Carcinogenic risks and chemical composition of particulate matter recovered by two methods: wet and dry extraction

Wet and dry extraction methods are two main methods used in toxicological in vitro and in vivo studies to recover particulate matter (PM) from filter papers. The aim of this study was to extract PM by wet and dry extraction methods and compare the elemental content and carcinogenic risks of extracts. PM10 samples were collected using fiberglass filters and a high-volume air sampler. For wet extraction, the method involved agitation in water, sonication in water bath, and agitation again. For dry extraction, the filters were sonicated and the PM was recovered using sweeping by a brush. Elemental composition of extracts was determined by inductively coupled plasma-optical emission spectrometry (ICP-OES). Excess lifetime cancer risks (ELCR) of As, Cd, Cr, Ni, and Pb in extracts were estimated. The average recovery efficiency () of dry and wet extraction methods were 36.8 and 58.5, respectively. The average elemental concentration that resulted from dry and wet methods was calculated to be 2.27 and 1.26 μg/m3, respectively. The total ELCR of all heavy metals in both methods exceeds the 1 � 10�6 limit. However, the total ELCR of heavy metals that resulted from the dry method was higher than that from the wet method. In conclusion, the dry method showed to be more effective to recover a representative extract from the filter. This can ultimately lead to a realistic and robust response in toxicological studies. However, a toxicological comparison between the extracts of these two methods is required. © 2020, Springer Nature Switzerland AG

Comparing effects of in-home decontamination procedures by common components on antioxidant activity and microbial load in some selected vegetables

Aims: Decontamination procedures are different in each country, as the other applications of disinfection, and standards. The aim of this study was to evaluate the effects of household decontaminations and storage time on the antioxidant activity and microbial load of salad vegetables. Instrument & Methods: This analytic-descriptive study was conducted on 4 types of salad vegetables; cucumber, tomato, lettuce, and sweet basil. After washing, samples with storage time of 0 day were analyzed immediately. Other samples were held in 4°C for 3 and 5 days. Five different washing and decontamination methods were compared; water washing, detergent washing, benzalkonium chloride, sequential washing and Kanz disinfecting method. The Ferric Reducing Ability of Plasma assay was used to measure the antioxidant activity. Aerobic mesophyll bacteria and total coliforms were chosen as microbial load index. ANOVA and Tukey post-hoc tests were used to analyze the data. Findings: By increasing the storage time, the antioxidant activity of all types of vegetables reduced. There was a significant decrease in antioxidant activity in all types of vegetables using sequential washing method with water, detergent, and benzalkonium chloride and Kanz disinfection method. All washing methods were effective in decontamination for either mesophyll bacteria or total coliforms, except for total coliforms in lettuce. There was no significant difference in microbial load among first 4 methods of washing (p>0.05), but a significant difference was observed in Kanz disinfection method (p<0.05). Conclusion: Kanz disinfection is the most effective decontamination method to eliminate microorganisms index, which also reduce the antioxidant activity

A letter about the airborne transmission of sars-cov-2 based on the current evidence

World Health Organization has suggested that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is transmitted through person-to-person transmission and contact with contaminated surfaces. However, rapid spread of the coronavirus disease 2019 (COVID-19) suggests other routes such as airborne transmission may be involved. A few research studies have been conducted to evaluate the potential transmission of this virus through air. Although some studies have found no evidence of airborne transmission, other more recent work is proving the presence of SARS-CoV-2 even in public places. Also, the past experiences and knowledge about the mechanisms of similar viruses such as SARS-CoV support this hypothesis. It seems that the best decision at the moment is to follow a conservative approach, and accept the hypothesis that SARS-CoV-2 is able to be transmitted through air. By this, control measures could be employed to prevent further COVID-19 infection. © Taiwan Association for Aerosol Research

