Trust in primary health care and COVID-19 vaccine uptake among Iranian pediatric: a web-based cross-sectional survey.

BACKGROUND: Children are the most vulnerable group to diseases. Thus, it's critical to evaluate parents' or guardians' willingness to vaccinate their children. This study aims to investigate the prevalence and predictors of pediatric COVID-19 vaccination in Iran and its relationship with trust in the Primary Health Care (PHC) system. METHOD: A cross-sectional online survey of 549 Iranian parents was conducted between January and March 2023. This study collected data from all provinces of Iran using a questionnaire shared on Google Forms and various social media platforms. After considering various background factors, we used a multivariable logistic regression model. This model explored how trust in the PHC system and parent-related and child-related factors were related to parents' vaccine uptake for their children. RESULTS: Of 549 parents aged between 19 and 67 years (median = 38 years), 65.2% (358) were female. The prevalence of vaccine uptake among parents was 46.8%. After adjusting for background features, child's age (adjusted odds ratio [AOR] 0.81, 95% CI 0.71-0.91), vaccine doses (1-dose: AOR 14.72, 95% CI 6.44-33.65, 2-dose: AOR 32.54, 95% CI 15.22-69.57), child's disease (AOR 5.31, 95% CI 2.19-12.85), and trust in PHC (AOR 1.01, 95% CI 1.00-1.02) were associated with parental uptake of the COVID-19 vaccine. CONCLUSIONS: The findings of this study suggest that the child's age, vaccine doses received, diseases, and trust in PHC are significant predictors of parental uptake of the COVID-19 vaccine for children in Iran. The results can be used in service planning regarding children's COVID-19 vaccination.

Spatio-temporal analysis of deaths from carbon monoxide poisoning in Iran between 2011 and 2018: An ecological study.

Background and Aims: Mortality caused by carbon monoxide every year threatens the lives of Iranian people, whose spatial and temporal distribution is not known for formulating prevention policies and interventions. This study was conducted to determine the trend of mortality rate changes due to carbon monoxide CO poisoning by Spatio-temporal analysis in Iran from 2011 to 2018. Methods: An ecological study was conducted based on data from the reports at the National Center for Statistics of Iran for 8 years from 21 March 2011 to 21 March 2018. The number of deaths due to CO poisoning and the annual mortality rates of CO poisoning per 100,000 populations were calculated. To determine the geographical and temporal distribution of death caused by carbon monoxide, spatiotemporal statistical analysis was used. Results: A total of 6078 deaths were reported due to CO poisoning 4497 deaths were male (74%) and 1596 were female (26%) from 2011 to 2018. Both sexes' mortality rate due to CO poisoning was 1.26 from 2011 to 0.91 in 2018. According to the results, the overall male-to-female ratio was 2.8. The mortality rate due to CO Poisoning had a decreasing trend. However, this trend did not have a linear trend (p = 0.37). The highest mortality due to CO poisoning was seen in the northern and western provinces of Iran. Conclusion: Our results showed that the mortality rate due to CO poisoning had a decreasing trend during the understudied period. Also, most of the deaths due to CO poisoning occurred in the northern and western provinces of Iran. So, designing prevention programs as well as increasing people's awareness in these regions is recommended.

Road traffic injuries and associated mortality in the Islamic Republic of Iran.

Background: Road traffic accidents are a major public health problem globally, causing millions of injuries, deaths and disabilities, and a huge loss of financial resources, especially in low- and middle-income countries. Aim: To determine the incidence of road traffic injuries and associated mortality from 1997 to 2020 in the Islamic Republic of Iran. Methods: This retrospective study used data from the Legal Medicine Organization of the Islamic Republic of Iran to estimate the annual rates of road traffic injuries and associated mortality from 21 March 1997 to 20 March 2020. The data were analysed using STATA version 14 and the annual rates are reported per 100 000 population. Results: During the study period, 5 760 835 road traffic injuries and 472 193 deaths were recorded in the Islamic Republic of Iran. The mortality rate increased from 22.4 per 100 000 in 1997 to 40 per 100 000 in 2005 and decreased to 18.4 per 100 000 in 2020. The injury rate increased from 111.1 per 100 000 in 1997 to 394.9 per 100 000 in 2005. It decreased in 2006 and 2007 and increased from then until 2010, finally reaching 331.8 per 100 000 in 2020. The male to female ratio for road traffic mortality was 3.9 in 1997 and 4.6 in 2020. The case fatality rate was highest (20.1%) in 1997 and decreased to 5.6% in 2020. Conclusion: Continuous interventions are needed to reduce the burden of road traffic injuries and associated mortality in the Islamic Republic of Iran.

