Ionizing radiation-induced changes in chlorinated hydrocarbons

Ionizing radiation-induced changes in chlorinated hydrocarbons

Ionizing Radiation-Induced Changes in Chlorinated Hydrocarbons Sir, Disposal of chlorinated pesticide residues is a considerable problem due to their ...

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Ionizing Radiation-Induced Changes in Chlorinated Hydrocarbons Sir, Disposal of chlorinated pesticide residues is a considerable problem due to their chemical stability. Methods of effective and economical treatment of discharges from manufacturing processes and other localized areas of high pesticide concentration have not been developed. This pilot study was undertaken to explore the effects of ionizing radiation on chlorinated hydrocarbon pesticides to determine whether more biodegradable products could conveniently be formed. Five common pesticides (aldrin, dieldrin, heptachlor, lindane and DDT) were dissolved in hexane in concentrations of 0.2 ppm with the exception of DDT, which was 1 ppm. The pesticides were exposed to 0.5-2.5 megarads of gamma radiation emitted by Co60 and 10-20 megarads of beta radiation. Analysis before and after radiation was made using gas chromatography (3~o SE-30 column; electron capture detector). The changes in concentrations induced by ionizing radiation are given in Table 1. Typical chromatograms are shown in Fig. 1. In this case at least three breakdown products are indicated by the new peaks. If these products represent less chlorinated derivatives of heptachlor (homolytic fission of carbon-

halogen bonds by ionizing radiation has been observed; Swallow, 1960), they are probably more readily biodegradable. The broader solvent peaks may include chlorinated hexanes and cyclohexanes. Saturated aliphatic hydrocarbons lose hydrogen fairly easily upon irradiation. These results confirm that gamma radiation in high levels induce degradation of chlorinated hydrocarbon pesticides.

TABLE 1 Ionizing radiation effects on selected pesticides Pesticide

Radiation Exposure (COO) (Megarads)

Aldrin Dieldrin DDT Heptachior Lindane

0.5 1.0 1-5 2.0 2.5

Percentage Change Run 1 Run 2 Run 3 0 25 50 42 58

6 19 35 33 56

22 33 53 40 54

There were no detectable changes noted after 20 megarads exposure to beta radiation.

b

Fig. 1 Chromatogram of Heptachlor (a) before irradiation and (b) after irradiation. 143

Law, was held in London on July 1 t. Fhe subject of this first colloquium was marine pollution, with particular emphasis on pollution from ships. The morning session was devoted to a review of recent international conventions dealing with marine pollution. Mr Y. Sasamura, Director of the Marine Environment Division of the Intergovernmental Maritime Consultative Organisation (IMCO), spoke of IMCO's work in this field, and summarized the agreements which have been concluded under its auspices, in particular, he dealt with The M a r i n e Pollution Bulletin is published monthly the international Convention for the Prevention of and sets out to cover all aspects of the fight for the life of lakes, estuaries, seas and oceans. It includes news, Pollution from Ships, the result of a conference held in comment, reviews and research reports not only on the London in November, 1973. The aim of this Conventiom threats of noxious substances to marine life but also on which covers all types of pollutants, is to eliminate the management and productivity of the marine environment in general. It publishes accounts of new and completely deliberate pollution from ships and to proposed research programmes as well as the results minimize accidental pollution. of those in progress. Dr Bo Johnson, of the Swedish Ministry of Foreign Contributions may be in the form of short notes not Affairs, gave an account of the Convention on the exceeding 650 words or articles of 1500-2000 words and should be submitted to the editor in double-spaced Protection of the Marine Environment of the Baltic typescript. They should be given a short one-line title Sea Area, the work of a conference held in Helsinki in and the text should be broken by short sub-headings. March this year. The Baltic has been particularly All measurements must be given in metric (S.I.) units. vulnerable to pollution not only because it is surrounded Reprints of articles can be supplied after publication by highly industrialized States, but also because of its and an order form for them is sent to contributors. Bulk orders of copies of the entire issue in which an article narrow entrances, the cold temperatures and the low appears can be supplied at a reduced rate to the salt content of its waters. Although a number of existing author, provided they are ordered in advance of international agreements apply to the Baltic, a special publication. Baltic agreement has not until recently been possible Edited by: Professor R. B. Clark, Department of Zoology, The University, Newcastle upon Tyne, England because of the German problem. The present Convention NE1 7RU. covers pollution from all sources (vessels, seabed installations, and land) and establishes a Baltic Marine Marine Pollution Bulletin is published by Macmillan Journals Ltd., 4 Little Essex Street, London WC2R 3LF. Environment Protection Commission to supervise its implementation. In addition, the Convention contains Annual subscription £6.00 (£7.50 USA and Canada). provisions on special routeing and radar requirements (Payment may be made in any currency at the current exchange rate. Orders must be accompanied by remittance. for large vessels; and Dr Johnson foresaw the day when Prices applicable only to subscriptions started before pilotage would be compulsory for all large vessels 31 st December, 1974.) operating in the Baltic. Cheques should be made payable to Macmillan Journals The afternoon session was on the theme 'Industry Ltd., Subscription Department, Brunel Road, Baaingstoke, Hants. RG21 2XS, England. Dialogue with the United Nations and its Agencies', and was addressed by Mr J. R. Keates, of the BP Tanker Company, and Mr J. W. Featherstone, Executive A. R. CEURVELS Secretary of the recently formed International Petroleum J. DERHOVANESlAN,JR. Industry Environmental Conservation Association (IPIECA). Mr Keates spoke of the work of the Oil Massachusetts Division of Marine Fisheries. Companies International Marine Forum, a body which Cat Cove Marine Laboratory, represents the vast majority of companies concerned Salem, Massachusetts 01970, U.S.A. J. KAYLOR with the marine transportation of oil. IPIECA has been formed to give the petroleum industry a single voice for National Marine Fisheries Service, communicating with the United Nations Environmental Atlantic Fishery Products Technology Center, Programme. Gloucester, Massachusetts 01930, U.S.A. A lengthy discussion session followed on all aspects covered by the colloquium. There was particular concern Swallow, A. J. (1960). Radiation Chemistry of Organic Compounds. over jurisdictional questions. Regarding the enforcement International Series of Monographs on Radiation Effects in of anti-pollution standards, there was general agreement Materials, Vol. 2. New York: PergamonPress. that when a ship was on the high seas or in passage through the territorial sea, sole responsibility for enforcing pollution standards should remain with the flag State: the extreme difficulty and danger of trying to arrest ships in passage makes any other approach impracticable. On the other hand, there was also a good deal of support for the idea that a State should have jurisdiction to enforce pollution standards against foreign ships present in its ports, provided that this l a w and the Sea The first of an occasional series of colloquia on right were made subject to certain safeguards to prevent 'International Law and the Environment', arranged by its abuse. R. R. CHURCHILL the British Institute of International and Comparative 144