Archives of

Background
About 90% of existing particulates in atmosphere have natural origin and the remained 10% have artificial origin (1-3). Health effects of particulates have a wide range but mostly are related to respiratory and cardiovascular systems. Although, population is affected by air pollution, intensity effect can be different according to age, health of persons and sensitivity to pollution (3,4). The rate of possible implications will be increased with increase in persons’ exposure to pollution (5,6). There are few evidences on a suggested threshold without any unfavorable effect in it. In fact, low levels of concentrations with proven unfavorable effects are not higher than mass concentration. Mass concentration is estimated to 3-5 µg/m³ for particulate matters with a diameter equal to or less than 2.5 micron in USA and West Europe (5). Epidemiological evidences also proved unfavorable effects of suspended particles with two short-term and long-term forms. Since, there is not any determined threshold for suspended particles and resistance of persons against a determined contact is distinguished, it is impossible to determine any standard or instruction for full protection against unfavorable effects of suspended particles (3,5). Particulates are a mixture of organic and inorganic materials which are classified based on their diameters in terms of chemical nature. Although, the diameter of particulates plays an important role in diagnosing the health effects, various requirements need to be observed for such selection (1,5). The first considered parameter by air pollution experts was “total suspended particles” which numerous rules were legislated by United States World Health Organization and Environmental Protection Agency with the aim of reducing this parameter (3,5). Then, this parameter was replaced with particles which had aerodynamic diameters of less than or equal to 10 microns. Nowadays, the majority of air quality monitoring stations prefer measuring PM₁₀ to other concentrations of particulate matters. Most of the epidemiological studies have also considered PM₁₀ as an index (3,5). Particulate matters with aerodynamic diameter of equal to or less than 10 µm have the highest effects due to their ability to penetrate the pulmonary alveoli and these particles are divided into two categories of large size (2.5-10microns) or small (less than 2.5 microns) (1,3). Large particulates with more than 2.5 diameter are formed by mechanical processes such as re-suspension of dusts or erosion and destruction of materials and objects. Fine particulates usually are formed by combustion processes, chemical reactions or cryopreservation of gaseous materials (1,5). Both categories of particulates are existing in the majority of urban environments while their ratio is different based on geographical situation, meteorology, transportation pattern and energy consumption in different cities. Toxicity of suspended particles will be increased if there are heavy metals or arsenic in them (3-5). Particles’ cleaning is treated as the first defensive line of respiratory system to protect body against harmful effects of remained particulates. The reaction of respiratory system can be distinguish based on the place in which the particle is remained (7). Macrophages exist in all parts of respiratory system and engulf particles remained in system. In fact, macrophages are white globules with diameters of 10-70 microns that metabolize the particles and bacteria during phagocytosis process (7-8). The deposited suspended particles in nose and throat are cleaned by mucosal secretions of respiratory system. The particles trapped and stopped by macrophages or mucosal layer of respiratory system would direct to upside though ciliary movement of airway cells (8). These secretions are discharged or swallowed through the mouth and nose through sneezing and coughing. It takes several hours to clean suspended particles in trachea and bronchi. A minor part of these particles can be more slowly removed. Evidences indicate that a small part of these particles travel to epithelial cells and underlying tissue. Suspended particles traveling to alveolus space would most probably engulfed by macrophages (8). Some particles that have traveled to macrophages gradually reach to terminal bronchioles then removed by ciliary epithelial lifter. Some of particles travel to regional lymph nodes through the lymphatic system and some other directly reach to blood flow (9). There have been many studies conducted on particulates’ effects. An epidemiological study conducted by Winkshein et al in Buffalo Erie, New york, USA in which, the two-year average of suspended particles ate four pollution levels reported as follows: lower than 80µg/m³ at level 1, between 80 and 100 at level 2, 100-135 at level 3 and more than 135 at level 4. Each of polluted regions divided into five socioeconomic classes. Mortality rate was increased due to fetal factors such as respiratory diseases and gastric cancer with an increase in particulates’ concentration, and the result was independent from economic situation of studied society (1,5). Morgan et al (1998) carried a study on a range of children from newborn to 15 year old and concluded that there is a relation between the concentrations of 130µg/m³ and infectious lower respiratory system (10). World Health Organization has estimated annual cost spent over health and hygiene sector caused by air pollution in Austria, France and Switzerland to 30 billion pounds equal to 6% of total mortalities (11). Annual health cost of high concentration of particulates is estimated to 23 billion pounds in USA (12). Suspended particles which are smaller than 2.5 microns would increase mortality by 6% per 10 µg/m³ increase in their concentrations during long-term exposures. Along with such increase, cardiovascular diseases will increase by 12% and lung cancer by 14% (13).
Aims of the study:
The purpose of this study was the estimation of respiratory deaths which were caused by exposure to PM₁₀ in Ahwaz, Bushehr and Kermanshah cities of Iran during 2015, by used Air model Q2.2.3.
 

