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Water Contaminants

KENNETH P. CANTOR, MARY H. WARD, LEE E. MOORE, and JAY H LUBIN

in Cancer Epidemiology and Prevention

This chapter discusses water contaminants that may contribute to the human cancer burden. Specifically, it addresses the epidemiologic evidence for several contaminants and includes information on ... More

This chapter discusses water contaminants that may contribute to the human cancer burden. Specifically, it addresses the epidemiologic evidence for several contaminants and includes information on their levels and environmental distribution, as well as individual susceptibility, where data exist. The three categories of drinking water contaminants that may be carcinogenic and that have been studied most systematically are arsenic, disinfection by-products, and nitrate. In addition, radionuclides, microbiological agents, organic compounds from human commerce, and asbestiform particles have been reported to cause cancer, either as they occur in drinking water or in other media, giving rise to suspicion about their carcinogenicity when ingested. Future research priorities and prevention strategies are discussed.Less

Ether/Or

in Image and Reality: Kekule, Kopp, and the Scientific Imagination

A paper by Alexander Williamson, read at the annual meeting of the British Association for the Advancement of Science in Edinburgh on August 3, 1850, was groundbreaking in a lot of ways. As the first ... More

A paper by Alexander Williamson, read at the annual meeting of the British Association for the Advancement of Science in Edinburgh on August 3, 1850, was groundbreaking in a lot of ways. As the first of an important series of papers on the formation of ethers, the constitutions of molecules, and reaction dynamics, Williamson's work would radically alter chemical theory. Whether consciously or only instinctively, Williamson understood the importance of using vivid mental images to comprehend and explore molecular reality in scientific fashion. His intellectual formation was influenced in part by the British chemist Thomas Graham, who in 1833 announced his discovery of the law of gaseous diffusion. Williamson discovered that he could form ether by reacting “ethylate of potash” (potassium ethoxide) with ethyl iodide. After his experiments on etherification, he published three papers charting the early stages of an investigative route toward the systematic conceptual dissection of organic compounds, offering the promise of a secure pathway into organic chemistry.Less

Introduction

Phoebe N. Okowa

in State Responsibility for Transboundary Air Pollution in International Law

This introductory chapter first sets out the purpose of the book, which is to examine what states claim in the context of disputes involving transboundary air pollution and what they protest to as ... More

This introductory chapter first sets out the purpose of the book, which is to examine what states claim in the context of disputes involving transboundary air pollution and what they protest to as part of the evaluation of the content of the applicable legal regime. The study focuses on three principal sources of pollutants, namely pollution from industrial activities (in particular acid deposition from sulphur and nitrogen emissions, as well as volatile organic compounds), atmospheric nuclear tests, and accidental radioactive contamination from the civil uses of nuclear energy. An overview of the subsequent chapters is also presented.Less

Outdoor Air Pollution

Andrea Hricko

in Safe and Healthy School Environments

This chapter discusses outdoor air pollution in school environments. Outdoor (ambient) air pollution presents a number of issues in the school environment, including exposure of children to diesel ... More

This chapter discusses outdoor air pollution in school environments. Outdoor (ambient) air pollution presents a number of issues in the school environment, including exposure of children to diesel exhaust from older buses, potential risks for students who play or exercise outdoors on smoggy days, and exposure to emissions from nearby traffic and industrial facilities. There are steps that school administrators can take to protect children and address pollution. These include limiting outdoor activities on high ozone days, keeping students indoors for recess and practices, and contacting the air pollution control authority with any concerns about sources of pollution very close to the school, and discuss the record of the polluting facility.Less

Costs of Air Quality Regulation

Randy A. Becker and J. Vernon Henderson

in Behavioral and Distributional Effects of Environmental Policy

An ongoing debate in the United States concerns the costs imposed by environmental regulations on industry. This chapter explores some of the costs associated with air quality regulation, focusing on ... More

An ongoing debate in the United States concerns the costs imposed by environmental regulations on industry. This chapter explores some of the costs associated with air quality regulation, focusing on regulation pertaining to ground-level ozone and its effects on two industries sensitive to such regulation: industrial organic chemicals and miscellaneous plastic products. Both of these industries are major emitters of volatile organic compounds and nitrogen oxides, the chemical precursors to ozone. Using plant-level data from the U.S. Census Bureau's Longitudinal Research Database (LRD), the chapter analyzes the effects this type of regulation has had on the timing and magnitudes of investments by firms in these industries and on their operating costs. As an alternative way to assess costs, it also employs plant-level data from the U.S. Census Bureau's Pollution Abatement Costs and Expenditures survey.Less

