Possible Causes for Concern

The findings of the chlorinated dibenzo-p-dioxin and dibenzofuran isomers in persons residing in contaminated areas and both measured and calculated levels of these compounds in breast milk in the United States presents a possible cause for concern regarding health effects in the nursing infant. Further study is indicated to determine if there is any real clinical risk at the levels found. 

This review briefly summarises the available evidence on the relative potency of the phytoestrogens, and discusses the evidence that beneficial effects on human diseases may potentially arise from consumption of foodstuffs containing these compounds, with particular regard to those effects that have been suggested as possibly being related to the hormone-receptor mediated activities of the phytoestrogens. Certain causes for concern regarding these compounds are also addressed. 

Solubilizing all or part of a sample matrix by contacting with liquids is one of the most widely used sample preparation techniques for gases, vapors, liquids or solids. Additional selectivity is possible by distributing the sample between pairs of immiscible liquids in which the analyte and its matrix have different solubilities. Equipment requirements are generally very simple for solvent extraction techniques. Table 8.2 [4,10], and solutions are easy to manipulate, convenient to inject into chromatographic instruments, and even small volumes of liquids can be measured accurately. Solids can be recovered from volatile solvents by evaporation. Since relatively large solvent volumes are used in most extraction procedures, solvent impurities, contaminants, etc., are always a common cause for concern [65,66]. 

With an adherent cell line, initially there will be few cells in the harvest and those that are recovered may be nonviable This is not necessarily a cause for concern, since viable cells will remain attached to the fibers With a nonadherent cell line, the first 50 mL of the initial harvests may yield a higher proportion of dead cells, because these tend to fall more rapidly to the bottom of the cartridge 29. In the early stages with a nonadherent cell line, too many cells may inadvertently be removed during harvesting After centrifugation, these cells may be suspended in the replacement medium and reintroduced into the bioreactor It is also possible to use cells from a well-established bioreactor to seed another... 

The possibility of this kind of reaction occurring in vivo and producing nitrosamines in the acidic medium of the stomach is some cause for concern over nitrites in the diet. Because of this possibility, nitrite levels have been reduced substantially in foods such as cured meats that formerly contained relatively high nitrite levels. 

Many symptoms of aluminum toxicity are similar to those of Alzheimer s disease and osteoporosis. This suggests that long-term accumulation of aluminum in the brain may contribute to the development of Alzheimer s disease. In addition, an unidentified protein not found in normal brain tissue has been discovered in the brain tissue of Alzheimer s patients. Because aluminum is excreted by the kidneys, toxic amounts of aluminum also may impair kidney function. People who worked in aluminum smelting plants for long periods have been found to experience dizziness, impaired coordination, and losses of balance and energy. Accumulation of aluminum in the brain was cited as a possible cause for these symptoms as well. This has caused concern, especially as it relates to neurotoxicology (Alzheimer s disease).19-21... 

Synthetic liquid fuels derived from coal and shale will differ in some characteristics from conventional fuels derived from petroleum. For example, liquid synfuels are expected to contain significantly higher levels of aromatic hydrocarbons, especially for coal-derived fuels, and higher levels of bound nitrogen. These differences can affect the combustion system accepting such fuels in important ways. In continuous combustors, i.e. gas turbines, the increased aromatics content of coal-derived fuels is expected to promote the formation of soot which, in turn, will increase radiation to the combustor liner, raise liner temperature, and possibly result in shortened service life. Deposit formation and the emission of smoke are other potential effects which are cause for concern. Higher nitrogen levels in synfuels are expected to show up as increased emissions of N0X (NO+NO2) An earlier paper presented results of an experimental study on the effect of aromatics and combustor... 

The perceived potential regarding the possibility that the toxicity of some phthalates like DEHP and DINP may be the result of endocrine disruption is the principal cause for concern over phthalates, however there is a general lack of relevant information concerning possible adverse effects of endocrine-dismpting chemicals on humans at environmental exposure levels. 

Several of IGF - l s properties are cause for concern. First, is this switching on of dormant genes. This recently discovered phenomena indicates that we all have these "off" genes that can be turned on by certain chemicals like IGF 1 -- some of these genes can have terrible effects like causing leukaemia or other forms of cancer. The chances are reasonably slim but there is a chance and the dice will roll when you use the stuff and this needs to be weighted up with the possible benefit. 

---