Epidemiology of Ocular Trauma in the Elderly: A Population-Based Study.

Purpose: To determine the prevalence of different types of ocular trauma and their relationship with some factors in the elderly population. Methods: The present population-based cross-sectional study was conducted on the elderly population aged 60 years and above in Tehran, Iran, using multi-stage stratified random cluster sampling in 2019. After selecting the samples and their participation in the study, demographic information and history of ocular trauma were obtained through an interview. Psychological evaluation was performed using the Goldberg's 28-question General Health Questionnaire. All study participants underwent optometric and ophthalmological examinations. Results: Three thousand three hundred and ten people participated in the study (response rate: 87.3%). Of these, 1912 individuals (57.8%) were female and the mean age of individuals was 68.25 ± 6.55 (from 60 to 97) years. 7.46% (95% confidence interval [CI]: 6.51-8.41) of the study participants reported a history of ocular trauma. Blunt and chemical traumas were the most and the least common types of ocular trauma, respectively (5.72% and 0.16%). 3.93% of cases visited an ophthalmologist for ocular trauma, 1.67% reported a history of hospitalization, and 1.47% underwent surgery. The prevalence of visual impairment in individuals with a history of ocular trauma was 12.53%. Visual impairment was more prevalent in people with a history of ocular trauma than those without a history of ocular trauma (P < 0.05). History of ocular trauma was only significantly related to low education level (odds ratio = 0.63, 95% CI = 0.40-0.99). Participants with a history of ocular trauma had more anxiety and higher mean psychological distress score than those without a history of ocular trauma (P = 0.035). Conclusions: The development of preventive programs against the occurrence of ocular trauma can play an important role in reducing the psychological damage of affected patients while reducing visual disorders. These interventions should be especially considered in groups with a lower education level.

Intensive care unit admission and associated factors in patients hospitalised for COVID-19: A national retrospective cohort study in Iran.

OBJECTIVES: This study aimed to determine factors associated with intensive care unit (ICU) admission in patients hospitalised due to COVID-19. DESIGN: Retrospective cohort. SETTING: Confirmed hospitalised patients from all over Iran were considered for the study. PARTICIPANTS: All patients with COVID-19 admitted to the hospital from March 2020 to May 2021 were included by census. ICU admission was defined by the following criteria: (1) admission to the ICU ward; (2) level of consciousness (loss of consciousness); and (3) use of invasive ventilation. METHODS: This is a secondary data analysis from the Medical Care Monitoring Center. The association between different variables and ICU admission was assessed by forward Logistic regression and restricted cubic spline method. RESULTS: The mean age of the 1 469 620 patients with COVID-19 was 54.49±20.58 years old, and 51.32% of the patients were male. The prevalence of ICU admission was 19.19%. The mean age of patients admitted to the ICU was higher than that of other hospitalised patients (62.49±19.73 vs 52.59±20.31 years). The prevalence of ICU admission was 17.17% in the first, 21.52% in the second, 19.72% in the third, 21.43 in the fourth and 17.4% in the fifth wave. In the multivariable model, age groups, sex, waves of the epidemic, comorbidities and saturation of peripheral oxygen (SpO2) <93% and acute respiratory distress syndrome (ARDS) were associated with an increased odds of ICU admission. The OR for ICU admission indicates a significant protective effect at a young age and then a significant risk factor for admission to the ICU ward at an old age. CONCLUSIONS: Men, older adults, people who suffer from ARDS, patients with SpO2 levels of less than 93% and cases with comorbidities had the highest odds of ICU admission. Therefore, these groups should take all necessary precautions to avoid contracting COVID-19.

