11984-04_Ch04.qxd
3/4/10
12:53 PM
Page 34
34 World Bank Working Paper
common method involves the measurement of small particulates. Small particulates are a heath concern because they have an impact deep in the lungs and are a major cause of respiratory illness. The most general measurements of particulate matter are called PM, with a number afterwards that represents the aerodynamic diameter of the particle. For example, PM10 refers to fine particulate matter with an aerodynamic diameter smaller than 10 micrograms (µg). PM2.5 has an aerodynamic diameter smaller than 2.5 µg. The exposure levels recommended by health and environmental agencies generally refer to the number of particulates of a certain diameter per cubic meter of air. The most recent standards of the World Health Organization for PM10 are 20 µg/m3 of air annual mean exposure levels and 50 µg/m3 24-hour mean exposure levels (WHO 2006). For PM2.5, the recommended levels are 10 µg/m3 annual mean exposure levels and 25 µg/m3 24-hour mean exposure levels. For Bangladesh, the standard for annual recommended average for PM10 is 50 µg/m3. Worldwide evidence indicates that women and their children bear the brunt of indoor air pollution (IAP). Moreover, poorer households, compared to wealthier ones, bear the heavier burden. In rural Bangladesh, age–sex composition of households indicates that generally women and children suffer greatest exposure. Adult men are the least exposed because they spend more time outside the home. Solid particulates, especially those with diameters smaller than 10 microns (PM10) are released into the air; and, if inhaled for prolonged periods, can lead to various diseases, loss of health, and early morbidity. Finer particles (PM2.5) are even more damaging. This section discusses various aspects of IAP caused by incomplete biomass combustion. Both male and female children spend many hours indoors in the cooking space or adjacent living area until 6 to 8 years of age, when gender-based patterns begin to diverge (see Table 4.1). Adolescent males begin to spend more time outdoors, while adolescent females move in the opposite direction, spending more time in indoor cooking and living areas. Women 20 to 60 years of age spend nearly 4 hours per day cooking, nearly 16 hours in the household living area, and the remaining hours outdoors. For those above 60 years of age, the patterns are somewhat reversed.
Table 4.1. Mean Daily Hours in Household Location by Age Group* Female Age Group 0–1 2–5 6–8 9–12 13–19 20–60 >60
Cooking Area 1.12 1.08 1.01 1.32 2.38 3.75 1.48
Living Area 20.04 18.44 16.40 15.55 15.71 16.05 19.76
Male Outdoors 3.01 4.52 6.61 7.19 5.97 4.27 2.93
Source: Dasgupta et al. (2004). *For seven regions in Bangladesh.
Cooking Area 1.11 0.93 0.48 0.31 0.28 0.19 0.17
Living Area 19.29 18.13 16.41 15.61 14.33 13.07 16.56
Female–Male Outdoors 3.57 4.97 7.17 8.06 9.41 10.79 7.37
Cooking Area −0.01 −0.15 −0.52 −1.01 −2.10 −3.56 −1.31
Living Area −0.75 −0.31 0.01 0.06 −1.38 −2.98 −3.20
Outdoors 0.56 0.45 0.56 0.87 3.44 6.52 4.45