Pathological and toxicological investigations of chronic nitrate poisoning in cattle

In this study, three stillborn and five premature and blind calves from cows suffering from chronic nitrate poisoning were examined pathologically. The live calves were euthanized, due to a poor prognosis. Complete necropsy was performed on all the eight affected calves. Hydroperitoneum and ascites were the most predominant lesions in the stillborn calves. Edema and hemorrhage were observed in the lungs of all the calves. Hemorrhages were seen in the digestive systems of four calves. Blood samples were taken from five live calves and their mothers, and from two cows that had delivered stillborn or blind calves, for biochemical observations and measurement of methemoglobin levels. Blood values of five healthy cattle from a herd with no history of stillborn or blind calves were used as controls. Water and feed samples were taken from five different farms with a history of stillborn or blind calves and examined for nitrates. Nitrate and nitrite levels of feeds ranged from 154 to 480 and 1.5 to 20?ppm respectively; these levels can cause chronic poisoning. Levels of nitrates and nitrites in blood samples from cows and calves were found to be high. While hemoglobin values were found to be low, methemoglobin values were very high. No differences were observed between liver enzyme levels of the affected and control cattle. There were no bacteria or virus isolated from these animals, and histopathological examination revealed no indication of any other diseases.     

Living with climate change risks: stakeholders’ employment and coastal relocation in mediterranean climate regions of Australia and Spain

Climate change impacts are no longer just a future issue for communities in the Mediterranean climate regions. This comparative study offers insights on climate change risk perceptions and attitudes among environmental, economic and social stakeholders in coastal areas in northeastern Spain and South Australia, as well as compares interviewed stakeholders’ risk perceptions with available documentary data and participant observation. Using a community risk assessment approach, the results show that some stakeholders perceive that climate change is already and/or may further continue to affect their employment, mostly in a predominantly negative way. Interestingly, some other interviewed stakeholders consider that climate change creates opportunities through new and additional areas of work. The findings also suggest that climate change may influence relocation of coastal residential populations in both case studies, which is likely to be an acceptable option among the stakeholders. This acceptance can be linked to the fact that in both areas there is a significant percentage of resident population with migrant background. This study calls for a need to understand better the personal experience of climate change in industrialized countries, as well as to consider coastal relocation in the integrated coastal planning and other territorial and population policies.     

Variation in spatial pattern of criteria air pollutants before and during initial rain of monsoon

Spatial patterns of various criteria air pollutants,like SO₂, NO₂, O₃, and TSP were studied atShahdara National Ambient Air Quality Monitoring stationin Delhi (India) in July 1999. The minimum pollutantconcentrations were observed during morning hours,whereas the highest concentrations were found during thelate night hours, which seem to be related with thevehicular emission. Pre-monsoon daily ambient airquality spatial pattern was compared with the spatialpattern during initial and subsequent rain shower ofmonsoon. These spatial patterns were found to beessentially the same before and during rain, however asignificant decrease in SO₂, NO₂ and TSPconcentrations (40-45%) was observed after initial andsubsequent rains of the monsoon, demonstrating theimportance of rainfall in the scavenging of thesecriteria air pollutants.     

Short-term variation in air quality associated with firework events: a case study

The effect of fireworks on air quality was assessed from the ambient concentrations of various air pollutants (SO2, NO2, PM10 and TSP) during Diwali festival in Hisar city (India), in November 1999. The extensive use of fireworks was found to be related to short-term variation in air quality. During the festival the concentration of SO2 was observed to be increased approximately 10-fold at few sites, whereas the concentrations of NO2, PM10 and TSP increased 2-3 times, compared to the data collected on a typical winter day in December 1999. The maximum NO2 concentration was observed a day after the festival. The diurnal pattern of the above pollutants showed a slight increase in the night. The levels of these pollutants observed during Diwali were found to be moderately high, which can be associated with serious health impacts.     

Low-mitochondrial diversity and lack of structure in the velvet swimming crab <Emphasis Type="Italic">Necora puber</Emphasis> along the Galician coast

The velvet swimming crab Necora puber is a common species along the European Atlantic coasts. Due to its increasing commercial importance, many studies have been carried out to characterize its growth and reproduction, but no genetic assessment has ever been attempted at the population level. Here, we describe the genetic diversity and population structure of N. puber in northwestern Spain (Galicia), including additional samples from France, Portugal, and southern Spain. To do so, we analysed two mitochondrial fragments of the COI and 16S genes in 217 individuals collected from ten localities. Our results unveil low-genetic diversity and weak population structure along the studied range. A range expansion after the last glacial maximum, followed by ongoing gene flow, seems to be the most likely explanation for the observed genetic pattern.     

