Infant health outcomes in mega-fire affected communities

ABSTRACT

We undertake a nationwide US study to estimate how mega-fires (defined as wildfires >100,000 acres in size) affect short-term infant health outcomes in communities located within the flame zone. This is the first study to look exclusively at mega-fires, which have unique characteristics compared to smaller wildfire events and are becoming more frequent in the US. We find that pregnant mothers in affected counties experience 0.8 percentage point greater instances of low birth weight and 1.2 percentage point greater instances of prematurity. The low birth weight finding is equivalent to what would be expected if a mother smoked approximately 6.2 cigarettes per day during pregnancy. Importantly, impacts are potentially non-linearly increasing in mega-fire size. Improved benefit-cost analyses are needed to account for mega-fire indirect impacts when making wildfire control and suppression decisions.

KEYWORDS:

• Mega-fires
• indirect impacts
• infant health
• flame zone impacts

JEL CLASSIFICATION:

• Q53
• Q51
• Q54
• I18

Disclosure of potential conflicts of interest

The authors have no interests to disclose and did not receive any funding for this work.

Disclosure of potential conflicts of interest

No potential conflict of interest was reported by the author(s).

Notes

¹ In the main analysis, both singleton and multiple births are examined. However, results are nearly unchanged (though with reduced sample size) when only singleton births are analysed.

² In the robustness checks (Appendix C), we consider only those counties with $\ge$50% mega-fire perimeter overlap (vs. ≥1% overlap in the main analysis).

³ While we have daily mega-fire perimeter data, the infant health data provided by the NCHS only identifies month of birth, thus, a daily matching of fires to individual birth outcome events is not possible.

⁴ This resulted in n = 21 counties being dropped. In the robustness checks (Appendix C), these counties are added back into the analysis and we find similar results.