Toxicity and hazard

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  • There is a commonly held myth in our society that anything that is “natural” is good, wholesome, and healthful, whereas anything that is “synthetic” is bad, toxic, and harmful. The mere mention of the word chemical is enough to strike terror into the heart of any food faddist. This attitude is, at best, naïve and, at worst, dangerous.

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  • Under moderate conditions the body automatically adjusts itself to keep its temperature within safe limits. Sweating is the body's most efficient means of getting rid of heat, but the more humid the air, the harder it is for sweat to evaporate and the harder it is for the body to cool off. Under hot and humid conditions, work becomes harder because much of our blood is going to the surface of the body, and less is available to the active muscles. Loss of salt from sweating can result in fatigue.

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  • The field of toxicology has grown enormously since Industrial Toxicology: Safety and Health Applications in the Workplace was first published in 1985. And while the original edition was hugely popular among occupational health professionals, the time is ripe to address toxic agents not only in the industrial setting but also in the environment at large.

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  • Dr. Samuel Luoma has given us an excellent description and analysis of the science of silver and nanosilver. His paper raises many questions for policy makers. Its subtitle, “Old Problems or New Challenges,” is appropriate, because the subject of the paper is both. Metals are among the oldest of environmental problems. Lead, silver and mercury have posed health hazards for thousands of years, and they are as persistent in the environmental policy world as they are in the environment.

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  • The study conducted by Hiller et al. (2011) to investigate the concentrations, distributions, and hazards of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs). PCBs are used mainly as coolant and electronic industries (capacitors, transformers), paints, sealants for wood, cutting and lubricating fluids, plasticizers, and as dielectric fluids. Therefore, at the former site of PCB manufacturing area in Slovakia, high concentrations of PCBs are detected in soils, sediments, humans, and wildlife (Kocan et al., 2001; Petrik et al., 2001; Hiller et al., 2011)....

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  • `Now you've got nothing to worry about, my dear,' he said, `except to get back your health and strength. I don't say anything about your looks because nothing affects them. You're a young woman and a very pretty one, and I have no doubt you'll marry again. But don't marry for love next time; it's a mistake; marry for position and companionship.' She laughed. She had had a bitter experience and had no intention then of ever hazarding again the risks of wedlock; it was odd that now she was contemplating doing exactly what the shrewd old lawyer had advised....

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  • In recent years, completion of the sequencing of the human genome as well as the genomes of dozens of other organisms and subsequent development of tools for comprehensive analysis of other cellular constituents have revolutionized biology. These new technologies, referred to broadly as “genomics,” have integrated biologic sciences with information sciences and engineering.

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  • Within the overall transport process, attenuation processes may cause movement of the chemical to differ from that of the bulk flowing groundwater, for example dispersion, sorption and chemical or biological degradation of the chemical. Such attenuation processes potentially act to mitigate the impact of chemicals and are a function of both the specific chemical and geologic domain. Indeed, attenuation may vary significantly between individual chemicals and within different geological settings.

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  • Chemicals are able to bring about both desirable and undesirable effects on organisms to which they are exposed, and the actions of medicines and poisons and toxic agents have been recognized for thousands of years. As a result of industrialization, modern man and the environment is now exposed to increasing numbers of chemicals. Because of their potential hazard, there is an appreciation of the requirement to assess the effects of these chemicals. Since chemical structure was elucidated (for a very brief history see Table 1.

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  • High cooking temperature and thus high pressure is needed when alcohols are used as cooking chemicals. Methanol has been used as an additive in kraft, sulphite and soda pulping. However, the use of methanol may be hazardous, since methanol is a highly flammable and toxic chemical. Demonstration plants using the alkaline sulphite-anthraquinone-methanol process (ASAM) (Patt & Kordsachia 1986, Khristova et al. 2002, Patt et al. 1999) and the soda pulping method with methanol (Organocell) (Schroeter & Dahlmann 1991) have been built.

