Impact of Improved Cooking Stove on Maternal Health in Rural Bangladesh: A Quasi-Experimental Study

Introduction: Two-thirds of all households in developing countries depend on unprocessed biomass fuel for cooking. Traditional stoves have poor combustion capacity which produces heavy smoke and numerous harmful pollutants. Switching to Improved Cooking Stove (ICS), a well-designed earthen made stove equipped with a chimney could be beneficial for health. The aim of this study was to assess the efficacy of ICS on maternal health in rural areas of Bangladesh. Methods: A quasi-experimental design was adopted to conduct the study. This study selected 150 Households from 5 villages (intervention) and 150 Households from two villages (control) from the Manikonj district of Bangladesh during January 1, 2012 to July 30, 2012. Differences between control and intervention group were examined by applying t-test or one-way analysis of variance (ANOVA). The conventional cut-off value of 0.05 was taken as statistical significance. Stata (version 13) was used to do the analysis. Results: Most of the respondents (62%) were less than 30 years of age. About 94% participants resided in tin-shaded houses, and 51% kitchens were small. After the intervention period, the measured mean concentrations of Particulate Matter (PM 2.5 ) for the intervention and control group was 259 µg/m 3 and 1285 µg/m 3 , respectively (p<0.05). However, lung function test (LFT) did not reveal significant differences between the two groups (p>0.05). Conclusion: ICS reduced the incidence of respiratory illness among the intervention group, however, did not demonstrate significant changes in LFT during the six months of the follow-up period. Therefore, this study found ICS might have the potential to be used to improve the maternal health in rural Bangladesh. However, more longitudinal investigations are expected to demonstrate the efficacy and impact of ICS on maternal health to support the statement.


Introduction
Biomass fuels refer to any woody fuels or animal- World Health Organization estimates that pollutants from biomass smoke can cause an estimated number of 1.5 million premature deaths per year among the women and young children due to severe respiratory illnesses [5]. Use of the biomass fuel has estimated to be linked to approximately 39 million disability-adjusted life years (DALY) [6]. In developed countries, a shift from biomass fuel to petroleum products (kerosene, LPG) and electricity for the purpose of cooking have been observed [7]. However, in most of the developing countries, despite having the refined fuels available, household often continue to use biomass due to inability to pay for good fuel [8]. Poverty has been considered to be the main barrier to the adoption of cleaner fuels by the poor villagers in many countries [9,10]. Therefore, the use of biomass fuel has been associated with at least 4 percent of the disease burden in developing countries [11].
Bangladeshi women who lived in the rural area are more exposed to the major concentrated particulate matters when they tend to spend

Study Design
This study adopted a quasi-experimental design to find out the effect of ICS on maternal health.

Study place and period
An approach was taken to assess the health hazards associated with biomass fuel use in the kitchen by comparing the respiratory illness between two groups of rural women: one group

Data Analysis
Frequency and proportions were used to present categorical variables. Mean and Standard Deviation (SD) were given to describe continuous variables. Differences between control and intervention group were examined by simple t-test and one-way ANOVA for the categorical variables.
A conventional cut-off value of 0.05 was taken as statistical significance. Stata (version 13 second edition) was used to do all the data analysis.

Ethical Approval and Consent to Participants
The study was approved by the Ethics Committee of the Dhaka Medical College of Bangladesh. Prior permission was taken from the Upazila health managers. All the study participants were informed verbally about the study design and purpose of the survey. Written consent was taken from the participants. They were given assurance that their information would not be disclosed.

Characteristics of Study Participants
Most of the respondents (62%) were less than 30 years of age. The average family size was five members. The household income was depended on the husbands' income and 34% of them were day labour. Most of the respondents (94%) resided in Tin-shaded houses, and 51% kitchens were small sized (25-50 square feet). All of the participants used dry leaves, solid plants, woods, crop residues and cow dungs for cooking, and 60% of them reported burning eye sensation due to smoke during cooking (table 1).
All participants were free from the respiratory illnesses during the baseline assessment, and Lung function test of the respondents was within the normal range. The air quality of both intervention and control area were almost same (around 125-130 µg/m3).   and observed the significant reductions as well. can save millions of lives by reducing air pollution.
Protecting the mother and infant from indoor air pollution due to combustion of biomass exposure needs to be addressed immediately through the public health action.

Limitation
The equipment and accessories were not adequate enough to cover a significant number of samples.
After the promotion of ICS, only six months were available to demonstrate the impact of ICS on lung function which was not sufficient to have substantial health effects, particularly in the lung functions. Therefore, the use of ICS might not demonstrate significant changes in LFT among the users during the six months of the follow-up period. Another limitation of this study was not to use advanced statistics to find out the association.
However, this was the first study of its kind to determine the impact of ICS among the rural mothers.

Conclusion
This study showed that the incidence of respiratory illness among the mothers who used ICS was lower in compare to the control group who used the traditional stove. ICS has the potential to be used to improve the maternal health in rural Bangladesh. However, more longitudinal investigations are expected to demonstrate the efficacy of ICS on maternal health to support the study findings.