Chemical time bombs

To emphasize our perspective, one should cite a known synonym of ecological risk, a chemical time bomb (CTB). In effect it says that the risk is uncertain as of now, but is both possible and highly probable. 

Lacerda L. D. and Salomons W. (1998) Mercury from Gold and Silver Mining a Chemical Time Bomb Springer, New York, 146pp. 

He.sterberg D., Stigliani W. M., and Ime.son A. C. (1992). Chemical time bombs Linkage to scenarios of socioeconomic development. IIASA Exec. Report No. 20, 1992. 

Hesterberg D, Stigliani WM and Imeson AC (1992) Chemical Time Bombs Linkage to Scenarios of Socioeconomic Development. Executive Report 20 (CTB Basic Document 2), IIASA, Laxenburg/ Austria. 

De Laceeda L and Salomons W (1998) Mercury from gold and silver mining a chemical time bomb Springer, Berlin-Heidelberg, Germany. 

Labrenz M, Draschel GK, Thomsen-Ebert T, Gilbert B, Welch SA, Kemner KM, Logan GA, Summons RE, De Stasio G, Bond PL, Lai B, Kelly SD, Banfield JF (2000) Formation of sphalerite (ZnS) deposits in natural biofilms of sulfate-reducing bacteria. Science 290 1744-1747 Lacerda LD, Salomons W (1998) Mercury from gold and silver mining a chemical time bomb Springer, Berlin... 

During the late 1980 s the public became generally aware of the fact that another chemical time bomb is ticking the chemical weapon (CW) munitions which were dumped after World War II in the Baltic and the North Sea. At the end of World War II, the Allies were faced with the problem of how to get rid of more than 300,000 tonnes of CW munitions which were left especially in Germany. The easiest and quickest solution was to load the weapons onto disabled ships and sink these ships in deep waters. Bombed and burned hulks were collected from all over northern Europe and patched up for their last journey. 

This conceptual approach has been developed in the framework of the concept of "chemical time bombs" (a waste deposit or contaminated hot-spot which initially appears to be relatively harmless, but which can eventually have disastrous environmental effects as toxic contaminants are released). The effects of these time bombs are non-linear and delayed, e.g. toxic metals can "break through" once the specific buffering capacity of a sediment or soil system has been surpassed. To make the scientific objectives clearer, it is useful to distinguish between two different mechanisms (Stigliani 1992) the first is direct saturation, by which the capacity of a soil or sediment for toxic chemicals becomes exhausted. The second way to "trigger" a time bomb is through a fundamental change in a chemical property of the substrate that reduces its capacity to adsorb (or keep adsorbed) toxic materials. 

Stigliani WM (1992) Chemical time bombs, predicting the unpredictable. In Chemical time bombs. European state-of-the-art conference on delay effects of chemicals in soils and sediments. Veldhoven, The Netherlands, Sept 2-5, p 12 Swift RS (1977) Soil organic matter studies. IAEA Vienna, pp 275-281 Turner RR, Lowry P, Levin M, Lindberg SE, Tamura T (1982) Leachability and aqueous speciation of selected trace constituents of coal fly ash. Final Report, Research Project 1061-1/EA-2588. Electric Power Research Institute, Palo Alto, California Voronkevich SD (1994) Engineering geochemistry problems and applications. Applied Geochemistry 9 553-559... 

Boels D, Fleming G (1993) Chemical time bombs from landfills appraisal and modelling. 

Spencer PS. 1990. Chemical time bombs Environmental causes of neurodegenerative diseases. In Russell RW, Flattau PE, Pope AM, eds. Behavioral Measures of Neurotoxicity Report of a Symposium. Washington, DC National Academy Press. Pp. 268—284. 

Sti aiii,W. M. Chemical Time Bombs Definition, Concepts, and Examples, E.R. 16, CTB Basic Document IIASA Luxembourg, Austria, 1991 pp 1-23. 

Mechanical clockwork time) 157 (Electrical chemical time) 168-69 171-72 (Mechanical aerial burst) 169-71 (Rocket bomb fuzes) 172-74 (Electrical aerial burst) 175-78 (Clockwork aerial burst) 177 179-81 (Mechanical antiwithdrawal, ZUS40,... 

Military explosives must be physically and chemically stable over a wide range of temperatures and humidity for a long period of time. They must be reasonably insensitive to impact, such as those experienced by artillery shells when fired from a gun or when they penetrate steel armor. They are used for a number of applications. They are fired in projectiles and dropped in aerial time bombs without premature explosion. The raw materials necessary to manufacture such explosives must be readily available for production in bulk during wartime. 

Remediation of landfill leachate plumes has, in most cases, focused on source control. This is due to the fact that landfills are so large that the mass of pollutants contained in the landfill body would be able to sustain the leachate plume for centuries making a remedy focusing on the plume a long and costly approach. Additional reasons for focusing on the source are that the landfill also may be a time bomb containing chemical waste in drums subject to corrosion, landfill gas emission needs to be controlled, improvements of landscape value is requested by the community, and potentially new landfilling capacity is in demand. 

In that sense, contamination by synthetic organic chemicals is like a water quality time bomb, ticking away for years under many communities before erupting in the form of a contaminated ground water supply". 

Imagine, for a moment, that a foreign nation has dispatched a band of terrorists to the United States. The intruders silently move across the landscape depositing toxic chemicals at a thousand sites around the country. Some of the toxic compounds quickly enter the rivers and underground reservoirs that supply America with drinking water. Other chemicals contaminate our neighborhoods and backyards where our children play. Still others sit like time bombs, destined to contaminate our water supplies after months, years, or even decades. The toxic chemicals carried by these enemies are the products of the most sophisticated laboratories on Earth. They cause birth defects, liver disease, and cancer. Their effects may be felt for generations. 

Kaffka, A.V. (Ed.), January 1996. Sea-Dumped Chemical Weapons Aspects, Problems and Solutions. Kluwer Academic Publishers, Dordrecht ISBN 0-7923-4090-61996 Kirby, A., UK s Undersea Ticking Time-bombs . http //news.bbc.co.Uk/l/hi/sci/tech/4032629. 

At the same time, the public s faith in science and technology was eroding. Radioactive fallout from atomic bomb tests was poisoning cows milk, and the thalidomide antinausea medicine prescribed to pregnant women in Europe had caused severe birth defects in 8000 children. Above all, the enormous growth of the chemical industry and pollution after World War II put public pressure on Congress to clean up the nation s air and water. 

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