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  • Since 1980, the principal form of crop loss assistance in the United States has been provided through the Federal Crop Insurance Program. The Federal Crop Insurance Act of 1980 was intended to replace disaster programs with a subsidized insurance program that farmers could depend on in the event of crop losses. Crop insurance was seen as preferable to disaster assistance because it was less costly and hence could be provided to more producers, was less likely to encourage moral hazard, and less likely to encourage producers to plant crops on marginal lands.

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  • Mercury health effects depend on the type of mercury to which a person is exposed. In general, health impacts include renal toxicity, damage to the immune system, alteration of genetic and enzyme systems and neurological damage, especially in babies exposed in utero. Methyl mercury is the most toxic form of mercury because it is absorbed quickly in the body and expelled much more slowly. Currently there is not enough human exposure data to make links between mercury and cancer.

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  • Congress has enacted laws requiring individuals and facilities to take measures to protect environmental quality and public health by limiting potentially harmful emissions and discharges, and remediating damage. Enforcement of federal pollution control laws in the United States occurs within a highly diverse, complex, and dynamic statutory framework and organizational setting. Multiple statutes address a number of environmental pollution issues, such as those associated with air emissions, water discharges, hazardous wastes, and toxic substances in commerce.

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  • Safety footwear must meet ANSI minimum compression and impact performance standards in ANSI Z41-1991 (American National Standard for Personal Protection-Protective Footwear) or provide equivalent protection. Footwear purchased before July 5, 1994, must meet or provide equivalent protection to the earlier ANSI Standard (ANSI Z41.1-1967). All ANSI approved footwear has a protective toe and offers impact and compression protection. But the type and amount of protection is not always the same. Different footwear protects in different ways.

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  • After creating toxic hazardous chemicals, society has followed an unsustainable course in using and disposing of toxins. More and more sites are being contaminated, cancer rates are rising, indoor air quality has declined to become often more contaminated than outdoor air, and toxic chemicals continue to be found in species as far away from civilization as the Arctic Circle. This chapter provides knowledge of hazardous chemicals: pollution and preventi.

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  • Every year in the U.S. factories release over 3 million tons of toxic chemicals into the land, air and water. This hazardous waste causes us to lose over 15 million acres of land every year, it leads to respiratory complications and other health problems and it makes our rivers and lakes too polluted for us to swim in and drink.

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  • Because of the potential public health implications, the importance of toxic air pollutants in ambient air has been recognized to some degree for many years. Efforts to “regulate” human activities resulting in the production of ambient air pollutants probably date back many centuries, even as the combustion of fossil fuels and air pollution from other organized human activities began having a noticeable impact on the environment.

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  • The past century has seen a tremendous expansion in the number of synthetic chemicals employed by humankind as materials, drugs, preservatives for foods and other products, pesticides, cleaning agents, and even weapons of war. An estimated 64,000 chemicals are currently in use commercially, with 5 billion tons being produced annually in the world. Some 4000 chemicals are used as medicinals and at least 1200 more as household products. An estimated 700 new chemicals are synthesized each year.

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  • The contamination of metals is a major environmental problem and especially in the aquatic environment. Some metals are potentially toxic or carcinogenic even at very low concentration and are thus, hazardous to human if they enter the food chain. Metals are usually dissolved into the aquatic system through natural or anthropogenic sources. Metal ions are distributed thoroughly during their transport in different compartments of the aquatic ecosystems, in biotic or abiotic compartment such as fishes, water, sediment, plant.

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  • PART 3 Further issues and future prospects © 2001 C. H. Walker CHAPTER 13 The ecotoxicological effects of herbicides 13.1 Introduction Chapters 5–12 deal with groups of pollutants that have been studied in some depth and detail, largely because they have appreciable – sometimes very high – mammalian toxicity and are perceived as human health hazards. Some of them are markedly persistent and undergo biomagnification with passage along food chains.

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