Air Pollution and Children

by

Maya Leventer-Roberts, Carla Campbell

• LAST REVIEWED: 26 August 2013
• LAST MODIFIED: 26 August 2013
• DOI: 10.1093/obo/9780199756797-0118

Introduction

Air pollution consists of undesirable chemicals and particles that are present in varying levels and have multiple and far-reaching negative health outcomes. The Clean Air Act in 1970 in the United States was a primary catalyst for a large volume of research, as it fueled the need to describe the type, quantity, and source of pollutants, as well as the associated health effects among multiple health systems and in different age groups and locations. Following the immediate response, subsequent research emerged evaluating the effects of interventions and regulations, as well as identifying new toxins and delineating new standards as the long-term data was further evaluated. Children are, not surprisingly, a group at high risk for negative outcomes given their smaller body mass and body surface area, as well as their developing bodies: particularly their lungs and brains. While much of the literature evaluated large cohorts, the concerns for air pollution as it affects children creates a unique challenge as it focuses on a population that is notoriously more difficult to enroll, measure, and follow. A large portion of the research is thus directed at frequent exposures and the most significant outcomes as the best way to highlight the most serious effects of air pollution on the health and well-being of children. This review has focused on chemical agents of pollution whenever possible. Some of the studies of different settings (such as school or child care) evaluate both indoor and outdoor exposures. Additionally, studies focusing on asthma outcomes looked at both chemical irritant and biologic (often allergenic) indoor air pollutants. The section on exposure in developing countries has focused on indoor air pollution exposures. Some of the references in the other sections were performed in developed countries other than the USA to illustrate how they are addressing air pollution issues.

General Overviews

Although the Clean Air Act was initially implemented in 1970, much of the literature describing the effects of air pollution on children began in the 1990s and escalated primarily in the early 2000s. There are several excellent reviews that focus on the exposures and disease processes specific to children: these reviews differ in duration, system, and type from the adult experience. Fuentes-Leonarte, et al. 2008; Salvi 2007; Bell and Samet 2010; American Academy of Pediatrics 2012; and Kim, et al. 2004 focus on the type, population, and quality of the available data, as well as on the content and highlights the main concerns specific to the unique qualities of children. In addition, Kim, et al. 2004 is a collaborative effort that in conjunction with an excellent summary links the data directly to the policy statements in affiliation with the American Academy of Pediatrics. Heinrich and Slama 2007 focuses on the outcomes related to fine particulate matter, an area that is separate from the evaluations preformed on specific chemical contaminants. Finally, O’Connor, et al. 2008 provides an example of a prospective study that displays a link between the changes in air quality and the disease processes in children.

• American Academy of Pediatrics. 2012. Air pollutants, outdoor. In Pediatric environmental health. 3d ed. Edited by Ruth A. Etzel and Sophie J. Balk, 313–327. Elk Gove Village, IL: American Academy of Pediatrics Press.

  This overview of outdoor air pollution and its impact on children’s health reviews routes of exposure, clinical effects and their treatment, and prevention of exposure. The Air Quality Index is described and reviewed for use by clinicians in advising patients to moderate their exposure to air pollutants.

• Bell, M. L., and J. M. Samet. 2010. Air pollution. In Environmental health: From global to local. 2d ed. Edited by Howard Frumkin, 387–415. San Francisco: Jossey-Bass.

  Authored by two major researchers in this field, this chapter gives an overview of the major outdoor air pollutants and their main health effects. It also covers the regulations and guidelines for the Environmental Protection Agency’s (EPA) National Ambient Air Quality Standards (NAAQS) and the World Health Organization (WHO). There is a discussion of local and regional pollution control on a public health level.

• Fuentes-Leonarte, V., J. M. Tenías, and F. Ballester. 2008. Environmental factors affecting children’s respiratory health in the first years of life: A review of the scientific literature. European Journal of Pediatrics 167:1103–1109.

  DOI: 10.1007/s00431-008-0761-7

  A review to summarize the existing data between 1996 and 2006, specifically on the nature of the association between environmental factors and respiratory health in children. Found that indoor and outdoor air pollution are overwhelmingly the main areas of study, with asthma as the most common disease. The paper also focused on the methods of obtaining the data and underlying knowledge of mechanism of disease exacerbation.

• Heinrich, J., and R. Slama. 2007. Fine particles, a major threat to children. International Journal of Hygiene and Environmental Health 210:617–622.

  DOI: 10.1016/j.ijheh.2007.07.012

  A succinct review of the specific relationship between fine particle exposure and several outcomes including death, lung function, and the respiratory and reproductive systems. The review categorizes and rates the quality of the available research as it relates to the specific concerns of children and their high exposure rates secondary to their immature development. Argues that even with incomplete or inconclusive studies, specific protection is needed given the high risk.

• Kim, J. J., and American Academy of Pediatrics Committee on Environmental Health. 2004. Ambient air pollution: Health hazards to children. Pediatrics 114:1699–1707.

  DOI: 10.1542/peds.2004-2166

  A collaborative effort detailing the evidence surrounding ambient air pollution and the associated risks in children leading to specific policy recommendations. The outline is on exposures and their general known effects. Much of the article is on prevention and the regulations involved, as well as criticisms of the current standards and their ability to protect the interests of children.

• O’Connor, G. T., L. Neas, B. Vaughn, et al. 2008. Acute respiratory health effects of air pollution on children with asthma in US inner cities. Journal of Allergy and Clinical Immunology 121:1133–1139.

  DOI: 10.1016/j.jaci.2008.02.020

  A large prospective analysis of the association between asthma symptoms in known asthmatic children and the measured air quality and concentration of pollutants with the Aerometric Information Retrieval System. This study outlines a specific relationship between the concentrations of pollutants, NO₂ in particular, and the increase in symptoms and asthma- related missed school days. The study further suggests that the NO₂ may be secondary to traffic-related causes. This study exemplifies the connection between fluctuations in air pollution and measured effects on disease and quality of life.

• Salvi, S. 2007. Health effects of ambient air pollution in children. Paediatric Respiratory Reviews 8:275–280.

  DOI: 10.1016/j.prrv.2007.08.008

  A short review of the overall connection between children and ambient air pollution. Salvi details the unique qualities of children through prenatal, neonatal, and key growth periods. He then outlines the associations with fine particles and asthma and allergy and the serious risk to lung function and development. He concludes the review by discussing possible mechanisms including oxidative stress and recommendations.