In farming, food safety refers to the production, handling, preparation and storage of foodstuffs in ways that best reduce the risk of diseases.
Dangers of consuming unsafe food have been demonstrated in the rise of food-borne diseases such as cholera. Safety of food is compromised at all stages, from input supplies, production, post-harvest handling and preparation.
Unsafe food affects urban dwellers most because most families rely on purchased food, unlike in rural areas where people grow their own. So, how do farmers compromise food safety?
Most farmers don't consider the source of inputs they use to produce food. For example, a majority use unclean water for irrigation leading to introduction of heavy metals and microbial pathogens into crops.
Again, farmers source manure directly from their livestock section or buy from neighbours and apply on the crops.
Manure that is not well-decomposed is a health hazard if applied to crops.
Similarly, some farmers use chemical fertilisers, herbicides, pesticides and fungicides without following the manufacturer's recommendation or having clear information about the active ingredients, disposal or even the pre-harvest interval (PHI).
"At the production level, poor site selection, like growing crops along sewer lines and roadsides, leads to contamination of food with pathogenic micro-organisms, automotive fumes and heavy metals such as lead," says Brian Ogwang an agronomist at Naro.
According to Ogwang, wrong choice of inputs such as undecomposed manure and polluted irrigation water contaminate farm produce. "Use of herbicides, pesticides and fungicides without due regard to PHI, recommended quantities and disposal methods also pose a threat to food safety."
PHI is the period that starts on the day the chemical is sprayed up to the time it remains on the crop or fruit.
During that duration, the chemicals on the plant breaks down through biological processes.
Only after the lapse of the PHI will the produce be free from any chemical residue and will be considered fit for human and animal consumption.
Most farmers do not read instructions indicated on the pesticide container or sachet or just ignore them.
These instructions give information on the use, rate of application, method of application and disposal of the container, pesticide residue or wash water.
Most herbicides contain glyphosate as the active ingredient which has been cited as a probable carcinogenic in humans.
Other than the herbicides getting directly into the crop, they end up in water sources through surface run-off, which contaminates water that is either used for domestic purposes or consumed by livestock and aquatic animals.
Some farmers also harvest immature produce, especially fruits either out of ignorance or deliberately. The latter use chemicals like calcium carbide to hasten the process of ripening bananas, mangoes, pineapple and oranges, which affects quality.
At this stage, food handlers who do not observe hygiene may introduce pathogens whereas the water used to clean the produce may introduce micro-organisms such as E. coli or Salmonella sp. At times produce is packaged or transported in unclean containers, leading to further contamination with pathogens, heavy metals and harmful chemicals.
Marketing of farm produce especially fruits and vegetables is mainly through the unstructured markets, which are poorly sited (along roads, next to garbage heaps and sewer lines) and in most cases, the produce is placed on the ground, which results in contamination with heavy metals coming from automotive fumes and pathogenic micro-organisms.