Elsevier

The Lancet

Volume 360, Issue 9341, 19 October 2002, Pages 1233-1242
The Lancet

Review
Air pollution and health

https://doi.org/10.1016/S0140-6736(02)11274-8Get rights and content

Summary

The health effects of air pollution have been subject to intense study in recent years. Exposure to pollutants such as airborne participate matter and ozone has been associated with increases in mortality and hospital admissions due to respiratory and cardiovascular disease. These effects have been found in short-term studies, which relate day-to-day variations in air pollution and health, and long-term studies, which have followed cohorts of exposed individuals over time. Effects have been seen at very low levels of exposure, and it is unclear whether a threshold concentration exists for particulate matter and ozone below which no effects on health are likely. In this review, we discuss the evidence for adverse effects on health of selected air pollutants.

Section snippets

A new era of air pollution research

20 years ago, the era of successful abatement of traditional air pollutants culminated in a voluminous review of the health effects of ambient particulates.23 At concentrations seen in the late 1970s in the developed world, adverse health effects were then regarded as unlikely. In the two decades since then, however, air pollution has re-emerged as a major environmental health issue. One reason is that, although air pollution from combustion of traditional fossil fuel is now present in much

Pollutants of current interest: ozone, particulates, nitrogen dioxide

Now that the concentration of sulphur dioxide has decreased strikingly, attention has shifted to ozone, nitrogen dioxide, and particulates. Before discussing these pollutants in more detail, some qualification is needed to put our discussion in a wider global perspective. For millions of people living in rural areas in developing countries, indoor pollution from the use of biomass fuels occurs at concentrations that are orders of magnitude higher than currently seen in the developed world.36, 37

Short-term studies

There have been abundant studies on the short-term effects of air pollution on health, with emphasis on mortality and hospital admissions. Panel studies have been done in volunteers, which have provided data on health endpoints such as respiratory and cardiovascular symptoms, and objective measures of lung or cardiac function on a daily or weekly basis. Large, collaborative efforts are under way in Europe and the USA which will be summarised.

In Europe, the APHEA (Air Pollution and Health: a

Mechanisms

Chamber studies provide a method by which to pursue the acute mechanisms of individual air pollutants, but do not reproduce either the mixtures or temporal variation that occur in natural exposures. Although individual air pollutants can exert their own specific individual toxic effects on the respiratory and cardiovascular systems, ozone, oxides of nitrogen, and suspended particulates all share a common property of being potent oxidants, either through direct effects on lipids and proteins or

Air quality guidelines and standards

Several guidelines and standards exist for ozone, nitrogen dioxide, and particulate matter in ambient air. The table lists the most recent air quality guidelines and standards recommended by WHO, the US Environmental Protection Agency, and the European Union (EU). The EU standards are targets to be reached in 2005 or 2010. The most remarkable difference lies in the annual value for nitrogen dioxide. The WHO and EU value is only 40% of the US value.

WHO has not proposed guidelines for particulate

Thresholds

A key question is whether threshold concentrations exist below which air pollution has no effect on population health. If such a threshold could be identified, no additional public-health benefits would be expected from bringing air pollution concentrations far below this level. Theoretical and empirical work has been done to shed light on this issue.108, 109 In an analysis of NMMAPS data, no evidence was found for a threshold for PM10 and daily all-cause and cardiorespiratory mortality.109 By

Disputing the evidence

In view of the potentially large costs and benefits associated with abatement of air pollution, questions surrounding the relation between air pollution and health have been an area of fierce debate in the past decade. The early time-series studies have been criticised for their analytical approach and inadequate control for confounding by weather variables etc, whereas the US cohort studies have been criticised for inadequate confounder and co-pollutant control. Reanalyses of such studies were

Concluding remarks

An excess risk of death of “0·5% per 10 μg/m3 PM10” requires some translation before the effect on public health becomes clear. For the Netherlands (16 million inhabitants, about 140 000 deaths per year, and an average PM10 concentration of >30 μg/m3), the number of deaths attributable to day-to-day variations in PM10 would translate into at least 2100 deaths brought forward by air pollution per year—almost twice the number of deaths due to traffic accidents. Estimates derived from the cohort

Search strategy and selection criteria

The key words “air pollution and health” produce over 500 references a year from Medline alone. The present review is therefore, of necessity, our selection of just some of the major studies. The selection is based on a systematic Medline search until early 2002, on more than 20 years of continuous research in the field, and on participation in many advisory boards nationally and internationally.

References (147)

  • LC Renwick et al.

    Impairment of alveolar macrophage phagocytosis by ultrafine particles

    Toxicol Appl Pharm

    (2001)
  • Mortality and morbidity during the London fog of December 1952

    Reports on Public Health and Medical Subjects No 95

    (1954)
  • J Firket

    Fog along the Meuse Valley

    Trans Faraday Soc

    (1936)
  • ML Bell et al.

