Elsevier

Environment International

Volume 60, October 2013, Pages 71-80
Environment International

Review
A review of airborne polycyclic aromatic hydrocarbons (PAHs) and their human health effects

https://doi.org/10.1016/j.envint.2013.07.019Get rights and content

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are a large group of organic compounds comprised of two or more fused benzene rings arranged in various configurations. PAHs are widespread environmental contaminants formed as a result of incomplete combustion of organic materials such as fossil fuels. The occurrence of PAHs in ambient air is an increasing concern because of their carcinogenicity and mutagenicity. Although emissions and allowable concentrations of PAHs in air are now regulated, the health risk posed by PAH exposure suggests a continuing need for their control through air quality management. In light of the environmental significance of PAH exposure, this review offers an overview of PAH properties, fates, transformations, human exposure, and health effects (acute and chronic) associated with their emission to the atmosphere. Biomarkers of PAH exposure and their significance are also discussed.

Introduction

Polycyclic aromatic hydrocarbons (PAHs) are a large group of chemicals with 2 to 7 fused aromatic rings (Arey and Atkinson, 2003, Di-Toro et al., 2000). Some PAHs are well known as carcinogens, mutagens, and teratogens and therefore pose a serious threat to the health and the well-being of humans (Boström et al., 2002). The physico-chemical properties of PAHs makes them highly mobile in the environment, allowing them to distribute across air, soil, and water bodies where their presence is ubiquitous (Baklanov et al., 2007, Latimer and Zheng, 2003, Sverdrup et al., 2002).

Polycyclic aromatic hydrocarbons are released into the environment from both natural and anthropogenic sources (WHO, 2003). The widespread occurrence of PAHs is due to their production by virtually all types of combustion of organic materials. The anthropogenic sources of PAHs and their derivatives are diverse and include: incomplete burning of fuels, garbage, or other organic substances such as tobacco and plant material. (Zhang and Tao, 2009). Likewise, forest fires and volcanic eruptions can also contribute to the natural budget of the PAH inventory (Zhang and Tao, 2009).

PAHs are widely distributed in the atmosphere and were one of the first atmospheric pollutants designated as a suspected carcinogen. The PAHs entering the atmosphere can be transported over long distances before deposition through atmospheric precipitation onto soils, vegetation or waters (Ravindra et al., 2008). As molecular weight increases, the carcinogenicity of PAHs also increases with reducing acute toxicity. The most potent PAH carcinogens have been identified to include benzo[a]anthracene, benzo[a]pyrene, and dibenz[ah]anthracene (Armstrong et al., 2004, Bach et al., 2003, CCME (Canadian Council of Ministers of the Environment), 2010). Given the ubiquitous presence of PAHs in the environment and the health risk associated with their exposure, the aim of this paper is to review contemporary information on the properties, fate, and risk associated with the presence of these compounds in the atmosphere.

Section snippets

Chemical characteristics of PAHs

PAHs are organic substances made up of carbon and hydrogen atoms grouped into at least two condensed or fused aromatic ring structures (CCME, 2010). They can be divided into two categories: low molecular weight compounds consisting of fewer than four rings and high molecular weight compounds of four or more rings. Pure PAHs are usually colored, crystalline solids at ambient temperature (Masih et al., 2012). The physical properties of PAHs vary with their molecular weight and structure. The

Fate and transformations of PAHs in atmosphere

The behavior of PAHs in the atmosphere depends on complex physico-chemical reactions, interactions with other pollutants, photochemical transformations, and dry and wet deposition (Delgado Saborit et al., 2010, Zhong and Zhu, 2013, Zhu et al., 2009). PAHs in the ambient air exist in vapor phase or adsorb into airborne particulate matter depending on the atmospheric conditions (ambient temperature, relative humidity, etc.), the nature (i.e., origin and properties) of the aerosol, and the

Atmosphere

The presence of PAHs in the environment is due primarily to emissions from incomplete combustion of carbon containing fuels from natural, industrial, commercial, vehicular and residential sources. Although low molecular weight PAHs are found more commonly as vapor in the troposphere, they can also exist in the particulate phase through condensation after emission. In contrast, the high molecular weight PAHs are dominantly found in the particulate phase.

