This volume of the IARC Monographs provides an evaluation of the carcinogenicity of outdoor air pollution.

Outdoor air pollution is a complex mixture of pollutants originating from natural and anthropogenic sources, including transportation, power generation, industrial activity, biomass burning, and domestic heating and cooking. The mix of pollutants in outdoor air varies widely in space and time, reflecting the diversity of sources and the influence of atmospheric processes. Commonly measured air pollutants include particulate matter (PM_2.5, PM₁₀), nitrogen dioxide, and sulfur dioxide; the concentration of particulate matter is often used as an indicator of pollution levels. Millions of people worldwide are exposed to outdoor air pollution at levels that substantially exceed existing health-based guidelines.

This evaluation is the culmination of a series that has examined individual pollutants that are contained in the mixture of outdoor air. Related previous evaluations have been published in IARC Monographs Volumes 92, 93, 95, 100C, 100E, 103, and 105.

An IARC Monographs Working Group reviewed epidemiological studies, animal cancer bioassays, and mechanistic data to assess the carcinogenic hazards of exposure to outdoor air pollution and particulate air pollution.

Contents

• NOTE TO THE READER
• List of Participants
• PREAMBLE
• GENERAL REMARKS
• 1. Exposure Data
  • 1.1. Definition of outdoor air pollution
    • 1.1.1. Characteristics of exposure to outdoor air pollution
    • 1.1.2. Pollutant concentrations
    • 1.1.3. Pollutants classified by IARC
  • 1.2. Sources of air pollutants
    • 1.2.1. Introduction
    • 1.2.2. Photochemical oxidants
    • 1.2.3. Particulate matter
    • 1.2.4. Sulfur dioxide
    • 1.2.5. Carbon monoxide
    • 1.2.6. Nitrogen oxides
    • 1.2.7. Lead and other toxic metals
    • 1.2.8. Volatile metals, including mercury
    • 1.2.9. Polycyclic aromatic hydrocarbons
    • 1.2.10. Other organic compounds, including VOCs, SVOCs, and particulate organic matter
    • 1.2.11. Mineral dust and fibres
    • 1.2.12. Bioaerosols
  • 1.3. Outdoor air pollution measurement methods
    • 1.3.1. Overview
    • 1.3.2. Types of air quality monitors
  • 1.4. Environmental occurrence and human exposure
    • 1.4.1. Outdoor pollutant concentrations
    • 1.4.2. Exposure assessment in epidemiological studies
    • 1.4.3. Personal exposure and biomarkers
    • 1.4.4. Occupational exposure of outdoor workers
  • 1.5. Guidelines and regulations
  • References
• 2. Cancer in Humans
  • 2.1. Cancer of the lung
    • 2.1.1. Cohort studies in North America
    • 2.1.2. Cohort studies in Europe
    • 2.1.3. Cohort studies in other regions
    • 2.1.4. Case–control studies
    • 2.1.5. Studies of outdoor workers and cancer of the lung
  • 2.2. Cancer of the urinary bladder
    • 2.2.1. Ecological studies
    • 2.2.2. Exposure to traffic
    • 2.2.3. Taxi drivers
    • 2.2.4. Bus drivers
    • 2.2.5. Truck drivers
    • 2.2.6. Other jobs with high exposure to outdoor air pollution
  • 2.3. Cancer of the breast
    • 2.3.1. Outdoor air pollution, including traffic emissions
    • 2.3.2. Emissions from waste incinerators, industrial facilities, or other sources
  • 2.4. Haematological malignancies: leukaemia and lymphoma
    • 2.4.1. Outdoor air pollution, including traffic emissions
    • 2.4.2. Emissions from waste incinerators
    • 2.4.3. Emissions from petrochemical plants or other industries
  • 2.5. Childhood cancer
    • 2.5.1. Case–control studies
  • 2.6. All cancers combined and cancers of other sites
    • 2.6.1. All cancers combined
    • 2.6.2. Cancers of other sites
  • References
• 3. Cancer in Experimental Animals
  • 3.1. Studies of components of outdoor air pollution in previous IARC Monographs
    • 3.1.1. Introduction
    • 3.1.2. Emissions from household combustion of coal or wood
    • 3.1.3. Exhaust emissions from diesel engines and gasoline engines
  • 3.2. Inhalation studies of exposure to outdoor air