Pyrolysis of tyres. Influence of the final temperature of the process on emissions and the calorific value of the products recovered

A study was made of the pyrolysis of tyre particles, with the aim of determining the possibilities of using the products resulting from the process as fuel. Three final temperatures were used, determined from thermogravimetric data. The design of the experiment was a horizontal oven containing a reactor into which particles of the original tyre were placed. After the process, a solid fraction (char) remained in the reactor, while the gases generated went through a set of scrubbers where most of the condensable fraction (oils) was retained. Finally, once free of this fraction, the gases were collected in glass ampoules. Solid and liquids fractions were subjected to thermogravimetric analyses in order to study their combustibility. The gas fraction was analysed by means of gas chromatography to establish the content of CO, CO2, H2 and hydrocarbons present in the samples (mainly components of gases produced in the pyrolysis process). A special study was made of the sulphur and chlorine content of all the fractions, as the presence of these elements could be problematic if the products are used as fuel. Tyre pyrolysis engenders a solid carbon residue that concentrates sulphur and chorine, with a relatively high calorific value, although not so high as that of the original tyre. The liquid fraction produced by the process has a high calorific value, which rises with the final temperature, up to 40 MJ/kg. The chlorine content of this fraction is negligible. Over 95% of the gas fraction, regardless of the final temperature, is composed of hydrocarbons of a low molecular weight and hydrogen, this fraction also appearing to be free of chlorine.     

Characterization of Chemically Modified Potato Starch Films Through Enzymatic Degradation

The present investigation was undertaken to characterize the biodegradation pattern of chemically modified starch films. Chemically modified starch films obtained by esterification of the hydroxyl groups of the polysaccharide have shown lower water sorption than native starch films, being therefore more attractive for a number of processing applications. However, no systematic study characterizing their biodegradation behavior and comparing it with the degradation pattern of native starch films has still been published. In the current contribution we characterized the enzymatic degradation pattern of three derivatized starch films by use of a commercial α-amylase from Bacillus licheniformis. Optimum degradation conditions were chosen upon assaying the effect of enzyme load and temperature on the reaction course of native starch films. Under the conditions selected, comparison of different derivatization procedures revealed that the starch film modified with octanoyl chloride was enzymatically hydrolyzed at a much higher rate than native starch film. Maleated starch films also showed higher susceptibility to α-amylolytic hydrolysis than native starch, whereas acetylated starch showed a hydrolysis pattern similar to that of native starch. Differences in degradation rates of chemically modified films were explained in terms of their amylose content which promotes dense networks that hinder the access of starch-degrading enzymes.     

Cadmium and lead in livestock feed and cattle manure from four agricultural areas of Bursa,Turkey

The cadmium and lead contents in cattle manure taken from four agricultural areas exposed to different degrees of environmental pollution and in the livestock feeds grown in those places were measured by Atomic Absorption Spectrophotometer (AAS). The levels of cadmium and lead contamination in the manures of the cattle, which were fed in the areas far from industries, traffic or urbanization, were less than those that were closer to heavy traffic and industrial activities. The highest heavy metal content was found in cattle manure collected from the region with heavy traffic, followed by the industrial region and the rural region. Among the live stock feeds used in the present study, the highest levels of lead were found in grass; and the lowest levels were obtained from the samples of straw.     

Leachate Characterization and Assessment of Groundwater Pollution Near Municipal Solid Waste Landfill Site

Leachate and groundwater samples were collected from Gazipur landfill-site and its adjacent area to study the possible impact of leachate percolation on groundwater quality. Concentration of various physico-chemical parameters including heavy metal (Cd, Cr, Cu, Fe, Ni, Pb and Zn) and microbiological parameters (total coliform (TC) and faecal coliform (FC)) were determined in groundwater and leachate samples. The moderately high concentrations of Cl⁻, NO⁻ ₃, SO²⁻ ₄, NH⁺ ₄, Phenol, Fe, Zn and COD in groundwater, likely indicate that groundwater quality is being significantly affected by leachate percolation. Further they proved to be as tracers for groundwater contamination. The effect of depth and distance of the well from the pollution source was also investigated. The presence of TC and FC in groundwater warns for the groundwater quality and thus renders the associated aquifer unreliable for domestic water supply and other uses. Although some remedial measures are suggested to reduce further groundwater contamination via leachate percolation, the present study demand for the proper management of waste in Delhi.     

Assessment of Air Quality After the Implementation of Compressed Natural Gas (CNG) as Fuel in Public Transport in Delhi, India

Public transport in Delhi was amended by the Supreme Court of India to use Compressed Natural Gas (CNG) instead of diesel or petrol. After the implementation of CNG since April 2001, Delhi has the highest fraction of CNG-run public vehicles in the world and most of them were introduced within 20 months. In the present study, the concentrations of various criteria air pollutants (SPM, PM₁₀, CO, SO₂ and NO_x) and organic pollutants such as benzene, toluene, xylene (BTX) and polycyclic aromatic hydrocarbons (PAHs) were assessed before and after the implementation of CNG. A decreasing trend was found for PAHs, SO₂ and CO concentrations, while the NO_x level was increased in comparison to those before the implementation of CNG. Further, SPM, PM₁₀, and BTX concentrations showed no significant change after the implementation of CNG. However, the BTX concentration demonstrated a clear relation with the benzene content of gasoline. In addition to the impact of the introduction of CNG the daily variation in PAHs levels was also studied and the PAHs concentrations were observed to be relatively high between 10 pm to 6 am, which gives a proof of a relation with the limited day entry and movement of heavy vehicles in Delhi.