ISSN-1996-918X Cross Mark Pak. J. Anal. Environ. Chem. Vol. 22, No. 1 (2021) 01 – 12 http://doi.org/10.21743/pjaec/2021.06.01 Ambient Air Quality, Pollutant Behavior, and Distribution Pattern in Rabigh City Using an Air Dispersion Model Aljahdali Mohammed Othman1*, Alhassan Abdullahi Bala1, Al-Ansari Ahmed Mohammed2,3 and Albeladi Mutaz Naser2 1Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21598 P.O. Box 80203, Saudi Arabia. 2Environmental Affairs, The General Authority of Meteorology and Environmental Protection, Jeddah 1358, P.O. Box 21431, Saudi Arabia. 3Department of Environmental Sciences, King Abdulaziz University, Jeddah 21598, P.O. Box 80208, Saudi Arabia. *Corresponding Author Email: [email protected] Received 11 November 2020, Revised 12 February 2021, Accepted 21 April 2021 -------------------------------------------------------------------------------------------------------------------------------------------- Abstract The rise in industrial development and modern technology is one of the major causes of atmospheric pollution, which negatively affects human health. In this study, meteorological conditions and atmospheric pollution dispersion in Rabigh city and its catchments were analyzed using measured data and an air quality dispersion model. The Hybrid Single-Particle Lagrangian Integrated Trajectory model was used to simulate the dispersion of atmospheric pollutants. A dataset from 2018 was analyzed to clarify the seasonal distributions of atmospheric pollutant concentrations in Rabigh and other areas (Thuwal and Khulais). A significant variation in atmospheric pollutants was recorded across the seasons, which may be caused by changes in meteorological conditions. Variations in other anthropogenic sources related to high population density or heavy traffic in the nearby road may also be involved in these fluctuations. Predictions indicated that pollutants would impact the Thuwal area (>50 µg m−3) and Khulais (>35 µg m−3) during the winter season and affect Thuwal (>20 µg m−3) and Rabigh (>20 µg m−3) during the fall season. The concentrations of pollutants were mostly negatively correlated with wind speed, except for carbon monoxide. We established variations in the seasonal concentration of pollutants and the effect of meteorological conditions on atmospheric pollutants for the year 2018 in the study area. Policymakers and stakeholders must provide solutions to mitigate the environmental effect of atmospheric pollution in Rabigh city, Thuwal, and Khulais for the health of inhabitants. Keywords: Source, Air pollution, Meteorological conditions, Dispersion model, Rabigh. -------------------------------------------------------------------------------------------------------------------------------------------- Introduction The majority of economic activities involving Air pollution has numerous sources; the use and transformation of energy cause air sources of air pollution can be natural, such as pollutants, thereby contaminating the volcanos and earthquakes, or man-made, such environment and harming human health [1]. as industrial and transportation activities [3]. The quality of air in urban environments is a The use of coal as a common fuel for heat and critical aspect of urban health status. People energy is one of the major sources of air living in urban settlements, especially pollution in industrial environments [4]. megacities, face severe health problems Various diseases, most of which are because of conditions related to air pollution respiratory, are common in industrial towns [2]. because of air pollution. Furthermore, the 2 Pak. J. Anal. Environ. Chem. Vol. 22, No. 1 (2021) increase in the number of people exposed to decrease in the life span of about 1.48 years in air pollutants may engender large public Saudi Arabia [11]. health problems [5]. Generally, sulfur dioxide (SO2), Outdoor air pollution is a primary hydrogen sulfide (H2S), NOx (e.g., nitric oxide environmental cause of the increase in [NO] and nitrogen dioxide [NO2]), carbon mortality from heart and lung diseases [6] and monoxide (CO), and ozone (O3) are pollutants of the occurrence of several diseases. In 2010, that represent the largest proportions of approximately 3.15 million reported deaths discharged gases into the air surrounding globally were associated with atmospheric industries such as refineries, sewage plants, pollution.In 2018, a study on the Global and power plants [11]. This study aimed to Burden of Disease estimated that 4.2 million evaluate the air quality status and predict deaths in 2015 were associated with outdoor pollutant behaviors and distributions using an air pollution [7]. air dispersion model. The use of a dispersion model is crucial to understand the behavior of