The global environment: Past,present and future

The changing status of the global environment, in both developed and developing countries, and our perception of these changes since the convening of the United Nations Conference on the Human Environment in Stockholm in 1972 are reviewed. The present as well as potential future environmental issues facing mankind are discussed under three interrelated broad categories: interrelationship between people, resources, environment and development, rational use of natural resources and new patterns of development and lifestyle.     

Source resolution and risk apportionment to augment the Bubble Policy: Application to a steel plant “bubble”

Source resolution and risk apportionment of emission source categories for risk reduction purposes can be used to enhance the Bubble Policy of the Clean Air Act. This is performed by incorporating receptor modeling techniques of factor analysis and chemical mass balances to assess noncarcinogenic and carcinogenic inhalation risks to a target population for certain pollutants coming from major emission source categories in a steel plant air shed. Source resolution, using factor analysis, statistically interprets a “source” from ambient data. By subsequently quantifying risks from identified metal emission sources using chemical mass balances and risk apportionment, a total additive risk from main source contributors in the steel plant is estimated. From this methodology, the Bubble Policy can be enhanced by targeting only main risk sources or by “risk-trading” with minor impact sources to reduce the total risk (if deemed significant) without arbitrarily reducing risk for all sources in an industrial source complex’s “bubble.”     

Are rainy season environmental stresses responsible for higher mortality in pashmina goats?

Summary A study was conducted to analyse the causes of death during the period January 1985 to December 1989, in pashmina kids and goats thought to be acclimatised to a medium altitude climate. In general, mortality was higher during the rainy season (up to 62 percent) than in the winter (17 percent) and summer seasons (21 percent). An exception was the year 1987 when mortality was lowest in the rainy season, presumably due to the effects of a drought. During the rainy season the majority of 6–12 month-old kids became dull, off-feed, weak, emaciated and anaemic. Occasionally these animals showed nasal discharge and diarrhoea. Haematological examination of randomly selected animals during rainy, post-rainy and early-winter seasons in 1985, 1986 and 1989 showed very low red blood cell counts (RBC), haemoglobin (Hb) and packed cell volume (PCV); with elevated erythrocytic sedimentation rates (ESR), neutrophilia, relative lymphopaenia, eosinopaenia, hypoproteinaemia, hypoalbuminaemia, hypogamaglobinaemia, increased A:G ratio and hypoglycemia. Red blood cells showed piokilocytosis, anisocytosis, punched out or ring shapes, presence of erythroblasts, basophilic stippling and Anaplasma marginale.Post-mortem examination revealed lesions of parasites either singly or in combination. These included lice, coccidia, Moniezia expansa, Haemonchus contortus,and Trichuris ovis.Poor or slightly improved health state, anaemic blood picture and moderated mortality were witnessed 45 days post-treatment or during the post-rainy season. Early-winter studies indicated that the goats were in an excellent health condition with normal blood picture and negligible mortality. It was concluded that the higher mortality in pashmina goats during the rainy season was association with high rainfall, humidity, partial or zero grazing, confinement of goats in sheds (all environmental stresses) and parasitism. This was supported in 1987, when the lowest mortality occurred during the rainy season due to the effect of drought and the absence of environmental stresses.Dr R. Somvanshi is a veterinary pathologist and is in charge of the Clinical Pathology and Medicine Section of Livestock Production Research. Dr J.C. Biswas works in the Animal Genetics and Breeding Laboratory. Dr B. Sharma is a biochemist in the Division of virology and currently a post-doctoral fellow at the Department of Virology at the Karolinska Institute, Stockholm, S-10521, Sweden. Dr G.L. Koul works in the Animal Genetics and Breeding Laboratory as Principal Scientist. All are based at the Indian Veterinary Research Institute.     

Blends of Zein and Nylon-6

Blends of zein and nylon-6 (55?k) in formic acid were used to produce solution cast films and electrospun fibers. When the amount of nylon-6 was 8?% or less blends were formed that had improved tensile strength and reduced solubility. The blends were analyzed using physical property measurements, DSC and IR spectra. Using between 2 and 8?% nylon-6 provided a 33?% increase in tensile strength. Young??s modulus increased by over 50?% in this range. In general elongation was lower for all formulations. Surprisingly the cast films having 0.5?C8?% nylon-6 had improved solvent resistance to 90?% ethanol/water. Electrospun fibers were produced from formic acid solutions of zein and nylon-6 where the amount of nylon was 0, 2 and 6. Fibers produced from 27?% spinning solids had average diameters on the order of 0.5???m. Reducing the spinning solids to 21?% provide slightly smaller fibers however, the fibers had more defects.     

Mathematical modelling and environmental decision-making

The primary role of a decision-maker is to make right decisions on the basis of available information and within the allowable time and resources constraints. The two basic types of models used for decision-making, technocratic and incremental, are discussed, and so are the common criteria of the decision-making process in a real world. The intensity and diversity of demands on our limited water resources have increased to such an extent that decision-makers are finding it increasingly difficult to consistently attain the needed flexibility and dexterity. Thus, even though decision-making has become exceedingly complex at present, and will become more so in the future, it is apparent that the average decision-maker has been provided with few, if any, new tools and concepts in the past several decades. One of these very few techniques is systems analysis.Even though modelling can add an important dimension to the decision-making process, surprisingly enough it still lacks credibility with the policy-makers. The several reasons that have given rise to this “credibility gap” are discussed in depth. Ten basic rules are suggested as guidelines for realistic model development. The positive and negative aspects of modelling as used for decision-making are discussed. Appropriate remedies are suggested to improve the image of modelling in the eyes of the decision-makers, which will reduce the proliferation of unvalidated, untested and unuseful models, much of which can be classified somewhere between dilettantism and academic exercises. It is concluded that even though some of our current models in this field are rather crude, and somewhat dependent on the experience and judgement of the analysts, the issue, in the final analysis, is very definitely on the side of having a model, even a crude one, against having no model at all.     

Multi-metal resistance and plant growth promotion potential of a wastewater bacterium Pseudomonas aeruginosa and its synergistic benefits

Water and soil pollution by toxic heavy metals (HMs) is increasing globally because of increase in population, industrialization and urbanization. It is a burning problem for the public, scientists, academicians and politicians how to tackle the toxic contaminants which jeopardize the environment. One possible solution for pollution abatement is a bioremediation-effective and innovative technology that uses biological systems for treatment of contaminants. Many bacteria synthesize indole-3-acetic acid (IAA) which is a product of l-tryptophan metabolism and belongs to the auxin class of plant growth-promoting hormone. The present study aimed at assessing the resistance pattern of wastewater bacteria against multiple HMs and plant growth promotion activity associated with IAA. A Gram-negative bacterial strain Pseudomonas aeruginosa KUJM was isolated from Kalyani Sewage Treatment Plant. This strain showed the potential to tolerate multiple contaminations such as As(III) (50 mM), As(V) (800 mM), Cd (8 mM), Co (18 mM), Cu (7 mM), Cr (2.5 mM), Ni (3 mM) and Zn (14 mM). The capability of IAA production at different tryptophan concentration (1, 2, 5 and 10 mg mL⁻¹) was determined, and seed germination-enhancing potential was also estimated on lentil (Lens culinaris). Such type of HM-resistant, IAA-producing and seed germination-enhancing P. aeruginosa KUJM offer great promise as inoculants to promote plant growth in the presence of toxic HMs, as well as plant inoculant systems useful for phytoremediation of polluted soils. Hence, P. aeruginosa KUJM finds significant applications in HM-contaminated poor agricultural field as well as in bioremediation of HM-contaminated wastewater system.