Indoor air quality, house characteristics and respiratory symptoms among mothers and children in Tamil Nadu State, India

Abstract

Air pollution is a problem affecting developing and developed countries concerned about the adverse health effects associated with exposure to indoor and outdoor air pollutants. In developing countries like India, the problem, particularly domestic air pollution, is worsened by the use of unprocessed solid fuels for cooking. Other indoor environmental risk factors include the characteristics of housing conditions, household activities, and low Socio-economic status (SES). The potential irritants include nitrogen dioxide (NO[subscript]2), formaldehyde (HCHO), volatile organic compounds (VOCs), indoor smoking, and particulate matter (PM[subscript]2.5-10) and carbon monoxide (CO).Indoor air pollutants, especially those in domestic households are major problems that can contribute to respiratory symptoms and poor health in mothers and children and, in particular, those who live in poorer households in developing countries. There is consistent evidence that mothers and young children from these countries spend more than 80% of their time indoors, especially in the kitchen. Therefore, domestic air quality may be related to the increase in the prevalence of respiratory symptoms and other allergic conditions. In this context, this study established risk factors in the domestic environment that can determine the concentrations of domestic air pollutants and prevalence of respiratory symptoms in mothers and children. Cooking for a long time, keeping young children and infants in cooking areas, the inadequacy of ventilation, and the use of biomass fuels can relate to debilitating health problems, especially respiratory symptoms among poor households’ mothers and children particularly in developing countries.This study is cross-sectional and aims to determine that domestic concentrations of fine particles (PM[subscript]2.5), carbon monoxide (CO), and the socio-economic status (SES) and/or poverty levels, house and kitchen characteristics and households’ activities, may have a detrimental role in the prevalence of respiratory symptoms among mothers and children. One hundred and seventy households (N=170) with young children (n=299) under 15-years-of-age were selected randomly from the City of Tirupur in Coimbatore district, Tamil Nadu in South India. This city was chosen as it has diversity in terms of its ethnic mix, economic activities, physical characteristics and income disparities. Each participating household was visited and 170 households’ mothers were interviewed using a questionnaire. During the visits, study data was also collected in 80 households by measuring of indoor concentrations of PM[subscript]2.5, CO and the physical parameters, humidity and temperature.According to the statistical analysis, using biomass for cooking affects mothers’ and children’s respiratory symptoms. The results of this study show that median exposure to fine particles (PM[subscript]2.5) (1.18mg/m[superscript]3) exceeds the recommended WHO standards. CO concentrations did not have any significant relationship with mothers’ and children’s respiratory symptoms as mean concentrations of CO were 4.63ppm or 8.80mg/m[superscript]3. The study shows that kitchens with brick/stone walls and tile roofs are associated with reduced concentrations of PM[subscript]2.5 (p=0.033). If a kitchen has mud walls, a thatched roof and a floor of clay/mud, the indoor air has higher concentrations of PM[subscript]2.5 (p=0.014), Floors, such as cement, can lower the domestic air concentration of PM[subscript]2.5, (p=0.014). The study finds that lower concentrations of PM[subscript]2.5 were also found when windows were open (OR=0.14), (p=0.018).The study shows that there is a significant relationship between the prevalence of asthma in children in relation to CO and more than one time (OR=1.19) with p=0.021. In this study, it was shown that mothers with lower incomes had shortness of breath (p=0.003), almost six times higher than mothers with higher incomes. Children with allergies (78.9%) in the current study came from families where the mothers were employed as labourers and their children had respiratory symptoms such as coughing (p=0.001) and wheezing (p=0.002). The most (p=0.001) significant respiratory symptom of children from families who did not own house/unit or land was a cough: 56 (42.4%) as they usually live either in semi-open air or very badly constructed dwellings).High R/H (%) and T[superscript]oC also seem to have an effect on domestic concentrations of PM[subscript]2.5. As revealed by the statistical analysis, high T[superscript]oC and RH (%) were associated with significant impacts on mothers’ respiratory symptoms but did not have any significant impact on children’s respiratory symptoms. High-income households’ mothers and children were seen to have less significant respiratory symptoms than low-income households’ mothers. Evaluation of the literature also assessed the extent to which SES and/or poverty levels and house and kitchen characteristics and households’ activities affected respiratory symptoms in mothers and children.In conclusion, this study’s results further highlight the role of susceptibility risk factors for respiratory symptoms and show that domestic environmental factors contribute as risk factors for respiratory symptoms in mothers and children, especially in poor households. In order to improve domestic air quality and thus decrease the prevalence of respiratory symptoms, much more effort needs to be made. Because the air quality in the domestic environment is modifiable, there may be opportunities for intervention to reduce respiratory symptoms and this needs greater attention. Low SES and/or poverty levels may cause greater susceptibility to disease through malnutrition, access to health care, better housing and children’s and adult education.This study also provides recommendations how to reduce the prevalence of respiratory symptoms by improving households’ SES and/or poverty levels, one of the main risk factors for adverse health effects of respiratory symptoms in mothers and children from Tamil Nadu, South India. Since the quality of the domestic environment is very important, further intervention is needed to reduce respiratory symptoms in mothers and children, particularly young ones at a time when immune deviation usually occurs, regarding where they grow and spend most of their time. Finally, in order to reduce indoor air pollutants and respiratory symptoms in mothers and children, much more effort and greater attention needs to be paid to improve households’ low SES and/or poverty levels. The main goal should be sustainable development and poverty reduction that will enable people eventually to switch to clean fuels. SES was the most significant predicator of cooking fuel choice to ensure good health.