Polycyclic Aromatic Hydrocarbons in the GCC Region: Exposure and Health Risk Assessment

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are persistent toxic pollutants of increasing concern in Gulf Cooperation Council (GCC) region due to rapid urbanization, industrialization and the dominance of oil and gas extraction activities. This review synthesizes evidence from eligible studies published between 2020 and 2025 that assessed PAH contamination in environmental dust from households, cars, mosques, and sporting walkways. Across these environments, total PAH concentrations ranged from several hundred to over 37,000 ng/g, frequently exceeding international safety benchmarks. While health risk assessments revealed benzo[a]pyrene-equivalent toxicity (BaP-TEQ) values reaching critical threshold of 700 ng/g in some scenarios, incremental lifetime cancer risks (ILCRs) in all the assessed studies spanned 10?? to 10?³, exceeding the U.S. Environmental Protection Agency’s acceptable limit of 10??. Dermal contact and ingestion were consistently the dominant exposure pathways, particularly for children and occupationally exposed groups such as taxi drivers. Smoking, incense burning, and proximity to high-traffic areas intensified PAH burdens. While non-carcinogenic risks were less frequently assessed, hazard index values(HI) occasionally exceeded the safety threshold of 1.0. These findings highlight substantial deficiency of research on chemical exposure-based health risk assessment across GCC countries beyond Kuwait and Kingdom of Saudi Arabia (KSA) and underscore the need for coordinated region-specific health risk frameworks to mitigate PAH exposure risks.

Introduction

• Polycyclic Aromatic Hydrocarbons (PAHs) are toxic semi-volatile organic compounds (SVOCs) formed during incomplete combustion of fossil fuels and biomass.

• They are environmental contaminants with serious health impacts: endocrine disruption, respiratory and neurological issues, hormonal imbalances, and cancer.

• In the Gulf Cooperation Council (GCC) region, PAHs are widespread due to heavy fossil fuel use and frequent dust storms, which facilitate their distribution and accumulation in dust.

2. Research Gap & Objective

• Existing studies in the MENA and GCC regions either:

  • Focused on contaminant distribution, or

  • Used biomonitoring without assessing environmental exposure routes.

• Gap identified: No comprehensive regional health risk assessment using environmental data (especially dust).

• Objective of the review: To assess human health risks from PAH-contaminated dust exposure in the GCC across multiple pathways:

  • Inhalation

  • Ingestion

  • Dermal contact

3. Methodology

• Systematic review using Scopus with strict inclusion criteria:

  • Years: 2020–2025

  • Focus: Dust as the medium

  • Countries: Any GCC member state

  • Data: Environmental PAH concentrations

  • Outcome: Quantitative health risk metrics

• Results: 15 studies found, 6 met criteria, all from Saudi Arabia (4) and Kuwait (2), indicating limited research in other GCC countries.

4. Key Health Risk Indicators

A. Carcinogenic Risk

• Evaluated using:

  • Benzo[a]pyrene Toxic Equivalents (BaP-TEQ)

  • Benzo[a]pyrene Mutagenic Equivalents (BaP-MEQ)

  • Incremental Lifetime Cancer Risk (ILCR)

  • Total Cancer Risk (CR)

i. BaP-TEQ

• Indicates the cancer-causing potential of PAH mixtures.

• Two calculation methods:

  • Using Toxic Equivalency Factors (TEFs) for all PAHs

  • Using only highly potent PAHs (e.g., BaA, BbF, BaP, etc.)

Risk Interpretation (BaP-TEQ):

ii. BaP-MEQ

• Reflects mutagenic potential of PAHs using Mutagenic Equivalency Factors (MEFs).

• Same calculation method as TEQ but with MEFs.

B. Incremental Lifetime Cancer Risk (ILCR)

• Probability of developing cancer due to lifetime exposure.

• ILCR = Daily Intake (DI) × Slope Factor (SF)

• Total cancer risk (CR) is sum of ILCRs for:

  • Inhalation

  • Ingestion

  • Dermal contact

Risk Interpretation (US EPA):

5. Non-Carcinogenic Risk Indicators

A. Hazard Quotient (HQ)

• Measures risk of non-cancer health effects for a single exposure route.

• HQ = Daily Intake (DI) / Reference Dose (RFD)

B. Hazard Index (HI)

• Sum of HQs across multiple exposure routes.

• HI = ∑HQ

Risk Interpretation:

6. Parameters for Risk Assessment

• Parameters vary for adults, children, and occupational groups (e.g., drivers), including:

  • Ingestion rates

  • Skin surface area & adherence factors

  • Exposure duration & frequency

  • Body weight

  • Inhalation rates

• Cancer slope factors (SFs) used:

  • Ingestion: 7.3

  • Inhalation: 3.85

  • Dermal: 25

7. Key Findings

• Dust is a major carrier of PAHs in the GCC, making it a critical focus for monitoring.

• BaP-TEQ and BaP-MEQ are useful for evaluating carcinogenic and mutagenic risks.

• In most reviewed studies:

  • PAH levels exceeded safe thresholds.

  • Carcinogenic and non-carcinogenic risks were evident, especially for children and sensitive populations.

• Kuwait and Saudi Arabia are better studied; other GCC countries lack data.

8. Conclusion & Policy Implications

• This review fills a critical gap by assessing PAH-related health risks in the dust pathway across the GCC.

• Results support:

  • Urgent need for broader environmental health monitoring.

  • Development of targeted mitigation strategies.

  • Informed policymaking for environmental safety in arid urban regions.

Conclusion

This review confirms that GCC populations are exposed to PAHs at levels exceeding international safety thresholds, particularly for carcinogenic risks. Children and workers with high exposure frequency are especially vulnerable. Based on the findings of this review , the following are recommended: 1) Establishing GCC-wide monitoring programs covering air, water, soil, food, and indoor environments. 2) Developing region-specific health risk guidelines that reflect unique environmental and cultural conditions. 3) Integrating environmental monitoring with biomonitoring and epidemiological studies. 4) Implementing stricter emission and waste management regulations while promoting public awareness of exposure risks. By adopting coordinated monitoring and policy frameworks, GCC states can mitigate risks, protect public health, and enhance environmental resilience in the face of chemical exposure.

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Copyright

Copyright © 2025 Koko, Isra , Ghanimeh, Sophia, AlMomani, Fares . This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.