Air Pollution with Asbestos Fibers in Some Heavy Traffic Areas of Baghdad

This research was conducted to measure the levels of asbestos fibers in the air of some dense sites of Baghdad city, which were monitored in autumn 2019. Samples collection was conducted via directing air flow to a mixed cellulose ester membrane filter mounted on an open‐faced filter holder using sniffer with a low flow sampling pump. Air samples were collected from four studied areas selected in some high traffic areas of Baghdad city, two of them were located in Karkh (Al-Bayaa and AlShurta tunnel) and two in Rusafa (Al-Jadriya and Al-Meshin complex), then analyzed to determine concentrations of asbestos. Measuring of levels of asbestos fibers on the filters was carried out via using scanning electron microscope SEM together with an energy dispersive X‐ray system (EDS). The results showed that the lowest level was recorded in Al-Jadriya intersection (0.0352 fiber/ml), while the maximum concentration was in Al-Bayaa (0.156 f/ml). Asbestos average concentration in the ambient air of the four studied areas was 0.0718 f/ml, which exceeded the standards of world health organization (WHO) for air which is equal to 0.0022 f/ml. This may be due to the presence of crowded traffic and the occurrence of industries near the city. Therefore, plans such as management of traffic, changing locations of industrial sites, and products substitution can be effective in minimizing the concentrations of airborne fibers .

were identified and counted via using scanning electron microscope SEM (TESCAN DynaTOM, USA) and energy dispersive X-ray spectroscopy (EDX) [14]. Al-Bayaa is one of the popular areas in the capital Baghdad due to its population density. It is also one of the important commercial cities of the capital, considering the presence of the famous and well-known market (Street no. 20) as well as another large market (Shorjah Al-Karkh or Shorjah). This vital district is located southwest of Baghdad, at the edge of Karkh side of the Tigris River, and the highway (Airport Road) passes through it, which also leads to the central and southern governorates.
Al-Jadriya is a neighborhood in Baghdad, along the Tigris river. Al-Jadriya shares a significant but comparatively smaller part of the peninsula with Karrada. Al-Jadriya is at the south tip of the peninsula where Tigris river makes its major turn and heads to the north-east. It has many shopping malls, services and governmental institutions such as University of Baghdad and many hospitals, reflecting a picture of how the area is crowded. It is also noted that the region has scarce vegetation cover.

Al-Meshin complex
Al-Meshin complex, a commercial and industrial area characterized by the presence of many factories with different industrial activities from the public and private sectors, including the general company for electrical industries, general company for the manufacture of batteries and electric poles, a factory of dyes, and food industries. Also, this site is crowded with high numbers of vehicles and the use of electric generators.
Al-Shurta tunnel Al-Shurta is located southwest of Baghdad on the Karkh side, and it is an important commercial area in the region, with a large vegetable market and another for meat, along with commercial markets for clothes and mobile phones, and there are primary and secondary schools for both sexes.

Sampling Sites
Sites of sampling were selected by taking into account the density of traffic, intensity of population, pollutants of industrial origin, and direction of prevailing winds, as describe in Table-1. Sniffer (SKC MCS Flite, Swedish) is a device used in the field to collect samples of air pollutants such as asbestos fibers, heavy metals, and total suspended particles TSP and the measurement unit is l/min. Cellulose filters, before sampling, were dried at 40 C 0 for 30 minutes and then weighted to record initial weight (W i ) by using a sensitive balance [15]. In the sampling location, the filter placed in the sampler sniffer device was put on a height of one meter or more above the ground, to avoid the dust by the movement of wind, and with the direction of the prevailing winds in the region [6,16]. Then at the end of sampling operation, the exposed filter removed was from the sampler, kept inside a sealed container, and weighted in the laboratory, which represents the final weight (Wf) [1]. Four samples from each site were collected. A map of the city and the sampling sites is illustrated in Figure-1. The filters were placed inside sealed plastic petri dishes and transferred to the nano laboratory of the minerals research office at the Iraqi Ministry of Science and Technology for preparation as well as SEM and EDS analyses.

Preparation and Analysis of Samples
SEM along with EDS was used to detect the asbestos fibers. EDS method gives a spectrum showing elemental content of the fibers. Filters were analyzed via SEM according to the method of BS ISO 14966 [17]. The filters were mounted on sample stub with two sided copper adhesive tape and then placed on coating device (EMITECH K 450X, EM Technologies Ltd. England) for coating by gold. Thereafter, SEM magnifications ranging from 500 to 10000 were used to detect fibers with length higher than 5μm, diameter higher than 3μm, and ratio of length to diameter of 3/1 were considered as asbestos fibers. SEM sensitivity was reported to be in the scale of 0.0001 f/ml of air [18].