Phytoplankton Productivity

John Raven

in Marine Plankton: A practical guide to ecology, methodology, and taxonomy

This chapter describes the productivity of phytoplankton, from the initial energy and chemical requirements for photosynthesis to the rate of production of heterotrophic organisms. Phytoplankton are ... More

This chapter describes the productivity of phytoplankton, from the initial energy and chemical requirements for photosynthesis to the rate of production of heterotrophic organisms. Phytoplankton are the planktonic organisms which account for most of the primary production in the ocean. Their characteristic trophic mode is the production of organic compounds using energy from light and chemical elements from inorganic compounds, known as phototrophy, or more strictly photolithotrophy. This process uses water as the electron donor and the reduction of inorganic carbon producing sugars, from which all other cell components are made using inorganic forms of nitrogen, phosphorus, and all the other chemical elements needed to produce cells.Less

Emissions and Urban Air

William G. Wilson

in Constructed Climates: A Primer on Urban Environments

This chapter looks at the issues involving air, covering the causes and consequences of contributions from both human and nonhuman organisms. Humans dominate emissions in urban areas. Air quality ... More

This chapter looks at the issues involving air, covering the causes and consequences of contributions from both human and nonhuman organisms. Humans dominate emissions in urban areas. Air quality studies categorize emission sources as either point or nonpoint, roughly corresponding to fixed or moving, respectively. Both types of emissions roughly match maps of population density, at least in the United States. Vegetation and soils also emit chemicals, often as a by-product of evolution in the face of herbivory, competition, and environmental stresses that yielded chemical responses and defenses. These emissions can reduce air quality in urban areas, with some tree species being worse “violators” than others. These emissions feed into, among other pollutants, ozone formation in the hot summer months. For a more complete understanding of urban pollution, the chapter provides an overview of the chemical reactions that link volatile organic compounds (VOCs), reactive nitrogen, sunshine, ozone, and eye-stinging pollutants.Less

Combustion Calorimetry

José A. Martinho Simões and Manuel Minas da Piedade

in Molecular Energetics: Consensed-Phase Thermochemical Techniques

Calorimetric studies of combustion reactions in oxygen and fluorine atmospheres have been a major source of enthalpy of formation data, particularly for ... More

Calorimetric studies of combustion reactions in oxygen and fluorine atmospheres have been a major source of enthalpy of formation data, particularly for organic and inorganic compounds. As referred to in the previous chapter, in bomb combustion calorimetry the reaction proceeds inside a pressure vessel—the bomb—at constant volume, and in this case the derived quantity is ΔcUo. In flame calorimetry the reaction occurs in a combustion chamber, which is in communication with the atmosphere, and the measurements lead to ΔcHo. The methods of combustion calorimetry will be described in the following paragraphs. “Conventional” combustion calorimeters operate on a “macro” scale, that is, they require samples of 0.5–1.0 g per experiment. Unfortunately, many interesting compounds are available only in much smaller amounts. In the case of oxygen combustion calorimetry, however, several combustion microcaloriemeters that only demand 2–50 mg samples have been developed in recent years. The achievements and trends in this area through 1999 have been reviewed, and interested readers are directed to these publications. Since then, a few new apparatus have been reported. Nevertheless, it should be pointed out that the general principles and techniques used to study compounds at the micro scale are not greatly different from those used in macro combustion calorimetry. Static-bomb combustion calorimetry is particularly suited to obtaining enthalpies of combustion and formation of solid and liquid compounds containing only the elements C, H, O, and N. The origins of the method can be traced back to the work of Berthelot in the late nineteenth century. Most static-bomb calorimeters used are of the isoperibol type, such as the one in figure 7.1. Here, the bomb A is a pressure vessel of ∽300 cm3 internal volume. Combustion bombs are usually made of stainless steel and frequently have an internal platinum lining to prevent corrosion. In a typical high-precision experiment, the platinum ignition wire B connects the two electrodes C, which are affixed to the bomb head. A cotton thread fuse D (other materials such as polyethene are also used), of known energy of combustion, is weighed to a precision of±10−5−10−6 g and tied to the platinum wire. Less

