The absorption, translocation and metabolism of 1,3-dichloropropene (a soil fumigant) in bush beans, tomato and carrot was studied under growth chamber and greenhouse conditions using solution culture, vermiculite and sand. Absorption was monitored using gas chromatographic analysis and isotope techniques. Plants were shown to absorb a maximum amount of dichloropropene by 24 to 48 hr from solution culture and vermiculite. The plant absorbed and translocated 1,3-dichlorpropene-14C-U readily to aerial parts of the plant. Bush beans, tomatoes and carrots absorbed and translocated 3-chlorallyl alcohol-14C-U from solution culture and vermiculite. Levels of 3-chloroallyl alcohol reached maximum at 24 to 48 hr after inoculation The gas chromatographic analysis of plant materials showed that 1,3-dichloropropene and 3-chloroallyl alcohol were rapidly metabolized by the plant. The three plants metabolize 1,3-dichloropropene to 3-chloroallyl alcohol, part of which is converted to 3-choroacrylic acid and 3-chloro-1-propanol. The metabolite identities were convirmed by co-chromatography with standard compounds and by mass spectral analysis. The sequence from this point (3-chloroacrylic of 3-chloro-1-propanol) is not known but coupled with the evidence from metabolite studies, it is apparent that a central metabolite (acetate pathway is indicated) has to be an intermediate in dichloropropene metabolism as label is located in glucose, TCA acids, amino acids, lipids and other normal plant products. The dichloropropenes are rapidly absorbed, translocated and metabolized by the plant. No parent dichloropropene was found in the plant after 72 hr incubation period and 3-chloroallyl alcohol was not detected after 96 hr in the plant. The data indicates that the dichloropropenes and 3-chloroallyl alcohols are not potential residue problems and that environmental concern about the ultimate fate of these compounds should be minimal.

La produzione e l’uso del Metile di Bromuro, un fumigante estesamente usato in agricoltura, sono stati sottoposti a severe restrizioni dovute alla sua azione di depletore dello strato di ozono. Questa tesi è rivolta ad indagare il destino e le caratteristiche ambientali di due tra le più importanti alternative chimiche all’uso del Bromuro di Metile: l’ 1,3-Dicloropropene (1,3-D) e la Cloropicrina (CP). 1,3-D è un fumigante del suolo, con spiccata attività nematocida, consistente di due isomeri (Z), e (E)-1,3-D; nella sua formulazione sono presenti, inoltre, un esteso numero di impurezze clorurate potenzialmente correlate al processo produttivo. In laboratorio, è stato effettuato uno studio per valutare la stabilità idrolitica delle impurezze clorurate e per prevederne, quindi, il destino ambientale. Allo stesso tempo un piano di monitoraggio è stato svolto per valutare il leaching dell’1,3-D, dei suoi metaboliti, e delle impurezze clorurate. La CP è anch’essa un fumigante del suolo, caratterizzato da un importante profilo tossicologico. Questo lavoro ha valutato l’esposizione degli operatori e l’emissione in atmosfera durante e dopo l’applicazione nel suolo, secondo le pratiche agronomiche vigenti. Infine tramite l’applicazione di modelli matematici quali FOCUS PELMO e FOCUS PEARL si è valutato il destino ambientale della CP rispetto alle acque di falda. La simulazione è stata eseguita in 5 scenari europei realistici. / Production and use of methyl bromide, a soil fumigant, are being restricted because of this chemical’s deleterious effects on stratospheric ozone concentrations. This research examines the environmental fate and properties of methyl bromide replacement: 1,3-Dichloropropene (1,3-D), and Chloropicrin (CP). 1,3-D is a broad-spectrum soil fumigant used to control numerous species of soil-borne plant-parasitic nematodes. 1,3-D consists of two isomers, (Z)- and (E)-1,3-D, and has a number of low-level chlorinated compounds that could potentially be part of the manufacturing process. This study has investigated the hydrolytic stability, under biotic and abiotic conditions, of an extensive representative list of 1,3-D potentially related chlorinated compounds. Furthermore, a monitoring programme was carried out to investigate the leaching of all of this compounds. CP is a broad-spectrum fumigant chemical which is extensively used in agriculture and has an important toxicological profile. This study has assessed CP emission in the atmosphere and operator exposure during and after application in soil through injection of the test substances with routine agronomical application. Finally the environmental fate of CP and its metabolite dichloronitromethane in groundwater were investigated through the use of simulation model FOCUS PELMO and FOCUS PEARL using fully justified input parameters in five realistic scenarios.