Cumulative Lifetime Burden of Cardiovascular Disease From Early Exposure to Air Pollution

Abstract

The disease burden associated with air pollution continues to grow. The World Health Organization (WHO) estimates ≈7 million people worldwide die yearly from exposure to polluted air, half of which-3.3 million-are attributable to cardiovascular disease (CVD), greater than from major modifiable CVD risks including smoking, hypertension, hyperlipidemia, and diabetes mellitus. This serious and growing health threat is attributed to increasing urbanization of the world's populations with consequent exposure to polluted air. Especially vulnerable are the elderly, patients with pre-existing CVD, and children. The cumulative lifetime burden in children is particularly of concern because their rapidly developing cardiopulmonary systems are more susceptible to damage and they spend more time outdoors and therefore inhale more pollutants. World Health Organization estimates that 93% of the world's children aged <15 years-1.8 billion children-breathe air that puts their health and development at risk. Here, we present growing scientific evidence, including from our own group, that chronic exposure to air pollution early in life is directly linked to development of major CVD risks, including obesity, hypertension, and metabolic disorders. In this review, we surveyed the literature for current knowledge of how pollution exposure early in life adversely impacts cardiovascular phenotypes, and lay the foundation for early intervention and other strategies that can help prevent this damage. We also discuss the need for better guidelines and additional research to validate exposure metrics and interventions that will ultimately help healthcare providers reduce the growing burden of CVD from pollution.

Keywords: air pollutants, environmental; cardiovascular abnormalities; cardiovascular disease; epithelial barrier.

Figure 1

Proportion of children aged <5 years of age living in areas in which World Health Organization air quality guidelines (particulate matter <2.5 μm) are exceeded (by country, 2016).From World Health Organization report on air pollution.14 PM _2.5 indicates particulate matter <2.5 μm.

Figure 2

Potential therapeutic targets on the interleukin‐1 pathway. IL indicates interleukin; IL1RAP, Interleukin‐1 receptor accessory protein; IL‐1R1, Interleukin 1 receptor, type I; IL‐1R2, Interleukin 1 receptor, type II; IRAK 1/2/4, interleukin‐1 receptor‐associated kinase 1, 2, 4; MyD88, Myeloid differentiation primary response 88; NF‐kB, Nuclear Factor kappa‐light‐chain‐enhancer of activated B cells; rh, recombinant human; rhIL‐1RA, recombinant human interleukin‐1 receptor antagonist; sIL‐1R, soluble type 1 interleukin‐1 receptor; and TRAF6, TNF receptor associated factor 6.

Figure 3

Early intervention can improve cumulative lifetime risk of cardiovascular disease.CVD indicates cardiovascular disease.

Figure 4

Combined population‐level and individual‐level approaches for reducing exposures to air pollution and reducing cardiovascular disease burden.CV indicates cardiovascular; and RCT indicates randomized clinical trial.