摘要:

Along with concern for environmental quality and the anticipated return to an appropriate technology by highly developed nations, it behooves us not to ignore such natural forces — as the earthworm — that have made possible our existence as managers of the Earth. In order to plan for the future use (and exploitation) of earthworms, an understanding of their biology and capabilities is highly desirable. This review endeavors to delineate earthworm structure, functioning, and the effects of environmental factors on earthworm performance. The value of earthworms in agriculture, gardening, and soil improvement, in general, Is recognized. An attempt is then made to portray the benefits and limitations of earthworms as waste disposers, strip mine reclaimers, pollution indicators, and as a source of nutrients for animals or the human species.

ISSN:0007-8999    

DOI:10.1080/10643388109381688

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The state‐of‐the‐art knowledge of atmospheric organic constituents in the lower troposphere has been compiled in order to reconcile sources, transport processes, fates, and relative contributions of natural background organic vs. anthropogenic organic emissions. Volatile compounds and residual particulate organic carbon are the dominant fractions in both urban and remote areas. The lipid fractions have highest concentrations in urban centers, intermediate concentrations in rural areas, and lowest over the oceans. The same distribution is found for residual organic carbon and total vapor phase organic carbon. This large burden of urban contamination is attributed to residues from incomplete combustion of fossil fuels and industrial processes. Comparisons of homologous‐series, molecular markers, and bulk properties of macromolecular organic matter are used for the chemical speciation of organic aerosols. The instrumental methods of analyses described are all in use for a variety of analytical purposes including atmospheric organic matter. A general discussion of sampling methods for various molecular weight regimes of organic aerosols is also presented.

ISSN:0007-8999    

DOI:10.1080/10643388109381689

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Despite continuing efforts at environmental control, occupational lung disease continues to be a major health problem. Asbestiform and siliceous dusts commonly are implicated as causative factors in fibrotic and carcinogenic pulmonary diseases. The basic pathogenetic mechanisms leading to these conditions are poorly understood and have been approached in a limited fashion. With the increasing availability of electron and X‐ray microanalytical techniques, investigators have been able to determine important associations between inhaled particles and specific anatomic and cellular lesions. In attempts to phagocytize, package, digest, and export particles, pulmonary cells and other functional units put out a variety of proteolytic, elastolytic, and inflammatory products. The alveolar macrophage, as the first line of cellular defense in the lower respiratory tract, plays a major role in mediating the biologic activities of many inhaled particulates. This chapter details electron optical techniques currently used to study the distribution, fate, and biologic activity of inhaled particulates and describes the information available on the mechanisms of particle‐induced lung disease.

ISSN:0007-8999    

DOI:10.1080/10643388109381690

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor