Association of air pollution exposure with overweight or obesity in children and adolescents: A systematic review and meta-analysis

Abstract

Childhood overweight and obesity is a global problem. 38 million children under five years old were reported as being overweight/obese in 2019. However, current evidence regarding the effects of air pollution on children weight status remains scarce and inconsistent. This study aimed to determine the association between air pollutants and the weight status of children and adolescents. Four databases were searched up to August 9, 2023. Adjusted merged odds ratios (ORs), regression coefficients (β), and their 95 % confidence intervals (95 % CIs) were calculated and pooled. A total of 27 studies were included. The results showed that air pollutants had adverse effects on the body weight of children and adolescents. Exposure to PM₁, PM_2.5, PM_coarse, and PM₁₀ were associated with increased risk of overweight/obesity, with pooled ORs (95 % CI) of 1.23 (1.09, 1.40), 1.18 (1.10, 1.28), 1.04 (1.03, 1.05) and 1.11 (1.06, 1.17) per 10 μg/m³ increment, respectively. Individuals with higher exposure levels to NO_X, O₃, SO₂ and CO (per 10 μg/m³ increment) were associated with 12 %, 6 %, 28 % and 1 % increased odds of being overweight/obese, respectively. With respect to the level of body mass index, the pooled β (95 % CIs) for each 10 μg/m³ increase in PM₁, PM_2.5, PM₁₀, and NO_X exposure were 0.15 (0.12, 0.18), 0.11 (0.06, 0.16), 0.07 (0.03, 0.10), and 0.03 (0.01, 0.04), respectively. PM₁ has relatively strong adverse effects on body weight status. The subgroup analysis revealed a significantly increase in the risk of overweight/obesity when the concentrations of PM_2.5, PM₁₀, and NO₂ exceeded 35 μg/m³, 50 μg/m³, and 40 μg/m³, respectively. Exposure to PM_2.5, PM₁₀ and NO_X increased the risk of overweight/obesity, especially in Asia. This study provides evidence of the association between air pollution and being overweight/obese in children and adolescents.

Keywords: Adolescent; Air pollution; Body mass index; Children; Obesity; Overweight.