In the Sunyani Municipality, rapid population growth and uncertainties in rainfall have encouraged the use of untreated surface water for irrigating vegetables. However, microbial levels of ready-to-eat vegetables remain untested, and the differences in exposure unexplored. Further, there is a paucity of studies that compare the quality of local and exotic vegetables. A mixed method approach was used to collect and analyse primary data for the study. Forty-one farmers were sampled whilst 24 vegetable samples were used. The results showed on-farm vegetables in the municipality had microbial counts beyond the acceptable World Health Organization (WHO) threshold. Comparatively, the microbial counts of on-farm vegetables in rural and peri-urban locations differed, and the quality of local and exotic vegetables also differed. Also, vulnerability to on-farm microbial contamination differed across space and among producers. It is recommended that vegetable farmers should be educated on the safety of vegetables by the Agricultural Extension Officers in the municipality.
TopIntroduction
Vegetables make up an essential component of the human diet because they contain minerals, carbohydrates, vitamins, proteins, and fibre. They are also a major supplier of nutrient and non-nutrient bioactive substances, that provide, minerals, dietary fibre, vitamins, and phytochemicals, especially antioxidants to the body (Slavin and Lloyd, 2012). Population growth and the quest to practice healthy eating and lifestyles has led to a sudden boost in the cultivation of vegetables for consumption by the teeming population in most urban areas creating an important livelihood activity for many people particularly in the developing world. Globally, an estimated 800 million people are said to be engaged in urban agriculture (FAO, 2016). Vegetable production is thus an important aspect of urban food production and contributes to the alleviation of food insecurity (Eigenbrod and Gruda, 2015).
However, in most growing urban areas in sub-Saharan Africa, uncertainties in rainfall and the difficulties associated with accessing clean water for irrigation purposes remains a perennial challenge. This has encouraged the resort to untreated surface water for the irrigation of vegetables to satisfy the ever increasing urban demand.
The microbial quality of vegetables in most parts of the world has raised major public health concerns due to contamination by pathogens, viruses and chemicals (Akinde et al., 2016; Alamnie et al. 2018; Houngla et al., 2019; Hussaini et al., 2013; Sharma et al., 2009). Alamnie et al. (2018) in their study in
Ethiopia observed high contamination of vegetables by pathogenic bacteria, exceeding the recommended levels of 10 to 100 coliforms CFU/g by the International Commission on Microbiological Specifications for Food (ICMSF, 1998). Similarly, research in urban gardening at Porto-Novo, Benin by Houngla et al. (2019), reported high microbial contamination of three leafy vegetables - amaranth, nightshade, and lettuce. In Ghana, Sunyani is increasingly becoming an important vegetable producing area. Here, vegetables cultivated include cabbage, carrot, garden eggs (types of eggplant), tomatoes and okra for the increasing population in the Municipality taking advantage of the numerous surface water (streams) available to irrigate the vegetables but the Ministry of Food and Agriculture (MoFA, 2010) has cautioned that, use of untreated water may contaminate vegetables produced.