The primary source of indoor air pollution comes from the use of semi-processed and unprocessed biomass fuels used in traditional, poorly designed, inefficient stoves that households depend on for their everyday cooking and heating needs. Even in the limited number of middle-income and high-income households in this region, inadequate supplies of clean fuel options such as liquefied petroleum gas (LPG) result in relatively common usage of inefficient cookstoves. Wood and cowdung cakes are primary fuel sources, and kerosene is used for lighting. Because women and children spend large amounts of time in the kitchen, this sub-population is disproportionately affected. Indoor air quality (IAQ) may be worse, depending on the number of hours the stove is lit, the kitchen size and household ventilation. The problem is further aggravated as most of the poor live in a single room, which serves as a kitchen as well as living and sleeping area.

In India, despite the large-scale government-sponsored National Programme on Improved Chulhas, launched in 1983, little quantitative monitoring and evaluation of improved stove projects has been previously undertaken by non-governmental organizations. DA distributed 1430 improved chimney cookstoves (a large portion of this was the ‘Sukhad’ model) in the Bundelkhand region from January 2003 to January 2005 under the ‘Energy Services for Village Households and Livelihood Enterprises’ project supported by the Shell Foundation. As part of this project, DA used quantitative methods, designed according to standard protocols, to undertake a comprehensive assessment of the impact of the ‘Sukhad’ improved cookstove under the Household Energy and Health project (HeH). The HeH project was designed to monitor IAQ in the kitchen area, measure stove performances and to assess any changes in the health of women and children due to the installation of the improved stove.

In the Bundelkhand region, the traditional cookstove or chulha is a single-pot U-shaped stove made of mud and clay, which can be either portable or fixed. Most households have two chulhas and typically keep one indoor and one outdoors.

The ‘Sukhad’ improved cookstove is a twin-pot stove with a chimney. It is a single structure made of reinforced concrete, and is generally suitable for a family with six to eight members.

From July 2004 to September 2005, continuous 48-hour carbon monoxide (CO) and fine particulate matter (PM) monitoring was carried out in 60 households that elected to buy an improved ‘Sukhad’ stove using a ‘Paired, before and after’ study design without controls in order to quantify the changes in indoor air quality (IAQ) in the kitchens of rural households in Bundelkhand. The study was designed and implemented with technical assistance and training by experts from the University of California, Berkeley, USA.

The project was implemented in three clusters of Bundelkhand region, i.e., Radhapur, Niwari and Thona. A total of 60 households with indoor kitchens and similar kitchens and family sizes were randomly selected after conducting a pre-monitoring survey. During the summer/pre-monsoon season, the sample size was reduced to 25 households due to households opting out of the study.

IAQ was assessed by continuously measuring concentrations of PM2.5 and CO for 48 hours in household kitchen locations in the same houses before and after the installation of the Sukhad stove in three phases (during different seasons). PM2.5 measurements were made using the UCB monitor (University of California Berkeley, USA) developed to monitor PM2.5 in rural biomass-burning kitchens. Carbon monoxide was monitored using the Hobo CO monitor (Onset Computer Corporation USA). Both the measurements were conducted according to standard protocols. Both instruments contain dataloggers, which store the minute-by-minute data over the entire measurement period in their memories. This data is then downloaded into a personal computer after monitoring. Standard post-monitoring on fuel use, stove use, cooking habits, etc., were routinely administered after the completion of the 48-hour monitoring period.

The table below represents typical CO and PM2.5 concentrations measured throughout the 48-hour sample period in the same household, before and after the installation of the ‘Sukhad’ improved stove. The CO and PM2.5 peaks occur together, as would be expected since both pollutants are produced during combustion. Due to the continuous nature of the data collected, both the time of actual cooking events and the peak exposure concentrations are recorded in the data.

Paired before-and-after comparisons of 48-hour CO and PM2.5 means in households that relied primarily on the ‘Sukhad’ stove for their cooking and heating needs (regular users) is given in the table below:

Overall, the ‘Sukhad’ stove was well accepted by the users. In a follow-up survey after the dissemination of the stoves, approximately 92% (900/980) of the households with installed ‘Sukhad’ stoves reported using it as their primary stove.

The two key benefits of this monitoring and evaluation exercise were obtaining qualitative data on stove design and use, and quantitative data about before and after IAQ concentrations.

Firstly, the results facilitated the design of more efficient and lower-emission stoves. As the project progressed, DA made several modifications to the ‘Sukhad’ stove on the basis of feedback provided by users. Subsequent stove models progressively became lighter in weight. Additionally, lighter-weight pottery and ceramic liners were designed to both improve stove thermal performance and to facilitate transportation of the stoves. The second benefit of the monitoring and evaluation efforts was the documentation of IAQ improvements due to primary use of the ‘Sukhad’ stove and this evidence can be used in promotional materials for stoves.