Study of Noise Pollution in Urban and the Suburbs Railway

  Background and aims: Noise pollution is one of the risk factors of the human environment that may seriously threat physical and mental health of human beings. One of the main sources of this type of pollution is the noise produced by urban transportation and traffic, particularly subway in the environment. This article aims at study and evaluation of the noise condition in drivers’ cabin and inside wagons of the subway of Tehran and the suburbs.   Methods: Noise level and noise frequency analysis in the trains of lines one, two, four and five of the subway which are among the active lines of Tehran subway and the suburbs have been measured and evaluated at 345 points within one week over two days while the train was moving and stopped of which 96 points were located inside the driver’s cabin and 258 points were in wagons. Noise was evaluated based on Free Air Standard approved by the Environment Higher Council of Iran and ACGIH Organization. The subway trains were also compared regarding noise pollution based on type of the train (TM, DC, AC ). Calibrated analyzer instrument, model CEL-450/490 was used to measure noise and the data were analyzed by statistical descriptive methods, t-test and analysis of variance by SPSS18 software.   Results: Mean equivalent noise level measured in the moving wagon was equal to 71.9 dBA that is significantly higher than the standard level (65 dBA) ( P<0.01). In case the mean equivalent noise level measured in the moving cabin is equal to 73.3 dBA, that is significantly less than the standard level (85 dBA) (P<0.01). There is a significant difference between mean noise pressure level in wagon and in driver’s cabin while moving and stoppage (P<0.01). However, there is no significant difference between noise pressure level in the wagon and driver’s cabin while moving (p=0.5). There is no significant difference between the mean noise pressure level while moving and stoppage in different frequencies inside the wagon (p=0.5). However, there is a significant difference between the mean noise pressure level while moving and stoppage in 250 and 500 frequencies in the cabin (P<0.01). TM1 and TM2 trains are in the same class considering mean noise equal level and noise pressure (P=0.667) and AC and DC trains are in the same class (P=0.5) and their mean noise is equal to 69.5 and 73, respectively.   Conclusion: The results obtained in this research showed that the mean equivalent noise level in the cabins is less than the authorized limit; however, it is higher than the authorized limit in the wagon. Therefore, it seems necessary to take control and prevention measures for noise reduction inside wagons.

Biological and environmental monitoring of lead and exposure in the automobile industry

Background and Aims: Soldering is one of the most common activities in metal industries. Lead is used in soldering process and has considerable toxic effects. The aim of this study, therefore, was biological and environmental monitoring and investigating the effects of exposure to lead in soldering unit workers at an automobile industry.     Methods: In order to evaluate biological and environmental exposure to lead, a case-control study was accomplished on 60 workers in soldering unit (case group) and 60 workers in official unit (control group). Demographical and medical information were gained by a questionnaire. Blood samples were collected and analyzed using the NIOSH 8003 method and Atomic Absorption Spectroscopy (AAS) respectively and air samples were collected and analyzed using the NIOSH 7300 method and Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) respectively.     Results: The obtained results shown that, with the increasing of age and work experience, the blood lead level is also increased.(p=0.033)(p=0.003) In exposed group, the blood lead mean value was significantly higher than the control group (p-value<0.001). Prevalence of digestive, nervous, respiratory, dermal, kidney disorders, anemia diseases, and disorder in bone metabolism in exposed group were higher than the control group. The amount of lead level was negatively correlated with hemoglobin (r=-0.287;p=0.026) and hematocrit (r=-0.336;p=0.009) but There was no significant correlation between air and blood lead level.     Conclusion: The blood lead level may be increased in lead exposure due absence of personal protective equipment and poor personal hygiene. Increased lead level in blood can be resulted to various diseases and decrease in hemoglobin and hematocrit levels in blood

Hiv-related knowledge and stigma among the general population in the southeast of iran

Background: HIV-related stigma is a barrier to effective HIV responses among people living with HIV (PLHIV). Objectives: The current study aimed at measuring HIV-related stigma, and its associated factors among the general population in the Southeast of Iran. Methods: The current cross-sectional study was conducted on a convenience sample of 900 individuals in Kerman, Southeast of Iran, from July to September 2016. Data was collected using a self-administered questionnaire, including (I) demographic and background characteristics; (II) HIV-related stigma; and (III) HIV-related knowledge. Data were analyzed with SPSS version 20 using descriptive statistics, as well as bivariable and multivariable linear regressions. Results: Low, moderate, and high levels of stigmatizing attitudes toward PLHIV were reported by 39.1, 57.8, and 3.1 of the participants, respectively. Female sex(beta = 0.33, P value = 0.01) and those not having a history of HIV testing (beta = 0.45, P value < 0.001) had, on average, higher levels of stigmatizing attitudes, while those with a higher level of education (beta =-0.97, P value < 0.001) had, on average, lower levels of stigmatizing attitudes. Conclusions: Gender-sensitive educational interventions need to be developed to reduce the negative attitude towards PLHIV in Iran. © 2020, Author(s)