Detailed estimates of PAH emissions in the

Human exposure to polycyclic aromatic hydrocarbons

The major route of exposure to PAHs in the general population is from breathing ambient (and indoor) air, eating food containing PAHs, smoking cigarettes, or breathing smoke from open fireplaces (ACGIH, 2005). A variety of PAHs from tobacco smoke are suspected human carcinogens (Lannerö et al., 2008). For non-smokers, the main route of exposure is through food. Processing (such as drying and smoking) and cooking of foods at high temperatures (grilling, roasting, and frying) are major sources of

Acute or short-term health effects

The acute effects of PAHs on human health will depend mainly on the extent of exposure (e.g., length of time), the concentration of PAHs during exposure, the toxicity of the PAHs, and the route of exposure, e.g., via inhalation, ingestion, or skin contact (ACGIH, 2005). Many other factors may also affect health impacts. These include factors such as pre-existing health conditions and age. Short-term exposure to PAHs also has been reported to cause impaired lung function in asthmatics and

Chronic or long-term health effects

For workers exposed to mixtures of PAHs and other work place chemicals, a series of health problems (an increased risk of skin, lung, bladder, and gastrointestinal cancers) have been reported (Bach et al., 2003, Boffetta et al., 1997, Diggs et al., 2011, Olsson et al., 2010). Long-term exposure to low levels of some PAHs (e.g., pyrene and BaP) has been identified as the cause of cancer in laboratory animals (Diggs et al., 2012). Animal studies have also shown adverse reproductive and

Biomarkers of exposure to PAH

Several methods have been developed to assess internal levels of PAHs after exposure from the environment and workplaces. In many studies, 1-Hydroxypyrene, a metabolite of pyrene, has been widely used as urinary biomarker of PAH exposure (Jongeneelen, 2001, Mcclean et al., 2004, McClean et al., 2012, Sobus et al., 2009, Stroomberg et al., 2003). Most importantly, pyrene is present in all PAH mixtures at relatively high concentrations (2–10% of the total PAH load). In certain environments, the

Regulation

PAH compounds are typically constituents of complex mixtures. Some PAHs are potent carcinogens, which may interact with a number of other compounds. U.S. government agencies have established standards that are relevant to PAH exposures in the workplace and the environment. There is a standard relating to PAH in the workplace as well as in drinking water. The National Institute for Occupational Safety and Health (NIOSH) has recommended that the workplace exposure limit for PAHs should be set at

Conclusion

To learn more about the significance of PAHs in the environment, enormous efforts have been devoted to quantifying the level of emissions, assessing ambient concentrations, characterizing speciation, and determining temporal/spatial trends. Currently, there is broad agreement on the main emission sources but harmonization of emission estimation and reporting is still at an early stage of development.

Data from a number of occupational health studies suggest that there is an association between

Acknowledgment

This study was supported by a grant from the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (MEST) (No. 2009-0093848).

References (104)

  • L. Nylund et al.

    Application of a semi-automated SOS chromotest for measuring genotoxicities of complex environmental mixtures containing polycyclic aromatic hydrocarbons

    Mutat Res

    (1992)
  • J.S. Park et al.

    Atmospheric distribution of polycyclic aromatic hydrocarbons and deposition to Galveston Bay, Texas, USA

    Atmos Environ

    (2001)
  • F. Perera et al.

    Prenatal environmental exposures, epigenetics, and disease

    Reprod Toxicol

    (2011)
  • M. Possanzini et al.

    Determination of phase-distributed PAH in Rome ambient air by denuder/GC-MS method

    Atmos Environ

    (2004)
  • K. Ravindra et al.

    Atmospheric polycyclic aromatic hydrocarbons: source attribution, emission factors and regulation

    Atmos Environ

    (2008)
  • S.K. Samanta et al.

    Polycyclic aromatic hydrocarbons: environmental pollution and bioremediation

    Trends Biotechnol

    (2002)
  • Y. Wang et al.

    Polycyclic aromatic hydrocarbons (PAHs) in soils and vegetation near an e-waste recycling site in South China: concentration, distribution, source, and risk assessment

    Sci Total Environ

    (2012)
  • P.A. White

    The genotoxicity of priority polycyclic aromatic hydrocarbons in complex mixtures

    Mutat Res

    (2002)
  • ACGIH (American Conference of Governmental Industrial Hygienists)

    Polycyclic aromatic hydrocarbons (PAHs) biologic exposure indices (BEI) Cincinnati

  • J. Arey et al.

    Photochemical reactions of PAH in the atmosphere

  • B.G. Armstrong et al.

    Cancer risk following exposure to polycyclic aromatic hydrocarbons (PAHs): a meta-analysis. Rep No 068. Sudbury, UK: this health and safety executive

  • B.G. Armstrong et al.

    Lung cancer risk after exposure to polycyclic aromatic hydrocarbons: a review and meta-analysis

    Environ Health Perspect

    (2004)
  • ATSDR (Agency for Toxic Substances, Disease Registry)

    Toxicological profile for polycyclic aromatic hydrocarbons

    US Department of Health and Human Services

    (1995)
  • P.B. Bach et al.

    Screening for lung cancer: a review of the current literature

    Chest

    (2003)
  • A. Baklanov et al.

    Integrated systems for forecasting urban meteorology, air pollution and population exposure

    Atmos Chem Phys

    (2007)
  • D. Boers et al.