Trend of Conflict Rate in Iran from 2014 to 2020: An Ecological Study.

BACKGROUND: Detecting the correlation of conflict rate within provinces over time provides a better understanding for health policymakers in identifying potential causes. The purpose of this study was to assess the trend of conflict rate in 31 provinces of Iran using the growth mixture model (GMM). METHODS: This ecologic study was conducted based on the data obtained from the Iranian Legal Medicine Organization (ILMO) by gender and provinces between March 21, 2014 and March 21, 2020. First, the 7-year cumulative incidence rates were described; second, the trend of conflict rate was modeled by a linear mixed-effects model according to gender and overall; finally, distinct classes of provinces with similar conflict trends in seven years were identified using the GMM. The significance level was considered less than 0.05. RESULTS: Among provinces, Ardebil and Sistan Baluchistan had the highest and the lowest 7-year conflict incidence rates (95% CI) with 66.6 (52.38, 84.67) and 20.79 (13.53, 31.95) per 100000, respectively. The results of the linear mixed-effects model showed that the annual rate of conflict in Iran decreased by 0.37% from 2014 to 2017 and then slightly increased by 0.07% after 2017. In addition, the GMM results indicated that the trends for Iranian provinces can be clustered into four distinct classes. CONCLUSION: Our study showed the increasing growth of conflict in the last years in most provinces of Iran. Necessary interventions are important to prevent the rising conflict rate due to the various effects of conflict on psychological, social, and health factors.

Risk Factors Associated with Severity and Death from COVID-19 in Iran: A Systematic Review and Meta-Analysis Study.

Objectives: This study aims to investigate the risk factors associated with severity and death from COVID-19 through a systematic review and meta-analysis of the published documents in Iran. Methods: A systematic search was performed based on all articles indexed in Scopus, Embase, Web of Science (WOS), PubMed, and Google Scholar in English and Scientific Information Database (SID) and Iranian Research Institute for Information Science and Technology (IRA)NDOC indexes in Persian. To assess quality, we used the Newcastle Ottawa Scale. Publication bias was assessed using Egger's tests. Forest plots were used for a graphical description of the results. We used HRs, and ORs reported for the association between risk factors and COVID-19 severity and death. Results: Sixty-nine studies were included in the meta-analysis, of which 62 and 13 had assessed risk factors for death and severity, respectively. The results showed a significant association between death from COVID-19 and age, male gender, diabetes, hypertension, cardiovascular disease (CVD), cerebrovascular disease, chronic kidney disease (CKD), Headache, and Dyspnea. We observed a significant association between increased white blood cell (WBC), decreased Lymphocyte, increased blood urea nitrogen (BUN), increased creatinine, vitamin D deficiency, and death from COVID-19. There was only a significant relationship between CVD and disease severity. Conclusion: It is recommended that the predictive risk factors of COVID-19 severity and death mentioned in this study to be used for therapeutic and health interventions, to update clinical guidelines and determine patients' prognoses.

Predictors of receiving COVID-19 vaccine among adult population in Iran: an observational study.

