
How Food Contamination Occur & How Can We Keep our Food Safe?
Safe food is essential for our health and well-being but each year, it is estimated that 600 million people get sick and 420,000 people die because of contaminated food. Let’s take a quick look at food safety, an important public health issue. We’ll look at what makes food unsafe, how it happens, what it leads to, and how we can prevent it.
Food can become unsafe when it gets contaminated. There are three types of Contaminations in food:
- Biological Contamination of food– due to micro-organisms or their products. This includes bacteria, viruses, parasites or fungi and many other food pathogens. Some of these produce toxins that can lead to illness. Prions are protein molecules that have the potential to cause severe disease.
- Chemical Contamination of food: Contamination could also be due to Chemicals – like heavy metals for example: lead, mercury, or arsenic; compounds such as polychlorinated biphenyls, and detergents
- Physical Contamination of food- such as through plastic, stones, or glass.
How the Food contamination Occur?
Getting food from where it is produced to where it is consumed requires several steps. This is called a food supply chain. Production involves raising animals or growing the plants that we use for food, although some could be caught or harvested from the wild. The processing step is where plants, animals, or their products are converted and packaged into a form that we buy as food. The distribution step is where the food gets from the farm or processing plant to the consumer usually through retail stores. The preparation step involves getting food ready to eat. Contamination can happen at any of these steps.
Let’s take a look at some examples of the food production steps which causes food contamination;
- Contamination can happen If animals are infected and transmit pathogens to their meat or to animal products such as eggs or milk.
- If the water used to irrigate fruits and vegetables contains food born pathogens or chemicals. Or if there is an inappropriate use of different types of pesticides which can lead to toxic pesticide residues in food.
- In the food manufacturing process, contamination can happen: During the meat processing, if pathogens from the animal’s gastrointestinal system contaminates the meat product. During processing, where pathogens, chemicals, or even physical contaminants such as glass could enter the food. For example, when contaminated water is used or when surfaces are not cleaned properly.
- Food adulteration is the fraudulent practice where unnecessary, inferior, or toxic, chemical or physical compounds are intentionally added to food to improve its appearance, taste, reduce cost or make it last longer.
- Examples of how food can get contaminated at the distribution stage include Storing food in areas that are not clean or are unsafe, can lead to the introduction of biological, chemical, or physical contaminants. Pests like rats, insects, or birds can introduce pathogens or physical contaminants like hair or droppings into food. And food that is not stored at the right temperature, could lead to the growth of pathogens.
- Contamination at the preparation stage could be due to:
- Not washing hands before food preparation.
- Cross contamination- for example, if the same knife is used for cutting raw meat and preparing food that is not going to be cooked
- not cooking food to the right temperature or from sick food handlers.
The food supply chain can be quite complex. Contamination can happen at any number of points in this chain. To add to this complexity is increased globalization, which means that food may contain ingredients sourced from many different countries.
Besides Contamination, Other Ways that Food Could be Potentially Harmful
If it is not labeled properly – this is of concern for people who have food allergies or potentially, from consuming food past its expiry date. Let’s have a look at what happens when people eat contaminated food.

- Contaminated food can lead to over 200 different food born illness, depending on the type of contaminant. There can be a range of symptoms, from asymptomatic illness to severe disease, and sometimes even death. Biological contaminants typically cause fever, abdominal pain, nausea, vomiting, and diarrhea. These tend to occur hours to days after exposure. There could be a range of complications such as kidney failure, arthritis, or miscarriage.
- Exposure to toxins, not only causes gastrointestinal disease but leads to a variety of health effects such as paralysis or cancer.
- Prions can lead to fatal neurological disease.
- Chemical compounds can cause short-term or long-term effects affecting almost any organ in the body including causing different types of cancers. It is usually due to repeated exposure to the chemical over a long period of time.
- Physical contaminants can cause injuries or serve as a way of introducing other types of contaminants. Although anyone can be impacted, there are some groups at higher risk. They include: Elderly people, especially those over the age of 65 years, Children under 5 years, Pregnant women and those who are immunocompromised.
At a broader level, unsafe food can:
- Strain economies due to the cost of illness and reduced productivity Have an impact on food security – which is availability and access to sufficient, nutritious, and safe food.
- Contribute to the growing issue of antimicrobial resistance.
Prevention
I. At International Level
Food safety is a complex problem that requires action at all levels. At a global level, there are international agencies like the World Health Organization and the Food and Agriculture Organization that works on initiatives like the “Codex Alimentarius”. This is a collection of international standards, guidelines and codes of practice. INFOSAN is a global network of national food authorities that share information and collaborate on food safety issues.
II. At National Level
At a national level, governments are responsible for the implementation and enforcement of food standards and codes and ensuring good agriculture and manufacturing practices. They are also responsible for the surveillance and management of foodborne illnesses and outbreaks. The industry has a crucial role in ensuring food safety at all stages of the supply chain. These include compliance with food safety legislation, regulations, and standards, having robust quality assurance programs, staff training, and having food safety management systems like “HACCP”. HACCP stands for “Hazard Analysis and Critical Control Point” which can be used to identify and control potential food hazards.
III. At Individual Level
And at an individual level, at home or in food establishments, there are simple steps that can be taken to reduce the risk of foodborne disease. These include keeping hands and preparation areas clean, separating raw and cooked food, cooking thoroughly, keeping food at a safe temperature, and using safe water and raw-materials.