Combined toxic effects of oil and pesticides on selected marine invertebrates

In recent years, pollution in general and sea water pollution in particular, has become an important topic for national and international considerations. Because of its impact on society, marine pollution has attracted great attention from politicians, administrators, natural scientists and technologists all over the world. To save our environment from further deterioration, it is essential to have an assessment of this problem This thesis involves investigation of the lethal and sub lethal effects of four pesticides and two petroleum oil, individually and in combinations on two commercially important bivalves. Among the four pesticides used two are organophosphates and the other two are organochlorines. Synthetic Pesticides, especially organophosphates and organochlorines have become increasingly important additions to chemical wastes polluting natural aquatic Communities special attention is given in the present investigation to delineate the combined toxic effect of oil and pesticides. The results are presented under different sections to make the presentation meaningful.

Studies on lemongrass oil

The thesis deals with the different properties and characteristics of oil of lemon grass.. The oil of lemongrass (Cymbopogon flexuosus) is one of the most important essential oils. It will continue to be one of the "big ten" of our essential oils1. Lemongrass oil is obtained from certain species of grasses of the genus cymbopogon. The genus consists of about 80 species, 10 to 12 of which are known to occur in India. Lemongrass is a stoloniferous plant. The plant grows wild in many tropical andsemitropical parts of Asia, Africa and in parts of Central America and South America. For the extraction of the oil however only cultivated lemongrass is employed. The trade distinguishes two Principal types of lemongrass oil, viz. the East Indian Oil and West Indian Oil. There was much confusion, years ago, about the taxonomy of the plants which yield theEast Indian and West Indian types of lemongrass oil, however Stapf2 ended the long controversy of identifying the plant yielding the East Indian type oil as Cymbopogon flexuosus (D.C.) Stapf and the plant yielding the West Indian type oil as Cymbopogon citrates (D.C.) stapf. The 2 plants have_been named variously also Andropogon nardus var. Flexuosus Hack or A. citratus D.C. respectively