Total and faecal coliform was found to be prevalent in all the stations sampled in Mpulungu. There was not a single station with coliform colony levels below 0/ 100 mls. The levels found in all stations were above the WHO Maximum Permissible Levels for coliform bacteria of 0 colonies/100 mls. Lunzua River Station recorded the highest mean colony levels of coliform of about 100 colonies/100 mls. For the stations on the lake itself, Mbete Bay recorded the highest levels. On the other hand, more total coliform colonies with a maximum value of 800 colonies/100mls and a mean value of 150 colonies/100 mls were recorded during the month of February. As regards faecal coliform, maximum value of 250 colonies/100mls and a mean value of 25 colonies/100mls were recorded during the month of December.

There were more coliform colony levels at the location of 100 m from the shore than at 232 m from the shore. More coliform was found at the depth (point) of 5 m than on the surface and at 10 m, for all the stations which were sampled. Despite the fact that for tap water samples, sodium thiosulphate was added in one sample (to inhibit the effect of chlorine), there was no significant difference in the levels of coliform in the two water samples. This implies that the chlorine added was not enough to kill the bacteria in drinking water.

Handling of petroleum products in Mpulungu has had a bearing on the presence of hydrocarbons in the surface sediments on Lake Tanganyika in Mpulungu. Out of the 3 bays sampled in Mpulungu, Musende Bay where the harbour is situated recorded an average of 0.4 %/g of oil in sediment. In Musende Bay, there was a significant relationship between depth of the lake, percentage of fine grains in sediment and the percentage of oil in sediment.

The most prevalent metal on Lake Tanganyika in Mpulungu was found to be Lead with a maximum value of 0.0383 mg/l (Above WHO Maximum permissible levels). The station with the highest concentration levels was in the most enclosed Chituta Bay at the most southerly point of Lake Tanganyika. Copper and aluminum were far below the Maximum Permissible Levels.

The most common water borne disease outbreaks found were that of cholera, dysentery and diarrhea, which are prevalent in the wet season and mainly found in Mpulungu Township itself, in villages along the lakeshore and in the fishing camps.

Though Lake Tanganyika is one of the biggest inland fresh Water Lake, water on Lake Tanganyika in Mpulungu is not safe to drink directly. According to Zambian Standard Guidelines on Drinking Water Quality and WHO Guideline for Drinking Water, water on the lake falls below required standards. People around Mpulungu have to take special precautions when utilising the water from the lake for domestic purposes. The presence of coliform bacteria particularly the faecal coliform in water signals a health harzard and this justifies the endemicity of gastro- intestinal diseases in the area.

Regarding the number of coliform which were found during this study, the numbers were fewer than what was found by Garbrecht, (1971) on the same lake where some stations had mean levels as high as 1000 colony count/100 mls and maximun value of 1760 colony count/100mls.

Oil and heavy metal pollution at the moment may not seem to be a health harzard, but looking at the increment of cargo at the harbour and the lack of control on the part of Government regarding the number of fishing vessels allowed on the lake (which throws used oil on land and in the water), the ship wrecks left in the lake, oil and heavy metal pollution will soon be a harzard. People currently might not notice the effect of lead in the water but the effect could be there through food chain, though in minute concentrations this could later become fatal.

3. Recommendations

In order to ensure continued good health of people around Lake Tanganyika and the people of Zambia depending on Mpulungu fish, the biodiversity of Lake Tanganyika and the sustenance of the lake itself, the following recommendations are made:

1. The port in Mpulungu should expand to cater for increased number of cargo passing through. This expansion should take storage and sanitation facilities of the harbour into consideration.
2. Mpulungu Council should improve its water purification system so that there is no coliform in drinking water above the Maximum Permissible Levels.
3. The council should set up a good wastewater and solid waste control strategies. Discharging raw sewage in the lake is quite dangerous for the lake, biodiversity and human beings.
4. The Food and Fisheries Department should strictly monitor the damping of shipwrecks into the lake and the painting of boats by the fishing companies.
5. Further research is required in the following areas:

• Assessment of the effect of lead on biodiversity, especially the possible presence of metals in fish.
• Assess the effect of pollution in the littoral zone on biodiversity, e.g. Fish mollusks etc. in terms of quantity and quality.
• Establish the relationship between water borne diseases and distribution of bacteria in the water. Different types of bacteria in water have to be singled out more especially the one likely to cause hepatitis A because this deadly disease can be confused with other ailments due to lack of proper diagnostic equipment. If the presence bacterium in water is ascertained, possible measures can be done to prevent the disease and in case of illness, proper treatment could be given in good time.