Metal pollution and its health effects present a challenge currently facing the developing countries. Metal poisoning is usually difficult and expensive to assess or screen in these countries due to limited resources, which means that policies, guidelines, regulations and institutional managements are limited. Hair and nail as biopsy materials were suggested as more

Nyambe MM. 2018. Phytochemical and antibacterial analysis of indigenous chewing sticks, Diospyros lyciodes and Euclea divinorum of Namibia. Biofarmasi 16: 29-43. The purpose of this study was to ascertain the phytochemical and antibacterial properties of Diospyros lycioides and Euclea divinorum and correlate the results obtained to their ethnomedicinal uses as chewing sticks. Fractions of powdered leaves, twigs, and roots were obtained from crude extracts using vacuum liquid chromatography with solvents of increasing polarity. Antimicrobial activities of the crude extracts and fractions were assessed using the agar overlay, disc diffusion, and agar dilution methods against the oral pathogens, Streptococcus mutans and Streptococcus sanguinis. In addition, the effect of fractions on the attachment of oral pathogens to tooth surface were also analyzed using saliva-coated hydroxyapatite beads (S-HA) as a model. Phytochemical screen tests revealed the presence of the following secondary metabolites in the twigs and roots of both plants: anthraquinones, cardenolides, saponins, tannins, polyphenols, and terpenoids. Alkaloids were detected only in the roots of both plants. Root fractions from both plants displayed higher antibacterial activity than twig fractions. This supports the preference of roots over twigs by stick users. D. lycioides root fraction displayed minimum inhibitory concentrations (MICs) of 0.625 mg/mL and 1.25 mg/mL against S. sanguinis and S. mutans, respectively. E. divinorum root fraction showed MICs of 1.25 mg/mL and 2.5 mg/mL against the aforementioned organisms. Adherence of the bacteria to S-HA was reduced more by root fractions from D. lycioides while twig fractions from both plants also showed significant anti-adhesive properties. Since fractions from both plants inhibited the growth of bacteria and reduced attachment to S-HA, it is an indication that these plants are potential sources of antibacterial and anti-adhesive agents and their use should be encouraged. The anti-adhesive activity of extracts from these plants has not yet being reported. Further research on isolation and characterization of the active compounds from fractions that showed antibacterial and anti-adhesive activity is recommended.

Suspended particles in water are a major concern in global pollution management. They affect the appreciation of water due to clarity, photosynthesis, and poor oxygen environment rendering water unsuitable for aquatic animals. Some suspended materials contain functional groups capable of forming complex compounds with metals making them available for poisoning. Such material promotes the growth of bacteria and fouling that give rise to unpleasant taste and odor of the water and thus requires removal. Removal of suspended solids is normally achieved through sedimentation or filtration. However, some suspended colloidal particles are very stable in water and cannot settle while others are able to pass through the filter due to small size, hence difficult to remove. This study investigated the use of triethanolamine-modified maize tassels to form a flocculent for their removal. The modified maize tassels were characterized using Fourier transform infrared (FTIR), and it was found that the triethanolamine was anchored within the cellulose structure of the maize tassels. Clarification parameters such as settling time, reagent dosage, and pH were investigated. The best clarification was at a pH of 6.0 with clearance being less than in 30 min. The optimal flocculent dosage was found to be 3.5 ml of the material, showing that the material has a potential of enhancing clarity in polluted water.

World Health Organization (WHO) among other health agencies recommends exclusive breast feeding during the first six months of infancy. However, Infant formula milk (IFM) has been increasingly used as a breast milk substitute due to maternal occupation, death and illness. The product has been associated with infant health complications and even deaths due to its contamination with aluminum (Al), cadmium (Cd), lead (Pb) and nickel (Ni). Both the Kenya Bureau of Standards (KEBS) and WHO have set maximum levels of concentration of these metals in IFM and the latter has set levels of provisional tolerable weekly intake (PTWI). Seven brands of IFM (for age 0-6 months) imported into the Kenyan market and shelved in stores in Nairobi County, were analysed for levels of Cd, Al, Pb and Ni. Except for Cd, all brands of IFM (0-6 months) contained the rest of the trace elements ranging as follows: Al (1.054±0.085 to 2.156±0.423 µg/g); Pb (0.018±0.001 to 0.059±0.002 µg/g) and Ni (0.022±0.001 to 0.032±0.001 µg/g). The estimated weekly intakes were below the PTWI thus indicating safety of the brands of IFM. Other than affirm presence of the elements Al, Pb and Ni in IFM though below the WHO set limits, the findings are a pointer to caution on consumption of IFM although this would be inevitable under unavoidable circumstances. The caution is justified since the consumption of IFM would pose health risk to infants due to exposure and bioaccumulation of the elements. Lead particularly was higher than the limits set by KEBS in most brands supporting this caution.

