Distribution of metal(loid)s in particle size fraction in urban soil and street dust: influence of population density.

Assessment of street dust is an invaluable approach for monitoring atmospheric pollution. Little information is available on the size distribution of contaminants in street dusts and urban soils, and it is not known how the population density would influence them. This research was carried out to assess the size distribution of trace metal(loid)s in street dust and urban soil, and to understand how population density might influence the size-resolved concentration of metal(loid)s. Three urban areas with a high, medium and low population density and a natural area were selected and urban soil and street dust sampled. They were fractionated into 8 size fractions: 2000-850, 850-180, 180-106, 106-50, 50-20, 20-10, 10-2, and < 2 µm. The concentration of Pb, Zn, Cu, Cd, Cr, Ni, As, and Fe was determined, and enrichment factor and grain size fraction loadings were computed. The results indicated that the concentration of Pb, Zn, Cu, Cd, and Cr was highly size dependent, particularly for particles < 100 µm, especially for street dust. Low concentrations of Ni and As in street dust and urban soil were size and population density independent. Higher size dependency of the metals concentration and the higher degree of elemental enrichment in the street dust fractions than the urban soils indicate higher contribution of human-induced pollution to the dust. Findings also confirm the inevitability of size fractionation when soils or dusts are environmentally assessed, particularly in moderately to highly polluted areas. Otherwise, higher concentrations of certain pollutants in fine-sized particles might be overlooked leading to inappropriate decisions for environmental remediation.

Efficiency of physical therapy on postural imbalance after stroke: study protocol for a systematic review and meta-analysis.

INTRODUCTION: Stroke frequently results in balance disorders, leading to lower levels of activity and a diminution in autonomy. Current physical therapies (PT) aiming to reduce postural imbalance have shown a large variety of effects with low levels of evidence. The objectives are to determine the efficiency of PT in recovering from postural imbalance in patients after a stroke and to assess which PT is more effective. METHODS AND ANALYSIS: We will search several databases from inception to October 2015. Only randomised controlled trials assessing PT to recover from poststroke postural imbalance in adults will be considered.Outcome measures will be the Berg Balance Scale (BBS), the Postural Assessment Scale for Stroke (PASS), the 'weight-bearing asymmetry' (WBA), the 'centre of pressure' (COP) and the 'limit of stability' (LOS). WBA, COP and LOS are measured by a (sitting or standing) static evaluation on force plate or another device.Two independent reviewers will screen titles, abstracts and full-text articles, evaluate the risk of bias and will perform data extraction. In addition to the outcomes, measures of independence will be analysed. This study will aim at determining the effects of PT on the function (WBA, COP, LOS), the activity (BBS, PASS) and the independence of patients. Subgroup analyses will be planned according to the location of brain lesion (hemispheric, brainstem or cerebellum), the time since stroke (early, late, chronic), the PT (type, main aim (direct effect or generalisation), overall duration), the type of approaches (top-down or bottom-up) and the methodological quality of studies. ETHICS AND DISSEMINATION: No ethical statement will be required. The results will be published in a peer-reviewed journal. This meta-analysis aims at managing the rehabilitation after postural imbalance by PT after a stroke. TRIAL REGISTRATION NUMBER: Prospero CRD42016037966;Pre-results.

Hypertension and mortality in the Golestan Cohort Study: A prospective study of 50 000 adults in Iran.

