Hydrocarbons in the atmospheric gas phase of a coastal city in Tunisia: Levels, gas-particle partitioning, and health risk assessment

Badreddine Barhoumi; Catherine Guigue; Soufiane Touil; Boris Johnson-Restrepo; Mohamed Ridha Driss; Marc Tedetti

doi:10.1016/j.scitotenv.2023.162986

Hydrocarbons in the atmospheric gas phase of a coastal city in Tunisia: Levels, gas-particle partitioning, and health risk assessment

Sci Total Environ. 2023 Jun 25:879:162986. doi: 10.1016/j.scitotenv.2023.162986. Epub 2023 Mar 22.

Authors

Badreddine Barhoumi¹, Catherine Guigue², Soufiane Touil³, Boris Johnson-Restrepo⁴, Mohamed Ridha Driss³, Marc Tedetti²

Affiliations

¹ Laboratory of Hetero-Organic Compounds and Nanostructured Materials (LR18ES11), Department of Chemistry, Faculty of Sciences of Bizerte, University of Carthage, 7021 Zarzouna, Tunisia; Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, 13288 Marseille, France. Electronic address: barhoumibadredine@yahoo.fr.
² Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, 13288 Marseille, France.
³ Laboratory of Hetero-Organic Compounds and Nanostructured Materials (LR18ES11), Department of Chemistry, Faculty of Sciences of Bizerte, University of Carthage, 7021 Zarzouna, Tunisia.
⁴ Environmental Chemistry Research Group, School of Exact and Natural Sciences, University Campus of San Pablo, University of Cartagena, Zaragocilla, Carrera 50 No. 24-99, Cartagena, 130015, Colombia.

PMID: 36958548
DOI: 10.1016/j.scitotenv.2023.162986

Abstract

Many studies have focused on aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (AHs and PAHs) in different environmental compartments, especially atmospheric particles (aerosols), due to their adverse effects on the environment and human health. However, much less information is currently available on the content of AHs and PAHs in the atmospheric gas phase, which is a major reservoir of volatile and photoreactive compounds. Here, for the first time, we assessed the levels, gas-particle partitioning, human health risks and seasonal variations of AHs and PAHs in the atmospheric gas-phase of Bizerte city (Tunisia, North Africa) over a one-year period (March 2015-January 2016). Σ₃₄PAH concentration in the gas phase over the period ranged from 6.7 to 90.6 ng m^-3 and on average was 2.5 times higher in the cold season than in the warm season. Σ₂₈AH concentration in the gas phase over the period ranged from 14.0 to 35.9 ng m^-3, with no clear seasonal variations. In the gas phase, hydrocarbons were dominated by low-molecular-weight (LMW) compounds, i.e. 3- and 4-ring for PAHs and < n-C₂₄ for AHs. Gas-phase concentrations of PAHs and AHs accounted for up to 80 % of the total (gas + particle phases) atmospheric concentrations of PAHs and AHs. Further analysis of gas-particle partitioning showed that LMW hydrocarbons preferential accumulated in the gas phase, and that gas-particle partitioning was not in equilibrium but dominated by absorption processes into the aerosol organic matter. Benzo[a]pyrene toxic equivalency quotient (BaP-TEQ) in the gas phase represented on average 37 % of the total atmospheric BaP-TEQ concentration, which was always higher in the cold season. Atmospheric gas is a significant factor in the risks of cancer associated with inhalation of ambient air. The Monte Carlo simulation-based exposure assessment model predicted that outdoor air exposure to PAHs does not pose a cancer risk to infants, but the children, adolescent, and adult populations may face a lower cancer risk during the warm season and a higher risk in the cold season.

Keywords: Atmospheric pollution; Gas phase; Gas–particle partitioning; Health risk; Hydrocarbons; North Africa.

MeSH terms

Adolescent
Adult
Aerosols / analysis
Air Pollutants* / analysis
Child
Environmental Monitoring
Humans
Neoplasms*
Particulate Matter / analysis
Polycyclic Aromatic Hydrocarbons* / analysis
Risk Assessment
Tunisia

Substances

Air Pollutants
Polycyclic Aromatic Hydrocarbons
Aerosols
Particulate Matter