Transport and Fate of Organic Compounds in the Global Environment

Abstract

Dedicated to Professor Heinz Hurnisch on the occasion of his 65th birthdayThe role of chemistry in our soon-to-be global industrial society requires a global perspective for the discussion of the uptake, transport, and conversion of chemical compounds in the environment. The fate of organic compounds in the volume flow of the atmosphere and hydrosphere can be categorized into transport pathways and adjustments of equilibria in the multiphase system atmosphere-oceans-land surface. The global volume flow in the atmosphere (wind, areas of high and low pressure) and in the hydrosphere (rivers, circulation of water in lakes, ocean currents) alone would account for the transport of organic compounds if they were stable and if all these compounds were molecularly distributed in these phases. However, this particular case is observed only for volatile chlorofluorocarbons and tetrachloromethane. For most organic compounds, complex adsorption/desorption processes on finely dispersed particle phases in the air and water as well as abiotic and biotic transformations determine the transport behavior.The global fate of a compound includes its accumulation as well as its decomposition in defined environmental compartments. Both phenomenon may have long-term consequences in the affected areas; this is indicated by the accumulation of polychlorobiphenyls and analogous compounds in marine mammals and deep-sea fauna, and is evident in the decomposition of chlorofluorocarbons in the stratosphere. The accepted definition of the level of a risk, the product of the probability of an event and the potential amount of damage, takes on a new dimension when viewed from a global perspective-especially when one further connects the extent of the damage to the possible means of correction. It is the responsibility of scientists to point out the irreparable regional to global consequences directly and indirectly connected to the production of chemicals and to provide suggestions for prevention. Politicians can only react by applying their methods to limit the damage; however, they cannot generate any solutions based on science.

Organic atmospheric aerosols: Review and state of the science

“…The specific cycling process for any compound depends on properties governed by molecular form (vapor pressure, water solubilit-y, etc.). Ballschmiter [1992] provides a thorough review of biogeochemical cycling and fates of known organic compounds in the environment.…”

Persistent Organic Pollutants in the European Atmosphere

“…The atmosphere, due to its large volume and elevated speed at which it can transport air masses over long distances, is the most important pathway for distribution of POPs into the environment [39,40]. (Table 1) which are in the range of phase changes at ambient temperatures.…”

Polychlorobiphenyl and pesticide residues in monkfish Lophius piscatorius and black scabbard Aphanopus carbo from the Rockall Trough

“…However, the processes moving volatile organic contaminants through the environment to the deep sea can be slow, and PCBs and pesticides persist in the environment long after bans. According to Ballschmiter (1992), it can take decades for organic contaminants to reach deep oceanic waters. He states that one mode of transportation is via the atmosphere to the poles, from where they precipitate into the cold waters; they ultimately dominate the deep sea.…”

“…Although the deep sea is distant from the primary sources of these compounds, most organochlorine compounds co-distil and are transported through the atmosphere to the poles. There they condense into the cold waters that subsequently provide the bulk of deep oceanic waters (Ballschmiter, 1992).…”