Ambient Air Pollution and Cardiopulmonary Health in Beijing, China: Evidence, Vulnerable Populations, Exposure Pathways and Clinical Implications

Abstract

Ambient air pollution remains an important environmental determinant of health in large Chinese cities despite substantial improvements in air quality over the past decade. Beijing provides an informative case study because of its large population, complex urban structure, historical particulate pollution, seasonal meteorological variability, traffic emissions, regional pollutant transport and continuing transition toward a more ozone- and secondary-aerosol dominated pollution profile. This narrative review examines the medical evidence concerning ambient particulate matter and gaseous pollutants in Beijing, with emphasis on PM2.5, PM10, ozone, nitrogen dioxide, sulfur dioxide and carbon monoxide. Evidence from Beijing time-series, case-crossover, hospital-based and exposure-assessment studies indicates that short-term exposure is associated with increased risks of respiratory and cardiovascular morbidity, including respiratory hospital admissions, acute exacerbations of chronic obstructive pulmonary disease, asthma-related healthcare use, ischemic stroke and cardiovascular admissions. Studies also indicate that combined PM2.5 and ozone exposure can have interactive effects on respiratory admissions. Vulnerability varies by age, underlying disease, season, occupation and exposure setting. Children and older adults warrant particular attention, while people with cardiovascular disease, chronic respiratory disease and other chronic conditions may experience clinically important effects at relatively modest increases in pollutant concentration. Medical interpretation should distinguish population-level epidemiological associations from individual diagnosis or prognosis. The review argues for closer integration of air-quality surveillance with clinical preparedness, exposure reduction, disease prevention and urban environmental management. Beijing’s experience also illustrates the importance of controlling multiple pollutants simultaneously rather than focusing exclusively on particulate matter. Continued reductions in PM2.5, prevention of ozone episodes, improved personal exposure assessment and targeted protection of susceptible populations are important components of an evidence-informed urban health strategy.

Beijing; China; air pollution; PM2.5; ozone; cardiovascular disease; respiratory disease; stroke; asthma; environmental health; epidemiology