Correction to: Indoor and outdoor concentrations of BTEX and formaldehyde in Tehran, Iran: effects of building characteristics and health risk assessment (Environmental Science and Pollution Research, (2018), 10.1007/s11356-018-2794-4)

The original publication of this paper contains a mistake. The correct name and affiliation of the 3rd Author is presented in this paper. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature

Airborne particulate matter in Tehran�s ambient air

In recent decades, particulate matter (PM) concentrations in Tehran have exceeded the World Health Organization�s (WHO) guideline on most days. In this study, a search protocol was defined by identifying the keywords, to carry out a systematic review of the concentrations and composition of PM in Tehran�s ambient air. For this purpose, searches were done in Scopus, PubMed, and Web of Science in 2019. Among the founded articles (197 in Scopus, 61 in PubMed, and 153 in Web of Science). The results show that in Tehran, the annual average PM10 exceeded the WHO guidelines and for more than 50.0 of the days, the PM2.5 concentration was more than WHO 24-h guidance value. The PM concentration in Tehran has two seasonal peaks due to poorer dispersion and suspension from dry land, respectively. Tehran has two daily PM peaks due to traffic and changes in boundary-layer heights; one just after midnight and the other during morning rush hour. Indoor concentrations of PM10 and PM2.5 in Tehran were 10.6 and 21.8 times higher than the corresponding values in ambient air. Tehran represents a unique case of problems of controlling PM because of its geographical setting, emission sources, and land use. This review provided a comprehensive assessment for decision makers to assist them in making appropriate policy decisions to improve the air quality. Considering factors such as diversity of resources, temporal and spatial variations, and urban location is essential in developing control plans. Also future studies should focus more on PM reduction plans. © 2021, Springer Nature Switzerland AG

Spatial and temporal trends of short-term health impacts of PM2.5in Iranian cities; A modelling approach (2013�2016)

Estimation of the spatial and temporal trends of health impacts attributable to air pollution is an effective measure for evaluating implemented interventions. The aim of this study was to estimate the short-term mortality attributable to exposure to PM2.5among individuals older than 30 years old in ten Iranian cities from March 2013 to March 2016 using the World Health Organization�s (WHO) AirQ+ software. Hourly concentrations of PM2.5were acquired from the Department of Environment and Tehran Air Quality Control Company. Only stations with 75 and 50 of valid data were qualified for Tehran and other cities, respectively. The annual average PM2.5concentrations in all ten of the cities were higher than the WHO guideline value of 10 µg m�3The total number of attributable short-term deaths during the three-year period in these 10 cities was 3284 (95 CI: 1207�5244). The average daily premature deaths were calculated to be 3. The highest number of premature deaths within the three-year period was estimated to be 548 in Tehran, largely reflecting its population of nearly 9 million. The western and southern cities of Iran experience severe dust storms and showed a high estimated rate of death attributed to air pollution. The health impacts in all cities decreased in the third year compared to the first year except for Ahvaz, Khoram Abad, and Ilam. Governmental interventions need to be enforced more effectively to reduce the high level of adverse health impacts in Iran. Special considerations should be given to the air quality of cities affected by dust storms. © Taiwan Association for Aerosol Research

Rodent-borne and rodent-related diseases in Iran

Abstract Rodents cause large financial losses all over the world; in addition, these animals can also act as a reservoir and intermediate host or vector of diseases. Rodents have an important role in the distribution of diseases in an area. Sometimes, the distribution of a particular disease in an area depends on the distribution of rodents in that area. This study focuses on the distribution of rodent-related diseases in Iran. Rodent-borne and rodent-related diseases and diseases with suspected relationship with rodents have been reviewed in this study. Iran, due to the circumstances in which different species of rodents are able to live, has a high prevalence of certain diseases associated with rodents in urban and rural areas. Awareness about the distribution of rodent-related diseases can be a great help to rodent’s control and prevention against the spread of the diseases. Keywords Rodent disease Disease transmission Pest control Public healt

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. © 202