BACKGROUND: Vaccination is one of the best ways to stop the transmission of coronavirus disease 2019 (COVID-19). In this regard, uunderstanding the features related to the intention of different populations to receive the COVID-19 vaccine is essential for an effective vaccination program. This study aimed to investigate the vaccination intention predictors in the general adult population of Iran. METHODS: A cross-sectional, web-based survey was conducted on social networks, including Telegram, WhatsApp, LinkedIn, Instagram, and Facebook. Multinomial logistic regression models were used to investigate predictors associated with the intention to receive COVID-19 vaccines, including sociodemographic characteristics, trust, worry, sources of information, and conspiracy beliefs. The main outcomes included unwillingness, undecidedness, and intention to receive the COVID-19 vaccine. RESULTS: Out of 780 respondents, 481 (61.6%) reported an intention to be vaccinated, 214 (27.4%) expressed their undecided status, and 85 (10.9%) reported unwillingness to receive any type of COVID-19 vaccine. A higher age (OR undecided = 0.97, 95% CI (0.96-0.99)), (OR unwilling = 0.97, 95% CI (0.95-0.99)); exposure with COVID-19 (OR unwilling = 0.82, 95% CI (0.76-0.89)), (OR undecided = 0.87, 95% CI (0.83-0.93)) were positively associated with vaccination intentions. No/low trust in vaccines, institutions, concerns about the future of the pandemic, and conspiracy beliefs were strongly and negatively associated with COVID-19 vaccination intentions. CONCLUSION: Most Iranians intended to get a COVID-19 vaccine. Higher vaccine acceptance needs to consider demographic features, exposure history, confidence in vaccines, trust in institutions, concerns, and conspiracy beliefs of people.

Adverse Impacts of Imposing International Economic Sanctions on Health.

BACKGROUND: International economic sanctions (IES) influence a country's economic development and the overall welfare of a nation's population. METHODS: An electronic search of PubMed, Embase and Web of Science was conducted until July 31, 2019. Additionally, a list of references to related articles was reviewed. Key search terms were "Economics", "Health", "Sanction", and their equivalents with no language or time restriction. RESULTS: Totally, 8624 records were identified of which 2869 duplicates were deleted. Finally, 24 papers met the inclusion criteria and were selected for drafting. The number of papers included for evaluating each factor included healthcare (n=16) and pharmaceutical industry (n=10). Nine and eight studies examined the effect of sanctions imposed on Iran and Iraq, respectively. France, Haiti, Serbia, Cuba, Syria, and other areas such as Africa were also evaluated. Sanctions lead to a decrease in immunization rates and government health care expenditures. Sanctions increase infant and under-five mortality rate, road traffic injuries and fatalities, severe malnutrition, infective diseases, neurologic and visual disorders, as well as shortage of medical or dental instruments and a variety of medicines. Sanctions have adverse impacts on female labor and are associated with disabling hospitals, dispersing medical workers, and facilities for radiation therapy. CONCLUSION: The health status of sanctioned nations in terms of healthcare, and pharmaceutical industry was adversely affected in targeted countries.

The association of cardio-metabolic risk factors and history of falling in men with osteosarcopenia: a cross-sectional analysis of Bushehr Elderly Health (BEH) program.

BACKGROUND: Osteosarcopenia, defined as sarcopenia plus osteopenia/osteoporosis, may increase the risk of fractures and affects morbidity and mortality in the older population. Falling is also common in the elderly and increases the risk of fractures and mortality. We examined the association of cardio-metabolic risk factors with a history of falling in osteosarcopenic men. METHODS: We used the baseline data of the Bushehr Elderly Health (BEH) program. Osteosarcopenia was defined as having both sarcopenia (reduced skeletal muscle mass plus low physical performance and/or low muscle strength) and osteopenia/osteoporosis (T-score ≤ - 1.0). Falling was defined as a self-reported history of an unintentional down on the ground during the previous year before the study. We used logistic regression analysis to estimate the adjusted odds ratio (AOR) with a 95% Confidence Interval (CI) to quantify the associations. RESULTS: All elderly men diagnosed with osteosarcopenia (n = 341), with a mean age of 73.3(±7.4) years, were included. Almost 50(14.7%) participants reported falling. Age showed a positive association with falling (AOR: 1.09, 95%CI: 1.04-1.14). An increase of 10 mmHg in systolic blood pressure(SBP), reduces the odds of falling by 26%(AOR:0.74, 95%CI:0.62-0.89), while a positive association was detected for fasting plasma glucose (FPG), as 10 mg/dl increase in the FPG, raises the chance of falling by 14%(AOR = 1.14, 95%CI:1.06,1.23). Hypertriglyceridemia was inversely associated with falling (AOR = 0.33, 95% CI: 0.12, 0.89). CONCLUSIONS: Falling is a major public health problem in rapidly aging countries, especially in individuals with a higher risk of fragility fractures. Older age-raised fasting plasma glucose and low SBP are associated with falling in osteosarcopenic patients.  Considering the higher risk of fracture in osteosarcopenic men, comprehensive strategies are needed to prevent fall-related injuries in this high-risk population.

