A systematic review on garbage enzymes and their applications in environmental processes.

Understanding the new insight on conversion of organic waste into value-added products can improve the environmental activities driven by microorganisms and return the nutrients to environment and earth. Here, we comprehensively review the available knowledge on application of garbage enzyme (GE) for different environmental activities including waste activated sludge, composting process, landfill leachate treatment, soil remediation and wastewater treatment with special focus on their efficiency. To identify peer-reviewed studies published in English-language journals, a comprehensive search was performed across multiple electronic databases including Scopus, Web of Science, Pubmed, and Embase. The search was conducted systematically using relevant keywords. The eligible studies were analyzed to extract data and information pertaining to components of GE, fermentation process operational parameters, type of hydrolytic enzymes and improved environmental performance. The findings derived from this current review demonstrated that GE produced from the fruit and vegetable peels, molasses or brown sugar (carbon source), and water within fermentation process contain different hydrolytic enzymes in order to facilitate the organic waste degradation. Therefore, GE can be considered as a promising and efficient pathway in order to improve the environmental activities depended on microorganism including, composting, wastewater and leachate treatment and bioremediation process.

Pesticides residues determination and probabilistic health risk assessment in the soil and cantaloupe by Monte Carlo simulation: A case study in Kashan and Aran-Bidgol, Iran.

Cantaloupe is a popular agricultural product in the hot season of Iran. On the other hand, the frequent use of pesticides in cantaloupe fields is the most important threat to the health of farmers and consumers. Therefore, the present study aims to measure the concentration of diazinon (DZN), chlorpyrifos (CPF), and malathion (MLT) in cantaloupe cultivated in Kashan and Aran-Bidgol (Iran) and to estimate the possible oral and dermal risk of these pesticides by Monte Carlo simulation (MCS). 36 cantaloupe samples, 18 samples before, and 18 samples after the latent period were collected from different places of cantaloupe cultivation from April to May 2021. After measuring the pesticides using the QuEChERS approach, oral and dermal risk assessments were calculated.The mean and standard deviation of the concentrations of chlorpyrifos, malathion, and diazinon in 18 cantaloupe samples, after the latent period, were (30.39 ± 13.85), (18.361 ± 1.8), and (21.97 ± 0.86) µg kg-1, respectively. Concentration of Malathion, diazinon, and Chlorpyrifos in the soil were 0.22, 0.25, and 0.3 mg kg-1, respectively, and pesticide cumulative risk assessment in soil was obtained 0.011 for Malathion, 0.05 for diazinon and 0.03 for Chlorpyrifos. Target Hazard Quotient (THQ) according to the cantaloupe consumption and dermal exposure in children and adults, was safe range. Although non-cancerous dermal and oral risk of cantaloupe is low, constant exposure can be harmful. Therefore, the findings of this study play an important role in increasing the understanding of the negative health consequences of pesticide contamination in cantaloupe for consumers, especially local residents, and can help by adopting remedial strategies to reduce environmental concerns.

Associations between long-term exposure to air pollution, diabetes, and hypertension in metropolitan Iran: an ecologic study.

Epidemiological studies on air pollution, diabetes, and hypertension conflict. This study examined air pollution, diabetes, and hypertension in adults in 11 metropolitan areas of Iran (2012-2016). Local environment departments and the Tehran Air Quality Control Company provided air quality data. The VIZIT website and Stepwise Approach to Chronic Disease Risk Factor Surveillance study delivered chronic disease data. Multiple logistic regression and generalized estimating equations evaluated air pollution-related diabetes and hypertension. In Isfahan, Ahvaz, and Tehran, PM2.5 was linked to diabetes. In all cities except Urmia, Yasuj, and Yazd, PM2.5 was statistically related to hypertension. O3 was connected to hypertension in Ahvaz, Tehran, and Shiraz, whereas NO2 was not. BMI and gender predict hypertension and diabetes. Diabetes, SBP, and total cholesterol were correlated. Iran's largest cities' poor air quality may promote diabetes and hypertension. PM2.5 impacts many cities' outcomes. Therefore, politicians and specialists have to control air pollution.

Exposure to outdoor particulate matter and risk of respiratory diseases: a systematic review and meta-analysis.