    • 3.2.1. Mice exposed to outdoor air in São Paulo, Brazil
    • 3.2.2. Mice exposed to outdoor air in Los Angeles, USA
    • 3.2.3. Rats exposed to outdoor air in Los Angeles, USA
  • 3.3. Non-inhalation studies of exposure to outdoor air
    • 3.3.1. Intratracheal instillation
    • 3.3.2. Subcutaneous injection
    • 3.3.3. Skin application
    • 3.3.4. Intravenous injection
    • 3.3.5. Intraperitoneal injection
  • References
• 4. Mechanistic and Other Relevant Data
  • 4.1. Toxicokinetic data
    • 4.1.1. Introduction
    • 4.1.2. Particulate matter
    • 4.1.3. Organic molecules
    • 4.1.4. Inorganic gases
    • 4.1.5. Metals, inorganic dusts, and organic dusts
  • 4.2. Genetic and related effects
    • 4.2.1. Mutagenicity
    • 4.2.2. Cytogenetic effects
    • 4.2.3. DNA damage and protein adducts
    • 4.2.4. Gene expression
    • 4.2.5. Epigenetic effects
  • 4.3. Other data relevant to carcinogenicity
    • 4.3.1. Oxidative stress and inflammation
    • 4.3.2. Non-cancer effects
    • 4.3.3. Genotoxic and other deleterious effects on germ cells
    • 4.3.4. Oncogenic cell transformation
  • 4.4. Susceptible populations
    • 4.4.1. Polymorphisms in carcinogen-metabolizing genes
    • 4.4.2. Age and sex
    • 4.4.3. Socioeconomic status
    • 4.4.4. Increased risk in diseased populations
  • 4.5. Mechanistic considerations
    • 4.5.1. Outdoor air pollution
    • 4.5.2. Gases
    • 4.5.3. Volatile organic compounds
    • 4.5.4. Semivolatile organic compounds
    • 4.5.5. Airborne particulate matter
  • References
• 5. SUMMARY OF DATA REPORTED
  • 5.1. Exposure data
    • 5.1.1. The agent and its components
    • 5.1.2. Sources
    • 5.1.3. Measurement methods
    • 5.1.4. Environmental occurrence
    • 5.1.5. Exposure assessment in epidemiological studies
    • 5.1.6. Personal exposure
    • 5.1.7. Guidelines and regulations
  • 5.2. Human carcinogenicity data
    • 5.2.1. Cancer of the lung
    • 5.2.2. Cancer of the urinary bladder
    • 5.2.3. Other cancer sites
  • 5.3. Animal carcinogenicity data
    • 5.3.1. Studies of air pollutants evaluated in previous IARC Monographs
    • 5.3.2. Inhalation studies of exposure to outdoor air
    • 5.3.3. Non-inhalation studies of exposure to outdoor air
  • 5.4. Mechanistic and other relevant data
    • 5.4.1. Toxicokinetic considerations, including inhalation, deposition, clearance, and metabolism
    • 5.4.2. Genetic and related effects of outdoor air pollution
    • 5.4.3. Other data relevant to carcinogenicity
    • 5.4.4. Susceptibility
    • 5.4.5. Mechanistic considerations
• 6. EVALUATION
  • 6.1. Cancer in humans
  • 6.2. Cancer in experimental animals
  • 6.3. Overall evaluation
• List of Abbreviations

This publication represents the views and expert opinions of an IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, which met in Lyon, 8-15 October 2013

Lyon, France - 2016

IARC MONOGRAPHS

In 1969, the International Agency for Research on Cancer (IARC) initiated a programme on the evaluation of the carcinogenic risk of chemicals to humans involving the production of critically evaluated monographs on individual chemicals. The programme was subsequently expanded to include evaluations of carcinogenic risks associated with exposures to complex mixtures, lifestyle factors and biological and physical agents, as well as those in specific occupations. The objective of the programme is to elaborate and publish in the form of monographs critical reviews of data on carcinogenicity for agents to which humans are known to be exposed and on specific exposure situations; to evaluate these data in terms of human risk with the help of international working groups of experts in carcinogenesis and related fields; and to indicate where additional research efforts are needed. The lists of IARC evaluations are regularly updated and are available on the Internet at http://monographs.iarc.fr/.

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