Assessment of Trace Metal Levels In Commonly Edible Vegetables From Selected Markets In Lagos State, Nigeria
Consumption of food contaminated with heavy metals is a major source of health problems for man and animals. Three commonly edible Leafy vegetables (Amaranthus hybridus, Celosia argentea ,Cochorus olitoris) from Agboju and Iba markets , Lagos Nigeria were sampled, identified, digested and analyzed with the aid of Atomic Absorption Spectrophotometer (AAS) as directed by APHA (American Public Health Association) to determine heavy metals concentration in them with the aim of ascertaining their edibility for human consumption. The mean concentration for each heavy metal in the samples gotten from each market were calculated, the comparison of these data was done amongst the two markets, and compared with the permissible levels set by the FAO and WHO. The results showed that the levels of Lead, Cadmium, Copper, Zinc, Iron, Nickel, Selenium and Chromium present in the vegetable concentrated in the following order Fe>Pb>Zn>Cd>Ni>Cu>Cr>Se. With regards to vegetables in questions, analysis of variance showed that some vegetables accumulated metals more than each other and as such indicated that metals like copper, cadmium, selenium, iron and zinc are significant at P 0.05). With significant values of lead, cadmium and nickel, recorded in both Amaranthus hybridus and Celosia argentea vegetables, vegetables consumers must be weary of vegetables to buy and the market that is save to buy from, especially markets located very close to highways or close to major busy roads .
Heavy metal concentration and bacterial contamination associated with selected leafy vegetables in Abeokuta Metropolis, southwest Nigeria
The assessment of heavy metal concentration (Cu, Fe, Zn, Pb, Cd, Co and Cr) and bacteriological contamination in five (5) most consumed vegetables Talinum triangulare , Celosia argentea , Vernonia amygdalina , Corchorus olitorus and Telfaria occidentalis in Abeokuta Metropolis was carried out because the consumption of vegetables on display in markets and roadsides had been associated with gastro-intestinal disorders. The vegetables were randomly purchased from six markets within the metropolis and analyzed using standard procedures involving Atomic Absorption Spectrometry (AAS) and Standard Plate Count (SPC). The levels of heavy metals in leafy vegetables varied significantly (P < 0.05) across locations and were within World Health Organisation (WHO)/Food and Agricultural Organisation (FAO), permissible limits except for Pb and Co found in T. occidentalis , C. argentea , T. triangulare and V. amygdalina . Eleven species of bacteria including Bacillus subtilis , Escherichia coli , Microccoccus species, Staphyloccocus aureus , Klebsiella aerogenes , Staphylococcus saprophyticus , Proteus mirabilis and Bacillus megaterium were isolated from the leafy vegetables. B. subtilis was the most abundant (93.3% occurrence) while B. megaterium and S. aureus were least abundant (8% occurrence). Total colony counts of bacteria ranged from 1.51 x 10 7 – 58.50 x 10 7 (CFU/g) with V. amygdlina and Celosia argentea both from Elega having the lowest and highest values respectively. The levels of heavy metals and bacterial contamination in selected vegetables were found to be unsafe. Public sensitisations on hygienic handling of vegetables from production to consumption in addition to frequent safety assessment are recommended to minimize human exposure to heavy metals and bacterial pathogens.
LABORATORY AND FIELD TESTING OF SEED SPACING UNIFORMITY FOR SUGARBEET PLANTERS
Five planter configurations were evaluated for seed spacing uniformity at three field speeds using a seed 
location method in the field and a laboratory method involving an opto-electronic sensor system. Planter seed spacing 
uniformity was described using the Coefficient of Precision (CP3) measure. Results showed that CP3 measures 
determined using the laboratory test method were significantly different from those determined using the field test method. 
This indicated the laboratory test method cannot be used to predict planter seed spacing uniformity in the field. Seed 
spacing uniformity determined in laboratory tests was higher than, or equal to, seed spacing uniformity determined in 
field tests. This indicated the laboratory test method may be useful to screen out planters or planter units with poor 
uniformity of seed metering. Field testing of the planters that perform well in laboratory tests must be conducted to 
adequately determine the seed spacing uniformity of those planters in the field. Results from laboratory and field tests 
could be useful in determining areas for improvement of planters or planter units.