According to epidemiological studies, particulate matter (PM) is an important air pollutant that poses a significant threat to human health. The relationship between particulate matter and respiratory diseases has been the subject of numerous studies, but these studies have produced inconsistent findings. The purpose of this systematic review was to examine the connection between outdoor particulate matter (PM2.5 and PM10) exposure and respiratory disorders (COPD, lung cancer, LRIs, and COVID-19). For this purpose, we conducted a literature search between 2012 and 2022 in PubMed, Web of Science, and Scopus. Out of the 58 studies that were part of the systematic review, meta-analyses were conducted on 53 of them. A random effect model was applied separately for each category of study design to assess the pooled association between exposure to PM2.5 and PM10 and respiratory diseases. Based on time-series and cohort studies, which are the priorities of the strength of evidence, a significant relationship between the risk of respiratory diseases (COPD, lung cancer, and COVID-19) was observed (COPD: pooled HR = 1.032, 95% CI: 1.004-1.061; lung cancer: pooled HR = 1.017, 95% CI: 1.015-1.020; and COVID-19: pooled RR = 1.004, 95% CI: 1.002-1.006 per 1 µg/m3 increase in PM2.5). Also, a significant relationship was observed between PM10 and respiratory diseases (COPD, LRIs, and COVID-19) based on time-series and cohort studies. Although the number of studies in this field is limited, which requires more investigations, it can be concluded that outdoor particulate matter can increase the risk of respiratory diseases.

Assessment of the risk of Legionella pneumophila in water distribution systems in hospitals of Tehran city.

When a sensitive host inhales aerosols containing these bacteria, Legionella infection occurs. Therefore, monitoring and assessing Legionella in the environment and water distribution systems of such places are critical due to the prone population in hospitals. However, the health risks of Legionella bacteria in the environment are not adequately evaluated. In this study, for hospitalized patients, we performed a quantitative health risk assessment of Legionella in selected hospitals in Tehran city using two scenarios of shower and toilet faucet exposure. This study identified Legionella in 38 cases (38%) out of 100 samples collected from toilet faucets and showers in 8 hospitals. The information gathered was used for quantitative microbial risk assessment (QMRA). The microbial load transmitted by inhalation was calculated using the concentration of Legionella in water. Other exposure parameters (inhalation rate and exposure time) were obtained using information from other studies and the median length of hospital stay (3.6 days). The exponential model was used to estimate the risk of infection (γ = 0.06) due to Legionella pneumophila (L. pneumophila) inhalation for each exposure event. For the mean concentration obtained for Legionella (103 CFU/L), the risk of infection for toilet faucets and showers was in the range of 0.23-2.3 and 3.5-21.9, respectively, per 10,000 hospitalized patients. The results were compared with the tolerable risk level of infection determined by the US EPA and WHO. The risk values exceeded the WHO values for waterborne pathogens in hospitals in both exposure scenarios. As a result, our QMRA results based on monitoring data showed that despite using treated water (from distribution networks in the urban areas) by hospitals, 38% of the samples were contaminated with Legionella, and faucets and showers can be sources of Legionella transmission. Hence, to protect the health of hospitalized patients, the risk of Legionella infection should be considered.

Extraction and determination of organic/inorganic pollutants in the ambient air of two cities located in metropolis of Tehran.

In the present study, PM2.5, volatile organic compounds (VOC), heavy metals, and polycyclic aromatic hydrocarbons (PAHs)-bonded PM2.5 as well as asbestos fibers were investigated in two cities in the east of Tehran, Iran. To this end, 72 samples were collected from six stations located in the cities of Varamin and Pakdasht from March 2018 to March 2019. The concentration of BTEX compounds, PAHs, and heavy metals were measured using gas chromatography-flame ionization detector (GC-FID), gas chromatography-mass spectrometry (GC-Mas), and inductively coupled plasma atomic emission spectroscopy (ICP-OES), respectively. In addition, phase contrast microscopy (PCM) method was used to identify the properties of asbestos fibers. The results obtained from the present showed that the mean concentrations of PM2.5, heavy metals, PAHs, BTEX, and asbestos fibers were 52.05 µg/m3, 319.08 ng/m3, 3.97 ng/m3, 40.58 µg/m3, and 2.84 f/L, respectively. In addition, the results obtained from PCA and heavy metals sources showed that transport fleets were the natural source of most of these pollutants. In case of PAH sources, transport and incineration of coal had the highest contribution in the emission. Furthermore, the risk assessment showed that most of the compounds have a higher risk value than the guideline value spatial distribution and also showed that stations close to airports, city terminals, and highways were more polluted than other parts of the city. Therefore, in order to have healthy air and with the least pollution, it seems necessary to formulate the necessary strategies in the cities of Varamin and Pakdasht.

