Environmental occurrence, analysis, and toxicology of toxaphene compounds.

Toxaphene production, in quantities similar to those of polychlorinated biphenyls, has resulted in high toxaphene levels in fish from the Great Lakes and in Arctic marine mammals (up to 10 and 16 microg g-1 lipid). Because of the large variabiliity in total toxaphene data, few reliable conclusions can be drawn about trends or geographic differences in toxaphene concentrations. New developments in mass spectrometric detection using either negative chemical ionization or electron impact modes as well as in multidimensional gas chromatography recently have led researchers to suggest congener-specific approaches. Recently, several nomenclature systems have been developed for toxaphene compounds. Although all systems have specific advantages and limitations, it is suggested that an international body such as the International Union of Pure and Applied Chemistry make an attempt to obtain uniformity in the literature. Toxicologic information on individual chlorobornanes is scarce, but some reports have recently appeared. Neurotoxic effects of toxaphene exposure such as those on behavior and learning have been reported. Technical toxaphene and some individual congeners were found to be weakly estrogenic in in vitro test systems; no evidence for endocrine effects in vivo has been reported. In vitro studies show technical toxaphene and toxaphene congeners to be mutagenic. However, in vivo studies have not shown genotoxicity; therefore, a nongenotoxic mechanism is proposed. Nevertheless, toxaphene is believed to present a potential carcinogenic risk to humans. Until now, only Germany has established a legal tolerance level for toxaphene--0.1 mg kg-1 wet weight for fish

Internationalization Of Research And Development-Causes And Consequences For A Small Economy

Taking note of the importance of outward foreign direct investment for knowledge creation in small countries, the article analyses causes and consequences of the internationalization of R&D. Using firm-specific data on Swedish manufacturing and a selection bias corrected regression method, variation across firms in the share of foreign R&D is explained with needs to overcome transfer costs and with technical progress, while influence of intra-firm trade is refuted. Complementary examination of affiliate characteristics speaks against small countries losing their edge in knowledge creation and production.Internationalisation of R&D, Technology diffusion, Vertical integration, JEL Classification: F2, L2, 03, F23, L22, 032, 033,