Factors Associated With Self-Burning Among Women in Reproductive Age of Ilam: A Case-Control Study in a Western Part of Iran.

OBJECTIVE: Self-burning is one way that some people choose to commit suicide, and it has been seen in many nations. This problem is considered as an uncommon method in developed countries and a common method of suicide in developing countries. The present study aimed to identify the factors associated with self-burning among Iranian women in reproductive age. METHOD: This case-control study was conducted among 228 (57 cases and 171 controls) women in reproductive age from the Imam Khomeini Hospital of Ilam. A self-report questionnaire was used to determine factors associated with self-burning, including job status, domestic violence, mental health status, education levels, smoking and alcohol use, forced marriage, socioeconomic status, drug history, and family history of self-burning. Data analysis was performed using simple and multiple logistic regression to control the effects of possible confounders. RESULTS: There was a significant positive association between self-burning and being unemployed and a housewife. Also, the presence of self-burning was increasingly associated with high domestic violence and having history of forced marriage and decreasingly associated with post-diploma education level and a high socioeconomic level. CONCLUSION: It is recommended that health and social policy makers pay attention to the social and economic aspects that cause self-burning in women to prevent this problem.

The effect of veiling luminance on the disability glare of car headlamps designed in Iran.

Objectives. One of the main risk factors involved in increasing driving accidents at night is due to the veiling luminance of the car's headlights reducing the contrast of images in the retina and, thus, reducing the visual performance of drivers. The aim of this study is to investigate the veiling luminance caused by the headlights of the best-selling vehicles in Iran. Methods. Using the Stiles-Holiday disability glare equation, the veiling luminance of headlights of common vehicles at distances of 10-100 m for both high-beam and low-beam modes of oncoming vehicles was measured on a road for healthy (young, middle-aged and older) drivers. Results. Under high-beam illumination, as the cars approached each other, the average illuminance of the car headlights gradually increased. Moreover, age had a significant impact on the veiling luminance. This study also showed that, in same-age groups, the Samand Souren and Peugeot Pars cars had the highest and lowest mean veiling luminance, respectively. Conclusion. The findings showed that the illuminance (at large distances between two cars) and the angle between the source of glare and the eyes of drivers (as two cars approach to each other) have a dominant influence on the disability glare.

Childhood socioeconomic status and adulthood mental health: results from the survey on employees of Tehran University of Medical Sciences.

BACKGROUND: Socioeconomic status, especially during childhood, is known as one of the key factors affecting health. This study's objective was to investigate the association between childhood socioeconomic and mental health status in adulthood. METHODS: This cross-sectional study was conducted on 2062 employees of Tehran University of Medical Sciences. Depression, stress and anxiety were measured using the validated DASS-42 questionnaire. A self-rated question was used to assess childhood socioeconomic status. Other variables including age, sex, marital status, and also wealth index, were measured. Linear regression models were used to analyze the data. RESULTS: 24.6% of men and 33.8% of women had degrees of depression (mild, moderate, severe or very severe). 32.9% of men and 29.4% of women had mild, moderate, severe or very severe anxiety. 36.3% of men and 45.2% of women also exhibited mild, moderate, severe or very severe stress. Results showed after adjusting for the current socioeconomic status, childhood socioeconomic status has a relationship with the mental health of individuals. CONCLUSION: People with a suboptimal childhood socioeconomic status seem to be a high-risk group for depression, stress and anxiety in adulthood. Strategies need to put into practice to improve the mental health of these people.

The effects of psychological risk factors at work on cognitive failures through the accident proneness.

