In Viet Nam, a diversified farming system at the household level integrating vegetation, aquaculture and use of cages in animal husbandry has contributed to improvements in both income and nutritional outcomes (Food and Agriculture Organization of the United Nations, 2013). For instance, improving fuel and combustion efficiency for the purpose of decreasing greenhouse gas emissions requires actions which may generate co-benefits in the health sector if they succeed in curbing air pollution and thereby ameliorate its health-related consequences and reduce the demand for health services. Air pollution is a classic example where public policy is required to enable environmental and health risks to be reduced at the same time.5 In a significant number of countries, mostly in sub-Saharan Africa, more than 95 per cent of the population uses solid fuels for cooking (Forouzanfar and others, 2015). Poor households, women and children in particular are exposed to indoor air pollution (Smith and others, 2014, World Health Organization, 2014).