Different methods aimed to quantify the effects of human activities on the natural environment have been developed. One of them is ecological footprint that is the total area of land, to produce all the resources a population consumes and to absorb all of the wastes it generates. An important impact of human activities on the environment is climate change that relates to the concentration of greenhouse gases in the atmosphere. The most important gas is CO 2 which is released to atmosphere as a result of burning fossil fuels in daily life of human activities. A main part of increasing CO 2 in urban atmosphere is road transportation; so estimation of ecological footprint of it can describe the situation of consuming fossil fuels in a city. To do so, the amount of different fuels consumed in a period of time, the area under transportation constructions and also the energy consumed in the process of network construction and annual road maintenance should be regarded. In this study the ecological footprint of transportation activities in the city of Isphahan in central Iran was estimated at 0.4 global hectares. It means that for each Isphahan resident, 0.4 global hectares area is needed to sequester the CO 2 released to atmosphere from different transportation activities.

Background: Finding the best location for the airport reduces the negative effects of construction and its activity on the environment. This study aimed to evaluate the establishment of the airports (Mehrabad and Imam Khomeini airports) in Tehran province through integration of multi-criteria decision making (MCDM) methods and noise pollution modeling software. Methods: The criteria for zoning the airports were determined using Delphi method, and then, were weighed using analytic network process (ANP). One of the criteria was noise pollution. The computer aided noise abatement (CadnaA) software was used to map the noise level at the airports. The geographic information system (GIS) software and weighted overlay method were used to zone Tehran province for construction of the airports. The percentage of voice annoyance was defined according to the questionnaire provided by the International Commission on the Biological Effects of Noise (ICBEN). Results: Prioritization between the selected criteria using ANP and TOPSIS showed that the most important criteria are the land use (0.069) and the distance from the city (0.0598), respectively. The highest percentage of highly annoyed (%HA) persons was reported at both airports at Lden levels above 70 dB. Conclusion: According to the results of this study, the location of Mehrabad and Imam Khomeini airports is considered 60% and 18% inappropriate, respectively. The results introduce a set of criteria that determines compatibility rate of different activities around the airports based on the noise levels. Finally, it is recommended to study the correlation between aircraft noise pollution indicators in other airports of Iran and design a local model for the whole country.

Background: Rice is the most important agricultural crop and the main food in Gilan and Mazandaran Provinces in northern Iran where organophosphorus pesticides, especially diazinon, are used. The excessive use of this insecticide in the paddy fields of Rasht County is a serious threat to people’s health. Methods: In this study, 30 rice samples were collected from five zones in the paddy fields of Rasht in summer. The samples were analyzed when rice is sold to assess the health risk caused by diazinon residues in rice. Following the digestion process, the samples were injected into a High-Performance Liquid Chromatography (HPLC) instrument. Analysis of Variance (ANOVA) and one-sample t-test were respectively used for analyzing data and the Health Risk Index (HRI) for assessing the risk of rice consumption. Results: According to the results, the mean residual diazinon concentration in the rice crops of the five studied zones at the time of consumption (three months after harvest) was 0.4±0.43 mg/kg-1. This was higher than the Iranian standard for permissible diazinon concentration in rice. The results of the health risk assessment for rice consumption indicated an HRI value of 0.13 for rice consumption, which did not constitute a serious risk for people who consume rice regularly. Conclusion: Although the results of this study showed that there are no potential health risks for consumers, with increasing the use of chemical pesticides for crops, to achieve food safety, regular monitoring of pesticide residues in crops is recommended