BACKGROUND: Various agents such as psychosocial items and accident proneness can affect cognitive failures through different paths. The probable paths are the direct effects of workplace psychosocial items on cognitive failures and their indirect effects on cognitive failures through the mediator variable of accident proneness, which has not yet been studied by others. Thus, the present study aimed to investigate these paths. METHODS: This cross-sectional study was conducted on 164 male employees of Karoon Sugar Company in 2018. The participants were asked to complete a background and demographic questionnaire, Broadbent cognitive failures scale, accident proneness questionnaire, and Copenhagen psychosocial questionnaire. Obtained data were analyzed and modeled using the statistical descriptive method, ANOVA, independent t-test, Pearson correlation test, and path analysis in the SPSS and AMOS software. RESULTS: The results of the path analysis showed that, not only, some psychosocial risk items had a significant direct effect on cognitive failures, but also, they could affect cognitive failures through the accident proneness, indirectly. Work-family conflict and social support from supervisors by coefficients of 0.188 and - 0.187 had the highest direct effects, respectively. The highest indirect effects belonged to justice and respect, and work-family conflict by coefficients of - 0.220 and 0.199, respectively. The highest total effects were also related to the work-family conflict and justice and respect by coefficients of 0.387 and - 0.381, respectively. CONCLUSIONS: In total, our results showed that some psychological items could, directly and indirectly, increase cognitive failure through accident proneness.

Aberration detection in influenza trends in Iran by using cumulative sum chart and period regression.

OBJECTIVES: This study aims to determine the alarm thresholds in influenza outbreaks and aberration detection in the influenza trend in Iran by using cumulative sum control chart (CUSUM) and period regression. METHODS: We used the weekly reported influenza-positive (types A and B) cases from Iran between January 2015 and November 2019. The period regression model and CUSUM chart were used as detection algorithms to figure out the alarm thresholds. RESULTS: The mean ± SD and the median (95% CI) of the determined threshold per week were 34.85 ± 15.29 and 28.30 (17.67-64.62). According to the period regression, there were nine epidemic periods of influenza from 2015 to 2019. By using the CUSUM and considering a different h (h is an appropriate value that leads to the desired estimation for upper control limit) for the calculation of the upper control limit, 88, 84, 73 and 67 weeks were determined as the epidemic period. CONCLUSION: According to the current study, the incidence of influenza showed a cyclic pattern and the epidemic recurred each year. Understanding this cyclical pattern can help health policymakers launch prevention programs such as vaccination during certain months of the year.

Students' Nutrition Literacy and the Existence of Health Care Providers in Iranian Schools.

BACKGROUND: The objective of this study was to investigate the relationship between Students' nutrition literacy and the existence of health care providers in Iranian schools. STUDY DESIGN: A cross-sectional study. METHODS: This study was conducted on 504 students in Ardebil City, northwestern Iran from Oct 2017 to Jan 2018. The FLINT questionnaire was used to assessment the food and nutrition literacy. Socio-demographic characteristics and the existence of health care providers were collected using demographic questionnaire. RESULTS: Nearly 75% of students had not a health care provider. Most students had a low FNLIT (62% males and 58.1% females). The probability of low FNLIT was lower in students with health care providers than those without them (OR=0.46, CI 95%; 0.10, 0.91). CONCLUSION: One of the reasons for the low nutritional literacy of students may be due to the lack of health care providers in schools. Health educational administrators employ specialized health care providers in Iranian schools.

Response to Letter to the Editor Entitled: Concerning the Article by Arezoo Maleki-Hajiagha et al. Entitled Serum Prostate-Specific Antigen Level in Women with Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis.

Dear Editor,We thank Kunicki et al. 1 for their interest in our paper 2 and for taking the time to give relevant and important comments regarding the inclusion of hirsutism or hyperandrogenism cases in our study. We agree with Kunicki et al. that the title is not appropriate, and it was better if the title of the article was: Serum Prostate-Specific Antigen Level in Women with Polycystic Ovary Syndrome and Hyperandrogenism: A Systematic Review and Meta-Analysis. Also, we should make some minor editing in the manuscript text.

