The burning question – are emissions from biomass burning harmful to human health?

Poor air quality, associated with high levels of air pollution, is a global problem. Particulate matter (PM) is an air pollutant that detrimentally affects people of all ages. PM is released into air from several sources including transport, industry, power generation, and biomass burning (e.g. crop burning, wildfires, domestic wood burners). In Thailand there are concerns about exposure of the population to PM. In particular, there are uncertainties about the health impacts of haze events. Haze pollution occurs when fire is used to clear agricultural land and the resulting smoke (haze) spreads across the country. Air pollutants released in Thailand may have local impacts and also affect the population of neighbouring countries (e.g. Malaysia, Indonesia). Epidemiological studies have identified that PM exposure is associated with a spectrum of adverse health effects. There is compelling evidence that PM has detrimental impacts on the respiratory and cardiovascular systems (e.g. increased incidence of lung cancer, asthma, heart attacks, stroke). Emerging evidence suggests associations between PM and neurological diseases (e.g. dementia), diabetes and developmental toxicity. It is therefore concerning that during haze events PM levels greatly exceed the permitted guidelines in Thailand. However, the majority of existing epidemiology studies that have investigated the adverse health effects of PM have been conducted in Europe and North America, with relatively fewer studies performed in SE Asia Furthermore, the bulk of existing evidence on the health impacts of PM has focused on exposure to urban (traffic derived) PM, with a lack of studies addressing the toxicity of PM emitted from other sources (e.g. haze events). As the PM source can be different in different countries it is essential to understand how the PM emission source influences PM toxicity. We will use a combination of observational epidemiological evidence and experimental toxicity assessments to provide conclusive evidence of the causation of haze derived PM on disease in Thailand. Our research will help inform the implementation of appropriate, evidence-based policy interventions by regional and national Governments that protect public health and improve the welfare of the Thai population.