Ambient air pollutants and respiratory health outcomes in Tabriz and Urmia, two metropolises of Iran.

Polluted air affects human life and it is crucial to assess air pollutants to inform policy and protect human lives. In this study, we sought to assess the respiratory outcomes associated with PM10, O3, SO2, and NO2 in the Iranian population. The required data, which included concentrations of air pollutants, meteorology, and population size, were obtained from the department of environment and meteorological organizations. The validity of the data was evaluated, and appropriate calculations were conducted on the data to extract the required values and parameters for modeling (using the AirQ2.2.3). This study was conducted in two megacities of Iran (Tabriz and Urmia) with over 2 million population. The annual averages of SO2, NO2, and PM10 concentrations were 9, 73, and 43 µg/m3 in Tabriz and 76, 29, and 76 µg/m3 in Urmia, respectively. Excess deaths from respiratory diseases associated with PM10 and SO2 were estimated to be 33.1 and 1.2 cases in Tabriz and 31.6 and 24.7 cases in Urmia, respectively. The proportions of hospitalizations for chronic obstructive pulmonary disease (COPD) attributable to SO2 and NO2 in Tabriz were 0.07% and 1.61%, respectively, whereas they were 2.84% and 0.48% in Urmia. O3 had an annual average of 56 µg/m3 in Tabriz and with 44.5 excess respiratory deaths and 42.5 excess hospital admissions for COPD, it had the greatest health impacts among the pollutants studied. Findings from this study add to the growing literature, especially from developing countries, that provides insights to help authorities and decision-makers develop and implement effective interventions to curb air pollution and save lives.

A systematic review and meta-analysis of human biomonitoring studies on exposure to environmental pollutants in Iran.

Population exposure to environmental contaminants can be precisely observed through human biomonitoring studies. The present study aimed to systematically review all the biomonitoring studies conducted in Iran on some selected carcinogen environmental pollutants. In this systematic review study, 11 carcinogen agents were selected including arsenic, cadmium, chromium, nickel, lindane, benzene, trichloroethylene (TCE), pentachlorophenol (PCP), radon-222, radium-224, - 226, - 228, and tobacco smoke. The Web of Science, PubMed, and Scopus databases were searched for peer-reviewed articles published in English. After several screening steps, data were extracted from the studies. Meta-analyses (a random-effect model using the DerSimonian-Laired method) were performed only for the biomarkers with more than three eligible articles, including cadmium in blood and breast milk, and arsenic in breast milk. Methodological quality of the studies was assessed using the Newcastle-Ottawa Quality Assessment Scale adapted for cross-sectional studies. Of the 610 articles found in the database search, 30 studies were eligible for qualitative review, and 13 were included in the meta-analysis (cadmium in blood (n = 3), cadmium in breast milk (n = 6), and arsenic in breast milk (n = 4)). The overall pooled average concentrations (95% CI) of cadmium in blood, cadmium in breast milk, and arsenic in breast milk were 0.11 (95% CI: 0.08, 0.14), 5.38 (95% CI: 3.60, 6.96), and 1.42 (95% CI: 1.02, 1.81) µg/L, respectively. These values were compared with the biomarker concentrations in other countries and health-based guideline values. This study showed that there is a need for comprehensive action plans to reduce the exposure of general population to these environmental contaminants.

Occurrence, spatial distribution, seasonal variations, potential sources, and inhalation-based health risk assessment of organic/inorganic pollutants in ambient air of Tehran.

