امیدرضا تونی

In general, increasing the production and exploitation of aquatic animals in the aquatic ecosystem without considering its relationship and balance with other parts of the ecosystem causes a wrong assessment of the real cost and benefits of these services to the environment and society, and in the future will have negative effects. The activities carried out in the aquaculture industry lead to a decrease in the quality of water and as a result the chemical balance in water is disturbed. On the other hand, the increase in metabolic activity in aquatic animals intensifies those effects. In the aquaculture industry, attention should be paid to quality control and monitoring methods. Knowing the basic conditions of the desired water body for the construction of breeding farms and predicting the future situation of the region based on the effluents entering is very necessary.

In this study, the physicochemical conditions of Sisangan region were investigated for setting up a fish farm.

In order to determine the state of sea water quality, water sample collected for one period to analyze pollution and physicochemical variables. After determining of the variables, the TRIX trophic index was calculated and the trophic conditions of the area were determined.

Measuring the physical parameters of water from 5 to 15 meters depth showed that the variables of temperature, electrical conductivity, salinity, oxygen and pH do not change much along the depth. The measurement of nutrients indicated that the total nitrogen in the sea in the study area varies from less than 0.1 mg/liter to 2.5 mg/liter. The amount of total phosphorus in the study range varies from less than the measuring limit of the device 0.003 mg/liter to 0.007 mg/liter. According to the measurements made in these studies, the result of calculating the TRIX index is an average numerical value of 2.3.

The results of this study showed that the area is tropically oligotrophic and the water quality of the area is very good.

The subject of air pollution has become important since the emergence of industrial societies. Based on statistics provided by the spokesman of the Ministry of Health and Medical Education on December 8, 2017, in Iran, due to air pollution, 2.48 percent of gross national product is wasted. Also, the amount of damage caused to the national economy caused by air pollution is 34 trillion tomans. Annually, $ 25 billion of the world's economy becomes smoke and goes to the air, due to air pollution. Meanwhile, metropolitan areas have a very significant contribution to this damage. According to the Economic Welfare Theory, any costs that are incurred in society must be paid by the causing factors. Today, in most countries in the world, external costs are estimated and included in the pricing calculations. Therefore, it is important to calculate the external costs of air pollution in codification of an appropriate management approach. For this purpose, the aim of this research is to consider an economic, engineering and management approach to external costs caused by the emission of PM, NOx, SO2, CO pollutants in order to plan and provide targeted solutions for reducing air pollution in Karaj.

The present study was carried out in order to examine the impact Cadmium on amount of iron in the blood of common carp. Sampling of common carp was carried out randomly from a fish culture pond in southeast of Babol by trawling. Firstly the fish were become compatible with the laboratory conditions during 48 hours and then have been influenced by different concentrations through one blank and 3 experimental groups of A (4.296 mg/l), B (7.127 mg/l) and C (8.656 mg/l). There were 12 aquariums, each including 12 pieces of fish. It was tried to apply an equal environmental condition for all of the aquariums during the experiment. Bleeding was done from the fish vein and heart after 48, 72 and 96 hours of anesthetizing.. Concentrations of cadmium and iron have been determined by ICP-OES after acid digestion of blood samples by Microwave. In analyzing Cadmium, the fish average weight and length (total length) were 163.6 g, 23.6 respectively In this study it has been identified that the absorption scale of Cadmium increases as the time passes and generally it showed a significant increase (p<0.05, n=3) during the time in cadmium concentrations of blood comparing the blank sample. This has no significant trend since the blood acts as a carrier and is a junction for heavy metals such as cadmium to the target organs. Furthermore, in addition to refusal of this theory that: "concentration of lead and cadmium ions by interactions with common carp blood iron has a significant impact on iron amount in blood", there has not seen any significant relation (p<0.05, n=3) between increasing of the amount of absorbed Cadmium and blood iron changes. Therefore, it could be concluded that probably no interaction between cadmium, and blood iron happens in blood circulation and the blood iron changes during the test is probably because of some physiological changes resulting from stress in fish blood.

