Prenatal exposure to air pollution and pediatric acute leukemia: A nationwide study

Childhood cancer, particularly leukemia, remains a leading cause of mortality among children, with unclear etiologies. Epidemiological studies suggest that air pollution could be a credible factor in triggering genotoxic effects, oxidative stress, and mutagenic characteristics. This article investigated the impact of prenatal air pollution exposure on childhood leukemia occurrences in Taiwan.

This research constitutes a comprehensive nationwide investigation, utilizing population-based data and employing a matched case-control design. We utilized data from Taiwan's Maternal and Child Health Database (MCHD) to identify 965 children under 16 years old with leukemia and matched them with controls without leukemia from 2004 to 2020. Prenatal exposure to air pollutant levels were derived from 71 Environmental Protection Administration monitoring stations across Taiwan, based on maternal residency during pregnancy. Incidence cases were identified as patients with either three clinic visits or being admitted to the hospital with a diagnosis of leukemia.

This nationwide study included 965 leukemia cases and 3860 controls in Taiwan. Prenatal O₃ exposure showed a marginal overall association with leukemia risk (OR = 1.02, 95 % CI: 1.00-1.04, p = 0.059), with significant dose-response effects at higher quartiles (Q3: OR = 1.31, 95 % CI: 1.07-1.60, p = 0.010; Q4: OR = 1.32, 95 % CI: 1.08-1.62, p = 0.007). Conversely, NO showed a protective association (OR = 0.97, 95 % CI: 0.95-0.99, p = 0.010), especially at higher exposure (Q4: OR = 0.79, 95 % CI: 0.64-0.96, p = 0.020). Trimester-specific analyses revealed protective effects of NO in the first and second trimesters, and CO in the first trimester. No significant associations were observed for PM_2.5, PM₁₀ or SO₂.

Prenatal O₃ exposure increases childhood leukemia risk in Taiwan, while NO and CO exhibit protective effects, supporting targeted air quality interventions and highlighting critical windows for prenatal environmental protection.