The present study evaluated the concentrations, spatial distribution, seasonal variations, potential sources, and risk assessment of organic/inorganic pollutants in ambient air of Tehran city. Totally, 180 air samples were taken from 9 sampling stations from March 2018 to March 2019 and were analyzed to determine the concentrations of organic pollutants (BTEX compounds and PM2.5-bound PAHs) plus inorganic pollutants (PM2.5-bound metals and asbestos fibers). The results revealed that the mean concentrations of ∑ PAHs, BTEX, ∑ heavy metals, and asbestos fibers were 5.34 ng/m3, 60.55 µg/m3, 8585.12 ng/m3, and 4.13 fiber/ml in the cold season, respectively, and 3.88 ng/m3, 33.86 µg/m3, 5682.61 ng/m3, and 3.21 fiber/ml in the warm season, respectively. Source apportionment of emission of the air pollutants showed that PAHs are emitted from diesel vehicles and industrial activities. BTEX and asbestos are also released mainly by vehicles. The results of the inhalation-based risk assessment indicated that the carcinogenic risk of PAHs, BTEX, and asbestos exceeded the recommended limit by The US environmental protection agency (US EPA) and WHO (1 × 10-4). The risk of carcinogenesis of heavy metal of lead and chromium also exceeded the recommended limit. Thus, proper management strategies are required to control the concentration of these pollutants in Tehran's ambient air in order to maintain the health of Tehran's citizens.

Degradation of furfural in aqueous solution using activated persulfate and peroxymonosulfate by ultrasound irradiation.

Furfural is a toxic compound that can cause many problems for human health and the environment. In this study, we addressed the degradation of furfural in aqueous solution using the activated persulfate (SPS) and peroxymonosulfate (PMS) through the ultrasonic (US) wave. Besides, the effect of various parameters (pH, oxidizing dose, initial furfural concentration, US frequency, Inorganic anions concentration, and scavenger) on SPS + US (SPS/US) and PMS + US (PMS/US) processes were examined. The results showed, in order to furfural removal, the US had excellent efficiency in activating SPS and PMS, as in SPS/US and PMS/US processes, 95.3% and 58.4% of furfural (at 25 mg/L concentration) was decomposed in 90 min, respectively. The furfural degradation rate increased with increasing oxidizing dose and US frequency in both SPS/US and PMS/US processes. Considering the synergistic effect, the best removal rate has occurred in the SPS/US process. In the SPS/US and PMS/US processes, furfural removal increased at natural pH (pH 7), and the presence of inorganic anions such as NO3- and Cl- had negative effects on furfural removal efficiency. Also CO32- and HCO3- acted as a radical scavenger in the SPS/US process but these anions in the PMS/US process produced more SO4-° radicals, and subsequently, they increased the furfural degradation rate. The results also showed that the predominant radical in the oxidation reactions is the sulfate radical. This study showed that the SPS/US and PMS/US processes are promising methods for degrading organic pollutants in the environment.

Estimation of cardiovascular and respiratory diseases attributed to PM10 using AirQ model in Urmia during 2011-2017.

Background: Quantification of the attributed effects of air pollution determines the impact of air pollutants on the community and shows the critical condition of air quality. This study aimed to quantify and estimate the cardiovascular and respiratory diseases attributed to PM10 in Urmia during 2011-2016. Methods: In this descriptive-analytic study, at first, hourly data of pollutant PM10 concentrations were received from air pollutants station located in the Department of Environmental Protection. The data were evaluated using AirQ2.2.3 software after primary and secondary processes and filtering. Results: The results showed that the mean annual concentration of PM10 during 2011-2016 was 88.66, 92.45, 81.22, 78.38, 113.78, and 92.67 µg /m3, respectively. The number of hospitalized cases due to respiratory diseases attributed to PM10 in this period was 486, 525, 459, 453, 684, and 552, respectively, and the number of cases due to cardiovascular diseases was 188, 203, 177, 175, 263, and 213, respectively. Conclusion: Considering the attributed health effects of PM10, the necessary measures should be taken to identify the causative agents and to understand the mechanisms of these processes and correct them.

Investigating the effect of several factors on concentrations of bioaerosols in a well-ventilated hospital environment.

