Cytotoxicity of resorcinol under short- and long-term exposure in vitro.

Cytotoxicity of resorcinol to 3T3 fibroblast in short- (3 hrs) and long-term (72 hrs or 6 weeks) exposure was investigated. The effects of resorcinol on cell viability (neutral red uptake, NRU assay), mitochondrial function (MTT assay) and total cell protein (Kenacid Blue assay) were estimated. As a model for long-term exposure an INTEGRA CL 6-WELL bioreactor was used. The concentrations of resorcinol producing 20, 50 and 80% inhibition of cell growth in the NRU test were lower than in the MTT test after 3 hrs of exposure. The use of an INTEGRA CL 6-WELL bioreactor allows continuous culturing and exposure to test chemical of cells for several weeks, but the strong adhesiveness of fibroblast and forming aggregates make it difficult to remove them from chambers. Resorcinol in concentration of 1 microg/cm(3) did not decrease the viability of cells to 50% of control in long-term exposure in the bioreactor.     

Responses of pikas (Ochotona princeps,Lagomorpha) to naturally occurring terrestrial predators

Summary The responses of individually marked pikas (Ochotona princeps) to terrestrial predators were investigated in 1980 and 1981 in the Rocky Mountains of Colorado. Pikas uttered short call vocalizations in a variety of contexts: preceding or following an individual's movement, and in response to conspecifics, other nonpredaceous mammals and predators. Adult pikas apparently discriminated contexts in which predators were present by short calling more frequently and for longer duration compared with calling in nonpredator contexts. Short calls uttered by juveniles were similar in all contexts.Adults responded differently to two types of terrestrial predators: weasels and pine martens. Pikas called less frequently in response to weasels than to martens and avoided weasels more often than martens. They delayed the initiation of calling following the first sighting of a weasel more often than to martens. Weasels were determined to be more effective predators of pikas than martens, and these asymmetries in behavior and alarm vocalizations may indicate that responses reduce an individual's risk of predaton by weasels.Both male and female pikas called in response to predators, and residents called more often than nonresidents. The possible function of predator-related vocalization in pikas is discussed. It is suggested that calls to predators may function to warn local residents, which in pikas are usually closely related.     

Chorionic villus sampling utilization following reports of a possible association with fetal limb defects

Prenatal diagnosis choices were reviewed in 473 women who presented for genetic counselling prior to 11 weeks' gestation for the indication of advanced maternal age. Group A consisted of 336 patients who were unaware of a possible association between chorionic villus sampling (CVS) and limb defects. Group B consisted of 137 patients who were provided this information. Fifty-one per cent of patients in group A and 45 per cent of patients in group B chose CVS. This difference was not significant by χ² analysis (P = 0·7). Patterns of prenatal diagnosis procedure utilization from 1987 to 1992 revealed a significant reduction in CVS utilization accompanied by a corresponding increase in amniocentesis after the association between CVS and limb defects was publicized. Referrals for CVS counselling also significantly declined. However, acceptance rates did not change for those patients who received genetic counselling. First-trimester genetic counselling, including a discussion regarding a possible association between CVS and limb defects, helps patients make informed decisions concerning prenatal diagnosis options, and, in our population, resulted in no change in CVS acceptance rates.     

From feathers to syngas - technologies and devices

The poultry waste produced by industrial slaughterhouses typically contains not only feathers, but also a mixture of animal entrails, nails, blood, beaks and whole carcasses. Economical utilisation of this mixture, varying strongly in composition and moisture content, is, in general, difficult. We demonstrate that this awkward material can be successfully used for gasification in a simple, fixed-bed gasifier. The method of gasification, which we developed, enables control of the gasification process and ensures its stability in the operational regime of a working poultry processing plant. The installation, which has been working in Poland for 2 years, utilises 2 tons of feathers per hour and produces syngas of stable composition and fairly high quality. The syngas is burnt in the combustion chamber adjacent to the gasifier. Heat is recuperated in a boiler producing 3.5 tons per hour of technological steam continuously used for the operation of the slaughterhouse. The whole process complies with the stringent emission standards. In the paper we present the end-use device for feather utilisation and describe the underlying gasification and syngas combustion processes. Key elements of the whole installation are briefly discussed. The environmental impacts of the installation are summarized.     

Furnace Sorbent Injection

Abstract

This paper summarizes information on the spatial and temporal variability of selected air toxics pollutants collected on a national basis primarily for a period encompassing 1990–2003. Spatial information on pollutant concentrations is characterized in terms of within-city and between-city variability. Temporal information is summarized as diurnal and seasonal variability and in multiyear trends. The information on variability is presented in the framework of a larger need for systematic documentation of information on air toxics pollutants to assess progress in air pollution control programs.     

Acceleration of tributyltin chloride (TBT) degradation in liquid cultures of the filamentous fungus Cunninghamella elegans

In this study, we have examined the effects of synthetic medium ingredients and culture incubation conditions on growth and tributyltin chloride (TBT) degradation activity of the fungus Cunninghamella elegans. The best efficiency of TBT conversion to less toxic derivatives: dibutyltin and monobutyltin was noticed on media which contained glucose, NH(4)Cl, K(2)HPO(4) and MgSO(4). Next, the constructed M3 medium (with the above components) ensured vigorous growth of C. elegans and allowed the reduction of 80% of the initial TBT content (10 mg l(-1)), after 3d of biodegradation. The further acceleration of the biocide utilization by C. elegans was achieved by additional oxygen supply (pO(2) >or = 20%) to the growing fungus (89% after 2d of incubation in the BioFlo II bioreactor). The efficient xenobiotic biodegradation was related to the intensity of fungal growth. The obtained results suggest a cometabolic nature of TBT utilization by C. elegans.     

Concentrations and source characteristics of airborne carbonyl compounds measured outside urban residences

This paper presents the analysis of ambient air concentrations of 10 carbonyl compounds (aldehydes and ketones) measured in the yards of 87 residences in the city of Elizabeth, NJ, throughout 1999-2001. Most of these residences were measured twice in different seasons; the sampling duration was 48 hr each time. The authors observed higher concentrations for most of the measured carbonyl compounds on warmer days, reflecting larger contributions of photochemical reactions on warmer days. The estimated contributions of photochemical production varied substantially across the measured carbonyl compounds and could be as high as 60%. Photochemical activity, however, resulted in a net loss for formaldehyde. The authors used stepwise multiple linear regression models to evaluate the impact of traffic sources and meteorological conditions on carbonyl concentrations using the data collected on colder days (with lower photochemical activities). They found that the concentrations of formaldehyde, acetaldehyde, acrolein, propionaldehyde, crotonaldehyde, benzaldehyde, glyoxal, and methylglyoxal significantly decreased with increasing distance between a measured residence and one or more major roadways. They also found significant negative associations between concentrations for most of the measured carbonyl compounds and each of the following meteorological parameters: mixing height, wind speed, and precipitation.