Transport and transportation pathways of hazardous chemicals from solid waste disposal.

Abstract

To evaluate the impact of hazardous chemicals in solid wastes on man and other organisms, it is necessary to have information about amounts of chemical present, extent of exposure, and chemical toxicity. This paper addresses the question of organism exposure by considering the major physical and biological transport pathways and the physicochemical and biochemical transformations that may occur in sediments, soils, and water. Disposal of solid wastes in both terrestrial and oceank environments is considered. Atmospheric transport is considered for emissions from incineration of solid wastes and for wind resuspension of particulates from surface waste deposits.Solid wastes deposited in terrestrial environments are subject to leaching by surface and ground waters. Leachates may then be transported to other surface waters and drinking water aquifers through hydrologic transport. Leachates also interact with natural organic matter, clays, and microorganisms in soils and sediments. These interactions may render chemical constituents in leachates more or less mobile, possibly change chemical and physical forms, and alter their biological activity. Oceanic waste disposal practices result in migration through diffusion and ocean currents. Surface area-to-volume ratios play a major role in the initial distributions of chemicals in the aquatic environment. Sediments serve as major sources and sinks of chemical contaminants. Food chain transport in both aquatic and terrestrial environments results in the movement of hazardous chemicals from lower to higher positions in the food web. Bioconcentration is observed in both terrestrial and aquatic food chains with certain elements and synthetic organics. Bioconcentration factors tend to be higher for synthetic organics, and higher in aquatic than in terrestrial systems. Biodilution is not atypical in terrestrial environments. Synergistic and antagonistic actions are common occurrences among chemical contaminants and can be particularly important toxicity considerations in aquatic environments receiving runoff from several terrestrial sources.

Sources, Transport and Alterations of Metal Compounds: An Overview. I. Arsenic, Beryllium, Cadmium, Chromium, and Nickel

“…Recent general reviews which are particularly germane are those of Summer and Silver (4) and Saxena (5) which addressed the environmental transformation of alkylated and inorganic forms of a number of metals and metalloids, while those of Lantzy and Mackenzie (6), Wagenet et al. (7), Anderson (8), Gibbs (9), and Van Hook (10) addressed the global cycles and assessment of man's impact, models of the environmental transport of heavy metals, movement of metallic contaminants through ground water flow systems, mechanisms of trace metal transport in rivers, and transport and transportation pathways of hazardous chemicals from solid waste disposal, respectively.…”

“…While the major focus on environmental sources of hazardous metals thus far has been on anthropogenic sources and their impact on atmospheric transport and pollution, we should additionally recognize the potential impact of transport and transportation pathways of these elements from solid waste (including sewage sludge) disposal in both terrestrial river and oceanic environments (10,(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40) and the consequences of biological concentration factors in aquatic and terrestrial environments for trace elements that may occur in hazardous wastes (10). Significant transport of trace metals by particulates is found in most rivers of the world (40).…”

“…The safety with respect to animal and human health of cropland application is currently the subject of considerable research activity (36,42,43). Figure 1 depicts the major physical and biological transport pathways of hazardous chemicals derived from solid waste disposal as delineated by Van 46 Hook (10). After substances enter the environment, they may be diluted, concentrated, or transformed by a variety of chemical, physical, and biological processes.…”

“…It is generally acknowledged that one of the most dangerous and pernicious forms of pollution arises from the potential mobilization of a spectrum of toxic trace metals and metalloids in our environment (1)(2)(3)(4)(5)(6)(7)(8)(9)(10). Among the most important elements in this regard are arsenic, beryllium, cadmium, chromium, lead, mercury, nickel, and selenium.…”

“…(A subsequent analogous treatment will focus on Hg and Pb.) This information is considered vital for the better assessment of the scope of potential human hazard (1)(2)(3)(4)(5)(6)(7)(8)(9)(10).…”