The atmospheric pollution status of pollutants and the detrimental effects on Saudi Arabia is a growing concern, which has subjected neighborhood areas in Rabigh city. led the government to establish several authorities and agencies to monitor and report Materials and Methods the status of air pollution across the country. Site Description and Initial Survey The scientific community is responsible for increasing public awareness of air pollution Rabigh (Fig. 1) is an industrial city and investigating the quality of air in major situated on the eastern coast of the Red Sea, cities where industrial activities and modern Kingdom of Saudi Arabia. Extreme heat is lifestyles are increasing [8]. Several experienced during the summer, with another companies contribute substantially to rise in temperature during the winter season. atmospheric pollution in Saudi Arabian cities. The high relative humidity, especially during For instance, in Jeddah City, oil refineries and the summer season, is a key characteristic of cement companies have played a major role in Rabigh that has been attributed to limited rain atmospheric pollution for years, which poses a showers. Several industries, such as the Petro- threat to the residence of this city [9, 10]. Rabigh oil refinery, a power plant, and Arabian Cement, are located in Rabigh. These Several potential air pollution sources three industries are considered the three major far from Jeddah can affect and contribute to its sources of air pollution. The closeness of these air quality. For instance, Rabigh city industries to residential areas could expose (approximately 150 km to the north of Jeddah) inhabitants to risks associated with produced contains numerous sources of pollution, such air pollutants. as the Petro-Rabigh refinery, desalination plant, power plant, cement company, and Data on the atmospheric pollutants and plastic company. These sources affect the air meteorological conditions of the study area quality status and the intensity of air pollution (Rabigh city: 22°47ʹ57.37ʹʹ N and in Rabigh through gaseous discharges that 39°02ʹ00.83ʹʹ E) from December 2017 to contribute significantly to atmospheric November 2018 were obtained from the pollution in this region. This region is mostly General Authority of Meteorology and affected by particulate pollution and Saharan Environmental Protection (GAMEP) during dust, and an increase in their levels causes a the initial survey and pre simulation. Site Pak. J. Anal. Environ. Chem. Vol. 22, No. 1 (2021) 3 selection was based on the possibility or probability that these sites had been affected by existing emission sources. Settlements refer to receptors were also put into consideration during the selection of sites. The possible wind directions of the area and sites and year-round variations were also considered. Receptors considered in this study were Rabigh (22°47ʹ57.37ʹʹ N and 39°02ʹ00.83ʹʹ E), Thuwal (22°16ʹ59.85ʹʹ N and 39°06ʹ00.06ʹʹ E), and Khulais (22°09ʹ22.08ʹʹ N and 39°20ʹ05.57ʹʹ E) (Fig. 1 and 2). Data collected for the whole year was later grouped Figure 1. Map showing rabigh city with other settlements refer by season (i.e., winter, spring, summer, and to as receptors. fall). (a) (b) (c) (d) Figure 2. Modeled seasonal dispersion of pollutants in a) winter b) spring c) summer and d) fall 4 Pak. J. Anal. Environ. Chem. Vol. 22, No. 1 (2021) Data on atmospheric pollutants, such and approximately 500 particles or puffs were as SO2,H2S, NOx (NO and NO2), CO, and O3, released at 30-min intervals. The mixing of and meteorological conditions, such as turbulence and turbulent speed per unit time atmospheric temperature, relative humidity, was calculated using a short-range diffusivity and wind speed, were utilized. These method from stability parameters. Ground- measurements followed the standard GAMEP level concentrations were calculated for a methods [11], which adhere to US EPA minimum of 50 m in each grid cell in a protocols for ambient air quality monitoring. It horizontal pattern [10, 11]. involved biweekly calibrations, span verifications, repetitive and preventative A sequence of simulations for maintenance, and regular inspection of site dispersion was performed using a successive activities every 3 to 6 weeks. integration technique with seasonal initialization. The continuous release of Air Quality Dispersion Modeling emissions was recorded from the source during the entire period of simulation, and the The Hybrid Single-Particle Lagrangian simulated concentrations of atmospheric air Integrated Trajectory (HYSPLIT) [11] model quality collected were used to prepare a series was used to simulate the dispersion of of data for analysis regarding the atmospheric atmospheric pollutants. HYSPLIT is a tool