Ionic liquids as lubricants or lubrication additives: An ecotoxicity and biodegradability assessment

This paper reports on the (eco)toxicity and biodegradability of ionic liquids considered for application as lubricants or lubrication additives. Ammonium- and pyrrolidinium-based cations combined with methylsulphate, methylsulphonate and/or (CF₃SO₂)₂N⁻ anions were investigated in tests to determine their aquatic toxicity using water fleas Daphnia magna, green algae Selenastrum capricornutum and marine bacteria (Vibrio fischeri). Additional test systems with an isolated enzyme (acetylcholinesterase) and isolated leukaemia cells from rats (IPC-81) were used to assess the biological activity of the ionic liquids. These compounds generally exhibit low acute toxicity and biological activity. Their biodegradability was screened according to OECD test procedures 301 B and 301 F. For choline and methoxy-choline ionic liquids ready biodegradability was observed within 5 or 10 d, respectively. Some of the compounds selected have a considerable potential to contribute to the development of more sustainable products and processes.     

Assessment of organotin pollution along the Polish coast (Baltic Sea) by using mussels and fish as sentinel organisms

Levels of tributyltin (TBT) and its degradation products, mono- (MBT) and dibutyltin (DBT), as well as triphenyltin (TPT), were monitored in 10 stations along the Polish coast (Baltic Sea). Mussel-Mytilus edulis-and fish-Platichthys flesus-were used as sentinel organisms. The bioaccumulation patterns of butyltin and phenyltin compounds varied substantially. Butyltins were detected in mussel tissue from all the sampled stations. Among them, organisms from the Gulf of Gdansk showed the highest residues (68 ng/g w.w. as Sn) in conjunction with elevated TBT/DBT ratios, which suggest recent inputs of TBT in the area. Additionally, flatfish were sampled in the Gulf of Gdansk, and different tissues (liver, digestive tube and gills) were analyzed separately. TPT, although undetected in mussels, was always present in fish. The highest organotin concentration was observed in the liver (369 ng/g w.w. as Sn) of fish caught near Gdansk port. Relatively high concentrations were observed in digestive tube, which points out the ingestion of organotin contaminated food as an important uptake route of those compounds in P. flesus.     

Knowledge,attitudes and practices of occupational risks in Colombian taxi drivers

Objective. The objective of this study was to learn about the health and safety strategies in a sample of taxi drivers in Bucaramanga, Colombia. Methods. A cross-sectional study was conducted among 138 taxi drivers. A survey was used to identify the socio-demographic and working characteristics, knowledge, attitudes and practices according to their occupational risk. Results. Eighty-five percent of the workers labored 9–15?h/day. Of those who suffered accidents, 27% were not affiliated to an occupational risk administrator (p = 0.028). Of the workers who had a work-related accident, 58% considered that the use of a cell phone while driving would not always reduce their attention, 50% always used their seat belt and 7% took active breaks and wore their seat belt (p = 0.01). Conclusions. Within this group of taxi drivers, having or believing to possess knowledge regarding an occupational risk did not ensure that they had a safe attitude or safe working practices.     

Particulate matter in the indoor and outdoor air of a gymnasium and a fronton

An indoor/outdoor monitoring programme of PM₁₀ was carried out in two sports venues (a fronton and a gymnasium). Levels always below 50 μg m^?3 were obtained in the fronton and outdoor air. Due to the climbing chalk and the constant process of resuspension, concentrations above 150 μg m^?3 were registered in the gymnasium. The chalk dust contributed to CO₃ ^2? concentrations of 32?±?9.4 μg m^?3 in this sports facility, which represented, on average, 18 % of the PM₁₀ mass. Here, the carbonate levels were 128 times higher than those registered outdoors. Much lower concentrations, around 1 μg m^?3, were measured in the fronton. The chalk dust is also responsible for the high Mg²⁺ concentrations in the gym (4.7?±?0.89 μg m^?3), unfolding a PM₁₀ mass fraction of 2.7 %. Total carbon accounted for almost 30 % of PM₁₀ in both indoor spaces. Aerosol size distributions were bimodal and revealed a clear dependence on physical activities and characteristics of the sports facilities. The use of climbing chalk in the gymnasium contributed significantly to the coarse mode. The average geometric mean diameter, geometric standard deviation and total number of coarse particles were 0.77 μm, 2.79 cm^?3 and 28 cm^?3, respectively.     

Application of simulation models to the diagnosis of MSW landfills: an example

Among the landfill simulation programs being developed by several research groups around the world as tools for the management of sanitary landfills is MODUELO, whose second version, MODUELO 2, has been presented elsewhere. It reproduces the operational history of the landfill and its hydrologic and biodegradation processes, allowing the estimation of the flow and pollutants emitted in the leachate and the generated landfill gas over time. This program has been used for a diagnosis study of an existing European MSW landfill. The construction and calibration of the facility's hydrologic model, based on the available data, allowed the detection and quantification of two sources increasing the flows reaching the leachate collection system: a small portion (6-7%) of the runoff over the landfill surface and the contribution of water coming from external hillsides of the same watershed that represent a total surface area of around 20ha. The contrast of the leachate quality (COD, BOD, NH(4)-N and TKN) simulation results and measured data showed the potential of these models for the assessment of other significant aspects in landfill operation such as the potential harnessing of the landfill gas. Nonetheless, in this case as in many others, the accuracy of the simulation results was limited by the scant quality of the available data, which highlights the need for implementing continuous monitoring and characterizing protocols to take advantage of these programs as a tool for landfill optimization.     