High blood pressure has been the second most important determinant of disease burden in Iran since the 1990s. Despite well-recognized evidence on the association of high blood pressure and mortality in other countries, this relationship has not been fully investigated in the demographic setting of Iran. The current study is the first large-scale longitudinal study of this association in Iran. Briefly, 50 045 subjects between 40 and 75 years of age have been recruited and followed. Blood pressure measurements were carried out at baseline. Causes of death were reported and verified by verbal autopsy throughout the follow-up period. The outcomes of interest were all-cause deaths and deaths due to ischemic heart disease (IHD) or stroke. Cox proportional hazards regression models were used to estimate hazard ratios (HRs). A total of 46 674 subjects free from cardiovascular disease at baseline were analyzed. Absolute mortality rates increased along with increasing systolic or diastolic blood pressure above 120 and 80 mm Hg, respectively. Adjusted HRs (95% confidence intervals) for each 20 mm Hg increase in systolic blood pressure in all age groups were 1.18 (1.13-1.23) for all-cause mortality, 1.21 (1.13-1.31) for deaths due to IHD and 1.50 (1.39-1.63) for deaths due to stroke. Unadjusted and adjusted HRs were higher in younger subjects and decreased with increasing age of the participants. High blood pressure is a serious threat to the health of Iranians. The entire health-care system of Iran should be involved in a comprehensive action plan for controlling blood pressure.

Time Trends of Gastro-esophageal Reflux Disease (GERD) and Peptic Ulcer Disease (PUD) in Iran.

BACKGROUND Epidemiology of diseases changes over time with changes in socio-economic status, culture and health care systems. Gastroesophageal reflux disease (GERD) and peptic ulcer disease (PUD) are among the diseases whose epidemiology has changed over the past few decades in the west. Studies addressing the trend of GERD and PUD occurrence in Iran are lacking. We aimed to look at the time trends of GERD and PUD in a referral endoscopy clinic in Tehran, Iran. METHODS All patients with dyspeptic symptoms who underwent upper GI endoscopy from 1993 to 2005 (inclusive) in a tertiary outpatient GI referral center in Tehran were enrolled. Erosive esophagitis (EE, used as a proxy for GERD as a whole), PUD, rapid urease test (RUT) status and demographic characteristics were recorded from the endoscopy reports according to the year the endoscopy was performed. RESULTS Over a period of 13 years, 8,029 endoscopic examinations were performed. The most common endoscopic diagnosis was EE that occurred in 4,808 patients (59.8%) followed by duodenal ulcer in 2,188 (27.3%) and gastric ulcer in 88 (1.1%). Over 13 years (1995-2005), the proportion of EE increased from 14.1% in 1993 to 75.1% in 2005 among dyspeptic patients in this referral clinic. The proportion of each grade of GERD according to the Los Angeles classification was as follows: GERD-A 76.0%, GERD-B 20.9%, GERD-C 2.8% and GERD-D 0.3%. RUT positivity decreased from 71.4% to 9.5% during the study period. CONCLUSION This study shows a remarkable increase in EE with a concomitant decrease in PUD and RUT positivity among dyspeptic patients in Tehran over a decade. This change in trend is important for future health care planning.

Mapping risk of cadmium and lead contamination to human health in soils of Central Iran.

In order to map Cd and Pb contamination in the soils of the region of Isfahan, Central Iran, we performed indicator kriging on a set of 255 topsoil samples (0-20 cm) gathered irregularly from an area of 6800 km(2). The measured Cd concentrations exceeded the Swiss guide value in more than 80% of the samples whereas Pb concentrations exceeded the respective guide value only in 2% of the samples. Based on the simulated conditional distribution functions, the probability of exceeding the concentration of Cd and Pb from the specific threshold was computed. The results indicated that in most parts of the region the probability of contamination by Cd is very large (>0.95) whereas it is small (<0.5) for Pb. Based on a misclassification analysis, we chose the probability of 0.45 as optimum probability threshold to delineate the polluted from unpolluted areas for Cd. In addition, we performed a loss analysis to separate risks to human health from potential losses due to remediation costs. Based on this analysis a probability threshold of 0.8 was found to be the optimum threshold for the classification of polluted and unpolluted areas in the case of Cd. Health risks were found to be larger in the western parts of the region. Misclassification analysis was sufficient for risk mapping for Pb as its concentration did not reach risk levels for human health. A probability of 0.7 for Pb was found to be the optimum threshold for the delineation of polluted and unpolluted lands.