Serum Prostate-Specific Antigen Level in Women With Polycystic Ovary Syndrome: A Systematic Review and Meta-analysis.

We undertook a comprehensive search of all published original articles evaluating the diagnostic value of prostate-specific antigen (PSA) for the detection of polycystic ovary syndrome (PCOS). Finally, 25 studies with a total of 1865 participants (1104 cases and 761 controls) met the inclusion criteria. Mean serum PSA levels were significantly higher in PCOS women compared to healthy women [Standardized mean difference (SMD)=1.73 ng/ml, 95% CI=1.22 to 2.25, p<0.001]. Only 5 studies reported accuracy indicators and were included in the bivariate random-effects model; with a total of 509 samples that included 332 (65.22%) confirmed PCOS women. The sensitivity of serum PSA for the diagnosis of PCOS varied between 66.3 and 90.6%, and, the specificity ranged from 62.5-86.7%. Meta-analysis revealed a pooled sensitivity of 72.3% (95% CI 67.1-77.00%) and specificity of 74.6% (95% CI 67.5-80.8%) with an area under the summary ROC curve equal to 0.82 (95% CI 0.75-0.83). The summary estimates were 2.92 (95% CI 1.98-4.31) for positive LR and 0.37 (95% CI 0.26-0.51) for negative LR. The pooled estimate of diagnostic odds ratio (DOR) of serum PSA was 9.01 (95% CI 4.35-18.64). Considering the methodological weaknesses existed in studies, lack of sufficient data regarding the accuracy indicators, and the complexity of the exact pathophysiology of PSA secretion in women, the precise position of PSA, as a diagnostic test for the detection of PCOS, in clinical practice is undetermined, and further studies are still needed.

Assessment of contrast perception of obstacles in a tunnel entrance.

Background: The purpose of this study was to assess the contrast perception of obstacles in a tunnel entrance which was placed in Ilam Province, Iran. Methods: An obstacle with the reflection coefficient of 20% was mounted at the entrance of thetunnel and then, the car was placed near the tunnel entrance and the intrinsic luminance of the road (Lr,intrinsic) and obstacle (Lo,intrinsic) were measured inside the car using the luminance meter. Results: Intrinsic luminance of obstacle and road at the entrance of the tunnel were measured as 41 and 17 cd/m2, respectively. The contrast perception of obstacle in deriver's eyes and in the safe stopping distance (SSD) from the tunnel entrance was determined as 2.79 cd/m2. At the entrance of the studied tunnel, the contrast perception of obstacles with the reflection coefficient of 20% was lower than the minimum contrast perception (28%) recommended by International Commission on Illumination. Conclusion: The main conclusion that can be drawn from it, is that this obstacle in the SSD from the tunnel entrance cannot be conceived by the drivers, which may lead to higher rate of road traffic crashes.

Evaluation of operational parameters role on the emission of fumes.

Electric arc welding is a routine operation in the construction of metallic structures, but the fumes generated during the welding process can threaten the health of welders. Fumes are undesirable products of the majority of welding operations and may have various detrimental effects on health. The purpose of this study was to investigate the effect of operational parameters of the shielded metal arc welding (SMAW) process on the emission of fumes. A dust monitor was used to measure the number and mass concentration of fumes generated by SMAW. Measurements were made at the distances of 23 cm (hood inlet) and 41 cm (welder's breathing zone) from the weld point, with different values assigned to three operational parameters, namely current intensity, travel speed, and heat input (HI). Number concentration (NC) decreased with the increase in particle size. The highest mass concentrations (MC) were observed for MC1 (0.35-0.5 µm) and MC8 (Larger than 6.5 µm). For reducing exposures to fumes, welders are recommended to use the lowest voltage and amperage and the highest travel speed to the extent that does not compromise in the quality of welds. For assessment of exposure to airborne particles in industrial workplaces and specially in welding operations, it is thought that taking, solely, mass concentration in to consideration and lack of attention to number concentration would not be able to reflect accurate assessment of the adverse effects of particles on the body organs.