Assessment of air quality for Kerbala city using field survey

The main objectives of this work are monitoring and analyzing air pollutant gases in Karbala city like (O3, SO2, H2S, VOCS, TSP, CO, CO2, NO2, PM1, PM2.5, PM7 and PM10). In this study, 11 deferent locations with 22 monitoring site has been selected to measuring the concentrations of air pollutants. The measuring period was six months starting from December (2015) to May (2016). The concentration results of TSP were more than Iraqi and world standard during April and May. The concentrations of CO recorded high values at the north of the city. The maximum concentration of NO2 was exceeding (1.5 ppm) at April 2016, while the minimum value was reached to (0.1 ppm) in many locations. The values of O3 were within international and Iraqi standard limits while the SO2 concentrations were above the International standard limits. High concentration of CO2 were founded in the north site of Karbala. There were high H2S concentrations in all sites, H2S values were between (0.006 ppm – 1.81 ppm) during the period study, which were exceeding acceptable limits value of the international. There is variation in the volatile organic compounds (VOCs), the highest concentration for VOCs was about (20 ppm) at December 2015. The minimum concentrations of VOCs were recorded during March 2016. In all sites the concentrations were within the acceptable limits (3 ppm). The results of field tests of air sites show that the highest pollutants concentrations were in December, April and May months, whereas lower concentrations of pollutants are observed during the remainder of the study, especially in March.


INTRODUCTION
Throughout the world, air pollution is a matter of concern at all levels. The worldwide epidemiological study on the effect of air pollution had revealed that gaseous pollutants and particulate matter had enough potential to cause severe health effect like respiratory, cardiovascular diseases and cardio pulmonary mortality [1,2]. Being a serious matter of concern now-a-day, a systematic monitoring program all over the world especially in urban cities are urgently needed as the level of air pollution is increasing rapidly in many areas of mega cities of the developing world [3]. It was found that the modernization and industrialization of developing countries had led to the increase use of fossil fuels and their derivatives. As such, developing countries were confronted with the great challenge of controlling the atmospheric pollution especially in the rapidly growing mega cities. Concern about air pollution in urban regions is receiving increasing importance worldwide, especially pollution by gaseous and particulate trace metals [4,5]. The urban centers might be viewed as dense sources of enormous anthropogenic emissions of pollutants, which could alter the atmospheric composition, chemistry and life cycles in its downwind regimes, extending over several hundred kilometers [6]. It had been found that world motor vehicle population growth had reached 700 million in the year 2000 [7]. Petrol and diesels engines of motor vehicles were found to emit a wide variety pollutants, principally, oxide of nitrogen (NOx) which had an increasing impact on urban air quality [8].

OBJECTIVE
The main objective of this work are measuring and analyzing air pollutant gases in Karbala city like (O 3 , SO 2

STUDY AREA
Karbala is an Iraqi city, located about 100 km southwest of Baghdad. Karbala is the capital of Karbala Governorate, the geographic location of the city is 32.61°N, 44.08°E, and has an estimated population of (1,151,200) people (Statistical Center Organization in Karbala, 2014). Karbala was one of Iraq's wealthiest cities, profiting from both religious visitors and its agricultural produce, especially dates. It split into two districts, "Old Karbala", the religious center, and "New Karbala", the residential district containing Islamic

METHODOLOGY AND SAMPLING
In this study, 11 deferent locations with 22 monitoring site has been selected to measuring the concentrations of air pollutants. The distribution of selected sites was to cover nearly all the area of Karbala city, including the mainly crowded intersections and different land classifications (residential, commercial, vegetation, barren and industrial areas). The measurement of concentrations has been done by using different devices to monitoring the concentrations of air pollutants such as (AEROCET 531, GIG450 devices, NOVA600 devices, MiniRAE 3000, Eco Sensors UV-100) as shown in Figure (3), which measure (TSP, PM 1 , PM 2.5 , PM 7 , PM 10 , H 2 S, NO 2 , SO 2 , CO 2 , CO, VOCs, O 3 ). The site locations were located by using Garmin GPS72. The measuring period was six months starting from December (2015) to May (2016).

RESULTS AND ANALYSIS
The results of this study deals with air pollutants (TSP, PM 1 , PM 2.5 , PM 7 , PM 10 , H 2 S, NO 2 , SO 2 , CO 2 , CO, VOCs, O 3 ) for six months starting from December 2015 to May 2016 and analysis their results. The average gases, TSP and PM concentrations measurements of air in the sites of the study area for six months are shown in Table (

Total Suspended Particulate (TSP)
The concentration of total suspended particulate (TSP) from (22) locations were obtained as shown in Figure  (4) below. The figure demonstrate high values of TSP above WHO standards in the April and May due to the increase the numbers of the cars.

