Degradation of 17α-ethinylestradiol by ozonation--identification of the by-products and assessment of their estrogenicity and toxicity

The presence of the synthetic estrogen 17α-ethinylestradiol (EE2) in waters at low levels is a concern due to its ability to act as an endocrine disruptor. Ozone (O₃) is commonly used in water treatment and reacts with EE2 to form by-products having characteristics that are mostly unknown. The aim of this study was to identify the by-products of E2 and EE2 ozonation and determine their estrogenicity and toxicity relative to the parent compound. Ozonation by-products were identified via LC-MS analysis. The estrogenicity was measured using the YES assay, and toxicity was determined by monitoring effects on histology of fetal rat testes and testosterone secretion by these tissues. Two EE2 by-products were identified with open phenolic ring structures (masses 302 and 344 u). The Yeast Estrogen Screening (YES) assay showed a decreased but incomplete removal of estrogenicity after ozonation of EE2. Histological analysis of fetal testes revealed that neither E2 nor EE2, with or without ozonation, had any effect on seminiferous cord formation; however, a remarkable negative effect on testosterone secretion was observed, with EE2 by-products after ozonation showing the most rapid and extensive inhibition. These results show that the removal of EE2 via reaction with O₃ resulted in the formation of by-products that are less estrogenic (as demonstrated by the YES assay), but have a greater negative impact on testosterone secretion. Thus, the disappearance of the parent compound is not a sufficient endpoint, as the by-products created may be more toxic. Care should be taken when implementing oxidation applications such as ozone during waste water treatment.     

Optimal spatial sampling schemes for environmental surveys

A practical problem in spatial statistics is that of constructing spatial sampling designs for environmental monitoring network. This paper presents a fractal-based criterion for the construction of coverage designs to optimize the location of sampling points. The algorithm does not depend on the covariance structure of the process and provides desirable results for situations in which a poor prior knowledge is available. The statistical characteristics of the method are explored by a simulation study while a design exercise concerning the Pescara area monitoring network is used to demonstrate potential designs under realistic assumptions.     

Measuring limitations in activities of daily living: a population-based validation of a short questionnaire

Purpose. A newly developed questionnaire assessing limitations in activity of daily living (LADL–Q) that should improve assessment of LADL is tested in a large population-based validation study. Methods. This survey was paper-based. Overall, 16,634 individuals who were representative of the working population in the German-speaking part of Switzerland participated in the study. Item analysis was used the final version of the LADL–Q to four items per subscale that correspond to potential problems in three body regions (back and neck, upper extremities, lower extremities). Analysis included tests for reliability, internal consistency, dimensionality and convergent validity. Results. Test–retest reliability coefficients after 2 weeks ranged from 0.82 to 0.99 (Mdn?=?0.87), with no item having a coefficient below 0.60. The median item-total coefficients ranged between moderate and good. Correlation coefficients between LADL–Q subscales and three validated clinical instruments (Western Ontario and McMaster Universities osteoarthritis index, shoulder pain disability index, Oswestry) ranged from 0.63 to 0.81. In structural equation modeling the three subscales were significantly related with two important outcomes in occupational rehabilitation: self-reported general health and daily task performance. Conclusion. The new LADL–Q is a brief, reliable and valid tool for assessment of LADL in studies on musculoskeletal health.     

Assessing the demand of solid waste disposal in urban region by urban dynamics modelling in a GIS environment

The twentieth century saw a dramatic increase in the production of urban solid waste, reflecting unprecedented global levels of economic activity. Despite some efforts to reduce and recover the waste, disposal in landfills is still the most usual destination. However, landfill has become more difficult to implement because of its increasing cost, community opposition to landfill siting, and more restrictive environmental regulations regarding the siting and operation of landfills. Moreover, disposal in landfill is the waste destination method with the largest demand for land, while land is a resource whose availability has been decreasing in urban systems. Shortage of land for landfills is a problem frequently cited in the literature as a physical constraint. Nonetheless, the shortage of land for waste disposal has not been fully studied and, in particular, quantified. This paper presents a method to quantify the relationship between the demand and supply of suitable land for waste disposal over time using a geographic information system and modelling techniques. Based on projections of population growth, urban sprawl and waste generation the method can allow policy and decision-makers to measure the dimension of the problem of shortage of land into the future. The procedure can provide information to guide the design and schedule of programs to reduce and recover waste, and can potentially lead to a better use of the land resource. Porto Alegre City, Brazil was used as the case study to illustrate and analyse the approach. By testing different waste management scenarios, the results indicated that the demand for land for waste disposal overcomes the supply of suitable land for this use in the study area before the year 2050.     

Mechanochemical treatment to recycling asbestos-containing waste

Numerous industrial and experimental facilities have been set up, particularly in the last ten years, as a result of studies and researches on treating asbestos-containing waste (ACW) to stabilise it and to enable its reuse. Some of the stabilisation processes reduce the hazards of ACW by imprisoning in a cement or resonoid matrix. Other processes modify the fibrous structure of asbestos and transform it into an inert substance. One such inactivation process is mechanochemical transformation. This new technology is extremely interesting both economically and industrially, especially in view of the European Directive 1999/3/CE of 24/4/99, which provides for the obligatory treatment of all types of waste material before its disposal.     

Factors associated with medical waste under pandemic situation: a case study of the Kingdom of Bahrain

Journal of Material Cycles and Waste Management - Exploring the factors influencing medical waste generation is vital for proper management due to its hazardous nature. Improper treatment would...     

Assessment of individual and mixed toxicity of bromoform,tribromoacetic-acid and 2,4,6 tribromophenol,on the embryo-larval development of Paracentrotus lividus sea urchin

Environmental Science and Pollution Research - Water chlorination is the most widely used technique to avoid microbial contamination and biofouling. Adding chlorine to bromide-rich waters leads to...     

Ambient halocarbon mixing ratios in 45 Chinese cities

During this study 158 whole air samples were collected in 45 Chinese cities in January and February 2001. The spatial distribution of different classes of halocarbons in the Chinese urban atmosphere, including chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), Halon-1211, and other chlorinated compounds is presented and discussed. Most of these compounds were enhanced compared to background levels. However, the mean enhancement of CFCs was relatively small, with CFC-12 and CFC-11 increases of 6% (range 1–31%) and 10% (range 2–89%), respectively, with respect to the global background. On the contrary, strongly enhanced levels of CFC replacement compounds and halogenated compounds used as solvents were measured. The average Halon-1211 concentration exceeded the background of 4.3 pptv by 75% and was higher than 10 pptv in several cities. Methyl chloride mixing ratios were also strongly elevated (78% higher than background levels), which is likely related to the widespread use of coal and biofuel in China.