Indoor Air Quality for Poor Families: New Evidence from Bangladesh Susmita Dasgupta ■ Research Department The World Bank

How serious is indoor air pollution in Bangladesh?

Data  Respirable particulates (PM 10 ) in indoor air was monitored for a stratified sample of 236 households in Dhaka and Narayanganj.  PM 2.5 was monitored for a sub sample of 85 households. Monitoring IAP Concentrations:  Thermo Electric Personal DataRAM (pDR-1000): real-time monitoring.  Airmetrics MiniVol Portable Air Sampler: average particulate concentration of ambient air for 24 hours.

How serious is indoor air pollution in Bangladesh? Among 236 Bangladeshi households, where PM10 in indoor air was monitored, daily average indoor concentrations of 300 ug/m3 are not unusual. Galassi, Ostro, et al. (2000), on health impacts in 8 Italian cities whose annual PM10 concentrations vary from 45 to 55 ug/m3, find that reducing these concentrations would yield large health benefits.

Additional Questions of Interest 1.Is exposure largely confined to cooking areas? 2.How much difference does fuel choice make for indoor air pollution? 3.How important is fuel choice for indoor air pollution when other household characteristics are accounted for? 4.Are there significant geographic variations in indoor air quality? 5.How serious is the indoor air quality problem for poor families? 6.Who suffers from indoor air pollution in Bangladesh?

Comparative PM 10 concentrations in 4 houses: kitchens and living rooms

Household PM 10 concentrations: kitchens vs. living rooms Correlation coefficient = 0.93

Sources of Variation in Household PM 10 Concentrations 1.Choice of fuel. 2.Cooking locations (e.g. attached/detached/open kitchen). 3.Household characteristics (e.g. ventilation characteristics of households: Structural characteristics and ventilation behavior).

Sample Composition (Kitchens): Thermo Electric Personal DataRAM Fuel TypeKitchen TypeConstruction Material Gas, Electricity, Kerosene 6Single room dwelling, no separate kitchen 9Wall: Thatch24 Firewood, Twigs, Leaves 31Kitchen with a partition (4 walls and a roof) 11Wall: Tin22 Cow Dung15Separate, attached kitchen (4 walls and a roof) 14Wall: Mud14 Rice Husks, Straw, Jute Sticks, Bagasse, Sawdust 15Separate, detached kitchen (4 walls and a roof) 31Wall: Brick/ Mud, Roof: Other than Concrete 4 Outside/ open kitchen (0 walls, no roof) 2Wall: Brick/ Mud, Roof: Concrete 1 Total Number of Households 67Total Number of Households 67Total Number of Households 65

Mean PM 10 concentration by fuel Fuel Mean (ug/m 3 )Households Dung29195 Firewood Sawdust2377 LPG/LNG2068 Straw19729 Jute19068 Twigs, Branches17346 Kerosene13418 Piped Nat Gas10120

Cooking Locations in Bangladeshi Households Stove denoted by A 4B 5 6

Determinants of PM10 Concentrations

Firewood Poor Ventilation Firewood Good Ventilation Clean Fuel Indoor Air Pollution (ug/m3) Ventilation Quality and Indoor Air Pollution Cooking Fuel

Fuel Biomass (B) Clean (CLN) F L M S Cooking location Inside (I) Outside (O) Building material Mud (M) Other (O) Space Kitchen (K) Living room (L)

Household Survey Regions Rangpur Rajshahi Jessore Sylhet Dhaka Faridpur Cox’s Bazar

Determinants of Indoor Air Pollution: 6 Areas of Bangladesh Sample Incidence of Pollution Factors Rural Area of: Mud Walls % Thatch Roof % Detached Kitchen % Open-Air Kitchen % Cox's Bazar Faridpur Jessore Rajshahi Rangpur Sylhet

Mean PM 10 Concentrations (μg/m 3 ) RegionRural Peri Urban Total Cox's Bazar Faridpur Jessore Rajshahi Rangpur Sylhet Total RegionRural Peri Urban Total Cox's Bazar Faridpur Jessore Rajshahi Rangpur Sylhet Total KitchensLiving Areas

Are there significant geographic variations in indoor air quality?  Results indicate great geographic variation, even for households in the same per capita income group. This variation reflects local differences in fuel use and, more significantly, construction practices that affect ventilation.  For the poorest households, rural PM10 concentrations vary from 410 ug/m3 in Cox’s Bazar to 202 ug/m3 in Faridpur.  Even in urban areas, concentrations differ by almost 100 ug/m3 between the highest areas, Jessore and Rajshahi and the lowest, Sylhet.  The poorest households in Rangpur face about the same mean indoor concentration (198 ug/m3) as the highest- income households in Cox’s Bazar (195 ug/m3).

Kitchen PM 10 Concentration by Income Group ($US/Day/Person) Region 0-$.50 $.51- $1.00 $1.01 $2.00 $2.01 $5.00 $5.01+ Cox's Bazar Faridpur Jessore Rajshahi Rangpur Sylhet Total

How serious is the indoor air quality problem for poor families in Bangladesh? Average PM 10 in Kitchen Rural275 ug/m 3 Peri-urban226 ug/m 3 Urban193 ug/m 3 Results for six Bangladeshi regions suggest that indoor PM 10 concentrations are quite high for many poor (per capita income < US$1/ day) families.

AreaFuel Inside Kitchen With Partition Inside Without Partition Detached Kitchen Open Air Kitchen KitchenSolid Gas70 86 LivingSolid Gas Ambient 91 AreaFuel Inside Kitchen Detached Kitchen Open Air Kitchen KitchenSolid Gas134 LivingSolid Gas129 Ambient UrbanPeri-Urban 8948 Comparative Results India (RSPM ≈.61 PM10) Bangladesh ( PM10)

Individual’s Exposure to Indoor Air Pollution  Differences within households attributable to family roles (daily location patterns of individuals in Bangladeshi households & daily pollution cycles).  Differences across households attributable to income and education.

Individual’s Exposure to Indoor Air Pollution: Differences within Households  High exposure – around 200- for infants and children, regardless of gender.  Gender-based divergence among adults, with women’s exposure nearly 2 times those for men in the age group 20-60, and about 40% higher for older women (over 60).

Individual’s Exposure to Indoor Air Pollution: Differences across Households  Female education, male education and family income all have large, highly-significant effects on pollution.  Overall, the poorest, least-educated households have twice the pollution levels of relatively high-income households with highly-educated adults.  Pollution exposures of young children and poorly- educated women in poor households are four times those for men in higher-income households organized by more highly-educated women.

Summary of Findings  High indoor PM 10 concentrations for many poor families.  Significant geographic variation in indoor air quality.  Although fuel choice affects indoor air pollution, its role appears secondary to the role of ventilation factors for households.  Pollution from cooking diffuses into living spaces rapidly and completely.  High levels of exposure for children and adolescents of both gender, with particularly serious exposure for children under 5.  The poorest, least-educated households have twice the pollution levels of relatively high-income households with highly-educated adults.

Recommendation-I  A national “clean household” promotion program: low-cost alterations in houses and cooking locations, combined with effective public education on the associated health benefits, could reduce Indoor Air Pollution exposure to much safer levels for many poor families.

 At present, young children are only outside for an average of 3 hours per day. For children in a typical household, pollution exposure can be halved by –increasing their outdoor time from 3 to 5 or 6 hours per day, and –concentrating outdoor time during peak cooking periods. Recommendation-II