Measuring the Concentration of Asbestos Fibers
Based on SEM results, the concentrations of asbestos fibers were determined by following this equation [6,16,19]. C SEM = (1000*N*A) / (V* n* a) where C: Concentration of asbestos fibers in the air in fibers/milliliter (f/ml), N: Number of counted fibers, A: Effective area of the filter (the area that varied in color compared with other areas of the filter due to flow of air stream), which was equal to 385 mm 2 , V: Volume of sampled air (liter), n: Number of counted fields of images, and a: Calibrated area of each image (mm 2 ).

Results and Discussion
Based on the results of SEM, the concentration of the fibers was the highest in Al-Bayaa area (0.156 f/ml) and the lowest was in Al-Jadriya (0.0352 f/ml), as shown in Figure-2. All these results exceed the standards level of the WHO which was set to be equal to 0.0022 f/ml. Those levels are higher than those measured in some other countries of the world. For example, in Romania, Anca reported an average level of 0.02702 f/ml from several points in Bucharest [20]. While in some cities in Italy, Gualtieri and his colleagues recorded an average level of 0.00056 f/ml [21,22]. Studies in Iran found that the average level of asbestos fibers was between 0.01364 f/ml and 0.01224 f/ml [6,16]. An examples of an SEM image of asbestos fibers is shown in Figure-3. The highest level of asbestos was founded in Al-Bayaa, which is attributed to the commercial nature of this region, with the activities of repairing and construction of streets that led to densely-polluted roads In addition, it can be attributed to the heavily-crowded bus garages located near this area. Other high polluted site was Al-Shurta tunnel, which is an industrial region with heavy traffic in most times, in addition to the presence of old buildings that are considered as an important source of asbestos in the air. The others two studied locations, Al-Jadriya and Al-Meshin complex, also recorded high levels of asbestos fibers due to the fact that they are commercial areas characterized by congested traffic. It is important to mention that natural sources such as weathering and erosion are among the important reasons for the spread of asbestos in the surrounding air [22,23].

Relationship between Asbestos Level and Meteorological Factors
Some parameters, such as speed of wind, temperature, and humidity were collected for each sampling day and correlated with the concentration of airborne asbestos fibers. The results revealed no notable relationship among levels of asbestos fibers and meteorological parameters [24,25]. These results are given in Table-3.

Energy Dispersive X-Ray Spectrometry (EDX) Results
Depending on the results obtained from the EDX analysis, the chemical composition of the asbestos fibers consisted mainly of magnesium (Mg) and silica (Si). Accordingly, all samples collected from the four studied areas contained Mg and Si in their chemical composition. The results showed Mg content between 0.785 -0.98%, while the proportion of Si was between 21% -31%. The chemical composition of the asbestos fibers is shown in Table-hj 4 and Figures-4, 5, 6 and 7. The results obtained from EDX analysis confirmed that asbestos fibers contained the elements that make them the most dangerous type of pollutants to human health [26,27]; due to the type of chemical bonding between these elements, it is difficult to eliminate the fibers from a contaminated person because of their ability to bond tightly with tissues of the lungs [28,29,30].

Conclusions
The data obtained from this study indicated that the levels of the fibers of asbestos in Baghdad are above the permitted limit for ambient air suggested by the WHO. In addition, it is higher than that recommended for the European countries. The presence of different anthropogenic sources of asbestos fibers as well as heavy traffic inside and in the surroundings of the cities are considered as the major causes for the high concentrations of asbestos fibers in the air and, hence, main causes of diseases. The high level of pollution by asbestos is attributed to the commercial and industrial nature of the studied areas. Owing to the high concentration of asbestos fibers, the health of the surrounding community, occupational groups, taxi drivers and traffic officers can be negatively affected. Also low speed of wind, little rain, desertification, and reduced green areas have possibly led to low dispersion, precipitation, and self-purification of atmosphere, which resulted in accumulation of air pollutants over Baghdad city.
Therefore, the better solutions to reduce asbestos emission are represented by management of traffic by preventing the presence of heavy cars in the city at rush hours of traffic, replacing asbestos with safe substances in different materials like gear and pads of clutch, development of green spaces that can help to reduce and even eliminate asbestos fibers and other pollutants emission from the environment. Asbestos ban is also one of the important options for eliminating asbestos pollution. In Iraq, the country of the current study, asbestos was banned in 2016, according to Iraqi government's