Measurement of pollution levels of organochlorine and organophosphorus pesticides in water, soil, sediment, and shrimp to identify possible impacts on shrimp production at Jiquilisco Bay

This study aims to identify levels of several organochlorine and organophosphorus compounds in shrimp-raising areas of coastal El Salvador, to assess potential impacts on shrimp growth and survival that hamper the sustainability of aquaculture in the region. The paper reports the current levels of γ-HCH, 4,4'-DDT, 4,4'-DDE, 4,4'-DDD, endrin, dieldrin, heptachlor, parathion, methyl parathion, and etoprophos in soils (depth 20 cm), sediments (depth 5 cm), shrimp (Penaeus sp.), and water of three rearing ponds and also in the sediment (depth 5 cm) and water surrounding those ponds in Jiquilisco Bay. Sampling was carried out during the dry (January-March) and rainy (June-August) seasons of 2008. The presence of pesticides in the samples of water, shrimp, and sediment at shrimp ponds was not detected in either season; however, in soil samples (depth 20 cm) taken from these ponds, heptachlor, endrin, dieldrin, 4,4'-DDD, and 4,4'-DDT were identified at concentrations below the method limit of quantification (LOQ), and 4,4'-DDE was found in a concentration falling in the range from 3.85 to 19.61 ng/g. In samples of water taken at the bay water intakes to the rearing ponds, we observed dieldrin concentrations in the range between 0.085 ng/mL and 0.182 ng/mL during the dry season. In the samples of sediments taken in the surrounding areas of shrimp ponds, we found-for both seasons-that in 60 % of the samples, 4,4'-DDE was present in concentrations ranging from 3.75 ng/g to 30.97 ng/g. Additionally, in the rainy season, we observed heptachlor in sediment at concentrations below the method quantification limit. It was concluded that organochlorine compounds from pesticides are still present in Jiquilisco Bay, trapped in deep sediment, even though they have been banned since the 1980s. These were not detected in shrimp tissue, surface water, and shallow sediment in rearing ponds, and hence, we do not believe their presence has any major impact on shrimp production in sampled areas.     

Emissions of C&D refuse in landfills: A European case

A field study was developed in a new landfill for refuse from construction and demolition (C&D) material recovery plants of small size (4 Ha.) in Europe, with the aim of evaluating the liquid and gas emissions in this type of facility at a large scale. It included characterization of the materials, monitoring leachate and gas quantity and composition. Besides thermometers, piezometers and sampling ports were placed in several points within the waste. This paper presents the data obtained for five years of the landfill life. The materials disposed were mainly made up of wood and concrete, similar to other C&D debris sites, but the amount of gypsum drywall (below 3% of the waste) was significantly smaller than other available studies, where percentages above 20% had been reported. Leachate contained typical C&D pollutants, such as different inorganic ions and metals, some of which exceeded other values reported in the literature (conductivity, ammonium, lead and arsenic). The small net precipitation in the area and the leachate recirculation into the landfill surface help explain these higher concentrations, thus highlighting the impact of liquid to solid (L/S) ratio on leachate characteristics. In contrast to previous studies, neither odor nuisances nor significant landfill gas over the surface were detected. However, gas samples taken from the landfill inside revealed sulfate reducing and methanogenic activity.     

Comparison and analysis of different approaches for estimating the human exposure to phthalate esters

The human exposure estimates for dibutyl (DBP) and bis(2-ethylhexyl) phthalate (DEHP) made by two models EUSES and ACC-Human, and by an estimation approach which utilized measured concentrations in exposure media, were compared. The approach which utilized the latest monitoring data for important exposure media, yielded median daily intakes for adult humans for DBP and DEHP of 2.7 and 5.6 microg/kg body weight per day, respectively, which were in the same range as previous estimates based on back-calculation from urinary metabolites. EUSES estimated average daily intakes of DBP and DEHP for humans that were between 8 and 13 times lower. ACC-Human does not estimate average daily intakes, but ACC-Human-estimated human milk concentrations/fugacities were more than a thousand times lower than measured concentrations/fugacities in human milk. It was concluded that the two models underestimate human exposure to phthalate esters because they consider only a few key pathways that are known to be important for other, more persistent, hydrophobic organic compounds. Further, it was shown that there are differences between the two models on the methodology for estimating concentrations in exposure media such as vegetation, milk, beef and fish. ACC-Human uses a mechanistic approach for estimating transfer through aquatic and terrestrial food chains that are known to be important for human exposure to persistent, hydrophobic organics and can, unlike EUSES, account for food chain metabolism. It proved difficult, however, to obtain organism metabolism rates needed as model inputs to ACC-Human. If exposure estimates of phthalate esters are needed, it is recommended to use an estimation approach based on high quality monitoring data as presented here and/or back-calculate daily intake from concentrations of metabolites in human urine samples from the general population.     

Nitrogen oxides and ozone in Portugal: trends and ozone estimation in an urban and a rural site

Environmental Science and Pollution Research - This study provides an analysis of the spatial distribution and trends of NO, NO2 and O3 concentrations in Portugal between 1995 and 2010....     

LCA to Evaluate the Environmental Impact for Chemical Pre-treatment in Plastics Metallization

The life cycle assessment methodology was used to calculate the environmental impacts of the current chemical pre-treatment with chromium(VI) for electroplating acrylonitrile butadiene styrene. The inventory comprised: the procurement of chemicals; the manufacturing process with successive baths and rinses that requires, in addition to chemicals, energy to heat baths, air agitation, filtration, and so forth, wastewater treatment and air emissions; and also the treatment of sludges from wastewater treatment and exhausted baths. Chromic acid was almost the unique responsible of eco-toxicity (97.5 %) and human toxicity-cancer (99.8 %) and it was one of the highest contributor to climate change, cumulative energy demand, fossil fuel depletion, human toxicity non-cancer, and in abiotic depletion.