Chemodynamics: transport and behavior of chemicals in the environment--a problem in environmental health.

Abstract

In the manufacture and use of the several thousand chemicals employed by technological societies, portions of these chemicals escape or are intentionally introduced into the environment. The behavior, fate, and to some extent the effects produced by these chemicals are a result of a complex interaction of the properties of the chemical with the various processes governing transport, degradation, sequestration, and uptake by organisms. In addition, such processes as adsorption, evaporation, partitioning, and degradation are influenced by ambient conditions of temperature, air movement, moisture, presence of other chemicals, and the concentration and properties of the subject chemicals. These influence the level and extent of exposure to these chemicals that man might receive. Study of the physicochemical properties of compounds in relation to these various processes has provided a basis for better understanding of the quantitative behavior. Such information is useful in development of predictive models on behavior and fate of the chemicals in relation to human exposure. Beyond this, it provides information that could be used to devise procedures of manufacture, use, and disposal that would minimize environmental contamination. Some of the physical principles involved in chemodynamics are presented in this review.

Dissipation of chlortetracycline in the aquatic environment: Characterization in terms of a generalized multiphase pseudo–zero‐order rate law

“…The dissipation of organic substances in the aquatic environment is attributed to evaporation, chemical, photochemical, and biochemical degradation. [22][23][24] In the covered distilled water control experiment, the observed initial slow linear rate of dissipation of 3 × 10 −4 g g −1 day −1 (Figure 2A) is attributed to a combination of evaporation and hydrolytic degradation, whereas the subsequent faster rate of 1.8 × 10 −3 g g −1 day −1 is attributed to microbial degradation as a result of contamination from the air since no preservative was added to the distilled water controls. Microbial degradation was confirmed using the procedure reported previously for oxytetracycline.…”

Physicochemical Properties of Chemical Pollutants Available in Food Contact Materials (FCM)

“…The physicochemical properties of these chemical pollutants as well as their transports, degradations processes and biotransformation mechanisms, affects the behavior, fate and subsequently the harmful effects of these chemicals. Therefore, new rules are enforced to shift toward eco-friendly industries and study the surroundings chemodynamic of various chemical pollutants rising the protection of human health and therefore the environment through the higher and earlier qualification of the fundamental properties of chemical substances [1].…”

Μελέτη της φωτοδιάσπασης και της τοξικότητας των φυτοπροστατευτικών προϊόντων Azinphos Ethyl, Azinphos Methyl, Dimethoate, Disulfoton και Fention σε φυσικά νερά και ιζήματα

“…Παρά την ιδιαίτερα εκτεταμένη χρήση των παραπάνω ενώσεων, ελάχιστες είναι οι πληροφο ρίες στη βιβλιογραφία που αφορούν τη συμπεριφορά και τη δραστικότητα τους στα υδατικά συστήμα-Κεφάλαιο 2" Υδρόλυση τα (Muhlmann and Schrader, 1957;Ruzicka et al, 1967 ;Faust and Gomaa, 1972;Heuer et al, 1974;Freed et al, 1977;Ellington, 19.87;Αλμπάνης, 1987;Ψαθάκη, 1994;Lartiges and Carrigues, 1995;Tomlin, 1997;Σακελλαρίδης, 1999). Επιπρόσθετα, τα λίγα δεδομένα που υπάρχουν δε φαίνεται να συμφωνούν μεταξύ τους, αφού δημοσιευμένες έρευνες υπολογισμού της σταθεράς ταχύτητας και του χρόνου ημτζωής υδρόλυσης των ίδιων ενώσεων, υπό τις ίδιες συνθήκες φαίνεται να διαφέρουν μεταξύ τους έως και πάνω από μία τάξη μεγέθους (Schwarzenbach et al, 2003).…”

“…Tomììn,1997 Ellington, 1987Ellington, 1987Ruzicka et al, 1967Ruzicka et al, 1967Ruzicka et al, 1967Freed et al, 1977Freed et al, 1977Lartiges and Carrigues, Lartiges and Carrigues, Lartiges and Carrigues, Lartiges and Carrigues, Lartiges and Carrigues, 1995Lartiges and Carrigues, 1995Lartiges and Carrigues, 1995Lartiges and Carrigues, 1995Lartiges and Carrigues, 1995Lartiges and Carrigues, 1995 Tomlin, 1997Tomlin,1997Tomlin, 1997Ψαθάκη, 1994Ψαθάκη, 1994Ψαθάκη, 1994Σακελλαρίδης, 1999Σακελλαρίδης, 1999Σακελλαρίδης, 1999Lartiges and Carrigues, 1995Lartiges and Carrigues, 1995Lartiges and Carrigues, 1995Lartiges and Carrigues, 1995Lartiges and Carrigues, 1995Lartiges and Carrigues, 1995Lartiges and Carrigues, 1995Lartiges and Carrigues, 1995Lartiges and Carrigues, 1995Lartiges and Carrigues, 1995 Κατ'αντιστοιχία με τους υπόλοιπους εστέρες, η υδρόλυση των οργανοφωσφορικών εστέρων λαμβάνει χώρα μέσω μηχανισμών όξινης, βασικής και ουδέτερης υδρόλυσης. Επειδή στους εστέρες αυτούς περιλαμβάνονται μόνο-, δι-και τρι-εστέρες, πρέπει να σημειωθεί ότι οι μονοεστέρες και οι διεστέρες υφίστανται υδρόλυση με μικρότερους ρυθμούς σε σχέση με τους τριεστέρες (Mabey and Mill, 1978;<...>…”

“…Σύμφωνα με μεγάλο αριθμό δημοσιευμένων ερευνητικών εργασιών για τη μελέτη του μηχανι σμού υδρόλυσης των οργανοφωσφορικών ενώσεων, η όξινη και ουδέτερη υδρόλυση είναι μία αργή διαδικασία με μεγάλους χρόνους ημίσειας ζωής (Muhlmann et al, 1957;Ruzicka et al, 1967 ;Faust et al, 1972;Heuer et al, 1974;Freed et al, 1977;Wolfe et al, 1977;Ellington, 1987;Αλμπάνης, 1987;Ψαθάκη, 1994;Lartiges et al, 1995;Tomlin,1997;Σακελλαρίδης, 1999).…”