Materials & Methods

Methods
The present research has been conducted to quantify and compare respiratory deaths attributable to PM₁₀ between three cities of Ahwaz, Kermanshah and Bushehr based on the model in 2015, using information which were derived from Environment Protection Organization. In this regard, the required raw data collected from Environment and Meteorological Organization, then, data were analyzed through EXCEL software and they were entered into AIR Q Model. To estimate the years-of-life-lost (YLL), second part of model called Life Table was applied. This model is a valid and a reliable model which was introduced by World Health Organization in order to estimate short-term effects of air pollutants.

Figure 1) Map of study areas (Ahwaz, Bushehr, and Kermanshah)
Research implementation steps are as follows:
Data collection
Information which were related to the concentration of PM₁₀ in 2015 were taken from Environment Organization of Ahwaz, Bushehr and Kermanshah in form of Excel file.
Providing input-file of model, using raw data;
To prepare this file, following steps were done, respectively:
Temperature and Pressure correction and unit compliance with the model
Since the data, which were obtained from Environment Organization of Ahwaz, Bushehr and Kermanshah are raw and obtained from direct reading instruments, the initial raw data changed to data based on pressure and temperature of measurement point and a new file was created to obtain the required unit.
Primary process
This stage consists of removal, sheet classification of pollutants and time integration for average estimation.
Secondary process
This stage consists of three parts including coding, mean calculation and condition modification.
Coding
Coding depends on pollutant type and considered mean. For instance, if the data of PM₁₀ and daily average are considered, the command Left (Ax; 5) is inserted in cell one located at right-hand column beside PM₁₀, and is generalized to remained cells.
Calculation of daily average based on coding
As mentioned in coding, the written command is different based on the type of pollutant   and considered average type. IF (B26<>B27; AVERAGE (C3:C26)) is a sample of this command that means: if the number in cell B26 (row 26 column B) is not equal to number in cell B27 then the average of C3-C26 should be calculated.
Condition modification
For instance, the modification of above command in cell in front of adjacent column will be IF (B26<>B27, AVERAGE (D3:D26)). The result will be rows including daily averages while the other rows consist of incorrect (Error) word.
Primary filtering
At this stage, we select item Sort & Filter, then select filtering command. The obtained result of this command will be 365-366 numbers that each of them shows the average of each day. The new file is saved with the name of  “Intermediate”.
Secondary filtering
This time, we activate auto-filter for Intermediate file then filtering is done for model between demanded concentrations’ distances.

Figure 2)A view of research
 

Results

This part of study represents the results which are obtained from the quantification of PM₁₀ in percent, states options of each implication in form of tables in Ahwaz, Bushehr and Kermanshah, 2015.
According to the calculated relative risk in table 1, cumulative number of death cases caused by PM₁₀ obtained to 164 members in Ahwaz, 2015.
According to the calculated relative risk in table 2, cumulative number of death cases caused by PM₁₀ obtained to 94 members in Kermanshah, 2015.
 

Table 1) Estimation of relative risk indexes, attributed component, and cases attributed to PM₁₀ for deaths caused by respiratory diseases (BI=66) (Ahwaz, 2015)

estimation index	relative risk (average)	attributed component	cumulative number of cases (person)
low	1.008	18.6568	119.3
average	1.012	25.5974	163.7
high	1.037	51.4748	329.2

Table 2) Estimation of relative risk indexes, attributed component, and cases attributed to PM₁₀ for deaths caused by respiratory diseases (BI=66) (Kermanshah, 2015)

estimation index	relative risk (average)	attributed component	cumulative number of cases (person)
low	1.008	11.8809	66.1
average	1.012	16.8220	93.6
high	1.037	38.4976	213.7

 
According to the calculated relative risk in table 2, cumulative number of death cases caused by PM₁₀ obtained to 94 members in Kermanshah, 2015.
 
 

Figure 3) Estimation of cumulative number of deaths caused by respiratory disease attributed to PM₁₀ in Ahwaz, 2015
 

Figure 4) Estimation of cumulative number of deaths caused by respiratory disease attributed to PM₁₀ in Kermanshah, 2015
 

Figure 5) Estimation of cumulative number of deaths caused by respiratory disease attributed to PM₁₀ in Bushehr, 2015
 

Table 3) Estimation of relative risk indexes, attributed component, and cases attributed to PM₁₀ for deaths caused by respiratory diseases (BI=66) (Bushehr, 2015)

estimation index	relative risk (average)	attributed component	cumulative number of cases (person)
low	1.008	13.6021	16.2
average	1.012	19.1039	22.8
high	1.037	42.1343	50.3