Assessment of particulate matter and inorganic gaseous pollutants in Bou-Ismail, Tipaza City, Algeria, including levels and health risks.

Abstract

This research presents a comprehensive evaluation of air pollution levels linked to vehicular traffic in Bou-Ismail using a  statistical methods to examine correlations, trends, and relationships between pollutant concentrations and meteorological variables, as well as to assess factors contributing to particulate pollution in the Bou-Ismail area. A monitoring station was established along a major roadway for six months from December 16, 2015, to June 29, 2016, to assess particulate matter (PM_2.5 and PM₁₀), ozone, sulphur dioxide, carbon monoxide, nitrogen oxides, and volatile organic compounds to investigate the factors and variables that contribute to particulate pollution in the Bou-Ismail area. The average concentrations of SO₂ and NO₂ for the campaign were equal to 0.14 and 12.07 ppb, respectively, respecting the national guidelines. Concentration in this study for PM₁₀ and PM_2.5 were 20.2 and 8.9 µg/m³. The predictive models applied to evaluate particulate matter concentrations demonstrated strong performance, yielding coefficient of determination (R²) values exceeding 0.83. No correlation was seen between PM and WS (wind speed), while O₃ concentration was positively correlated with temperature. PC1 (35.38%) indicates that cars contribute the most to local air pollution, with significant particle and petrol emissions but low VOCs. PC2 (21.75%) relates CO to vehicles, while buildings have the most VOCs, followed by transport and agriculture. The PM_2.5 Air Quality Index (AQI) exceeded guideline thresholds on more than 42 days out of 196 days recorded, which indicates that the air quality is unhealthy to very unhealthy for sensitive groups. The hazard quotient (HQ) in our investigation was below 1, which signifies a tolerable level of risk. The average monthly ELCR (Excess lifetime cancer risk) of PM_2.5 in this research surpassed the recommended guideline value of 1.0E-06.  According to HYSPLIT back-trajectory investigations, western European air pollution reached western Algeria via Portugal and southern Spain. Mauritanian air masses may have carried Saharan dust to Mali and south Algeria. The second to last phase saw eastern Algiers air masses migrate north into the Mediterranean, signifying pollution export. PM_2.5 and PM₁₀ concentrations increase in westerly and southerly airflows.