The paper presents the study carried out in a peri urban settlement of Nairobi Kenya and involved treatment of raw grey water generated from bathroom, kitchen and laundry for flushing toilet and laundry work. The study utilized both chemical and physical treatment. The chemical treatment involved alum addition in the raw grey water and pH adjustment using bicarbonate salts. The physical treatment involved filtration using Quartz sand and filtration of pH adjusted treated grey water using filter paper. The major ions studied were ions which could interfere with lathering of soaps or could cause stains on clothes and toilet fixtures or could be potentially health hazardous. These ions were Fe, Mn, Ca, Mg, Pb and Hg. The levels of these ions in raw grey water and in treated grey water were determined using atomic absorption spectroscopy. The results for the levels of these ions before treatment were compared to the set standards for potable water by Kenya Bureau of Standards [1]. The levels of these ions in the treated grey water after adjusting the pH were found to be within the Maximum Contaminant Limits (MCL) set by KEBS [1]. Thus the overall treatment of the raw grey water produced water of good quality which complied with the set standards for potable water by KEBS [1]. The results of this treatment could contribute immensely in the fulfillment of the millennium development goals.

This paper describes the determination of the levels of lead (Pb), cadmium (Cd), zinc (Zn), calcium (Ca) and iron (Fe) in the toenails and fingernails of children under the age of six years in urban and rural areas in Kenya by atomic absorption spectrophotometer. Lead levels in urban areas ranged from 8.0-49.0 µg/g in fingernails and 7.0-62.0 µg/g in toenails as compared to those in rural areas (5.0-36.5 µg/g and 5.5-31.5 µg/g, respectively). A similar trend was observed for Cd where significantly high levels were found in children in urban areas than those in rural areas. The Fe and Zn levels were significantly higher in children in rural areas than those in the urban areas. The levels of all the metals studied were higher in the toenails except for Fe and Ca where the levels were higher in fingernails; however, the difference in the levels was not significant. These results indicate that either the toenails or fingernails can be used as a reference for levels of metals environmental exposure.

The enrichment by microbial fermentation of agro industrial waste to alleviate their nutritional problems has been proposed but the nutritional value of the subsequent feed for animal consumption has not been fully elucidated. This study investigates whether solid state fermentation of pineapple waste using the fungi Aspergillus niger and Trichoderma viride could improve its nutrient content. Results show that fermentation of pineapple waste by solid state fermentation using the fungi A. niger and T. viride significantly (P < 0.05) enriches the nutrient content of the waste, particularly increasing the crude protein and ash content while lowering the crude fiber content. The most significant nutrient enrichment was recorded at 72 h of fermentation using A. niger and at 96 h of fermentation using T. viride. Indiscernible changes were noted in the mineral content of pineapple waste (PW). Dry matter increased significantly (P < 0.05) as fermentation progressed with the highest values recorded at 96 h. This study establishes no significant differences (P > 0.05) in the fermentation abilities of the two fungi, A. niger and T. viride. Fermented pineapple waste may be a potential supplement in compounding animal feed provided that it is acceptable and highly digestible.

Availability of clean water is of concern due to pollution and diminishing supply pollution. However, purification is possible depending on the incorporated contaminants. Domestic wastewater contains dissolved organic matter and its remediation can be done by oxidation. The best oxidation can be achieved by electron transfer the same way metabolic processes occur. This study exploited the use of a film of iron (III) doped titanium dioxide applied on an electrode which was found to be effective. Natural light conditions generated electrons that migrated through the electrode leaving behind holes which oxidized the contaminants as the excess electrons were discharged at the cathode after passing through the casted proton exchange membrane (PEM) separating the two half cells of the prepared reactor. This electrochemical method has the advantage in that the organic pollutants are oxidized to carbon dioxide with no secondary pollutants and the inorganic pollutants into insoluble matter. The assembled cell was applied to purify both synthetic and real water samples of green leafy vegetable solution from the kitchen by clarification. The clarification process was monitored by UV-Vis using distilled water as a reference to compare the light that transmitted through a sample. It was observed that the electro-oxidation process took place showing a high potential 105 mV within the first 150 min followed by degradation at a high rate. The oxidation of the organic matter was confirmed by UV-Vis analysis as well as by cyclic voltametric analysis of iron released into the solution of the synthetic samples. The electro chemical treatment of the water was then applied to purify real water samples made from a sample of 4.5 g minced of green vegetables dispersed in one liter of water (4.5 g/l). The green leafy coloured solution was clarified after 154 h of continuous oxidation. The degradation process was confirmed to be independent of intermediates or other species present in solution as it was of first order reaction kinetics. The electrochemical oxidation of organic matter in water using iron (III) doped titanium dioxide coated graphite electrode has potential application on the purification of water.