    Reassessment of the lethal London fog of 1952: novel indicators of acute and chronic consequences of acute exposure to air pollution

    Environ Health Perspect

    (2001)
  • Anon

    An anti-smog bottle

    BMJ

    (1955)
  • CA Goldsmith et al.

    Particulate air pollution and asthma: a review of epidemiological and biological studies

    Rev Environ Health

    (1999)
  • T Nicolai

    Air pollution and respiratory disease in children: what is the clinically relevant impact?

    Pediatr Pulmonol Suppl

    (1999)
  • CA Pope

    Mortality and air pollution: associations persist with continued advances in research methodology

    Environ Health Perspect

    (1999)
  • K Donaldson et al.

    Asthma and PM10

    Respir Res

    (2000)
  • T Gordon et al.

    Cardiovascular toxicity of inhaled ambient particulate matter

    Toxicol Sci

    (2000)
  • BF Nyberg et al.

    Epidemiologic studies on the health effects of ambient particulate air pollution

    Scand J Work Environ Health

    (2000)
  • PopeCA

    Epidemiol fine particulate air Pollut Hum health: biologic mechanisms and who's at risk?

    Environ Health Perspect

    (2000)
  • S Takafuji et al.

    Air pollution and allergy

    J Investig Allergol Clin Immunol

    (2000)
  • DW Dockery

    Epidemiologic evidence of cardiovascular effects of particulate air pollution

    Environ Health Perspect

    (2001)
  • K Donaldson et al.

    Ambient particle inhalation and the cardiovascular system: potential mechanisms

    Environ Health Perspect

    (2001)
  • MI Gilmour et al.

    Air pollutant-enhanced respiratory disease in experimental animals

    Environ Health Perspect

    (2001)
  • G Oberdorster

    Pulmonary effects of inhaled ultrafine particles

    Int Arch Occup Environ Health

    (2001)
  • J Sunyer

    Urban air pollution and chronic obstructive pulmonary disease: a review

    Eur Respir J

    (2001)
  • A Sydbom et al.

    Health effects of diesel exhaust emissions

    Eur Respir J

    (2001)
  • GD Thurston et al.

    Epidemiological studies of acute ozone exposures and mortality

    J Expo Anal Environ Epidemiol

    (2001)
  • WW Holland et al.

    Health effects of particulate pollution: reappraising the evidence

    Am J Epidemiol

    (1979)
  • HE Wichmann et al.

    Health effects during a smog episode in West Germany in 1985

    Environ Health Perspect

    (1989)
  • W Dassen et al.

    Decline in children's pulmonary function during an air pollution episode

    J Air Pollut Control Assoc

    (1986)
  • B Ostro

    A search for a threshold in the relationship of air pollution to mortality: a reanalysis of data on London winters

    Environ Health Perspect

    (1984)
  • J Schwartz et al.

    Mortality and air pollution in London: a time series analysis

    Am J Epidemiol

    (1990)
  • DW Dockery et al.

    An association between air pollution and mortality in six US cities

    N Engl J Med

    (1993)
  • PopeCA et al.

    Particulate air pollution as a predictor of mortality in a prospective study of US adults

    Am J Respir Crit Care Med

    (1995)
  • DE Abbey et al.

    Long-term inhalable particles and other air pollutants related to mortality in nonsmokers

    Am J Respir Crit Care Med

    (1999)
  • B Brunekreef

    Air pollution and life expectancy: is there a relation?

    Occup Environ Med

    (1997)
  • PopeCA et al.

    Lung cancer, cardiopulmonary mortality, and long-term exposure to fine particulate air pollution

    JAMA

    (2002)
  • F Nyberg et al.

    Urban air pollution and lung cancer in Stockholm

    Epidemiology

    (2000)
  • B Brunekreef

    All but quiet on the particulate front

    Am J Respir Crit Care Med

    (1999)
  • G Hoek, B Brunekreef, S Goldbohm, P Fischer, P Brandt: Association between mortality and indicators of traffic-related...
  • AJ McMichael et al.

    Seeking a global perspective on air pollution and health

    Epidemiology

    (1999)
  • KR Smith et al.

    Indoor air pollution in developing countries and acute lower respiratory infections in children

    Thorax

    (2000)
  • N Vichit-Vadakan et al.

    Air pollution and respiratory symptoms: results from three panel studies in Bangkok, Thailand

    Environ Health Perspect

    (2001)
  • B Ostro et al.

    The impact of particulate matter on daily mortality in Bangkok, Thailand

    J Air Waste Manag Assoc

    (1999)
  • WHO

    Air Quality Guidelines for Europe, 2nd edn

    WHO Reg Publ Eur Ser

    (2000)
  • K Katsouyanni et al.

    Short-term effects of air pollution on health: a European approach using epidemiological time-series data. The APHEA project: background, objectives, design

    Eur Respir J

    (1995)
  • K Katsouyanni et al.

    Confounding and effect modification in the short-term effects of ambient particles on total mortality: results from 29 European cities within the APHEA2 project

    Epidemiology

    (2001)
  • Cited by (0)

    View full text