Abstract:
The increased use of wastewater and sludge from wastewater stabilization ponds in agriculture predisposes the consumers to the health risks. The objective of this study was to evaluate the bioactivity of Synadenium glaucescens (Pax) extracts on helminth eggs and larvae from wastewater and sludge in Morogoro. Helminth eggs and larvae were recovered using Bailenger and Baerman methods, and then quantified using McMaster techniques. Extracts (S. Glaucescens) used during hatchability and larvicidal bioassays were obtained using hot and cold solvent extraction. The effect of S. glaucescens extracts on hatchability and larvicidal was tested using in vitro and in vivo methods. One litre of wastewater was collected from anaerobic, facultative and maturation ponds. One hundred grams of sludge were sampled from the ponds and piles. Lethal concentration fifty (LC50) and inhibitory concentration fifty (IC50) were used to determine larvicidal and hatchability effects. The identified helminth eggs were from nematodes including Ascarid, Strongylid and Trichuris. Minimum amount of ≤ 1 e.p.l. were found in wastewater sampled from maturation ponds, same amount recommended by WHO guideline of 2006, and a maximum of 700 e.p.l. from anaerobic ponds. It was found that sludge samples contained a minimum of ≤ 1 e.p.g. from maturation ponds and maximum of 100 e.p.g. in anaerobic pond. The ethanol extracts of root bark and leaves were the most effective with IC50 19.34 and 39.56 μgml-1. The two extracts also demonstrated the highest LC50 of 19.41 and 30.19 μgml-1 respectively. The root bark extracts were more active than leaves extracts. This study demonstrated a high potential of using S. glaucescens extract in controlling helminths in wastewater and sludge.
