Indoor and Outdoor Air Pollution
Both indoor and outdoor air pollution are of concern to pulmonary physicians. Exposures to indoor and outdoor air pollutants may both exacerbate and cause respiratory diseases and also increase the population’s risk for morbidity and mortality from malignant and nonmalignant diseases. This chapter provides a broad introduction to indoor and outdoor air pollution. It begins with a brief review of the emergence of indoor and outdoor air pollution as clinical and public health issues. The chapter then considers general principles and concepts related to inhalation injury, exposure, and health outcomes. The health consequences of indoor and outdoor air pollution are covered separately, although this distinction is artificial, given the penetration of outdoor pollutants into indoor environments and the overlap between the pollutants found in indoor and outdoor locations. The chapter concludes by considering two issues of direct concern to clinicians: susceptible populations and control strategies, both at the public health and individual levels. Pulmonary physicians have a key role in advising their patients and in carrying out research relevant to air quality management.
Air pollution has probably had adverse effects on health throughout history. The use of fire for heating and cooking brought exposure to smoke, a problem that persists today for the billions who still use biomass fuels, and the rise of cities concentrated the emissions of pollutants from dwellings and manufacturing facilities within restricted locales. Industrialization and electric power generation brought new point sources of pollution; that is, localized sources such as power plants, and sometimes immense emissions of combustion by-products, particles, nitrogen oxides (NOx), and sulfur oxides into areas where people lived and worked. During the twentieth century, mobile sources, including cars, trucks, and other fossil fuel–powered vehicles, created a new type of pollution – photochemical pollution, or “smog” – first recognized in the Los Angeles air basin in the 1940s. The unprecedented growth of some urban areas to form “megacities,” such as Mexico City, São Paulo, and Shanghai, has led to unrelenting air pollution from massive vehicle fleets, snarled traffic, and polluting industries and power plants. During the twentieth century, there was increasing recognition that the air pollution problem extends into indoor environments. In less-developed countries, exposure to smoke from biomass fuel combustion (e.g., open burning of wood for heating and cooking inside the home) is widespread, as it was in past centuries. In the more developed countries, indoor pollutants are generated by human activities (e.g., cooking, personal care products, etc.) and released from the materials used for construction and in furnishings, and often maintained at unhealthy concentrations by building designs that seal pollutants within.
Health effects of air pollution have long been of concern. During the reign of Edward I (1272–1307), the pollution of London by coal smoke prompted a royal proclamation banning burning of “sea coal” in open furnaces.1 In 1661, John Evelyn published Fumifugium ...