Joshua Olowoyo

This study investigated the effects of four different rates of sewage sludge amendment (100, 200, 300, and 400g) on Spinacia oleracea (Leafy vegetable) and Daucus carota (Root vegetable) on the growth and the accumulation of heavy metals. The yield of S. oleracea and D. carota was measured in terms of weight while heavy metals levels at harvest were measured using ICP-MS. The growth and yield at harvest in S.oleracea were in following order 300g > 400g > 200g > 100g while in D.carota the order for the yield was 400g > 200g > 300g > 100g. Elemental concentrations showed that iron (Fe) had the highest average concentration for both plants and ranged between 68.60 ± 2.82mg/kg − 1503.00 ± 82.31mg/kg. Differences obtained as a result of the amendments were significant for heavy metals such as Fe, Pb, Cd from the different plant parts. Concentrations of Pb and Cr recorded in the leaves of S. oleracea were above the recommended limit for human consumption with the exception from leaves of S. Olereacea harvested from soil treated with 400g of sewage sludge. There was no particular trend of heavy metals accumulation noted in the experiment except for the values obtained for trace elements in the roots of D. caraota where, roots parts harvested either from soil treated with 300g or 400g recorded the highest concentrations of these elements. The bioaccumulation factor showed that the elements were bioaccumulated from the soil.

Background: Amyotrophic lateral sclerosis (ALS) is an always fatal neurodegenerative disease characterised by a gradual death of motor neurons in the spinal cord and brain. The cause of ALS is unknown. A number of occupations are associated with elevated risks for both ALS and lead (Pb) exposure, indicating a possible connection between these two risks. Gasoline station forecourt attendants, also known as petrol station assistants, show one of the highest occupational ALS risks ever calculated, i.e. OR 8.31; 95% CI 1.79 to 38.54

Objectives and Methods: Here, we investigated blood concentrations of Pb in petrol station forecourt attendants (n=38) and a control group (n=36). Participants were divided into groups based on number of years worked. A questionnaire was designed to investigate the health status and work-related life style habits of the participants. Blood samples were collected by medical professionals and analysed for Pb concentration by ICP-MS.

Results and Discussion: A positive correlation between number of years worked and Pb blood concentrations was observed in the petrol station forecourt attendants. The Pb blood levels were also influenced by smoking. Together with the increased ALS risk, the elevated blood Pb levels in forecourt attendants strengthen the hypothesis that lead exposure contributes to ALS, among forecourt attendants as well as other occupations.