Nickel in the muscle tissues of freshwater fish from north eastern Poland should not cause human health concerns

Excessive intake of nickel (Ni) is known to produce adverse health effects in humans, including carcinogenicity and allergenicity. The main route of exposure for humans is diet, including fish. There is, however, little information concerning Ni content in freshwater fish in Poland. The aim of the study was to determine the concentrations of Ni in meat tissues of three fish species from north eastern Poland and assess toxic potential to healthy and susceptible sub-groups of individuals. The settings for the study lakes span a range of anthropogenic influence from protected areas to a basin with a town and several villages and another one influenced by a pesticide tomb leakage. Fish were netted and kept frozen until analysis. After defrosting, the fish were filleted and minced. The ashed samples were dissolved in nitric acid and analyzed for Ni by flame atomic absorption spectrometry. Roach meat contained 6.6–23 µg kg^?1 Ni, bream 9.5–178 µg kg^?1, and carp 16.5–139 µg kg^?1. These concentrations are low, indicating that the fish were not excessively contaminated with the metal. Consuming a 250 g portion of fish would result in an average nickel intake of 4 µg for roach, <10 µg for bream, and <20 µg for carp. These values represent only 0.4–2% of the maximum level that is likely to pose a risk of adverse effects as established in the USA. Consumption of fish from the study region need not necessarily pose a health threat.     

Comments on the Carcinogenicity and Mutagenicity of metals and their compounds†

The carcinogenicity of metals has received extensive study, both epidemiologically and in the laboratory. These have included case reports of occasional human occurrence or clusters of cancer cases as well as extensive epidemiologic studies; in addition, there has been significant laboratory research on the whole animals and in vitro systems. This body of information will be examined selectively.

I will not in this paper attempt a comprehensive review of the mutagenicity and carcinogenicity of metals and their compounds. Rather, I will attempt to set forth some historical perspectives, and to comment on some current gaps and needs.

Other papers in this workshop have presented thorough and very current reviews of most of the topics briefly noted in this presentation and do not require repetition here.

The cancer issue has been studied and reported on far more extensively than that relating to heritable mutations. There has been in recent years increasing interest in the use of short term tests for mutagenicity and cell transformation. These, however, are primarily with respect to their relationship to cancer production rather than to germ cell injury. Interest in cancer from metal compounds goes back a long time; in fact, one of the earliest reports was on the carcinogenicity of arsenic not many decades after the pioneering report of Sir Perceval Pott on cancer in chimney sweeps. Since then cancer has been definitely associated in humans with chromium compounds, nickel, and with less assurance but probably definitely with beryllium and cadmium. The confirmation of these findings in laboratory animals has been uneven. In the case of arsenic, for example, there has been only limited success in the production of cancer in laboratory animals with arsenic.

Many other metals have been found in laboratory studies to produce cancer, although with most of these, evidence of production of cancer in humans is either absent or extremely uncertain.

The extensive body of recent information relating to the testing of metals with a variety of short term tests will be briefly reviewed.     

The use of the embryo‐culture techniques in the research on the Teratogenic and Mutagenic properties of metals†

Actually, embryos can be cultured from the one‐cell stage up to the blastocyst stage, and their development can be easily monitored at any time: severe effects caused by toxic compounds are traduced by rapid embryonic death, less pronounced effects can be expressed by a lowered cleavage activity or by an arrest of the development from a particular stage. The system can be improved by transferring the embryos at the blastocyst stage in another more complete medium where they can “implant”; and form an inner cell mass with differentiated ectoderm and endoderm. Since last years, it has also become possible to culture postimplantation rodent embryos for short periods involving a number of particularly critical stages of organogenesis, such as the formation and closure of the anterior neuropore. Embryo‐culture also represents a useful system to study cytogenetic effects of chemicals which are often linked to lethal or teratogenic effects. These different possibilities are illustrated by examples of studies already performed with metals, and dealing with their teratogenic and/or cytogenetic effects on pre‐ and postimplantation rodents.     

