Air Pollution Exposure and Blood Pressure: An Updated Review of the Literature

Abstract

Both high arterial blood pressure (BP) and elevated levels of fine particulate matter (PM2.5) air pollution have been associated with an increased risk for several cardiovascular (CV) diseases, including stroke, heart failure, and myocardial infarction. Given that PM2.5 and high BP are each independently leading risk factors for premature mortality worldwide, a potential relationship between these factors would have tremendous public health repercussions. Therefore, the aim of this review is to summarize recent evidence linking air pollution and BP. Epidemiological findings demonstrate that particulate pollutants cause significant increases in BP parameters in relation to both short and long-term exposures, with robust evidence for exposures to PM2.5. Moreover, recent epidemiological studies suggest a positive association between residence within regions with higher levels of ambient PM and an increased incidence and prevalence of overt hypertension. Studies provide consistent results that elevated concentrations of pollutants increase hospital admissions and/or emergency visits for hypertensive disorders and also support that PM levels increases BP in vulnerable subsets of individuals (pregnant women, high CV risk individuals). In this context, PM-mediated BP elevations may be an important pathway which acts as a potential triggering factor for acute CV events. Mechanistic evidence illustrates plausible pathways by which acute and chronic exposures to air pollutants might disrupt hemodynamic balance favoring vasoconstriction, including autonomic imbalance and augmented release of various pro-oxidative, inflammatory and/or hemodynamically-active mediators. Together these responses may underlie PM-induced BP elevations; however, full details regarding the responsible mechanisms require further studies. As a consequence of the ubiquity of air pollution, even a small effect on raising BP and/or the prevalence of hypertension, i.e. the major risk factor for mortality and morbidity worldwide, would have enormous global public health implications.

Cardiovascular and Cerebrovascular Emergency Department Visits Associated With Wildfire Smoke Exposure in California in 2015

“…ED visits for heart failure appeared first at lag 0 and increased with time, with the highest RR at lag 3. In contrast to the mechanisms accounting for the triggering of myocardial infarction, hospitalizations for heart failure are most likely secondary to exacerbations of pre‐existing heart failure worsened by PM‐induced increases in systemic blood pressure, and systemic and pulmonary vasoconstriction 38, 39, 40, 41. All these outcomes were most strongly associated with the aged.…”

Ambient Air Pollution and Risk of Gestational Hypertension

“…A priori selected covariates were extracted from medical records: age at childbirth (continuous), race/ethnicity (white, black, Hispanic, Asian/Pacific Islander, other/unknown), marital status (married, unmarried, missing/unknown), insurance (private, public, self-pay/other), parity (nulliparous, multiparous), prepregnancy body mass index (calculated as weight (kg)/ height (m) 2 ; <18.5, 18.5-24.9, 25.0-29.9, ≥30.0, or unknown), preexisting chronic disease (any (diabetes mellitus, asthma, thyroid disease, or human immunodeficiency virus), none), smoking during pregnancy (yes, no), alcohol consumption during pregnancy (yes, no), and season of conception (spring, summer, fall, winter). Analyses were also adjusted for study site to account for both measured and unmeasured area-level indicators, including but not limited to socioeconomic status, case ascertainment, and sources of air pollution exposures.…”

“…Emerging data have linked air pollution to hypertensive disorders (2). In particular, pregnancy is characterized by profound hemodynamic changes in response to the needs of the developing fetus (3).…”

A Generalized Additive Model Combining Principal Component Analysis for PM2.5 Concentration Estimation

“…Due to its potential threat to human health and the environment, PM 2.5 has been given high priority in research activities in the fields of air pollution and environmental health [2][3][4]. Recent epidemiological studies have shown an association between PM 2.5 and adverse effects on human health, including an increased risk of cardiovascular diseases [5,6], heart problems and lung cancer [7], and a significantly reduced birth rate [8,9]. PM 2.5 pollution has become one of the critical air problems and seriously affects people's daily lives worldwide.…”