This study characterized and quantified the bacterial and fungal bioaerosols in nine wards of the Razavi Hospital (Mashhad, Iran) that is equipped with an advanced heating, ventilating, and air conditioning (HVAC) system including HEPA filters for air cleaning. In this study, 432 samples were taken from the indoor air of multiple hospital wards during the morning and afternoon shifts during summer and autumn. The particle number concentrations with sizes of > 0.3, > 0.5, > 1, > 2, > 5, and > 10 µm were measured using a 6-channel handheld particle counter. A greater diversity of bioaerosol types were observed during the morning shifts and during summer. The microbial load was not affected significantly by the temperature, relative humidity, working shift, season, and number of visitors, indicating the effectiveness of a well-designed ventilation system to eliminate site-specific variations. For microbial number concentrations, a significant correlation was only observed between the number of particles with a diameter of > 10 µm and the airborne microbial loading. Thus, passive sampling may not properly reflect the actual concentrations of smaller bioaerosols. In conclusion, HEPA filters in the HVAC system successfully decreased the bioaerosol concentrations in the hospital environment. Additionally, we recommend that active sampling be used in cases where a well-functioning HVAC system exists.

Exposure to BTEX in beauty salons: biomonitoring, urinary excretion, clinical symptoms, and health risk assessments.

Benzene, toluene, ethylbenzene, and xylene (BTEX) concentrations were measured in beauty salons (BS) and in the urine of the beauty practitioners and a control group. Indoor and outdoor concentrations of BTEX were measured in 36 randomly selected salons. Before- and after-shift urinary BTEX were measured from one female non-smoker employee in each salon, and repeated three times. Clinical symptoms in that beautician were assessed by a physician. Thirty-six unexposed women were included as the control group. Cancer and non-cancer risks of exposure were assessed using deterministic and stochastic methods. Average indoor concentrations of BTEX were higher than those in the ambient air. Urinary BTEX concentrations in the beauty practitioners were significantly higher than in the control group. Linear regression showed that 77% of urinary benzene and toluene variations can be explained by their airborne concentrations. A positive significant relationship was found between age and urinary BTEX concentrations. Although the BTEX cancer and non-cancer risks were not significant, BTEX led to irritation of the eyes, throat, lung, and nose. In addition, toluene caused menstrual disorders among beauty practitioners. These results suggest that it is essential to decrease the exposure of beauty practitioners to BTEX compounds.

The association of hospital emergency admissions due to respiratory-cardiovascular diseases and acute myocardial infarction with air pollution in Tehran during 2005-2014.

Background: Air pollution is one of the main reasons for disease and emergency hospitalizations. Therefore, air pollution control and hospital preparedness are of paramount importance. This study was conducted to determine the association of air pollutant levels with the rate of hospital emergency admissions due to respiratory and cardiovascular diseases and acute myocardial infarction in Tehran during the last decade. Methods: This was a cross sectional study. At first, information on hourly concentration of air pollutants was gathered from Tehran Environmental Protection Agency and Air Quality Control Company. Raw data and meteorological parameters were used in Excel format to prepare an input file. The number of emergency hospital admissions due to pollutant exposure was assessed using the AirQ2.2.3 model. Results: Results of this study revealed that there were 54 352 cases of emergency hospitalizations due to respiratory diseases in a relative risk of 1.0048 [1.0008-1.0112] and 20 990 cases of emergency hospitalizations due to cardiovascular diseases in a relative risk of 1.009[1.006-1.013] during 2005-2014. In addition, 3478 patients were admitted to the emergency department because of acute myocardial infarction with RR of 1.0026 [1.0026-1.0101]. Conclusion: This study demonstrated that a high percentage of hospital emergency admissions was because of respiratory and cardiovascular diseases. Moreover, it was found that acute myocardial infarction could be due to the high level of air pollution and could increase admissions to the emergency department. Therefore, appropriate measures are needed to reduce air pollution and increase hospital preparedness.

Health benefits of PM10 reduction in Iran.

Air pollution contains a complex mixture of poisonous compounds including particulate matter (PM) which has wide spectrum of adverse health effects. The main purpose of this study was to estimate the potential health impacts or benefits due to any changes in annual PM10 level in four major megacities of Iran. The required data of PM10 for AirQ software was collected from air quality monitoring stations in four megacities of Iran. The preprocessing was carried out using macro coding in excel environment. The relationship between different presumptive scenarios and health impacts was determined. We also assessed the health benefits of reducing PM10 to WHO Air Quality Guidelines (WHO-AQGs) and National Ambient Air Quality Standards (NAAQSs) levels with regard to the rate of mortality and morbidity in studied cities. We found that the 10 µg/m3 increase in annual PM10 concentration is responsible for seven (95% CI 6-8) cases increase in total number of deaths per 2 × 105 person. We also found that 10.7, 7.2, 5.7, and 5.3% of total death is attributable to short-term exposure to air pollution for Ahvaz, Isfahan, Shiraz, and Tehran, respectively. We found that by attaining the WHO's proposed value for PM10, the potential health benefits of 89, 84, 79, and 78% were obtained in Ahvaz, Isfahan, Shiraz, and Tehran, respectively. The results also indicated that 27, 10, 3, and 1% of health impacts were attributed to dust storm days for Ahvaz, Isfahan, Shiraz, and Tehran, respectively.

Contaminants of emerging concern: a review of new approach in AOP technologies.

The presence of contaminants of emerging concern (CECs) such as pharmaceuticals and personal care products (PPCPs), endocrine-disrupting compounds (EDCs), flame retardants (FRs), pesticides, and artificial sweeteners (ASWs) in the aquatic environments remains a major challenge to the environment and human health. In this review, the classification and occurrence of emerging contaminants in aquatic environments were discussed in detail. It is well documented that CECs are susceptible to poor removal during the conventional wastewater treatment plants, which introduce them back to the environment ranging from nanogram per liter (e.g., carbamazepine) up to milligram per liter (e.g., acesulfame) concentration level. Meanwhile, a deep insight into the application of advanced oxidation processes (AOPs) on mitigation of the CECs from aquatic environment was presented. In this regard, the utilization of various treatment technologies based on AOPs including ozonation, Fenton processes, sonochemical, and TiO2 heterogeneous photocatalysis was reviewed. Additionally, some innovations (e.g., visible light heterogeneous photocatalysis, electro-Fenton) concerning the AOPs and the combined utilization of AOPs (e.g., sono-Fenton) were documented.

The safety of non-incineration waste disposal devices in four hospitals of Tehran.

BACKGROUND: The safe management of hospital waste is a challenge in many developing countries. OBJECTIVES: The aim of this study was to compare volatile organic compounds (VOCs) emissions and the microbial disinfectant safety in non-incineration waste disposal devices. METHODS: VOC emissions and microbial infections were measured in four non-incineration waste disposal devices including: autoclave with and without a shredder, dry heat system, and hydroclave. Using NIOSH and US EPA-TO14 guidelines, the concentration and potential risk of VOCs in emitted gases from four devices were assessed. ProSpore2 biological indicators were used to assess the microbial analysis of waste residue. RESULTS: There was a significant difference in the type and concentration of VOCs and microbial infection of residues in the four devices. Emissions from the autoclave with a shredder had the highest concentration of benzene, ethyl benzene, xylene, and BTEX, and emissions from the hydroclave had the highest concentration of toluene. The highest level of microbial infection was observed in the residues of the autoclave without a shredder. CONCLUSIONS: There is an increased need for proper regulation and control of non-incinerator devices and for monitoring and proper handling of these devices in developing countries.

Evaluating the photocatalytic performance of MOF coated on glass for degradation of gaseous styrene under visible light.