Occupational exposures,delivered doses and exposure limits for chromium and nickel†

The interaction of HCH (50 mg/kg) and dietary protein levels on microsomal drug metabolizing enzymes system and liver lipids were studied in the rats for 90 days. The results indicated that rats fed a lower protein diet and HCH has a higher rate of mortality, lower rate of growth and an increased liver weight. A significant induction in the hepatic microsomal aminopyrine‐N‐demethylase, p‐nitroanisole‐O‐dealkylase, benzo(a)pyrene hydroxylase and glutathione‐S‐transferase activity was observed in pesticide treated animals as compared to control animals. The pathological changes observed in liver of HCH treated animals consisted mainly of necrosis and fatty degeneration of hepatocytes. HCH also induced the significant accumulation of cholesterol, triglycerides, phospholipid and total lipid in liver in low protein diet animals. Protein accelerates the metabolism of HCH, resulting in a decrease of HCH concentration with the increase of dietary protein level. A close correlation existed between lipid accumulation, induction of drug metabolizing enzyme system and deposition of HCH in liver.     

Large plasmids governing multiple resistances to heavy metals: A genetic approach∗

Gram negative bacteria classified as Alcaligenes eutrophus and carrying large resistance plasmids (generally two) were found in various industrial sites highly contaminated by heavy metals (Zn⁺⁺, Cu⁺⁺, Co⁺⁺,...). These strains were detected by DNA hybridization with a probe made with a 9kb fragment (ccz⁺ fragment) encoding for resistances to Cd⁺⁺, Co⁺⁺ and Zn⁺⁺, and cloned from plasmid pMOL30. This plasmid was isolated from the representative strain A. eutrophus CH34 which harbours the plasmids pMOL30 (240 kb) and pMOL28 (165 kb). Phenotypes related to pMOL28 and pMOL30 include the tolerance to Cd⁺⁺, Co⁺⁺, Cr0₄ ⁼, Cu⁺⁺, Hg⁺⁺, Ni⁺⁺, Pb⁺⁺ and Zn⁺⁺. The described genetic properties of these plasmids refer to some cloned or mapped functions and to some plasmid rearrangements. Plasmid pMOL85 (250 kb) which is related to pMOL30 was also described. Its host (A. eutrophus DS185) was isolated from a zinc desert. pMOL85 can efficiently self transfer in plasmidfree derivatives.     

化学镀镍清洁生产工艺的研究

根据清洁生产的特征和实施原则,结合我们长期在化学镀镍领域内工作的实践及目前化学镀镍的现状,分析了在该领域内实施清洁生产的必要性、可行性,提出了建立化学镀镍清洁生产工艺的方案。     

Degradation of H-acid in aqueous solution by microwave assisted wet air oxidation using Ni-loaded GAC as catalyst

A novel process, microwave assisted catalytic wet air oxidation( MW-CWO), was applied for the degradation of H-acid( l-amino8-naphthol-3, 6-disulfonic acid) in aqueous solution, Ni-loaded granular activated carbon (GAC), prepared by immersion-calcination method, was used as catalyst. The results showed that the MW-CWO process was very effective for the degradation of H-acid in aqueous solution under atmospheric pressure with 87.4% TOC (total organic carbon) reduction in 20 min. Ni on GAC existed in the form of NiO as specified by XRD. Loss of Ni was significant in the initial stage, and then remained almost constant after 20 min reaction. BET surface area results showed that the surface property of GAC after MW-CWO process was superior to that of blank GAC.     

龙口褐煤对Ni^2＋,Mn^2＋,Hg^2＋等重金属离子的吸附特性

本文以龙口褐煤作吸附剂,对重金属离子Ｎｉ＾２,Ｍｎ＾２＋,Ｈｇ＾２＋的单组分水溶液进行吸附研究,探讨了吸附剂的吸附性能,影响吸附的因素和吸附机理。结果表明：褐煤对Ｎｉ＾２＋,Ｍｎ＾２＋,Ｈｇ＾２＋的吸附均表现出Ｌａｎｇｍｕｉｒ特征,ＰＨ值是影响吸附的一个重要因素。     

镍对厌氧消化过程的抑制作用研究

采用混合式厌氧反应器,以酒糟废水为基质,在相同条件的不同反应器中每日加入不同浓度的镍离子（以硝酸镍形式加入）,研究不同浓度的镍离子对厌氧体系的抑制作用,以及体系中溶解态的镍离子含量与抑制程度的关系。结果表明,日加入镍量低于３６．４ｍｇ／Ｌ时,对体系无影响;在４０－６０ｍｇ／Ｌ时,产生轻微的抑制;超过８０ｍｇ／Ｌ时,对体系造成严重的抑制。当体系中溶解态镍离子浓度低于２．５ｍｇ／Ｌ时,体系不受影响。厌