Chemicals in the Environment

Ana.lytica.1 Methods. Since 1984, dramatic technical advances have been made in the analysis of trace organic chemicals in the environment. Indeed, these advances have been largely responsible for the increased pubUc and governmental awareness of the wide distribution of herbicides in the environment. The abiUty to detect herbicides at ppb and ppt levels has resulted in the discovery of trace herbicide residues in many unexpected and unwanted areas. The realization that herbicides are being transported throughout the environment, albeit at extremely low levels, has caused much pubUc and governmental concern. However, the pubUc health implications remain unclear. 

J. Oehlmann, U. Sehulte-Oehlmann, E. Stroben, B. Bauer, C. Bettin and P. Fiorni, in Endocrinologically Active Chemicals in the Environment, Umweltbundesamt, Berlin, 1996, pp. 111-118. 

Richardson, M.L. (ed.) (1988) Risk Assessment of Chemicals in the Environment, The Royal Society of Chemistry, London. 

What has become an even greater concern in recent years is the phenomenon known as multiple chemical sensitivity disorder triggered by exposures to many chemicals in the environment. Synthetic chemicals are all around us. They are in the products we use, in the clothes we wear, in the food we eat, in the air we breathe at work. Because chemicals are everywhere in the environment, it is not possible to escape exposure. For this reason many people have become sensitized to the chemicals around them. In fact, it is estimated that 15% of the population has become sensitized to common household and commercial products. For some people the sensitization is not too serious a problem. They may have what appears to be a minor allergy to one or more chemicals. Other people are much more seriously affected. They may feel tired all the time, and suffer from mental confusion, breathing problems, sore muscles, and a weakened immune system. Such people suffer from a condition known as Multiple Chemical Sensitivity (MCS). 

The heaviest products obtained directly from oil arc lubricants, waxes, asphalt, and coke. These products have both domestic and industrial uses. Lubricants, for example, are applied in the operation and maintenance of industrial equipment and machinery. Asphalt, because it is not reactive to chemicals in the environment, is a superb material of construction in the building of roads and in roofing. It is also used in the waterproofing of concrete, the manufacture of black paints, and as a material lor tire threads, battery housing, electrical insulation, and other applications. The heaviest of all the petroleum products, coke, is used extensively as a major component of industrial electrodes and as a commercial fuel. 

G.24 The concentration of toxic chemicals in the environment is often measured in parts per million (ppm) or even parts per billion (ppb). A solution in which the concentration of the solute is. 1 ppb by mass has. 3 g of the solute for every billion grams (1000 t) of the solution. The World Health Organization has set the acceptable standard for lead in drinking water at... 

Waddel, T.E. Bower, B.T. Managing Agricultural Chemicals in the Environment the Case for a Multimedia Approach The Conservation Foundation Washington, D.C., 1988 pp 42-43. 

FIGURE 7.1 Life cycle of chemicals in the environment. Our approach to environmental and safety... 

Envlroiunental testing Is a critical element In this process since It enables the qualitative and quantitative determination of toxic chemicals In the environment and the definition of environmental pathways which may lead to human exposure This paper briefly reviews the overall process of health risk assessments and the particular role which environmental testing plays Recent efforts to assess environmental health risks In relation to Love Canal Illustrate both the usefulness and the limitations of environmental testing In risk assessment ... 

Evaluation of Persistence and Long-Range Transport of Organic Chemicals in the Environment Klecka, Boethling, Franklin, Grady, Graham, Howard, Kannan, Larson, Mackay, Muir, van de Meent, editors... 

Carcinogenic agents include chemicals in the environment, such as aniline and benzene, which are associated with the development of bladder cancer and leukemia, respectively. Environmental factors, such as excessive sun exposure, also may result in cancer. Viruses, including the human papilloma virus and hepatitis B, maybe associated with the development of cancer. Some of the chemotherapy agents cause secondary cancers after therapy has been completed. Numerous factors may contribute to the development of cancer. 

Today, the scientific community can identify tiny trace amounts of chemicals in the environment. A quarter-century after Wallace Carothers introduced science-based industrial research to the United States, Clair Patterson adapted techniques developed for determining the age of the Earth to identify microtraces of global pollutants. Today scientists can analyze industrial contaminants in the parts per billion in 1991 when a university scientist discovered in the atmosphere a harmful, low-level contaminant produced by the manufacture of nylon, industry volunteered within weeks to change production methods. 

The need to balance costs against benefits both in the public and private sectors resulted in a search for methods of predicting the fate and effects of chemicals in the environment. Actual field testing of all cases of interest is both too costly and too dangerous to perform. Mathematical models, therefore, have been developed to provide descriptive tools and predictive approaches to this problem. At the symposium on which this book is based, a collection of user-oriented information was presented and covered the following aspects of environmental fate modeling ... 

This symposium concerns models for predicting the fate of chemicals in the environment. Strictly speaking, the topic of this paper does not fall into the usual definition of fate models. However, every fate model has at least one source term. Although the source term for one fate model may be the output of another fate model (as when air transport models provide the deposition rates that are the inputs to an aquatic fate model), the chain always has to be traced to the original sources, whether they are natural or associated with human activities. 

In this paper, we characterize the various sources for chemicals in the environment and discuss methods for describing the releases from them in terms sufficiently quantitative for use by fate models. 

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