36 research outputs found
Evaluation of chemical quality in 17 brands of Iranian bottled drinking waters
Background: The purpose of study was to evaluate and compare chemical quality of Iranian bottled
drinking water reported on manufacturer's labeling and standards.
Methods: This study was a cross-sectional descriptive study and done during July to December 2008.
The bottled mineral water collected from shops randomly were analyzed for all parameters address on
manufacturer's labeling and the results were compared with the manufacturer's labeling data, WHO
Guideline Values, USEPA Maximum Contaminant Levels and the maximum contaminant levels of drinking
water imposed by the Iranian legislation. Statistical analysis on data was done with the Kolmogorov-Smirnov
test for normal distribution, the paired t-test to compare the data with manufacturer's labeling
and the one-sample t-test to compare with standard and MCL values at P < 0.05 of confidence level.
Results: The results showed a statistically significant difference with manufacturer's labeling values,
however there was no significant difference between the values of magnesium and pH and manufacturer's
labeling values (P> 0.05). In addition, pH and calcium values were significantly higher than
their proposed values indicated by Iranian National Legislation and international MCLs (P< 0.05).
Conclusion: Our results are extremely important for the health supervisory agencies such as Ministry
of Health and Institute of Standards & Industrial Research of Iran to have more effective controls on
bottled water industries, and to improve periodical the proposed standard values
Removal of bisphenol, using antimony nanoparticle multi-walled carbon nanotubes composite from aqueous solutions
This study focuses on preparing Antimony Nanoparticle Multi-walled Carbon (ANMWC) composite as an effective adsorbent and then the effect of produced composite in BPA removal from aqueous solutions was studied. ANMWC were prepared using chemical method and characterized with X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and Brunauer-Emmett-Teller (BET). Moreover, the removal efficiency of prepared AMWCNT and Nanoparticle Multi-walled Carbon (MWCNT) in removal of Bisphenol A was investigated. Results revealed that the BPA removal efficiency by AMWCNT increased from 80 to 93 with the increase of contact time 5 to 60 min. The maximum removal efficiency for the both adsorbents was seen at pH 7, which was 85 for MWCNT and 95 for ANMWC composite. According to the results obtained, pHzpc for both adsorbents was 7. Results showed that the adsorption process followed the pseudo-first order model with a high correlation value and BPA adsorption on MWCNT followed the Langmuir isotherm model
Growth performance and age composition of Salmo trutta caspius in Iranian part of Caspian Sea
The aim of this project is to study the growth and age structure in the Caspian trout, comparison with other coldwater species and check the trend of these parameters in recent years. This study was conducted during 2013 till 2015. Totally, 43 specimens for back calculation and 101 specimens for biometrical study of the Caspian trout have been caught in two month period. Biometric parameters such as length, weight and age of the fish were recorded. Base on Back calculation method in 1393, the average length of fish at ages 1, 2 and 3 years old were 18.98 ± 3.5, 30.5 ± 7.24 and 41.7 ± 9.1 cm. So these age groups are under the adult age and don’t approaching to near the beach and rivers for spawning behavior. Therefore, these length groups cannot be observed in catch composition. The result showed, the mean of gonad weight in this fish was about 11 percent of total weight and number of eggs per gram of gonad calculated about 10.8 numbers. Minimum age and maximum age of this species determined 4 years and 7 years (mean = 5.6) and the most frequency allocated to 5 age group and the frequency of 6 and 7 years has been remarkable. The average length of salmon was 69.2 ± 6.2 cm (minimum 57 and maximum 81 cm) and the average weight was measured 3323 ± 677 g (2400 to 5600 g) in the catch composition. Growth parameters such as k, L_∞ and ø’ was measured 0.18, 104 cm and 3.289 respectively. The amount of b for relation length and weight was 2.9 which imply negative allometry. L_∞ and growth coefficient (K) on the Caspian trout were acceptable range, that it shows good growth the fish in the sea water. Most of the fishes were catched from Cheshmehkileh River. As at present Shilat uses just the broods of the Tonekaboon region for restocking of this species, we recommend using the broods of the western region separately for rehabilitation of the stocks of this region
Global age-sex-specific fertility, mortality, healthy life expectancy (HALE), and population estimates in 204 countries and territories, 1950–2019: a comprehensive demographic analysis for the Global Burden of Disease Study 2019
