Rahele Valizadeh Ardalan; Mitra Mohammadi; Mohammad Sadegh Bahadori
Abstract
Background and Purpose: Increasing population growth and technological advancements in cities inevitably result in rising noise pollution levels. The emergence of the coronavirus disease worldwide, including Iran, has significantly altered people's daily lives. This has presented a unique opportunity ...
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Background and Purpose: Increasing population growth and technological advancements in cities inevitably result in rising noise pollution levels. The emergence of the coronavirus disease worldwide, including Iran, has significantly altered people's daily lives. This has presented a unique opportunity to assess changes in sound levels. Therefore, this study aims to investigate sound level variations before the outbreak and during the COVID-19 restrictions at a pivotal intersection in Mashhad.Materials and Methods: The initial segment of this study examined the sound equivalent level in April 2018 and 2019 without considering any specific circumstances at the Shohada crossroad. In the second segment, employing SPSS22 software and the Wilcoxon test, we compared the alterations in various sound level indicators before the disease prevalence (April 2018) and during the restrictions (April 2019).Results: The results of the first part of the study revealed that the hourly equivalent sound level (Leq) in April 2018 and 2019 was 70.48 and 70.39 dB, respectively. The results of the second part indicated a significant difference between the two periods under investigation in terms of equivalent sound levels. The maximum and minimum sound equivalent levels (LMax, Lmin) reduction during the disease outbreak compared to the pre-outbreak period was 0.16 and 0.08 dB, respectively. Additionally, during the night curfew hours (21-03) in April 2019, the sound equivalent level decreased by 0.09 dB compared to 2018. Conclusion: The findings of this study demonstrate that the equivalent sound level at the Shohada crossroad in Mashhad exceeded national standards before the disease prevalence. However, noise pollution levels have decreased due to decreased economic activities during the outbreak and the associated restrictions. Nonetheless, the equivalent sound level still surpasses the established standards, indicating that noise pollution at the mentioned intersection persists. Further research is warranted on this subject, encompassing traffic modeling, noise pollution emission inventories, establishing links between land use patterns and noise pollution, and the influence of weather conditions on sound levels.
Mitra Mohammadi; Sepideh Ansari; Zeinab Asghari; Samaneh Najafi; Zohreh Mirzaei Niko; Elahe Khayyami
Abstract
Background and purpose: Vegetables are among the valuable foods. However, in addition to essential elements, they may contain toxins in excess of permissible concentrations, which has raised many concerns about the quality and safety of these products and human health. Therefore, the present study was ...
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Background and purpose: Vegetables are among the valuable foods. However, in addition to essential elements, they may contain toxins in excess of permissible concentrations, which has raised many concerns about the quality and safety of these products and human health. Therefore, the present study was conducted to investigate the effect of atmospheric pollutants of carbon dioxide, gasoline and acid rain on the resistance of basil and parsley.Materials and Methods: This factorial study was performed based on a completely randomized design with 3 replications and 54 treatments . In this study, CO2 with three concentrations of 0, 1000 and, 1800 ppm, gasoline with three conditions without adding gasoline, with ordinary gasoline and with the addition of super gasoline, and acidic solution at two levels of pH 4 and 6 were studied. It should be noted that distilled water with pH = 7 was selected as a control treatment.Results: The results showed that the concentration of 1000 ppm carbon dioxide increased plant yield by 178.63%, while its concentration up to 1800 ppm, led to the destruction of the plant in two days. It was also found that super gasoline due to the high-octane number and supplements in it has a less polluting effect (5.7%) on the plant than regular gasoline. In addition, no significant difference was observed between different concentrations of acidic solution on plant resistance. In this experiment, parsley showed more resistance to contaminants than basil.Conclusion: carbon dioxide than other pollutants and also its key role in global warming, we need effective management to promote public health and control the production sources of this gas in the atmosphere.