Chemicals public health importance

Knowledge on the type of interaction is of profound importance. While the knowledge on synergistic interaction is of paramount public health importance, the knowledge on antagonistic interaction is necessary to reduce the unnecessary utilization of resources for cleanups. Because of the potential unexpected toxicity due to interaction of chemicals, toxicology of mixtures is an active area of scientific investigation. 

Anon. (1984), Chemical Methods far the Control of Arthropod Vectors amt Pests oj Public Health importance. WHO, Geneva. 

Vector bom diseases continue to be of global public health importance and there is continued reliance of chemical control of vectors. 

Chavasse, D. C., and Vap, H. H. (Eds.). (1997) Chemical Method. for the Control of Vectors and Pesi.s of Public Health Importance. Document WHO/CTDAVHOPES/97,2. World Health Organization, Geneva. 

An inadequate intake in the diet of those food chemicals that are essential nutrients results in health risks. Indeed these risks are by far the most important in terms of the world s population where malnutrition is a major public health problem. But, unlike the toxic chemicals, they would show a very different dose-response if they were subject to similar animal bioassays. At very low doses there would be a high risk of disease that would decrease as the dose was increased, the curve would then plateau until exposure was at such a level that toxicity could occur. Figure 11.2 shows this relationship which is U- or J-shaped rather than the essentially linear dose-response that is assumed for chemicals that are only toxic. The plateau region reflects what is commonly regarded as the homeostatic region where the cell is able to maintain its function and any excess nutrient is excreted, or mechanisms are induced that are completely reversible. 

One way to see if a chemical will hurt people is to learn how the chemical is absorbed, used, and released by the body. In the case of a radioactive chemical, it is also important to gather information concerning the radiation dose and dose rate to the body. For some chemicals, animal testing may be necessary. Animal testing may also be used to identify health effects such as cancer or birth defects. Without laboratory animals, scientists would lose a basic method to get information needed to make wise decisions to protect public health. Scientists have the responsibility to treat research animals with care and compassion. Laws today protect the welfare of research animals, and scientists must comply with strict animal care guidelines. 

Mineral Oil Hydraulic Fluids and Polyalphaolefin Hydraulic Fluids. Limited information about environmentally important physical and chemical properties is available for the mineral oil and water-in-oil emulsion hydraulic fluid products and components is presented in Tables 3-4, 3-5, and 3-7. Much of the available trade literature emphasizes properties desirable for the commercial end uses of the products as hydraulic fluids rather than the physical constants most useful in fate and transport analysis. Since the products are typically mixtures, the chief value of the trade literature is to identify specific chemical components, generally various petroleum hydrocarbons. Additional information on the properties of the various mineral oil formulations would make it easier to distinguish the toxicity and environmental effects and to trace the site contaminant s fate based on levels of distinguishing components. Improved information is especially needed on additives, some of which may be of more environmental and public health concern than the hydrocarbons that comprise the bulk of the mineral oil hydraulic fluids by weight. For the polyalphaolefin hydraulic fluids, basic physical and chemical properties related to assessing environmental fate and exposure risks are essentially unknown. Additional information for these types of hydraulic fluids is clearly needed. 

Section 2.4, "Relevance to Public Health," contains basic information known about the substance. Other sections such as 2.6, "Interactions with Other Chemicals" and 2.7, "Populations that are Unusually Susceptible" provide important supplemental information. 

Flies and mosquitoes are vectors for a number of other diseases that constitute significant menaces to public health, but we do not yet know what role chemical signals play in all of them. Where natural chemicals are important, much additional research will be essential to establish whether they offer realistic approaches to managing these afflictions. The results with leishmaniasis and African trypanosomiasis indicate that such research can both increase our understanding of how fly vectors live and also lead to practical measures for fighting the diseases they carry. 

Again, it is important to point out that the chemical industry provides products and materials that are essential to the U.S. economy and to the so-called good life, the standard of living we presently enjoy. In addition to the economic consequences of a successful homegrown or foreign terrorist attack against chemical industry facilities, there is also the potential of a threat to public health and safety and the environment. 

Some points to consider related to the six basic elements listed above are included in table 5.1. The manner in which the vulnerability assessment is performed is determined by each individual water/wastewater utility. Throughout the assessment process it is important to remember that the ultimate goal is twofold to safeguard public health and safety and to reduce the potential for disruption of a reliable supply of chemicals. 

Many facilities already measure the above parameters (and many others) on a regular basis to control plant operations and confirm chemical mixture quality more closely monitoring these parameters may create operational benefits for facilities that extend far beyond security, such as reducing operating costs and chemical usage. Chemical industrial facilities also should thoughtfully monitor customer complaints and improve connections with local public health networks to detect public health anomalies. Customer complaints and public health anomalies are important ways to detect potential contamination problems and other environmental quality concerns. 

The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), commonly known as Superfund, 1980, created a tax on the chemical and petroleum industries and provided broad federal authority to respond directly to releases or threatened releases of hazardous substances that may endanger public health or the environment. The act was amended by the Superfund Amendments and Reauthorization Act (SARA) in 1986 and stressed the importance of permanent remedies and innovative treatment technologies in cleaning up hazardous waste sites. 

Several NCI scientists began, in the early 1960s, to think there was a need for standardized protocols. They thought that one extremely important public health goal was simply to identify, using well-understood animal models, chemicals that had the capacity to induce malignancies. The regulatory and public health community could then decide how and to what extent human exposure to those substances should be controlled. 

All of these questions are about risks to human health resulting from past, current, and (in the case of the food additive) future exposures to chemical substances. They seem to be highly important questions, and if we are ourselves members of one or more of the exposed populations, we would press scientists and physicians in our public health and regulatory institutions for answers to them. And, if those in authority in those institutions are doing their job, they have programs in place to provide the answers. 

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