Top-down pressures and indirect defences

Edward E. Farmer

in Leaf Defence

Plant populations are remodelled after carnivore removal, and the animals that eat herbivores can play critical roles in the biology of the leaf. Of particular interest is the fact that plants often ... More

Plant populations are remodelled after carnivore removal, and the animals that eat herbivores can play critical roles in the biology of the leaf. Of particular interest is the fact that plants often facilitate the task of the carnivore in its quest to find food, either by providing information to predators or by housing them. The chapter examines several interactions between bottom-up and top-down defence and uses an example to illustrate a mechanism that helps to maintain chemical polymorphism. Ant–plant interactions, extrafloral nectaries and food bodies are discussed with reference to ant vachellias from the neotropics. Examples of mite domatia are also given. The chapter then moves on to an examination of predator and parasitoid attraction by volatile organic compounds released by plants and uses examples from maize and other plants to illustrate the important role of oral secretions in the elicitation of volatile production. The use of plant volatiles to attract predators may be more far-ranging than is often thought. Finally, to demonstrate that some of the literature on plant volatiles needs to be read with caution, a potentially misleading report on acacias that were damaged by kudus is examined.Less

Air Pollution, Air Quality, and Climate Change

Alan H. Lockwood

in Heat Advisory: Protecting Health on a Warming Planet

The effects of climate change on air quality are difficult to model due to the large number of unpredictable variables. Hotter temperatures favor ozone production. Higher atmospheric water content ... More

The effects of climate change on air quality are difficult to model due to the large number of unpredictable variables. Hotter temperatures favor ozone production. Higher atmospheric water content may blunt this effect in some regions. Higher levels of natural volatile organic compounds (VOCs), such as terpenes from plants, are likely to act synergistically with anthropogenic VOCs to favor ozone production. Droughts increase wildfire risks that produce particulate pollution and carbon monoxide, a VOC involved in ozone production. Some models predict increased ozone concentrations in many urban settings. Future revisions of National Ambient Air Quality Standards, a process driven by politics and science, should consider these effects.Less

The Atmospheric Component of Biogeochemical Cycles in the Amazon Basin

Paulo Artaxo

in The Biogeochemistry of the Amazon Basin

Tropical forests, with their high biological activity, have the potential to emit large amounts of trace gases and aerosol particles to the atmosphere. The accelerated ... More

Tropical forests, with their high biological activity, have the potential to emit large amounts of trace gases and aerosol particles to the atmosphere. The accelerated development and land clearing that is occurring in large areas of the Amazon basin suggest that anthropogenic effects on natural biogeochemical cycles are already occurring (Gash et al. 1996). The atmosphere plays a key role in this process. The tropics are the part of the globe with the most rapidly growing population, the most dramatic industrial expansion and the most rapid and pervasive change in land use and land cover. Also the tropics contain the largest standing stocks of terrestrial vegetation and have the highest rates of photosynthesis and respiration. It is likely that changes in tropical land use will have a profound impact on the global atmosphere (Andreae 1998, Andreae and Crutzen 1997). A significant fraction of nutrients are transported or dislocated through the atmosphere in the form of trace gases, aerosol particles, and rainwater (Keller et al. 1991). Also the global effects of carbon dioxide, methane, nitrous oxide, and other trace gases have in the forest ecosystems a key partner. The large emissions of isoprene, terpenes, and many other volatile organic compounds could impact carbon cycling and the production of secondary aerosol particles over the Amazon region. Vegetation is a natural source of many types of aerosol particles that play an important role in the radiation budget over large areas (Artaxo et al. 1998). There are 5 major reservoirs in the Earth system: atmosphere, biosphere (vegetation, animals), soils, hydrosphere (oceans, lakes, rivers, groundwater), and the lithosphere (Earth crust). Elemental cycles of carbon, oxygen, nitrogen, sulfur, phosphorus, and other elements interact with the different reservoirs of the Earth system. The carbon cycle has important aspects in tropical forests due to the large amount of carbon stored in the tropical forests and the high rate of tropical deforestation (Jacob 1999). In Amazonia there are two very different atmospheric conditions: the wet season (mostly from November to June) and the dry season (July-October) (see Marengo and Nobre, this volume). Biomass burning emissions dominate completely the atmospheric concentrations over large areas of the Amazon basin during the dry season (Artaxo et al. 1988). Less