Background: Accurate and up-to-date assessment of demographic metrics is crucial for understanding a wide range of social, economic, and public health issues that affect populations worldwide. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 produced updated and comprehensive demographic assessments of the key indicators of fertility, mortality, migration, and population for 204 countries and territories and selected subnational locations from 1950 to 2019. Methods: 8078 country-years of vital registration and sample registration data, 938 surveys, 349 censuses, and 238 other sources were identified and used to estimate age-specific fertility. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate age-specific fertility rates for 5-year age groups between ages 15 and 49 years. With extensions to age groups 10–14 and 50–54 years, the total fertility rate (TFR) was then aggregated using the estimated age-specific fertility between ages 10 and 54 years. 7417 sources were used for under-5 mortality estimation and 7355 for adult mortality. ST-GPR was used to synthesise data sources after correction for known biases. Adult mortality was measured as the probability of death between ages 15 and 60 years based on vital registration, sample registration, and sibling histories, and was also estimated using ST-GPR. HIV-free life tables were then estimated using estimates of under-5 and adult mortality rates using a relational model life table system created for GBD, which closely tracks observed age-specific mortality rates from complete vital registration when available. Independent estimates of HIV-specific mortality generated by an epidemiological analysis of HIV prevalence surveys and antenatal clinic serosurveillance and other sources were incorporated into the estimates in countries with large epidemics. Annual and single-year age estimates of net migration and population for each country and territory were generated using a Bayesian hierarchical cohort component model that analysed estimated age-specific fertility and mortality rates along with 1250 censuses and 747 population registry years. We classified location-years into seven categories on the basis of the natural rate of increase in population (calculated by subtracting the crude death rate from the crude birth rate) and the net migration rate. We computed healthy life expectancy (HALE) using years lived with disability (YLDs) per capita, life tables, and standard demographic methods. Uncertainty was propagated throughout the demographic estimation process, including fertility, mortality, and population, with 1000 draw-level estimates produced for each metric. Findings: The global TFR decreased from 2•72 (95% uncertainty interval [UI] 2•66–2•79) in 2000 to 2•31 (2•17–2•46) in 2019. Global annual livebirths increased from 134•5 million (131•5–137•8) in 2000 to a peak of 139•6 million (133•0–146•9) in 2016. Global livebirths then declined to 135•3 million (127•2–144•1) in 2019. Of the 204 countries and territories included in this study, in 2019, 102 had a TFR lower than 2•1, which is considered a good approximation of replacement-level fertility. All countries in sub-Saharan Africa had TFRs above replacement level in 2019 and accounted for 27•1% (95% UI 26•4–27•8) of global livebirths. Global life expectancy at birth increased from 67•2 years (95% UI 66•8–67•6) in 2000 to 73•5 years (72•8–74•3) in 2019. The total number of deaths increased from 50•7 million (49•5–51•9) in 2000 to 56•5 million (53•7–59•2) in 2019. Under-5 deaths declined from 9•6 million (9•1–10•3) in 2000 to 5•0 million (4•3–6•0) in 2019. Global population increased by 25•7%, from 6•2 billion (6•0–6•3) in 2000 to 7•7 billion (7•5–8•0) in 2019. In 2019, 34 countries had negative natural rates of increase; in 17 of these, the population declined because immigration was not sufficient to counteract the negative rate of decline. Globally, HALE increased from 58•6 years (56•1–60•8) in 2000 to 63•5 years (60•8–66•1) in 2019. HALE increased in 202 of 204 countries and territories between 2000 and 2019. Interpretation: Over the past 20 years, fertility rates have been dropping steadily and life expectancy has been increasing, with few exceptions. Much of this change follows historical patterns linking social and economic determinants, such as those captured by the GBD Socio-demographic Index, with demographic outcomes. More recently, several countries have experienced a combination of low fertility and stagnating improvement in mortality rates, pushing more populations into the late stages of the demographic transition. Tracking demographic change and the emergence of new patterns will be essential for global health monitoring. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens
Global burden of 87 risk factors in 204 countries and territories, 1990�2019: a systematic analysis for the Global Burden of Disease Study 2019
Background: Rigorous analysis of levels and trends in exposure to leading risk factors and quantification of their effect on human health are important to identify where public health is making progress and in which cases current efforts are inadequate. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 provides a standardised and comprehensive assessment of the magnitude of risk factor exposure, relative risk, and attributable burden of disease. Methods: GBD 2019 estimated attributable mortality, years of life lost (YLLs), years of life lived with disability (YLDs), and disability-adjusted life-years (DALYs) for 87 risk factors and combinations of risk factors, at the global level, regionally, and for 204 countries and territories. GBD uses a hierarchical list of risk factors so that specific risk factors (eg, sodium intake), and related aggregates (eg, diet quality), are both evaluated. This method has six analytical steps. (1) We included 560 risk�outcome pairs that met criteria for convincing or probable evidence on the basis of research studies. 12 risk�outcome pairs included in GBD 2017 no longer met inclusion criteria and 47 risk�outcome pairs for risks already included in GBD 2017 were added based on new evidence. (2) Relative risks were estimated as a function of exposure based on published systematic reviews, 81 systematic reviews done for GBD 2019, and meta-regression. (3) Levels of exposure in each age-sex-location-year included in the study were estimated based on all available data sources using spatiotemporal Gaussian process regression, DisMod-MR 2.1, a Bayesian meta-regression method, or alternative methods. (4) We determined, from published trials or cohort studies, the level of exposure associated with minimum risk, called the theoretical minimum risk exposure level. (5) Attributable deaths, YLLs, YLDs, and DALYs were computed by multiplying population attributable fractions (PAFs) by the relevant outcome quantity for each age-sex-location-year. (6) PAFs and attributable burden for combinations of risk factors were estimated taking into account mediation of different risk factors through other risk factors. Across all six analytical steps, 30 652 distinct data sources were used in the analysis. Uncertainty in each step of the analysis was propagated into the final estimates of attributable burden. Exposure levels for dichotomous, polytomous, and continuous risk factors were summarised with use of the summary exposure value to facilitate comparisons over time, across location, and across risks. Because the entire time series from 1990 to 2019 has been re-estimated with use of consistent data and methods, these results supersede previously published GBD estimates of attributable burden. Findings: The largest declines in risk exposure from 2010 to 2019 were among a set of risks that are strongly linked to social and economic development, including household air pollution; unsafe water, sanitation, and handwashing; and child growth failure. Global declines also occurred for tobacco smoking and lead exposure. The largest increases in risk exposure were for ambient particulate matter pollution, drug use, high fasting plasma glucose, and high body-mass index. In 2019, the leading Level 2 risk factor globally for attributable deaths was high systolic blood pressure, which accounted for 10·8 million (95 uncertainty interval UI 9·51�12·1) deaths (19·2% 16·9�21·3 of all deaths in 2019), followed by tobacco (smoked, second-hand, and chewing), which accounted for 8·71 million (8·12�9·31) deaths (15·4% 14·6�16·2 of all deaths in 2019). The leading Level 2 risk factor for attributable DALYs globally in 2019 was child and maternal malnutrition, which largely affects health in the youngest age groups and accounted for 295 million (253�350) DALYs (11·6% 10·3�13·1 of all global DALYs that year). The risk factor burden varied considerably in 2019 between age groups and locations. Among children aged 0�9 years, the three leading detailed risk factors for attributable DALYs were all related to malnutrition. Iron deficiency was the leading risk factor for those aged 10�24 years, alcohol use for those aged 25�49 years, and high systolic blood pressure for those aged 50�74 years and 75 years and older. Interpretation: Overall, the record for reducing exposure to harmful risks over the past three decades is poor. Success with reducing smoking and lead exposure through regulatory policy might point the way for a stronger role for public policy on other risks in addition to continued efforts to provide information on risk factor harm to the general public. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens
Effect of Dose and Oxadiargyl Application Time at the Different Growth Stages on Weed Biomass and Tuber Yield of Potato (Solanum tuberosum L.)
