at risk from household air pollution as they inhale and absorb higher levels of particles given the same exposure as adults (Bruce et al., 2013; Kurt et al., 2016; Sturm, 2012). To assess health among this population, a trained enumerator measured height (or recumbent length for children under two years of age) which was then standardized into a z-score relative to a representative, well-nourished child of the same age in months and gender using the Centers for Disease Control and Prevention growth tables (CDC, 2012). Height, conditional on age and gender, is both straightforward to measure and a well-established indicator of health status during very early childhood, reflecting both the genetic endowment and the influence of the disease environment during the in utero period and the first two to three years of life, commonly referred to as the “1<sup>st</sup> 1,000 days” (Cusick and Georgieff, 2016; Martorell and Habicht, 1986; Victora et al., 2010; Waterlow et al., 1977). As there is limited potential for catch-up growth to offset early-life deficits, child height is a powerful predictor of attained height as an adult and is thereby associated with reduced mortality and morbidity, as well as greater economic prosperity, educational attainment, and cognitive function (Adair et al., 2013; Fogel, 2004; Glewwe and Miguel, 2008; Hoddinott et al., 2008; LaFave and Thomas, 2017; Strauss and Thomas 1998).

Understanding the biological mechanisms linking biomass smoke exposure and child growth is an active area of inquiry (e.g. Burnett et al., 2014; Gordon et al., 2014; Rylance et al., 2015) with a recent National Institutes of Health review noting the link between household air pollution and child growth a specific priority (Martin et al., 2013). Exposure to particulate matter from biomass smoke is a risk factor through in utero exposure as well as direct inhalation during early life (Jayachandran, 2009; Pope et al., 2010). Prenatal impacts occur both as a result of the effect of pollution on the mother and the transfer across the placenta of toxins present in wood smoke that reduce nutrient flows and disrupt the central nervous system of the fetus (Perera et al., 1998; Perera et al., 1999; Poursafa and Kelishadi, 2011). Additional medical evidence links exposure to wood smoke among children to increased inflammation and a weakened immune system (Rylance et al., 2015).

Second, we assess the presence of symptoms indicating respiratory disease for all children and each adult cook in the household. Participants were asked whether they have experienced a series of symptoms over the prior four weeks, including various types of coughs, difficulty breathing, wheezing, and eye problems. Prior studies show that such symptoms are closely linked to clinical markers of respiratory infection and chronic obstructive pulmonary disease (e.g. Bensch and Peters, 2015; Hanna et al., 2016; Pattanayak and Pfaff, 2009) and sensitive to particulate matter exposure (e.g. Duflo et al., 2008).

Finally, each primary cook within the household also provided information on their physical functioning through their ability to perform regular tasks. For each activity of daily living (ADL), the 7