Effect of Habitat Complexity on Richness, Abundance and Distributional Pattern of Forest Birds

Structurally complex forests provide more diverse conditions in comparison to homogenous forests because of greater variety of microhabitats and trees. This study assesses the association of bird species richness, abundance, and distributional pattern with habitat complexity (HC) in Kheyrud Forest in the north of Iran. Birds were surveyed during spring 2009 by 100 point counts. In each point count six habitat features related to the index of HC were computed and scored from 0 to 3. Then the scores were summed and divided into two groups of low and high complexity, HC ≤ 6 and HC > 6, respectively. To compare bird richness and abundance in different HCs, a two sample t-test was used. Presence and absence of bird species at each plot as a dependent variable were compared with the vegetation characteristics as an independent variable by means of the Canonical Correspondence Analysis. The results revealed bird species richness and abundance were significantly higher in more complex habitats. Bird species can be divided into two groups, the first group including species which associated with late successional stages and the second group, species belonging to early successional stages. Numbers of birds belonging to the first group declined in less complex forests, whereas the numbers of birds belonging to the second group increased. At the stand scale, our results reveal that bird abundance and richness are strongly associated with the complexity of vegetation structure in the study area.     

Association of serum lead and mercury level with cardiometabolic risk factors and liver enzymes in a nationally representative sample of adolescents: the CASPIAN-III study

This study aims to determine the difference of serum Pb and Hg levels in adolescents with or without metabolic syndrome (MetS) and the association of serum levels of these heavy metals with cardiometabolic risk factors and liver enzymes in Iranian adolescents. The study population consisted of 320 adolescents (160 with MetS and 160 healthy controls). The relationship between serum heavy metals and cardiometabolic risk factors was assessed by linear regression. The odds ratios (OR) of having metabolic syndrome across Pb and Hg quartiles were determined by multiple logistic regression analysis. The mean (SD) of Pb and Hg concentrations were higher in adolescents with MetS than in those without it (0.83 (0.27) and 0.17 (0.01) vs. 0.65 (0.15) and 0.10 (0.08)?μg/L, P?=?0.01 and 0.0001, respectively). Increase in serum Pb and Hg was associated with increase in some cardiometabolic risk factors. Among boys and girls, diastolic blood pressure (DBP), fasting blood glucose, total cholesterol (TC), triglycerides (TG), and alanine aminotransaminase increased significantly across quartiles of serum Pb. Among girls, SBP, DBP, TC, and TG had a significant increase across Hg quartiles. The corresponding figure among boys was significant for SBP, DBP, and TG. Higher quartiles of Pb increased the risk of having MetS (OR 95 % CI 3.10, 2.25–4.27), the corresponding figure was 2.03, 1.75–3.16, across Hg quartiles. Our study showed significant associations between serum Pb and Hg levels with cardiometabolic risk factors in adolescents. In future surveys, the role of potential confounders should be considered more extensively. The clinical significance of these findings needs to be confirmed in longitudinal studies. By considering the origins of chronic diseases from early life, controlling environmental pollutants should be considered as a health priority for primordial or primary prevention of noncommunicable diseases.     

Investigation of the association between pesticide exposure and the prevalence of type 2 diabetes in Shahedieh population in Yazd

Environmental Science and Pollution Research - This study aimed to investigate the effect of exposure to pesticides and the prevalence of type 2 diabetes (T2D). In a cross-sectional study with a...     

Systematic review and meta-analysis on the association between phthalates exposure and insulin resistance

Environmental Science and Pollution Research - This study aims to provide an overview of human studies on the association of exposure to phthalates and insulin resistance. We systematically...     

Design and optimization of a hybrid process based on hollow-fiber membrane/coagulation for wastewater treatment

Environmental Science and Pollution Research - Treatment of textile wastewater using ultrafiltration membranes was carried out in this study. Since membrane fouling is a major operational problem...     

Daily dietary intakes of zinc,copper, lead,and cadmium as determined by duplicate portion sampling combined with either instrumental analysis or the use of food composition tables,Shiraz, Iran

Estimation of essential and toxic element intakes is crucial to evaluate the risks of deficiency or toxicity. The purpose of this study was to investigate and also to compare the dietary intakes of zinc (Zn) and copper (Cu) by adults living in Shiraz, Iran, determined by two procedures: duplicate portion sampling of 21 hospital meals combined with either instrumental analysis (voltammetric measurement) or the use of food composition tables (FCTs). The level of exposure to lead (Pb) and cadmium (Cd) was evaluated as well. The daily Zn intakes of both methods were not significantly different and were higher than the RDA values except the value measured by the instrumental analysis which was lower than the RDA established for a male adult. Daily intake of Cu determined by instrumental analysis was significantly lower and closer to RDA for adults compared with the value estimated by FCTs. The dietary intakes of Pb and Cd were 313 and 61 % of the respective provisional tolerable weekly intakes (PTWIs), respectively. The accuracy of two methods used for estimation of Zn intake was similar. In the case of Cu, the use of FCTs, in which the influence of environmental conditions and dietary habits of meal preparation is not taken into account, overestimated dietary intake. The risk of zinc deficiency was found in adult males. Moreover, the estimated intake of Pb, but not Cd, could be a cause of concern for Shiraz population. Thus, conducting regular periodic studies to assess the dietary intake of mentioned elements are recommended.     

Health risk assessment of potentially toxic elements intake via food crops consumption: Monte Carlo simulation-based probabilistic and heavy metal pollution index

Environmental Science and Pollution Research - The aim of this study is to assess the content of heavy metals and their potential health risk in consumed food crops. To this end, the samples from...     

Operational leeway in work situations: do ergonomic risk assessment tools consider operational leeway for job analysis?

Our study shows that information on operational leeway is limited in the originator articles of the ergonomic risk assessment tools for prevention of musculoskeletal disorders (MSDs). The tools’ underlying theoretical models do not consider the indicators of operational leeway, and they cannot determine the sufficiency of the situational operational leeway in a work situation. Consequently, regulation of the activity, which ensures the performance goals and the individual's health, has been overlooked. The lack of literature on indicators of situational operational leeway is one of the reasons for this deficit. Defining the indicators for this concept would be an innovation in the approach of MSD risk prevention. Developing empirically the concept of situational operational leeway in risk assessment tools would help to progress the current approach of MSD prevention. This study therefore proposes indicators of situational operational leeway to increase the representativeness and reliability of the risk assessment tools for MSDs.     

Biosorption potential of Cr(VI) by Kocuria sp. ASB107, a radio-resistant bacterium isolated from Ramsar,Iran

Heavy metal pollution in soil and wastewater is a worldwide environmental issue in which microorganisms play a significant role for its removal. In the present study, biosorption of Cr(VI) by the live and dead cells of Kocuria sp. ASB107, a radio-resistant bacterium, was investigated. The effect of contact time, solution pH, initial hexavalent chromium concentration and adsorbent dose on biosorption efficiency was studied. Also, live cells were further immobilised on various matrices by different techniques and then were examined for tolerance to chromium biosorption. Experimental results indicated that the removal efficiency of chromium increased with decrease in pH, initial Cr(VI) concentration, and also increase in adsorbent dose and the contact time. The maximum removal efficiency of live and dead cells at acidic pH of 4–4.5, contact time of 24 hours, adsorbent dose 1.6?g/100?mL and initial chromium concentration 25?mg/L were 82.4% and 69.2%, respectively. The adsorption data was described well by Langmuir isotherm model. Among all immobilisation techniques tested, cross-linking showed the highest biosorption of Cr(VI). Results indicated that live cells of Kocuria sp. ASB107 were better than dead ones.