Styrene is a volatile organic compound with various applications, especially in the plastics and paint industries. Exposure to it leads to symptoms such as weakness, suppression of the central nervous system, and nausea, and prolonged exposure to it increases the risk of cancer. Its removal from the air is a topic that researchers have considered. Various methods such as absorption, membrane separation, thermal and catalytic oxidation, biofiltration have been used to remove these compounds. The disadvantages of these compounds include the need for high energy, production of secondary pollutants, large space, providing environmental conditions (temperature and humidity) and long time. The photocatalyst process is considered as an advanced process due to the production of low and safe secondary pollutants. MOFs are nanoparticles with unique photocatalytic properties that convert organic pollutants into water and carbon dioxide under light irradiation and in environmental conditions, which prevent the production of secondary pollutants. The present study aimed to investigate the efficiency of MIL100 (Fe) nanoparticles coated on glass in removing styrene vapor from the air. Surface morphology, crystal structure, pore size, functional groups, and chemical composition of the catalyst were analyzed by SEM, XRD, BET, FTIR, and EDX analysis. The effect of parameters such as initial pollutant concentration, temperature, time, relative humidity, and nanoparticle concentration was evaluated as effective parameters in the removal process. Based on the results, MIL100 (Fe) 0.6 g/l with an 89% removal rate had the best performance for styrene removal. Due to its optimal removal efficiency, it can be used to degrade other air pollutants.

Evaluating the mortality and health rate caused by the PM2.5 pollutant in the air of several important Iranian cities and evaluating the effect of variables with a linear time series model.

All over the world, the level of special air pollutants that have the potential to cause diseases is increasing. Although the relationship between exposure to air pollutants and mortality has been proven, the health risk assessment and prediction of these pollutants have a therapeutic role in protecting public health, and need more research. The purpose of this research is to evaluate the ill-health caused by PM2.5 pollution using AirQ + software and to evaluate the different effects on PM2.5 with time series linear modeling by R software version 4.1.3 in the cities of Arak, Esfahan, Ahvaz, Tabriz, Shiraz, Karaj and Mashhad during 2019-2020. The pollutant hours, meteorology, population and mortality information were calculated by the Environmental Protection Organization, Meteorological Organization, Statistics Organization and Statistics and Information Technology Center of the Ministry of Health, Treatment and Medical Education for 24 h of PM2.5 pollution with Excel software. In addition, having 24 h of PM2.5 pollutants and meteorology is used to the effect of variables on PM2.5 concentration. The results showed that the highest and lowest number of deaths due to natural deaths, ischemic heart disease (IHD), lung cancer (LC), chronic obstructive pulmonary disease (COPD), acute lower respiratory infection (ALRI) and stroke in The effect of disease with PM2.5 pollutant in Ahvaz and Arak cities was 7.39-12.32%, 14.6-17.29%, 16.48-8.39%, 10.43-18.91%, 12.21-22.79% and 14.6-18.54 % respectively. Another result of this research was the high mortality of the disease compared to the mortality of the nose. The analysis of the results showed that by reducing the pollutants in the cities of Karaj and Shiraz, there is a significant reduction in mortality and linear modeling provides a suitable method for air management planning.

Biological feasibility of discharge a local WTTP sludge to sewer network and centralized WWTP; a case study: Tehran, Iran.

Over the recent years, ever-increasing population growth and higher wastewater production has been a challenge for decentralized wastewater treatment plants (WWTPs). In addition, sludge treatment due to high cost for equipment and place make authorities to find a sustainable approach in both of economical and technical perspectives. One of the proposed solutions is transferring the sludge produced from decentralized WWTP to centralized WWTP. However, the appropriate proportional ratio of raw sludge to raw sewage is a challenge, otherwise, it make anaerobic conditions and sewage rotting along the sewer network based on permissible limit of dihydrogen sulfide (H2S) gas (5 ppm). In the present study, seven reactors with different ratios of sludge to raw sewage (0, 15, 20, 25, 50, 75, 100) were used to stimulate the feasibility of transferring Shahrake Gharb WWTP sludge along the wastewater transfer pipe to the centralized sewage treatment south Tehran WWTP plant in Tehran, Iran. The septic situation and H2S emission of different reactors within 7 h (Time to reach the compound in the south treatment plant) was analyzed by gas meter. The results indicated that the optimum ratio of sludge to raw sewage was 15% without H2S production during 7 h. In addition, due to the high volume of sludge produced by the Shahrake Gharb WWTP, the optimal ratio of lime to total solids (TS) in sludge (gr/gr) (0.6) increased the sludge loading rate from 15 to 30% without any H2S emission during the stimulation study period. Therefore, the lime stabilization and transfer of sludge from a decentralized WWTP to a centralized WWTP is a feasible way to manage the sludge and enhance the treatment capacity in local WWTP.