To evaluate the effects of dose and application time of oxadiargyl, as a postemergence herbicide, on weed biomass and tuber yield of potato, a factorial experiment based on randomized complete block design with 3 replications was conducted at Alaroog Research Station at the University of Mohaghegh-Ardabili in 2013. Treatments consisted of oxadiargyl dosages (0, 0.05, 0.1, 0.2, 0.4, 0.6 and 0.8 lit a.i /ha), and its time of applications at different potato growth stages (potato emergence, stolon initiation and potato tuber bulking), weed free treatment was considered as control. Statistical analysis showed that 0.8 lit a.i/ha of oxadiargyl reduced biomass of weed by 66.16 percent. Oxadiargyl application at emergence time resulted in highest percent reduction of weed biomass. Results, also, showed that application 0.8 lit a.i/ha of oxadiargyl, after weed free condition, increased number of seed tuber and total tuber yield by 82.16 and 51.59 percent respectively, but it reduced number of non seed tuber by 43.17 percent. Application of oxadiargyl at emergence time, as compared with the other application times, resulted in highest increase in the number of seed tuber and total tuber yield, but it did not affected number of non seed tubers. Interaction effect of dose by time of oxadiargyl application revealed that using 0.8 lit a.i/ha dose at potato emergence time increased number of edible tubers by 100%. It may be conducted that application of this dose at potato emergence time was highly efficient in controlling weeds and increasing potato tuber yield
Evaluation of Oxadiargyl Efficiency on Weed Control of Potato (Solanum tuberosum L.) at Different Growth Stages
Introduction: Potato (Solanum tuberosum L.) is one of the most important root crops in the world. Weed is biotic stress that reduces yield and quality of crops through competition. Chemical weed control seems indispensable and has proved efficient in controlling weeds. Metribuzin and Paraquat are registered herbicides for potato production in Iran which are using early in the growing season. Metribuzin and Paraquat are dual purpose herbicides and destruct photosystem sites of action (Metribuzin is photosystem Ⅱ inhibitor and Paraquat is photosystem Ⅰ inhibitor) which are not control summer weeds. Oxadiargyl belongs to the oxidiazole chemical group and acts as a protoporphyrinogen oxidase inhibitor and primarily has been developed for general weed control in rice and sugar cane. It is commonly used in rice, potato, sunflower, onion, cabbage, chickpea, spanish and lettuce and lavender. Weed control obtained with oxadiargyl at rates above 0.30 kg a.i/ ha was comparable to the standard metribuzin at 1.0 kg a.i/ ha; Oxadiargyl was superior comparing to the standard on Solanum nigrum, a weed of common occurrence in potato plantations, and Panicum subalbidum. The objective of our research was to evaluate the efficacy of Oxadiargyl for weed control and determination of appropriate application time in potato fields.
Materials and Methods: Trials were conducted in Ardabil Agriculture and Natural Resources Research Station during 2013. The factorial experiment with control (with and without weeding) was performed based on randomized complete block design with three replications. Potato cultivar was Agria (common cultivar in Ardabil). The first factor was Oxadiargyl dosages with six levels (0.05, 0.1, 0.2, 0.4, 0.6 and 0.8 Lit a.i/ ha), and the second factor was time of application (at different potato growth stages; potato emergence, stoloning and tuber bulking), as well as two treatments (with and without weeding) were considered as control. Tubers were hand sown on 22th May in rows 75 cm apart and 20 cm on the rows at 10 cm depth. Oxadiargyl was applied by backpack sprayer fitted with 8001 flat fan nozzles. Three weeks after treatment, Weed sampling was carried out by a (0.75× 0.50 m2 quadrate). Tubers were harvested from center row to determine total tuber yield per hectare.
Two three parameter model were fitted to the data including:
Three parameter logistic function ( )
Three parameter sigmoid function ( )
a: maximum weed biomass and total yield, b: The slope and x0 (ED50): the dose causing 50% reduction in weed biomass.
Data were statistically analyzed using SAS 9.1 software and MSTAT-C. Analysis of variance was used to test the significance of variance sources, while Duncan’s Multiple range test (P = 0.05) was used to compare the differences among means.
Results and Discussion: Results showed that maximum reduction percent for redroot pigweed (Amaranthus retroflexus L.), prostrate pigweed (Amaranthus blitoides S. Watson) and total weed biomass achieved by 0.8 lit a.i/ha application. Interaction between oxadiargyl dose and application time showed maximum reduction percent for common lambsqurter (Chenopodium album L.) at 0.8 lit a.i/ha in potato emergence. Alebrahim et al.