Efficiency and degradation products elucidation of the photodegradation of mefenpyrdiethyl in water interface using TiO2 P-25 and Hombikat UV100

The photodegradation of mefenpyrdiethyl (MFD), an herbicide safener, was investigated in aqueous suspensions by using Degussa P-25 and Hombikat UV100 titanium oxide under simulated sunlight irradiation. The effects of initial concentration of the herbicide, pH, catalysts and hydrogen peroxide doses as well as their combinations were studied and optimized. Accordingly, the kinetic parameters were determined and the effectiveness of the processes was assessed by calculating the rate constants. A pseudo first-order kinetics was observed. Under experimental conditions, the degradation rate constants were strongly influenced using P-25 and no noticeable effect was observed for Hombikat UV100. DFT calculations with B3LYP/6-311+G(2d,p)//B3LYP/6-31+G(d,p) level of theory were performed to check whether significant conformational changes occur when the charge state of the MFD substrate changes and whether these changes could play a role in the dependency of photodegradation rate constant on the studied pH. High resolution mass spectrometry (FT-ICR/MS) was implemented to identify the main degradation products.     

Zamzam water: concentration of trace elements and other characteristics

Many Muslims drink Zamzam water for use either medicinally or religiously. Millions of pilgrims drink it and take bottles of it to their home countries. Heated scientific and political debates appeared after BBC reported in May 2011 that Zamzam water is poisonous, because of the high levels of arsenic. The World Health Organizations classifies arsenic as a human carcinogen, but some types of arsenic are also used as medicines. Adequate scientific studies on the Zamzam water are absent. This paper will provide, for the first time, basic and comprehensive information regarding the geochemical properties of Zamzam water for more than 30 indicators and using the state-of-the-art laboratory facilities. The data will help us to understand the sources of pollution under discussion, reactions at both local and international levels; and will highlight the potential healing capacity of Zamzam water. Thirty Zamzam water samples were collected by three distinct methods; from 10 pilgrims living in different locations in Germany in 2007, 10 samples from shops in Frankfurt and Berlin in 2011, and 10 samples directly from Makkah in 2011. The samples were analyzed 2 weeks after collection for more than 30 indicators: pH, EC, Eh, Cl, F, Br, NO₃, PO₄, SO₄, HCO₃, Ag, Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Sr, and Zn beside others. Four major instruments were used; the IC, the ICPOES, the ICPMS and the HGAAS. The quality of the water did not change for 2 years and there was an excellent agreement among the results of the 30 water samples as well as between the results of the 2 years for the same samples analyzed in 2007 and 2008. The water is alkaline (average pH is 8) with an average Li concentration of 15 μg L⁻¹. The average concentrations of As and NO₃ showed values three times higher than the WHO standards (27 μg L⁻¹ and 150 mg L⁻¹, respectively). The averages of Ca and K were 95 and 50 mg L⁻¹, respectively. Very urgent steps are required to scientifically screen for the elevated parameters As, NO₃, Ca, and K in all Zamzam water sources and locations with full transparency. The resultant information should be made available to the public, and the relationship between pollution and human health should be addressed. The alkalinity of Zamzam water and the presence of trace amounts of As and Li may cause the healing power. However, a scientific strategy should be developed and adopted to enable further research and studies on toxicology and treatment technologies could be applied if needed.     

Facilitators and barriers to occupational health and safety in small and medium-sized enterprises: a descriptive exploratory study in Ontario,Canada

Purpose. The purpose of this particular study was to test a newly created instrument in describing the facilitators and barriers to occupational health and safety in small and medium-sized enterprises (SMEs) in Ontario, Canada. Methods. A cross-sectional design was used to identify the occupational health and safety culture of SMEs in public and private sectors in Ontario. Results. A total of 153 questionnaires were completed. The majority of respondents were female (84%) with a mean age of 49.8 years (SD 10.6). Seventy-four percent were supervisors. Seventy percent of respondents were from the private sector while 30% derived from the public sector including healthcare, community services, and non-profit organizations. Further, conducting regular external safety inspections of the workplace was found to be statistically associated with a safe work environment 2.88 95% CI [1.57, 5.27]. Conclusions. Strategies and training opportunities that focus on how to adapt occupational health and safety legislation to the nature and diversity of SMEs are recommended. Furthermore, employers may use such information to improve safety in their SMEs, while researchers can hopefully use such evidence to develop interventions that are applicable to meeting the occupational health and safety needs of SMEs.     

The influence of age on the morbidity and mortality of pedestrian victims

OBJECTIVES: The present study examined the influence of age on the morbidity and mortality of pedestrian victims while controlling for confounding factors. METHODS: The Pedestrian Crash Data Study (PCDS) database was used for a cross-sectional study to compare the outcome of senior (age >or=60 years) and adult (age 19 to 50 years) pedestrian victims. The outcome measures were the Injury Severity Score (ISS), Maximum Abbreviated Injury Score (MAIS), Abbreviated Injury Scale (AIS), and Mortality. Logistic regression models were used to estimate age-associated risks while controlling for confounders such as vehicle type, impact speed, and pedestrian height, weight, and gender. RESULTS: Compared to the adult victims, the seniors had a higher average ISS (23 vs. 16, p = 0.018) and higher mortality (30 percent vs. 11 percent, p or=9 (odds ratio = 2.72; 95 percent CI: 1.31-5.68) and to die (odds ratio = 6.68; 95 percent CI: 2.37-19.88). The seniors were approximately twice as likely to have higher AIS scores to almost every body region. CONCLUSIONS: The adjusted age-dependent risks indicated by the current study should be considered when calculating or projecting pedestrian morbidity and mortality. Adjustment in statistical models is essential to achieve precise risk estimates and in turn to appropriately allocate public health rescores.     

The occurrence of lithium in the environment of the Jordan Valley and its transfer into the food chain

Lithium is found in trace amounts in all soils. It is also found in plants and in nearly all the organs of the human body. Low Li intake can cause behavioral defects. Thus, this study was conducted to investigate the concentration and distribution of water-soluble Li in soils of the Jordan Valley and its concentration in citrus trees and some important food crops in view of the significant implications of Li for human health. The concentration of soluble Li was measured in 180 soil samples collected at two depths (0–20 and 20–40 cm) whereas its content was determined in fully expanded leaves collected from citrus and different vegetable crops. Concentrations of soluble Li in soils vary from 0.95 to 1.04 mg l⁻¹ in topsoil and from 1.06 to 2.68 mg l⁻¹ in subsoil, while Li concentration in leaves ranged from 2 to 27 mg kg⁻¹ DM. Lithium concentrations in leaves of crops of the same family or different families vary with location in the valley; i.e., they decreased from north to south. It is concluded that soluble Li in soils and the plant family did not solely affect Li transfer in the food chain. In addition, soil EC, Ca, Mg, and Cl, which increased from north to south, might adversely affect plant Li uptake. The current study also showed that consuming 250–300 g FW of spinach day⁻¹ per person is recommended to provide consumers with their daily Li requirement necessary for significant health and societal benefits.     

Impacts of horseradish peroxidase immobilization onto functionalized superparamagnetic iron oxide nanoparticles as a biocatalyst for dye degradation

Environmental Science and Pollution Research - To enhance the dye removal efficiency by natural enzyme, horseradish peroxidase (HRP) was immobilized onto amine-functionalized superparamagnetic iron...