31. Persistent Organic Pollutants in Mauritius

by Mr. I. Atchia

Mauritius is a small island of volcanic nature found in the Indian Ocean quite near the Eastern coast of Malagasy Republic. The island has a surface area of about 1860 sqkm with a relatively flat topography and has no natural resource. It has a tropical climate and is often threatened by cyclones of varying intensity during summer season. The highest rainfall also occur in summer.

Mauritius has had a rapid economic growth during the last two decades mainly due to the development of textile industries and tourism industry.

Agriculture is also very important to Mauritius - 48% of the land are under agriculture, 88% of which are sugar cane fields. Sugar cane from Java was first introduced into the island in 1650 by the Dutch. Sugar cane production represents about 34% of the foreign earnings of the island. Diversification of agriculture is also an important issue. Potatoes, beans, maize, groundnuts, tomatoes and vegetables are grown under the diversification program.

Because of the importance of agriculture, the climate and diseases, quite large amount of pesticides, herbicides and fungicides are imported and used. Herbicides are essentially used in the cane fields against weeds. As early as 1950’s 2 millions of Mauritian Rupees were spent on herbicides. The production of sugar cane for that same period was around 500 millions metric tons. In 1996 about 990 thousand kgs of herbicides were imported.

Pesticides like Aldrin, Dieldrin and Lindane have been used in the cane fields in the 1960’s to control grasshoppers’ (Locusta migratoria) invasion which were doing great harm to the crops.

DDT on the other hand was mainly used to control malaria disease which was transmitted by Anopheline Mosquitoes (A. gambia). Malaria disease was eradicated in 1953. The malaria disease killed around 20 thousand people in 1865 on the lower grounds. The disease persisted until its eradication. DDT is still stocked by the Ministry of Health to be used in case of outbreak of malaria disease.

Many pesticides among which are organochlorine pesticides (including those in the Pop’s list) have been banned from use in the 1980’s by the "Pesticides Control Board". The board was set up under the "Pesticides Control Act" of 1972. The Act was established because of the need to control the use and import of pesticides. The board consist of representatives from different ministries and is chaired by a medical officer from Ministry of Health. The board fix the conditions to be observed for the import, sale and distribution of pesticides. The board advise on any matter relating to pesticides and in protection against contamination by pesticides. The Ministry of Health is also coming up with a "Dangerous Chemical Control Bill" to control substances which do not fall within the "Pesticides Control Act".

Polychlorinated biphenyls were also banned in the 1980’s together with the phasing out CFC’s. A brief study showed the absence of polychlorinated biphenyls in heavy oils and transformers of electricity plants round the island. According to officers from the Electricity board no polychlorinated biphenyls has ever been used in transformers in Mauritius.

Little is known of Dioxins and furans in Mauritius. The absence of most of the activities which might generate Dioxins and furans should be pointed out. No pesticides, disinfectants or paper are produced in the country. Organochlorine have been completely banned and CFC are being phased out. Moreover the Ministry of Environment strictly discourage the burning of solid wastes. Only small incinerators are used in some hospitals. These units are not operated continuously and have to be cold started when used. This kind of practice along with the burning of sugar cane fields can eventually cause dioxins and furans. Another source of dioxins and furans if they are present at all might be the combustion of leaded gasoline by most motor vehicles in the island.

To date most of the Persistent Organic Pollutants are absent in the island. Only dioxins and furans might be a subject of concern to the Mauritian environment.

List of Some of Pesticides BANNED in Mauritius

DDT

Aldrin

Dieldrin

Endrin

Chlordane

Heptachlor

Hexachlorobenzene

Mirex

Toxaphene

List of some dangerous chemicals in Mauritius

Polychlorinated biphenyl (banned)

Dioxins

Furans

Examples of Pesticides/Herbicides used in Mauritius

Carbaryl

Atrazine

Chlorpyriphos