Hazards synthetic chemicals

Reducing the intrinsic hazard of chemicals is the most effective and most fundamental of the risk reduction options available. Intrinsic risk reduction is based on the principle that the structure of a chemical drives hazard and molecular intentional, informed manipulation will result in the design of safer chemicals. Wastewater treatment plants employ large filters packed with granular activated carbon to remove polluted water. Synthetic chemists are... 

Hazardous substances include not oidy synthetic chemicals, but also some natural materials such as mineral (dust or fibres) and a range of metals. It is very difficult to estimate the production volume and distribution of these materials. 

The main efficiency question in the synthetic chemical industry is not what to do about past disposal practices but, rather, what to do about current hazards. Current chemical prices should reflect the damages that chemicals will create. The cleanup of past emissions might be a worthy endeavor given current real income, just as the... 

In the UK chemicals strategy the statement The Government is very concerned that we do not have adequate information about the hazards of most chemicals released into the environment in large quantities is emphasized in bold in section 1.7 (DETR, 1999). The EU strategy states that The lack of knowledge about the impact of many chemicals on human health and the environment is a cause for concern (CEC, 2001, p4). The Royal Commission on Environmental Pollution held an inquiry into chemicals that reported in 2003. They consider that our failure to understand the interactions between synthetic chemicals and the natural environment, and most of all our failure to compile even the most basic information about the behaviour of chemicals in the environment, is a serious matter (RCEP, 2003, pi). 

Chemicals risk assessment attempts to characterize the system — of a chemical in the environment or in the human body — and then estimate the risk of the chemical causing harm. A key question is whether the system can be adequately characterized to reliably estimate the probability of harm, or even to identify what harm the chemical may cause. Just as engineering systems have caused harm because they failed in ways that were not predicted, the most serious hazards of synthetic chemicals have often been unexpected, and not considered in risk assessments. 

B. N. Ames, M. Profet, and L. S. Gold, Nature s Chemicals and Synthetic Chemicals Comparative Toxicology, Proc. Natl. Acad. Sci. U.S.A. 87 (1990) 7782-86 B. N. Ames, M. Profet, and L. S. Gold, Dietary Pesticides 99.99 Percent All Natural, ibid., 7777-81 L. S. Gold, T. H. Slone, and B. N. Ames, Prioritization of Possible Carcinogenic Hazards in Food, in D. Tennant, ed., Food Chemical Risk Analysis (London Chapman Hall, 1997), pp. 267-95. 

Gaining a broad perspective about the vast number of chemicals to which humans are exposed can be helpful when setting research and regulatory priorities. Rodent cancer tests by themselves provide little information about how a chemical causes cancer or about low-dose risk. The assumption that synthetic chemicals are hazardous has led to a bias in testing, and such chemicals account for 76 percent (451 of 590) of the chemicals tested chronically in both rats and mice (Table 1). The world of natural chemicals has never been tested systematically. 

The possible carcinogenic hazards from synthetic pesticides are minimal compared to the background of nature s pesticides, though neither may be a hazard at the low doses consumed. Analysis also indicates that many ordinary foods would not pass the regulatory criteria used for synthetic chemicals. Caution is necessary in drawing conclusions about the occurrence in the diet of natural chemicals that are rodent carcinogens. These di-... 

Although the details are beyond the scope of this book, health problems can be caused by solids and liquids suspended in water (for example, in waste-tailings streams) or in air (for example, in stack-emission plumes). Specific potential hazards have been associated with a diverse spectrum of colloidal materials, including synthetic chemicals, coals, minerals, metals, pharmaceuticals, plastics, and wood pulp. Limits for human exposure for many particulate, hazardous materials are published [504,505],... 

The chemical industry is facing a crisis in terms of its sustainability. Public trust in the industry needs to be restored in many EU countries and economic growth in the sector needs to be uncoupled from increased production volumes. REACH only begins to address these two issues. While REACH will generate information on chemical risks and will reset the frame of reference on what constitutes sufficient toxicological data for carrying out hazard assessments, it does not address how to control exposure levels. Apart from the authorisation process, REACH does not even propose specific mechanisms to control the increasing concentrations of synthetic chemicals in human blood and environmental media. 

The exact nature of the environmental hazards generated by the release of various synthetic chemicals into the environment is under constant debate. There is little doubt that this debate will continue until science unequivocally resolves the uncertainties in toxicological data (exposure, fate, and transport) and risk analyses. 

A chemical can be natural or synthetic. There is nothing intrinsically different between a natural and a synthetic chemical and they can be equally hazardous. To a scientist a chemical is a collection of atoms, ranging from one or two to hundreds of thousands. Collections of atoms are called molecules, thus H2O (water) is a molecule composed of two hydrogen atoms and one oxygen atom. Water is a chemical and a very unusual one at that. Without it fife as we know it would be impossible. 

However the fear and anxiety of harm from synthetic chemicals saturates our psyches, and thus truth and realities are ignored in favor of the tenets of virtual toxicology. As the legal case history develops in support of this argument, it effectively becomes law. Is this the proper forum for risk assessment If hysteria and emotion are allowed to determine whether a chemical is toxic or not, society is doomed since the real hazards to our health, found in the natural world, are still there. I hope that this book can help dissuade this opinion. 

A useful resource related to carcinogenicity, includes a wide array of publications from the Carcinogenic Potency Project. The references include papers on methodological analysis of the relevance of carcinogenicity prediction from bioassays, species comparisons, target organs, mechanism of carcinogenesis, risk assessment techniques, possible cancer hazards of natural and synthetic chemicals, and causes and prevention of cancer. 

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