Air pollution is today a major problem for modern societies. It has long been recognized as a potentially lethal form of pollution. Increasing pollution levels due to rapid urbanization and growth in emission related to vehicular transportation are now caused major concern. The mobilization of heavy metals into the biosphere by human activities has become an important process in the geochemical recycling of these metals. Pollution of the natural environment by heavy metals is a worldwide problem because these metals are indestructible and most of them have toxic effects on living organisms. While some of these elements are essential for humans, at high levels they can also mean toxicological risks. According to numerous studies, the pollution sources of heavy metals in environment are mainly derived from anthropogenic sources. In urban soils and urban road dusts, the anthropogenic sources of heavy metals include traffic emission (vehicle exhaust particles, tire wear particles, weathered street surface particles, brake lining wear particles), industrial emission (power plants, coal combustion, metallurgical industry, auto repair shop, chemical plant, and etc.), domestic emission, weathering of building and pavement surface, atmospheric deposited and so on. In recent times, studies of air pollution especially in the urban environment have focused largely on road deposited dust. Street dust, particles deposited on road, originates from the interaction of solid, liquid and gaseous materials produced from different sources. Road dusts have been implicated to have the potential to carry a high loading of contaminant species such as heavy metals and organic pollutants. Dust kicked up by vehicles traveling on roads may make up 33% of air pollution. Street dust consists of deposition of vehicle exhausts and industrial exhausts, tire and brake wears, dust from paved roads or potholes, and dust from construction sites. Street dust represents a significant source contributing to the generation and release of particulate matter into the atmosphere. Control of street dust is a significant challenge in urban areas, and also in other spheres with high levels of vehicular traffic upon unsealed roads. It is easily re-suspended back into the atmosphere, where they contribute a significant amount of trace elements. Dust borne heavy metals accumulate in topsoil due to atmospheric deposition by sedimentation, impaction and interception. Karaj is as the capital city of Alborz Province in Iran. At the 2011 census, population of the city was 1.9 million, making it the third-largest city in Iran. It is situated 36 km west of Tehran, at the foot of the Alborz Mountains. Twenty sampling sites were selected for road dust sample collection. The samples were collected from Karaj-Qazvin highway (10 samples), Mallard road (7 samples) and Taleghani Boulevard (3 samples). Karaj-Qazvin highway experiences intense traffic and Mallard road is selected because a power plant is located in 7 km of the road. Taleghani Boulevard was selected for comparing, because it is a road with light traffic and away from any industrial activities. At each sampling point, approximately 50 g of road dust particles was collected from three points at the road sides with a brush and transferred into polyethylene tubes for transportation to the laboratory. All the samples were dried at 105 0C for 24 hr to drive out moisture. On cooling each sample was sieved through a sieve of 250 µm diameter. Then, the sieved road dust samples were digested using the milestone Ethos one microwave digestion system. Finally, the total concentrations of Cr, Cu, Ni, Pb, Zn, and Mn were determined by AAS. The assessment of soil or sediment enrichment can be carried out by many ways. In this work, the index of geoaccumulation (Igeo), Enrichment Factor (EF), Contamination Factor (CF) and Pollution Load Index (PLI) have been applied to assess heavy metals (Cr, Cu, Mn, Ni, Pb and Zn) distribution and contamination in the road dust samples of the various categories of roads in Karaj. The Igeo is used to assess heavy metal contamination in urban soils by comparing current and pre-industrial concentrations. It is also employed in pollution assessment of heavy metals in urban road dust. Geoaccumulation index is computed using the following equation: Igeo = log2 ((Cn) ×1/ 5Bn Enrichment factor (EF) has been employed for the assessment of contamination in various environmental media by several researchers. Its version was adapted to assess the contamination of various environmental media as follows: EFX = [XS / ES (ref)]/ [XC / EC (ref)] To assess the extent of contamination of heavy metals in road dust and also provide a measure of the degree of overall contamination along a particular road, contamination factor and pollution load index has been applied. Enrichment Factor (EF) of an element in the studied samples is based on the standardization of a measured element against a reference element. A reference element is often the one characterized by low occurrence variability. In this study, Mn was selected for this purpose. The contamination Factor (CF) and pollution load index parameters are expressed as: CF = C metal / C background PLI = n√ (CF1 × CF2 × CF3 ×. ....... CFn) The results of contamination assessment indices that mentioned above for three roads are showed in Table 1. Discussion and The range of heavy metals concentration in road dust samples is as follow: Pb: 48-629 µg/g, Ni: 19-224 µg/g, Cu: 86-271 µg/g, Mn: 609-784 µg/g, Zn: 282-1212 µg/g, Cr: 40-117 µg/g. Heavy metal contents and their possible sources in (The concentrations and sources of the heavy metals) road dust samples collected from the selected roads in Karaj have been examined in this study. Four contamination indices namely, enrichment factor (EF), geo-accumulation index (Igeo), contamination factor (CF) and Pollution Load Index (PLI) were used in the assessment of level of metal contamination in the study area. The Igeo, EF, and CF obtained for Pb, Zn, and Cu in all the roads give an indication of anthropogenic origin. The EF calculated for the elements showed that Cu, Zn, and Pb gave moderate to significant enrichment of the elements in road dust. The computed Index of Igeo gave values in the range of unpolluted (for Ni, Cr and Mn) to extremely polluted (for Zn, Cu and Pb) indicating the accumulation of Zn, Cu, and Pb from anthropogenic sources. In some stations (m5, m6 and m7) at the Mallard road the concentrations of Cr and Ni were found to be higher than the alert values. It is probably due to industrial activity of the power plant, because the electric utility industry is the number two emitter of nickel and chromium. However, the average concentration of these two elements in all the roads showed that they have low level of pollution. To compare whether the three roadways suffer contamination or not, the Pollution Load Index (PLI) described earlier was applied. The PLI is aimed at providing a measure of the degree of the overall contamination at all the sampling sites and along the various roadways. The results of the PLI indicated that k1 (Kalak) and m6 (power plant) are the most contaminated site followed by k7(Kalak) and k2 (Fardis) in that order. The results of PLI for all the roads show that the pollution load in Karaj-Qazvin freeway is the highest. EF, Igeo, and CF values for Pb in Karaj-Qazvin were higher than others. Karaj-Qazvin Freeway is a road with high traffic capacity in vicinity of Karaj. Chen et al attributed this high Pb contamination to the emission of Pb from automobile exhaust and its deposition near highways and roads which has been reported worldwide. The major industrial source for Zn is smelting. Therefore, zinc used as a vulcanization agent in tires was the most likely source. The source of Cu in street dust was indicated by research as being due to corrosion of metallic parts of cars derived from engine wear, thrust bearing, brushing and bearing metals.