The Koshi’s Revenge

Cheryl Colopy

in Dirty, Sacred Rivers: Confronting South Asia's Water Crisis

The Koshi spoke during the monsoon of 2008. She opened a new path, just as Dinesh Mishra predicted. The river breached an apparently ill-constructed and certainly ... More

The Koshi spoke during the monsoon of 2008. She opened a new path, just as Dinesh Mishra predicted. The river breached an apparently ill-constructed and certainly ill-maintained embankment. A photo taken as the flood began shows the ridge of sand dissolving as water poured through a widening gap in the embankment and flowed southeast. In both Nepal and Bihar, villages and farms that had not seen a flood for the past half century were devastated. The embankments on the Koshi had already breached seven times at various spots downriver. This time the entire river below the Siwalik range in Nepal, where the land flattens, had essentially jumped out of its straitjacket and returned to one of its old channels—one it had flowed down two centuries ago. In Nepal the Koshi River is known as the Saptakoshi, or “seven Koshis,” because seven Himalayan rivers merge to create it. The Tamur flows down from Kanchenjunga in eastern Nepal near its border with Bhutan and India; the Arun comes down from Tibet. Out of the Khumbu comes the Dudh Koshi, the milky blue river that entranced me on the way up to Gokyo. The Dudh Koshi joins the Sun Koshi, which is also fed by the Tama Koshi, which in turn receives water from the Rolwaling Khola and Tsho Rolpa, the threatening glacial lake I visited during the monsoon of 2006. From farther west, toward Kathmandu, come the Likhu and the Indrawati. The latter receives the as yet undiverted waters of the Melamchi Khola. These seven tributaries of the Saptakoshi drain more than a third of the Nepal Himalaya, the wettest and highest of the great range, which includes the Khumbu and Ngozumpa glaciers. The Koshi drains almost thirty thousand square miles. It is Nepal’s largest river and one of the largest tributaries of the Ganga. Less than ten miles above the plains, three of these great rivers come together in a final merging: the Sun Koshi from the west, the Arun from the north, the Tamur from the east. Less

One of the Best Enterprises in Russia

Peter Thomson

in Sacred Sea: A Journey to Lake Baikal

The Angara River races out of Lake Baikal like a daughter fleeing her angry father for the arms of her lover. So goes the legend of the powerful river that ... More

The Angara River races out of Lake Baikal like a daughter fleeing her angry father for the arms of her lover. So goes the legend of the powerful river that is Baikal’s only outlet. Until the 1950s, you could see a huge rock near the mouth of the river that was said to prove the legend—the rock hurled by father Baikal toward his recalcitrant offspring, hoping to block her way as she ran off to join her beloved Yenisei, the great river to the west. Today, only a tiny tip of what’s known as Shaman Rock is still visible. Powerful Baikal could not block his daughter’s way and tame her energies, but humans could. They captured daughter Angara behind a series of hydroelectric dams and put her to work for the good of the Soviet people. One of the dams raised the level of Baikal by a meter and submerged most of the great rock in the river. Isolated in the middle of sparsely populated Siberia, its colossal depths and unique ecosystem enclosed behind its barrier of mountains, it would be easy to imagine that Baikal remains a world unto itself. But today that would be just an act of imagination. The lake may have stood apart for millions of years, but in the last 100 years, humans have speeded up time and collapsed space, and Baikal can no longer blithely follow its own, idiosyncratic course. Some changes were already evident early in the twentieth century. The Barguzin sable, source of so much wealth over more than 200 years, was on the verge of extinction, its long decline punctuated by Nicholas II’s belated decision to protect it with the Barguzinsky Nature Reserve. The limits of the limitless lake itself were starting to be tested, too—Baikal’s populations of omul and sturgeon were crashing as human populations rose, spawning habitat was disrupted, and new fishing technology was introduced. And along its southern shores, workers were clearing, blasting, flattening, and filling in, laying the path for the needle that would truly puncture Baikal’s bubble of isolation, 250 years after the arrival of the first Russians. Less