Wildfires are becoming more frequent and destructive. Fuelled by climate change, droughts and heatwaves, these fires destroy homes and forests (Intergovernmental Panel on Climate Change, 2022). But they also produce a less visible threat: smoke. While we often focus on the immediate devastation of the flames, the air pollution generated by wildfires travels long distances and lingers, posing significant risks to people who may live far from the fire itself (see Figure 1).
In my research with Rubí Arrizaga, Damian Clarke and Cristóbal Ruiz-Tagle, published recently in the Journal of Environmental Economics and Management, we look beyond the burned acres to understand how wildfire smoke affects human potential (Arrizaga et al, 2025).
Focusing on Chile – a country that faces intensifying wildfire seasons – we investigate how exposure to smoke harms the health of infants and the education of children. We find that breathing wildfire smoke does not just send people to hospital today: it leaves lasting scars on human development that can persist for years.
Figure 1: PM2.5 concentrations over time
Source: Arrizaga et al (2025)
Tracing the invisible damage
To understand the true cost of wildfires, we analyse data from over 1,000 large fires in Chile between 2002 and 2021.
Rather than simply drawing a circle around a fire and assuming everyone inside was exposed, we use advanced atmospheric modelling – the HYSPLIT model – to simulate exactly where the wind carried the smoke (Stein et al, 2015). This allows us to match smoke exposure with millions of health and school records. Figure 2 uses the 2017 Nilahue-Baraona wildfire to exemplify this process.
Figure 2: Modelling smoke exposure: satellite image three days after ignition and map of exposed municipalities
Source: Arrizaga et al (2025)
Our findings reveal damage across three critical timelines:
- Immediate health effects: Smoke is dangerous for the youngest among us. We find that for infants (children under one year old), a single additional day of smoke exposure increases emergency department visits and hospital admissions for respiratory issues by roughly 15% and 11%, respectively. When we look at the cumulative effect over eight weeks, the increase in hospitalisations is even more dramatic. The dynamic effects shown in Figure 3 reveal a significant increase in hospitalisations one week after exposure.
- Outcomes at birth: The harm begins even before birth. Mothers exposed to wildfire smoke during pregnancy – specifically during the second trimester – have babies with lower birthweights and smaller sizes. For example, one extra day of exposure reduces birthweight by approximately 6.4 grams (0.2%), and the effects are greater for newborns of mothers with lower educational attainment.
- Educational setbacks: The effects spill over into the classroom. Pupils exposed to smoke during the summer break show lower enrolment rates and lower educational achievement in the following school year. Furthermore, smoke exposure in utero appears to have long-term cognitive costs, evidenced by lower standardised test scores ten years after birth. It is worth noting that these negative effects on grades are found in government schools and voucher schools, but not in private schools, which suggests that wealthier families may have better resources to shield their children from pollution.
Figure 3: Dynamic effects of wildfire exposure on infants’ respiratory hospitalisations
Source: Arrizaga et al (2025)
The long shadow of pollution
Economics is fundamentally about people – and our research shows that the ‘social cost’ of wildfires is much higher than the cost of firefighting or rebuilding homes.
First, our study bridges the gap between short-term symptoms and long-term consequences. While a cough or an asthma attack might seem temporary, we show that early life exposure to pollution can alter a child’s trajectory. A baby born smaller or a pupil who falls behind in school faces challenges that can limit their opportunities later in life.
Second, this is a story about inequality. The data show that vulnerable families suffer the most. When we look at birth outcomes, the negative effects of smoke are significantly larger for children whose mothers have less education. Wealthier families appear better equipped to adapt – perhaps by buying air purifiers, taking days off or moving away from the smoke – while poorer families bear the brunt of the pollution (Hoffmann and Rud, 2024).
Finally, the scale of the problem is growing. In 2017 alone, wildfires in Chile burned an area larger than the US state of Rhode Island. During these events, air pollution levels in cities can spike to ten times the normal average. As climate change makes these ‘megafires’ more common, understanding these health and human capital costs is essential for policy-makers.
Policy implications
Our findings suggest that we need to rethink how we protect people during wildfire seasons.
- Better warning systems: We need effective early warning systems that track smoke plumes, not just fire locations. Since smoke travels far downwind, people hundreds of kilometres away need to know when to stay indoors or wear protection.
- Targeted support: Public health responses should focus on the most vulnerable. This includes pregnant women, infants and lower-income communities who may lack the resources to protect themselves.
- Accounting for long-term costs: When governments calculate the budget for fire prevention, they often look at the value of timber or property. They must start including the value of human health and education. Investing in fire prevention today saves money on healthcare and education tomorrow.
By acknowledging the invisible damage of smoke, we can better protect the health and future of the next generation.