(2) reported that application of oxadiargyl as pre and post emergence 160 gr/ha reduced biomass of common lambsquarter by 78 and 87 percent, respectively, and oxadiargyl application pre and post emergence 200 gr/ha educed biomass of common lambsquarter by 84 and 93 percent, respectively. Also oxadiargyl application pre and post emergence 240 gr/ha reduced biomass of common lambsqurter by 87 and 94 percent, respectively. Alebrahim et al. (1) reported application of oxadiargyl post emergence 0.4, 0.5 and 0.6 Lit ai/ ha reduced biomass of common lambsqurter 87.75, 93.25 and 94.75 percent respectively. Alebrahim et al., (3) reported greenhouse application of oxadiargyl post emergence 0.1 and 0.6 Lit ai/ ha reduced biomass of common lambsqurter 70.17 and 100 percent respectively. Alebrahim et al., (2) reported that application of oxadiargyl pre and post emergence at 160 gr/ ha reduced biomass of redroot pigweed 76 and 82 percent respectively and applying 200 gr/ ha pre and post emergence reduced redroot pigweed biomass 79 and 90 percent respectively. and 240 gr/ha reduced redroot pigweed biomass 85 and 95 percent respectively. Alebrahim et al., (1) reported application of oxadiargyl post emergence 0.4, 0.5 and 0.6 Lit a.i/ ha reduced redroot pigweed biomass 82.75, 90.75 and 95 percent respectively. Furthermore greeonhouse application of Oxadiargyl post emergence 0.1 and 0.6 Lit a.i/ha reduced biomass of common lambsqurter 65.92 and 100 percent respectively (3). Barb et al., (7) reported application of oxadiargyl 0.25, 0.30, 0.35, 0.40, 0.45 and 0.50 kg a.i/ ha reduced total weed biomass 73, 77, 77, 82, 82 and 86 percent 5 week after treatment and 74, 73, 80, 80, 83 and 84 percent 8 week after treatment respectively. Among oxadiargyl application time at different potato growth stages, potato emergence reduced redroot pigweed and total weed biomass 60.01 and 44.51 percent respectively as compared to control (weedy); also tuber bulking reduced Prostrate pigweed biomass 67.49 percent as compared to control (weedy). Application of 0.8 Lit a.i/ ha and potato emergence stage produced maximum total tuber yield per hectare. Alebrahim et al., (1) reported potato tuber yield 27.60, 32.30 and 35.3 ton/ha while oxadiargyl applied 0.4, 0.5 and 0.6 Lit a.i/ ha pre emergence and 33.17, 35.93 and 36.85 ton/ha while applied 0.4, 0.5 and 0.6 Lit a.i/ha post emergence.
Conclusion: Results showed that maximum reduction percent for redroot pigweed, prostrate pigweed and total weed biomass was achieved by 0.8 lit a.i/ha application. Interaction between herbicide dose and application time showed 0.8 lit a.i/ha at potato emergence reduced common lambsquarter biomass 87.94 percent. Application of oxadiargyl at potato emergence stage reduced redroot pigweed and total weed biomass and increased total tuber yield. However suggested to carry out the experiment over several years, to evaluate potato tolerance of varieties to Oxadiargyl and the effectiveness of other herbicides mixing with Oxadiargyl for future researches
Investigation Of Clinoptilolite Natural Zeolite Regeneration By Air Stripping Followed By Ion Exchange For Removal Of Ammonium From Aqueous Solutions
The purpose of this study was to regenerate clinoptilolite natural
zeolite by air stripping followed by removal of ammonium from aqueous
solutions. The research was carried out in continuous system. The
characteristics of graded clinoptilolite from Semnan (one of the
central provinces in Iran) mines were determined and then regeneration
tests were done by contacting of 1 N NaCl solution with given weights
of ammonium saturated zeolite. Then the brine of column was transferred
to the air stripping column for regeneration. The pH of brine solution
before entrance to a stripping column was increased to 11. Air stripped
ammonia from the brine was converted to the ammonium ion by using acid
scrubber. The outlet effluent from stripping column was collected for
reuse. The results showed that the cation exchange capacities were
17.31 to 18.38 mg NH4+/g of zeolite weight. Regeneration efficiency of
zeolite by NaCl solution and air stripping was in the range of 92%-97%
under various operational conditions. However, the efficiency of acid
absorption of released ammonia in stripping process was 55% with a
major rejection of the surplus ammonia to the atmosphere. It could be
concluded that the method studied may be considered as an advanced and
supplementary process for treating effluents of aqueous solution and
fishponds in existing treatment plants
A Comparative Study On Arsenic (III) Removal From Aqueous Solution Using Nano And Micro Sized Zero-Valent Iron
The present study was conducted for Arsenic (III) removal, one of the
most poisonous groundwater pollutants, by synthetic nano and micro size
zerovalent iron (n-mZVI). Batch experiments were performed to
investigate the influence of As (III), nZVI and mZVI concentration, pH
of solution and reaction time on the efficiency of As (III) removal by
Fe0 particles. Nano ZVI was synthesized by reduction of ferric chloride
by sodium borohydrid. Scanning Electron microscope and X-Ray
diffraction were used to determine particle size and characterization
of produced nanoparticles. Results showed up to 99.9% removal
efficiency for arsenic (III) that was obtained by nZVI dosage of 1 g/L
at equal time of 10 min and pH=7. The maximum removal efficiency by
mZVI obtained in initial arsenic concentration of 1 mg/L and mZVI
dosage of 10 g/L after 120 min. and pH=7. It could be concluded that
the removal efficiency was enhanced with increasing n-mZVI dosage and
reaction time, but decreased with increasing of arsenic concentration
and pH for both nano and micro sized ZVI. Nano ZVI presented an
outstanding ability to remove As (III) due to not only a high surface
area and low particle size but also to high inherent activity