The Challenges In Monitoring And Control Of Indoor Air Pollution Due To Combustion In Kitchens In Urban And Rural Areas

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1 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 India

2 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

3 Various Types of Kitchens Combustion in Kitchens Rural Regions (Biomass Fuel) Urban Regions Domestic Commercial ( Kerosene/ LPG) Others (Schools/ Hospitals) Urban Slums (Biomass/ Kerosene) Middle/ Upper Income Group (Kerosene/ LPG) 3

4 (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: Health : High conc. of air pollutants Climate : Emissions of GHGs and black carbon which contribute to global warming Energy : Low energy efficiency exerts stress on fuel demand, natural resource base and human labor and time. 4

5 In India about 90% of rural population depends on biofuels. Several Interventions: Improvement in stoves, fuels, ventilation and child care practices. Under a National Program of Improved Smokeless Stoves (SI) by Government of India 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

6 Comparative study on exposure assessment of traditional and improved biostoves in tribal villages on a longitudinal basis Sampling Protocol: Cooking Session: Kitchen Living Room Personal Indoor Background: Between Meals Outdoor: Outside House Far Away 6

7 Mean RPM and CO Concentration During Cooking Sessions for Traditional (ST) and Improved Stoves (SI) STOVE TYPE PERSONAL SAMPLING (COOK) RPM (μg m -3 ) AREA SAMPLING (KITCHEN) AREA SAMPLING (LIVING ROOM) CO (ppm) TRADITIONAL 906 ± ± ± ± 6.8 IMPROVED 570 ± ± ± ± 4.4 % REDUCTION 37% (p=0.021) 54% (p=0.0026) 35% (p=0.0034) 54% (p= ) DELHI, INDIA (1999) (S T ) During cooking RPM conc. at the centre is more compared to near the stove due to plume shadow effect. 7

8 EXPOSURE ASSESSMENT RPM EXPOSURE (mg h m -3 ) STOVE TYPE COOKING INDOOR BACKGROUND DAILY INTEGRATED TRADITIONAL IMPROVED 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 S T and 118 μg m -3 for S I 8

9 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 = 82 µg/m 3 Dose Response Parameter : Additional annual mortality = 8.26 x 10-6 risk per person per 1 µg/m 3 change in PM Change in annual mortality = 6.77 x10-4 risk for improved stove Value of Statistical Life (VSL= WTP/change in risk) = 6.4 x 10 6 INR Annual benefit of mortality = (~80 USD) risk reduction per person Cost of improved stove = INR (Life Span of 5 years) 9

10 The improved smokeless stoves have several benefits of health, climate and energy but other challenges for the promotion of intervention are: Dissemination : * Proper installation * Training needed for maintenance Placement : * Proper ventilation and dispersion Awareness and Education : * Communication of health benefits 10

11 (II) Study Region: Exposure Assessment for Low Income Population Groups in Urban Areas: Urban slums near industries. Worst Outdoor Air Pollution : Vehicles + Fugitive Worst Indoor Air Pollution : Low Grade Fuel Dense Houses/ Poor Ventilation Poor Nutrition/ Health Outcomes of the Study : Personal Exposure (PE) levels and its variation Risk factors effecting PE and Health Health linkages with PE Models for exposure prediction and health benefit assessment. 11

12 PERSONAL EXPOSURE TO RPM Personal Exposure (PE) to RPM RPM Exposure in μg/m WHO NAAQS AAQ TP COW AOW WHO, NAAQS: Standards AAQ: Ambient Air Quality TP: Traffic Police COW: Casual Outdoor Workers AOW: All Outdoor Workers *PE > NAAQS, f = 3.3 > WHO, f = 4.7 > AAQ, f =

13 An Int Study : NO X measurements ( ppb) in 11 countries ( Harvard Univ,US) City [HARVARD and Country UNIV., US] Indoor (I) Outdoor (O) Personal I/O ratio Taejon, Korea 38.7± ± ± ±0.5 Bombay, India 40.8± ± ± ±0.6 Sapporo, Japan 23.1± ± ± ±1.6 Manila, 23.4± ± ± ±0.2 Philippines London, UK 21.7± ± ± ±0.3 Boston, US 19.2± ± ± ±0.4 Geneva, Switzerland 8.3± ± ± ±0.6 I/O > 1 for all Asian Countries 13

14 Components of Total Daily Exposure To RPM (mg h/m 3 ) RPM Exposure in mg h/m Marol ( Low Ambient Level) Sakinaka (High Ambient Level) Combined (Average) Others Residential Occupational Site Residential Exposure ~ Outdoor Exposure Rural v/s Urban area (i) PM 5 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

15 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: 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

16 Observed Baseline Ambient Concentrations Predicted Control Scenario Ambient concentrations Predicted Concentration in Micro-environments Population Distribution and Time Activity Patterns Regulatory Strategies Reduction in Population level exposure Predicted Control Personal Exposure Predicted Baseline Personal Exposure Reduction in Health effect Incidence (mortality and morbidity) Monetary Benefits Reduction in 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 (11.4USD) per capita per year. 16

17 (III) Domestic Combustion in Urban Kitchens Study done in typical middle income households, where LPG (Liquefied Petroleum Gas) fuel is used. PM 5 conc. during cooking ranged as high as μg/m 3. PM during cooking is generated from: I. Fuel combustion II. 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: Natural ventilation An exhaust fan An electric chimney 17

18 Concentration of Air Pollutants in μg/m 3 with Different Control Techniques During Cooking Session Type of Pollutant Concentration in μg/m 3 Percent Reduction in Concentration Natural Ventilation Exhaust Fan Electric Chimney With Exhaust Fan With Electric Chimney PM NO SO CO 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

19 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 μm Non-Cooking Session 19 Cooking Session

20 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) Mode 2 (Coarse) Total Non-cooking Mode 1 (Fine) Mode 2 (Coarse) Total 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

21 (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

22 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

23 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: 23

24 1. Energy Savings: Water was used as the cooling fluid in the heat exchanger and its temperature rose by almost o C. The heated water could be reused causing energy savings. Total heat recovered = 22.5 kwh/d Hence, earned carbon credits could be 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

25 2. Air Pollution Reduction Concentration (µg/cu. m.) Cooking with oil use [with control] Cooking with oil use [without control] Cooking without oil use [with control] Cooking without oil use [without [Without control] control] 50 0 Stove PM10 Stove PM 2.5 Work PM10 Sampling Site Work PM to 48% reduction in particulate concentration Reduction in fine particles (PM 2.5 ) more than larger size (PM 10 ) especially for oil use 25

26 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

27 (V) Assessment of IAQ in Schools Objective To characterize IAQ in representative schools of different socio-economic status and identify suitable mitigation measures Measurements Comfort parameters: Temp., RH Pollutants: Ventilation PM 10, PM 2.5, CO 2, 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

28 CFD 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

29 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

30 Regulatory/ Policy Interventions: Policies should include Personal Exposure and IAQ Health based air quality management Exposure effectiveness of sources should be accounted Standards and Regulations Indoor sources/ IAQ/ Personal Exposure Building/Ventilation Codes Technological Interventions: Cost effective solutions Co-benefits should be the target 30

31 Energy Air Pollution Climate This nexus offers opportunity for win-win strategies Investment in strategies which provide health benefit and energy conservation on local scale and mitigate climate change on global scale should be promoted 31

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