Every year, an estimated 600 million people worldwide suffer from foodborne illness for various reasons, but the main preventable cause is cross-contamination.
- What is accidental contamination?
It is the transmission of harmful microbes between food or equipment used to prepare food and surfaces that come into contact with food, which include:
Hands, clothing, cleaning towels, and surfaces on which food is prepared such as shelves, kitchen counters, cutting boards, and utensils (knives and plates).
Many people believe that foodborne illnesses mostly come from eating food from restaurants, food trucks, or eating it outside in the dark, but there are many ways cross-contamination can occur.
- There are some points that can also cause accidental contamination unintentionally, which include:
- Primary food production: from plants and animals on the farm.
- While harvesting plants or slaughtering animals.
- Secondary food production: which includes food processing and manufacturing.
- Food transportation.
- Food storage.
- Food distribution: grocery stores, farmers markets,...
- Food preparation and serving: at home, restaurants, and general food processing and handling areas.
What are the types of accidental pollution?
There are three main types of accidental contamination:
- From food to food.
- From equipment to food.
- From food traders to food.
- From food to food:
Adding contaminated foods to uncontaminated foods results in cross-contamination from food to food allowing harmful bacteria to spread.
Raw, undercooked or improperly washed foods can contain large amounts of bacteria, all of which can be harmful to health if ingested.
Foods that pose the highest risk of bacterial contamination include leafy vegetables, beans, and rice from plant sources. They also include animal sources, which are the highest risk, such as unpasteurized milk, cheese, and meat, in addition to raw eggs, poultry, meat, and seafood.
Leftover food that is kept in the refrigerator for a long time can lead to bacterial overgrowth. Therefore, eat leftovers within 3-4 days and cook them at appropriate temperatures.
- From equipment to food:
Transfer from equipment to food is one of the most common types of cross-contamination. Bacteria can survive for long periods on surfaces such as countertops, utensils, cutting boards, storage containers and food processing equipment.
When equipment is not washed properly or is inadvertently contaminated with bacteria, it can transfer large amounts of harmful bacteria to food. This can happen at any time during food production whether at home or in food processing facilities.
In 2008, an accident at a Canadian-based meat company led to the death of 22 customers due to cutting meat contaminated with Listeria.
A common example of this at home is using the same cutting board and knife to cut raw meat and vegetables, which can be harmful if the vegetables are consumed raw.
- From food traders to food:
A person can easily transfer bacteria from their body or clothing to food during many food preparation steps.
For example, it is possible for a person to cough into his hand or touch raw poultry and continue preparing a meal without washing his hands in between.
In a 2019 study of 190 adults, only 58% of participants reported washing their hands before cooking or preparing food, while only 48% said they washed their hands after sneezing or coughing. 
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