Photochemical activation of chloroethenes leading to destruction of photosynthetic pigments

Abstract

Summary. All major photosynthetic pigments in spruce needles (Picea abies) are rapidly destroyed when the latter are UV-irradiated in the presence of tri-or tetrachloroethene at concentrations about 10-fold higher than those present in the lower atmosphere of industrialized countries. Uptake of chlorocarbons by spruce needles is fast, and the partition coefficients between the lipophilic compartments, such as the cuticle and cellular lipid membranes, and air are high. Volatile halogenated hydrocarbons are therefore suspected of being initiators ofa phytotoxic phenomenon usually referred to as new forest decline. In conjunction with the fact that they seem to be preferentially deposited along the western slopes of mountain ranges receiving high precipitation, the phenomena reported here may indicate the initiation of a severe ecotoxicological manifestation by these widely used compounds.

Luftgetragene, organische Stoffe in Blattorganen

“…Die Gegen(iberstellung zeigt, daft die 14C-F-Konzentrationen in allen Bestandteilen der behandelten Fichtenzweige stets um mehr als eine Zehnerpotenz fiber den vergleichbaren ~4C-TCEKonzentrationen lagen. Ein durch Zahlen belegter quantitativer Vergleich zwischen der Aufnahme yon Furfural und der von TCE durch Fichtenzweige ist jedoch nicht m6glich, da das in die Begasungskfivette eindosierte gasf6rmige 14C-F, das wegen der verwendeten Applikationstechnik ebenso GRIMMER et al, 1986;BOWEN et al, 1953;SCHLICHT et al, 1972;FRANK et al, 1986;DEBUS, SCHR(3-DER 1989 Auch hier ist nicht bekannt, ob sich die anderen luftgetragehen natfirlichen oder anthropogenen Aldehyde in ihrer Wechselwirkung mit Pflanzen ~ihnlich wie das von uns untersuchte Furfural verhalten. V611ig often ist die Frage, fiber welche Mechanismen bereits ad-/absorbierte atmogene Aldehyde in die physiologisch-biochemischen Prozesse der Pflanzen eintreten und dort wirken.…”

Uptake of airborne tetrachloroethene by spruce needles

“…The median air concentration of tetrachloroethene in rural areas is ~1 jug/m3 (3). Under consideration of the partition ratios determined in model experiments (6), the employed method must allow detection of tetrachloroethene down to 100 pg/g of needle. A recently published method of capillary gas chromatography and electron capture detection (GC-ECD) has a detection limit of 3 ng of tetrachloroethene/g of needles (10), but this is insufficient for the present study.…”

“…An important feature of the less volatile halocarbons is their great lipophilicity (5); as shown in model experiments, they may be enriched in lipids and waxes of cuticles and cellular membranes (6) due to their large partition ratios (Ostwald solubility coefficients), e.g. 2000 (22 °C) for tetrachloroethene.…”

Products and reaction paths in the liquid phase oxidation of trans-1,2-dichloroethene with oxygen

“…6) or chlorinated acetyl chlorides (14), recent work has been c 0 focused on health (15) and environmental (4,10,18) aspects. u Thus, it has been claimed that chloroethenes may be metabolized via potentially carcinogenic chlorinated epoxides (15) on the one hand, and that they may be a significant cause for the hen omen on called forest decline ( 18).…”

“…u Thus, it has been claimed that chloroethenes may be metabolized via potentially carcinogenic chlorinated epoxides (15) on the one hand, and that they may be a significant cause for the hen omen on called forest decline ( 18).…”