TITLE:
Microbial Contamination in Vegetables at the Farm Gate Due to Irrigation with Wastewater in the Tamale Metropolis of Northern Ghana
AUTHORS:
Samuel Jerry Cobbina, Mohammed Clement Kotochi, Joseph Kudadam Korese, Mark Osa Akrong
KEYWORDS:
Helminthes; Faecal Coliform; Irrigation Water; Vegetables; E. coli
JOURNAL NAME:
Journal of Environmental Protection,
Vol.4 No.7,
July
15,
2013
ABSTRACT: The rational for this study
was to assess the microbial quality of fresh vegetables at the farm gate of the
Water Works road vegetable farm at Gumbihini in the Tamale Metropolis. A total
of thirty-six (36) vegetables comprising lettuce, amarantus and cabbages and
eight (8) wastewater samples were collected at random and analysed for a period
of four months, to assess the microbial contamination level. Samples were
analysed for total coliforms, faecal coliforms, E. coli and helminthes eggs. All vegetables sampled during the
study period recorded high levels of total and faecal coliform bacteria. Mean
faecal coliforms for the various vegetables were as follows; lettuce 3.7 ± 0.5 CFU.g-1, amarantus 3.5 ± 0.6 CFU.g-1 and cabbage 3.1 ± 0.6 log CFU.g-1 fresh weight. FC levels
were above the International Commission on Microbiological Specifications for Foods (ICMSF) recommended
level of 3 log CFU.g-1 fresh weight. E. coli were recorded in lettuce (3.3 ± 0.6 log CFU.g-1 fresh weight) and
amarantus (0.6 ± 0.1 log CFU.g-1 fresh
weight) but not in cabbages. Lettuce generally recorded high levels of
microbial contamination because of the large surface area occupied by its
leaves. Two helminth eggs (Strongiloides stercoralis) were identified in lettuce while
four (Ascaris lumbricoides) were
identified in wastewater. Microbial loads recorded in wastewater were generally
higher than that of vegetables. Since most of these vegetables are eaten fresh
or slightly cooked, there is course for concern as public health will be
adversely affected. Education of farmers and consumers on food safety has to be
intensified to avert a possible outbreak.