Particulate Matter (PMs)
There is appositive relationship between (TSP) and particular matter Figures (5a and 5b) shows the concentrations of PM10 and PM2.5 were withen the WHO standards.

Carbon Monoxide (CO)
It was notice that highest concentrations of CO was in the north of city at locations No. (10, 11, 12, 13, 14, and 15) during the study period as shown in Figure (6) below. Although these value are high but within acceptable limits of Iraqi standards that is (35 ppm) and exceeding international standards, which is (9 ppm). The remaining sites ranging between (0.15 ppm -14 ppm) and were within acceptable standards.
The increase in the car number and using bad-quality of benzene led to increase the CO emission which generates carbon monoxide gas instead of carbon dioxide gas, and the high temperature increase the value of CO.  Figures (6), this location is in the west north of city and conceder as agriculture area with low traffic volume.

Nitrogen Dioxide (NO 2 )
Figure (7) shown that the concentration of NO 2 was higher than International limits which is about (0.11 ppm).

Figure (8).
Showed that the concentrations of O 3 ranging between (0.01-0.08 ppm) not exceeded the Iraqi and international standard, which are (0.08 ppm), and (0.12 ppm) high values of O 3 were in site (No.14) measured in December While the minimum value of ozone gas was in many locations through different periods.

Sulfur Dioxide (SO 2 )
The concentrations of SO 2 were exceeding the International standard limits in almost locations for the city as shown in Figure (9) .
In December, the minimum value (0.18 ppm) was founded at location (No.20) south of city. On the other hand, the maximum value of (0.9 ppm) founded in the location of (No.16). While the remaining sites, their concentrations ranging between (0.18 -0.8 ppm).
Finally, it can be notice that the concentration of SO 2 increased due to industrial activity in this area.

Carbon Dioxide (CO 2 )
the values of CO 2 were highly recorded in the north and the middle of city due to the main road that connect with Baghdad, also the main intersection in Karbala city. High concentrations were resulting from passing a significant number of big trucks that produce a large quantities of carbon dioxide and contaminated the surrounding air.
The highest concentration was in December 2015 (380 ppm) and this value was above the WHO limits (250 ppm) as shown in Figure (10) at site No.6 and the lowest concentration was (300 ppm) in site No.3 during study period.
The minimum concentrations during the study period were during March that witnessed decreasing in concentrations in all sites during this month. The next two months witnessed gradually increase in CO 2 concentrations.

Hydrogen Sulfide (H 2 S)
The concentrations of H 2 S ranging between 0.006-1.81ppm and these values above the acceptable limits 0.047ppm, as shown in Figures (11).
highest concentration recorded at May 2016 in all sites with concentrations ranging between (0.3 ppm) to (1.81 ppm). While the lowest concentration was (0.004 ppm) at many locations during several months as shown in Figures (11).
The lowest concentration of H 2 S was founded at almost months while The high concentrations of H 2 S recorded in the north of the city at may 2016 due to industrial activity in the area ,destruction of sewer networks. Figure (12) show, the highest concentration for VOCs was in site No.14 with value about (20 ppm) at December 2015, due to high traffic volume in this area and the proximity from petrol station and textile factory. While the lowest values of VOCs measured to be zero ppm in many sites during several periods.

Volatile Organic Compounds (VOCs)
The concentrations of VOCs at locations (No.14, 18, 19, 20, 21, and 22) exceeding the acceptable limit standards. The presence of petrol stations in middle and north of the city is the main source to increase the values of VOCs.

CONCLUSIONS
 High pollution by gases has increased in summer seasons for all gases while decreased in wintertime.  The results of field tests of air sites show that the highest pollutants concentrations were in December, April and May months, whereas lower concentrations of pollutants are observed during the remainder of the study and especially in March. The study took into consideration the rainfall and its impact on the air clearness of pollutants, as well as the effect of wind direction and speed in the transfer of pollutants.  values of (TSP) were above the permissible limits during April and May and high concentrations of PMs was founded in the same sites contain high values of TSP.  highest concentrations of CO was in the north of city at locations No. (10, 11, 12, 13, 14, and 15). the concentration of NO 2 was higher than International limits  The concentrations of SO 2 were exceeding the International standard limits in almost locations for the city. the concentrations of O 3 ranging between (0.01-0.08 ppm) not exceeded the Iraqi and international standard.  the values of CO 2 were highly recorded in the north and the middle of city. The concentrations of H 2 S ranging between 0.006-1.81ppm and these values above the acceptable limits and the highest concentration for VOCs was in site No.14 with value about (20 ppm) at December 2015.