    The influence of occupational exposure to pesticides, polycyclic aromatic hydrocarbons, diesel exhaust, metal dust, metal fumes, and mineral oil on prostate cancer: a prospective cohort study

    Occup Environ Med

    (2005)
  • P. Boffetta et al.

    Cancer risk from occupational and environmental exposure to polycyclic aromatic hydrocarbons

    Cancer Causes Control

    (1997)
  • C.-E. Boström et al.

    Cancer risk assessment, indicators and guidelines for polycyclic aromatic hydrocarbons in ambient air

    Environ Health Perspect

    (2002)
  • A.S. Brown et al.

    Correlations in polycyclic aromatic hydrocarbon (PAH) concentrations in UK ambient air and implications for source apportionment

    J Environ Monit

    (2012)
  • R.J.C. Brown et al.

    Principal component analysis as an outlier detection tool for polycyclic aromatic hydrocarbon concentrations in ambient air

    Water Air Soil Pollut

    (2012)
  • A.S. Brown et al.

    Twenty years of measurement of polycyclic aromatic hydrocarbons (PAHs) in UK ambient air by nationwide air quality networks

    Environ Sci Process Impacts

    (2013)
  • R.J.C. Brown et al.

    A temperature-based approach to predicting lost data

    Environ Sci Process Impacts

    (2013)
  • R.J.C. Brown

    Data loss from time series of pollutants in ambient air exhibiting seasonality: consequences and strategies for data prediction from highly seasonal pollutant data sets

    Environ Sci Process Impacts

    (2013)
  • T.J. Buckley et al.

    An examination of the time course from human dietary exposure to polycyclic aromatic hydrocarbons to urinary elimination of 1-hydroxypyrene

    Br J Ind Med

    (1992)
  • D.M. Butterfield et al.

    Polycyclic aromatic hydrocarbons in Northern Ireland

    NPL Report AS 66, NPL, Teddington

    (2012)
  • CCME (Canadian Council of Ministers of the Environment)

    Canadian soil quality guidelines for potentially carcinogenic and other PAHs: scientific criteria document

    (2010)
  • CEN (European Committee for Standardisation)

    EN 15980 — air quality — determination of the deposition of benz[a]anthracene, benzo[b]fluoranthene, benzo[j]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenz[a,h]anthracene and indeno[1,2,3-cd]pyrene., Brussels

    (2011)
  • B.H. Chen et al.

    Formation of polycyclic aromatic hydrocarbons in the smoke from heated model lipids and food lipids

    J Agric Food Chem

    (2001)
  • R.W. Clapp et al.

    Environmental and occupational causes of cancer: new evidence 2005–2007

    Rev Environ Health

    (2008)
  • J.M. Delgado Saborit et al.

    Determination of atmospheric particulate-phase polycyclic aromatic hydrocarbons from low volume air samples

    Anal Methods

    (2010)
  • D.L. Diggs et al.

    Polycyclic aromatic hydrocarbons and digestive tract cancers: a perspective

    J Environ Sci Health C Environ Carcinog Ecotoxicol Rev

    (2011)
  • D.L. Diggs et al.

    Tumor microsomal metabolism of the food toxicant, benzo(a)pyrene, in ApcMin mouse model of colon cancer

    Tumor Biol

    (2012)
  • D.M. Di-Toro et al.

    Technical basis for narcotic chemicals and polycyclic aromatic hydrocarbon criteria. I. Water and tissue

    Environ Toxicol Chem

    (2000)
  • T. Duarte-Salles et al.

    Smoking during pregnancy is associated with higher dietary intake of polycyclic aromatic hydrocarbons and poor diet quality

    Public Health Nutr

    (2010)
  • S.C. Edwards et al.

    Prenatal exposure to airborne polycyclic aromatic hydrocarbons and children's intelligence at 5 years of age in a prospective cohort study in Poland

    Environ Health Perspect

    (2010)
  • European Commission

    Directive 2004/107/EC of the European Parliament and of the Council of 15 December 2004 relating to arsenic, cadmium, mercury, nickel and polycyclic aromatic hydrocarbons in ambient air

    Off J

    (2005)
  • European Environment Agency
  • W.A. Garcia-Suastegui et al.

    Seasonal variations in the levels of PAH-DNA adducts in young adults living in Mexico City

    Mutagenesis

    (2011)
  • M.J. Gunter et al.

    Leukocyte polycyclic aromatic hydrocarbon-DNA adduct formation and colorectal adenoma

    Carcinogenesis

    (2007)
  • S.S. Hecht

    Tobacco smoke carcinogens and lung cancer

    J Natl Cancer Inst

    (1999)
  • Cited by (1801)

    View all citing articles on Scopus
    View full text