was
conducted to assess IAQ of
CK and a control device was
designed based on heat
recovery from exhaust
gases which gave three
major co- benefits as
follows:
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1. Energy Savings:

Water was used as the cooling fluid in the heat exchanger and its
temperature rose by almost 15-20oC. The heated water could be
reused causing energy savings.

Total heat recovered = 22.5 kWh/d

Hence, earned carbon credits could be 0.014 per day.

Thus, under some assumptions total carbon credits earned for
Mumbai city can be 30,000/yr.

This, can help in reducing global warming and has a good
prospect of earning revenue and carbon trading.
24
2. Air Pollution Reduction
300
Concentration (µg/cu. m.)
250
200
Cooking with oil use [with
control]
Cooking with oil use [without
control]
Cooking without oil use [with
control]
Cooking without oil use
[Without
control]
[without
control]
150
100
50
0
Stove PM10 Stove PM 2.5 Work PM10 Work PM2.5
Sampling Site

20 to 48% reduction in particulate concentration

Reduction in fine particles (PM2.5) more than larger size
(PM10) especially for oil use
25
3. Improved Work Environment :
• Indoor temperatures
reduce - so better
thermal comfort
(climate) for workers
Conclusions

Develop codes/guidelines for ecodesign of kitchens to
assist builders/architects to :
reduce pollution +
conserve energy +
improve work environment
26
(V) Assessment of IAQ in Schools
¾ Objective
To characterize IAQ in representative
schools of different socio-economic
status and identify suitable mitigation
measures
¾
Measurements
Comfort parameters: Temp., RH
Ventilation
Pollutants: PM10, PM2.5, CO2, CO
Bioaerosols
Average PE in PMS about 4 times higher
than ASB due to greater occupant density
and poor ventilation
Schools of different economic status:
ASB/ High; KV IIT/ Medium; PMS/Low
27
¾CFD tool FLUENT 6.2 used for simulation of velocity and temperature
profiles, to test the adequacy of air circulation in class rooms.
• Poor ventilation indicated for Powai Municipal School
• Simulation with additional ventilator (skylight) and exhaust fans gave
considerable improvement.
(a)
(b)
Temperature profile developed for classroom of Powai Municipal School
(a) Initial (b) Skylights on internal wall
28
Conclusions:
What are the challenges and needs?

Monitoring and Exposure Assessment:

Large Scale/ Long Term studies needed
Measurements highly resource intensive so need studies on :

I/O Relation
Area v/s Personal Sampling
Proxy Indicators
Protocols and Instruments
Epidemiological Studies:

Linking exposure and health risk.
Models for health benefit evaluation of control strategies.
29

Regulatory/ Policy Interventions:
¾
Policies should include Personal Exposure and IAQ
•
•
¾
Standards and Regulations
•
¾

Health based air quality management
Exposure effectiveness of sources should be accounted
Indoor sources/ IAQ/ Personal Exposure
Building/Ventilation Codes
Technological Interventions:
¾
¾
Cost effective solutions
Co-benefits should be the target
30
Energy
Air Pollution
Climate
¾This nexus offers opportunity for
win-win strategies
¾Investment in strategies which provide
health benefit and energy conservation on local
scale and mitigate climate change on global scale
should be promoted
31
32